- Open Access
Medicinal plants used for treating cancer in Kenya: an ethnopharmacological overview
Bulletin of the National Research Centre volume 46, Article number: 148 (2022)
Cancer is one of the major causes of mortality worldwide. Though 30% of cancers can be treated when detected at early stages, their treatment has been compounded by resistance of tumor cells to anticancer drugs, side effects of the therapies, high treatment costs and limited access to medical services. In Africa, and particularly in the East African botanical plate, various ethnic groups cherish their traditions and embrace distinguished use of medicinal plants in the management of ailments like cancer. This study aimed at reviewing the ethnobotanical knowledge on the use of wild and cultivated plants as remedies for cancer treatment in Kenya as well as their phytochemical composition and reported anticancer activities.
Through extensive electronic review in PubMed, Science Direct, Scopus, Google Scholar, Web of Science, Scientific Electronic Library Online and the Google search engine, 145 plant species from 125 genera spread across 55 families were found to have been reported for cancer treatment in Kenya. The malignancies treated using the herbal remedies include squamous cell carcinoma of the gum, prostate, blood, bone, breast, colorectal, colon, oesophageal, lung, liver, skin, stomach, throat and uterine cancers. Most of the identified species have reported anticancer activities, with Toddalia asiatica, Annona muricata, Carica papaya, Catharanthus roseus, Moringa oleifera, Ocimum gratissimum, Prunus africana and Zanthoxylum paracanthum being the most studied.
Despite the widespread use of medicinal plants in the management of cancer in Kenya, the bioactivity, safety aspects, responsible anticancer molecules and clinical studies are required to elucidate the mechanism of action of the compounds and confirm the potential of the unstudied species.
Cancer is listed among the leading causes of deaths globally and a great twenty-first century barrier to the increase in life expectancy (Chimezie and Ofure 2022; Dalmartello et al. 2021; Wekha et al. 2021). According to recent global statistics based on GLOBOCAN, about 19.3 million new cancer cases were reported in 2020. This led to at least 10 million cancer deaths (Sung et al. 2021). For this period, breast cancer was the most prevalent, with 2.3 million new cases (11.7%). The other malignances followed the order: stomach cancer (5.6%) < prostate cancer (7.3%) < colorectal cancer (10.0%) < lung cancer (11.4%). Nevertheless, lung cancer was the major cause of cancer-related mortalities accounting for about 18% (1.8 million) deaths. Colorectal (9.4%), liver (8.3%), stomach (7.7%) and breast (6.9%) cancers also made significant contributions to the estimated cancer mortalities (Sung et al. 2021).
Trickling down to the African continent, cancer has a skewed distribution and this is compounded by inadequate epidemiological expertise, diagnostic equipment and research resources, and the complex treatment seeking behavior of cancer patients (Hamdi et al. 2021). According to the National Cancer Institute of Kenya (NCI 2022), cancer is the leading cause of mortalities in Kenya after infectious and cardiovascular diseases. Of these, breast cancer (with 5985 new annual cases or 12.5%) of all new cases is the leading cancer in Kenya (Macharia et al. 2019). The main drivers behind the increasing cancer cases in Kenya include consumption of mycotoxin and heavy metal-contaminated foods, genetic causes and residential combustion of unprocessed solid fuels such as dung, wood, charcoal and agricultural residues (Omara et al. 2021a). Coupled with antitumor drug resistance, inaccessibility and side effects of commercial drugs, indigenous communities utilize medicinal plants for managing ailments.
The World Health Organization reported that more than 80% of the emerging world’s population subsists on traditional medicine for various ailments. Medicinal plants have remained an incredible source of promising drug entities (Omara et al. 2021b). Over the years, anticancer agents have been derived from plants and currently used to treat different types of cancers in clinical practice. Thorough investigation of cytotoxic compounds in plants previously used in traditional cancer phytotherapy led to the discovery of anticancer drugs and lead compounds. For example, the chemical structure of cytotoxic phytocompound podophyllotoxin was first elucidated in 1932 (Jones 2014), followed by the discovery of the vinca alkaloids (vinblastine and vincristine) in Catharanthus roseus in 1958 (Sottomayor and RosBarcelo 2006). This was ensued by the identification of paclitaxel in 1971 (Barbuti and Chen 2015). Such molecules of plant origin have revolutionized cancer treatment, but more lead compounds need to be discovered as cancer cells are rapidly evolving and developing resistance to these drugs. It is argued therefore that novel therapeutic molecules will be developed from medicinal plants in close association with leads furnished by traditional knowledge and experiences (Omara et al. 2021c).
In the East African botanical plate, Kenya is known as one of the richest countries with diverse ethnic groups utilizing medicinal plants (Omara 2020). A recent review (Jaleny 2020) gave an overview of the herbal remedies for cancer used across rural Kenya. This study expands on the list through a comprehensive literature search exploring the ethnobotanical knowledge, phytochemistry and antiproliferative activities of plants used in the management of various types of cancer in Kenya, East Africa.
Materials and methods
Elaborate independent literature search in PubMed, Science Direct, Scopus, Google Scholar, Web of Science, Scientific Electronic Library Online and the Google search engine was done from September 2021 to April 2022. The keywords used were cancer, carcinoma, prostate cancer, breast cancer, lung cancer, liver cancer, anticancer plants, cancer of the blood, leukaemia, plant extract, traditional medicine, alternative medicine, natural medicine, ethnopharmacology, ethnobotany, herbal medicine, herb, decoction, infusion, macerate, cancerous, hepatocellular carcinoma, Kaposis sarcoma, Burkitt’s lymphoma, cancer of the bone, cancer of the eye, cancer of the colon, cancer of the cervix uteri, skin cancer combined with Kenya. Journal articles, books, theses, dissertations, patents, and other reports covering anticancer plants in Kenya dated until April 2022 were included in the study. The retrieved studies were analyzed in Microsoft Excel. The botanical families, folk names, growth habit, part (s) used, preparation and administration mode of the different anticancer plants were captured. Further search was done to retrieve information on the anticancer activity of the extracts or isolated compounds from the claimed plants.
Inventory of plants used in the management of cancer in Kenya
The electronic search identified 24 reports with information on ethnomedicinal plants used in Kenya for preparation of herbal remedies for treatment of prostate, blood, bone, breast, colorectal, colon, oesophageal, lung, liver, skin, stomach, throat, uterine cancers and squamous cell carcinoma of the gum (Table 1). These sources reported a total of 145 botanical species claimed in traditional management of cancer in Kenya. The identified species were from 125 genera, spread across 55 families. Fabaceae (19 species, 13.1%), Asteraceae (11 species, 7.6%), Euphorbiaceae (8 species, 5.5%) and Rutaceae (7 species, 4.8%) were the most represented families (Fig. 1). Plant species from these families have been previously indicated for use in traditional treatment of different malignancies in other countries (Abu-Darwish and Efferth 2018; Ayele 2018; Bourhia et al. 2019; Kuruppu et al. 2019).
The study identified more 89 plant species (from 19 botanical families), adding onto the 55 species identified in the review by Jaleny (2020). This could be attributed to more studies reporting on ethnomedicinal plants usage in Kenya since the last review, and also the differences in the choice of the electronic databases used in the previous study and the current study. The most cited species encountered are Prunus africana (12 times), Launaea cornuta (4 times), Tabernaemontana stapfiana, Maytenus obscura, Flueggea virosa and Moringa oleifera (3 times each). Interestingly, some of the species recorded such as Zanthoxylum chalybeum are used in Tanzania (Matata et al. 2018), Uganda (Omara et al. 2020) and Ethiopia (Tuasha et al. 2019) for the management of cancers.
The identified plants are trees (63 species, 43.4%), shrubs and herbs (40 species each, 27.6%) or climbers (2 species, 1.4%). For anticancer herbal remedies, leaves (27.3%), roots (19.0%) and stem bark (12.2%) are the most commonly used (Fig. 2). The different plant parts are used for preparation of poultices (30%), decoctions (21%) and infusions (20%) as shown in Fig. 3. However, reproductive structures such as seeds, fruits and bulbs are less commonly used, similar to reports from other countries (Omara et al. 2020). In some use reports, the plant parts used were not specified and this may be explained by the top secrecy associated with herbal medicine use in Kenya (Kuria et al. 2001; Omara 2020).
Phytochemistry and antiproliferative activities of anticancer plants reported in Kenya
Many plant species have been claimed in folklore to possess anticancer properties, and some important anticancer molecules and drugs have been isolated from such plants. For example, Camptotheca acuminata elicited antiproliferative activity against rectal, brain, liver, gastrointestinal and breast tumors and this led to the isolation of Camptothecin, an anticancer drug (Kaur et al. 2011). In Kenya, the pioneer institution in cancer research is the Center for Traditional Medicine Research (CTMDR) of the Kenya Medical Research Institute (KEMRI), Nairobi, Kenya. To date, at least 20 species of Kenyan anticancer herbal plants have been studied extensively in the laboratory, but there is little move from bench-scale experiments to product development due to underfunding by the government (Gathura 2019). Herbal anticancer products derived from Prunus africana: Tadenan, Prostafx and Pygenil are widely traded in Kenya and the East African region (Nyamai et al. 2015; Omara et al. 2020).
A review of the identified plants used for treatment of malignancies that have been reported to possess antiproliferative activities was undertaken. The most studied anticancer plants included Toddalia asiatica, Annona muricata, Carica papaya, Catharanthus roseus, Moringa oleifera, Ocimum gratissimum, Prunus africana and Zanthoxylum paracanthum (Table 2) and have various compounds reported in them (Fig. 4). However, some of the most utilized plant species such as Tabernaemontana stapfiana and Flueggea virosa have hardly been studied or have given conflicting results. For example, some potentially bioactive compounds isolated from Flueggea virosa (fluevirines E and F) elicited no appreciable antiproliferative effect against human cancer cell lines: SW480, A549, SMMC-7721, HL-60 and MCF-7 (Yang et al. 2020).
Phytochemicals elicit anticancer activity through various pathways such as inducing cleavages that yield reactive oxygen species (thereby inducing oxidative stress), inducing apoptosis, reducing cell proliferation through cell cycle arrest, inhibiting angiogenesis and tissue invasion of the tumor and cancer metastasis (Lichota and Gwozdzinski 2018). For example, β-amyrin and β-sitosterol-3-O-glucoside from Prunus africana elicited anticancer activity against Caco-2 cell line through induction of apoptosis (Chepkoech 2014). In addition, some of the compounds demonstrate different mechanisms of anticancer action contingent on their doses. For example, the Catharanthus alkaloids at low concentrations (< 1 µmol) inhibit microtubule dynamics and stabilize them, while at high concentrations (> 1–2 µmol), they disintegrate the microtubules and damage the mitotic spindle, triggering apoptosis by inhibition of mitosis (Lee et al. 2015). Other than the isolated compounds, it is important to note that various compounds that may be present in a plant extract can synergistically induce anticancer activity through the different mechanistic pathways.
Clinical trials utilizing standardized extracts or compounds from anticancer plants reported in Kenya are yet to be done. However, extracts and compounds from species such as Catharanthus roseus and Prunus africana have previously been subjected to clinical trials in other countries (Grace et al. 2003; Kumar et al. 2013). Thus, there is need to investigate the anticancer activity of the unstudied species identified in Kenya, along with phytochemical analysis and elucidation of their mechanism of action. This review emphasizes the need for increased budgetary allocation for investigation of Kenyan anticancer plants from laboratories to clinical trials.
The current review had the following limitations: (1) direct studies pertaining to toxicity of the plant extracts or the isolated cytotoxic compounds were not reviewed, (2) though major abstracting and indexing databases were used for retrieving the reports reviewed in this study, some reports may have not been encountered and therefore not included in this review.
Ethnobotanical knowledge on the use of herbal remedies in the management of cancer in Kenya is immense. However, investigation of bioactivity, safety aspects, anticancer molecules, pre-clinical and clinical studies are required to elucidate the mechanism of action of the compounds and confirm the potential of the unstudied species.
Availability of data and materials
This is a review study and no raw data were collected. Any data collected or analyzed are within this article.
Abu-Darwish MS, Efferth T (2018) Medicinal plants from near east for cancer therapy. Front Pharmacol 9:56
Al-Asmari AK, Albalawi SM, Athar MT, Khan AQ, Al-Shahran H, Islam M (2015) Moringa oleifera as an anti-cancer agent against breast and colorectal cancer cell lines. PLoS ONE 10(8):e0135814
Amado NG, Predes D, Fonseca BF, Cerqueira D, Reis A, Dudenhoeffer A et al (2014) Isoquercitrin suppresses colon cancer cell growth in vitro by targeting the Wnt/β-catenin signaling pathway. J Biol Chem 289(51):35456–35467
Artanti AN, Astirin OP, Prayitno A (2016) Cytotoxic activity of non polar fraction from Annona muricata L. leaves on Hela and Raji cell lines. J Pharmaceut Sci Clin Res 1:112–118
Ayele TT (2018) A Review on traditionally used medicinal plants/herbs for cancer therapy in Ethiopia: current status. Chall Future Perspect Org Chem 7:192
Bah F, Aimée Dozolme PM, Cabral M, Touré A, Lam A, Mobio TA et al (2020) Cytotoxicity of roots methanolic extract of Maytenus senegalensis. Adv J Toxicol 4(1):011–016
Barbuti AM, Chen ZS (2015) Paclitaxel through the ages of anticancer therapy: exploring its role in chemoresistance and radiation therapy. Cancers 7:2360–2371
Berkovich L, Earon G, Ron I, Rimmon A, Vexler A, Lev-Ari S (2013) Moringa Oleifera aqueous leaf extract down-regulates nuclear factor-κB and increases cytotoxic effect of chemotherapy in pancreatic cancer cells. BMC Complement Altern Med 13:212
Betancur-Galvis LA, Saez J, Granados H, Salazar A, Ossa JE (1999) Antitumor and antiviral activity of Colombian medicinal plant extracts. Mem Inst Oswaldo Cruz 94:531–535
Bourhia M, Shahat AA, Almarfadi OM, Nasser F, Abdelmageed W, Said A et al (2019) Ethnopharmacological survey of herbal remedies used for the treatment of cancer in the greater Casablanca-Morocco. Evid Based Complement Alternat Med 2019:1613457
Byamukama R, Ganza B, Namukobe J, Heydenreich M, Kiremire BT (2015) Bioactive compounds in the stem bark of Albizia coriaria (Welw. ex Oliver). Int J Biol Chem Sci 9(2):1013–1024
Chaemsawang W, Prasongchean W, Papadopoulos KI, Ritthidej G, Sukrong S, Wattanaararsakit P (2019) The effect of Okra (Abelmoschus esculentus (L) Moench) seed extract on human cancer cell lines delivered in its native form and loaded in polymeric micelles. Int J Biomat 2019:9404383
Chen H, Lee M, Kuo C, Tsai P, Liu J, Kao S (2011) Ocimum gratissimum aqueous extract induces apoptotic signalling in lung adenocarcinoma cell A549. Evid Based Complement Alternat Med 2011:739093
Chen Q, Li P, Li P, Xu Y, Li Y, Tang B (2015) Isoquercitrin inhibits the progression of pancreatic cancer in vivo and in vitro by regulating opioid receptors and the mitogen-activated protein kinase signalling pathway. Oncol Rep 33(2):840–848
Chen F, Chen X, Yang D, Che X, Wang J, Li X et al (2016) Isoquercitrin inhibits bladder cancer progression in vivo and in vitro by regulating the PI3K/Akt and PKC signaling pathways. Oncol Rep 36(1):165–172
Chepkoech M (2014) Phytochemistry and anti-cancer potential of compounds isolated from kenyan medicinal plants, Moringa oleifera and Prunus africana. MSc thesis, University of KwaZulu-Natal, South Africa
Chimezie A, Ofure O (2022) Non-communicable diseases pose huge burden on Africa’s overstretched health systems. https://businessday.ng/opinion/article/non-communicable-diseases-pose-huge-burden-on-africas-overstretched-health-systems/#:~:text=Non-communicable%20diseases%20%28NCDs%29%20%E2%80%94primarily%20heart%20and%20lung%20diseases%2C,annually%2C%20according%20to%20the%20World%20Health%20Organisation%20%28WHO%29. Accessed 23 Mar 2022
Chivandi E, Cave E, Davidson BC, Erlwanger KH, Moyo D, adziva MT, (2012) Suppression of Caco-2 and HEK-293 cell proliferation by Kigelia africana, Mimusops zeyheri and Ximenia caffra seed oils. In Vivo 26:99–105
Dai Y, Hogan S, Schmelz EM, Ju YH, Canning C, Zhou K (2011) Selective growth inhibition of human breast cancer cells by graviola fruit extract in vitro and in vivo involving downregulation of EGFR expression. Nutr Cancer 63:795–801
Dalmartello M, La Vecchia C, Bertuccio P, Boffetta P, Levi F, Negri E, Malvezzi M (2021) European cancer mortality predictions for the year 2022 with focus on ovarian cancer. Annals Oncol. https://doi.org/10.1016/j.annonc.2021.12.007
Dharani N, Yenesew A (2010) Medicinal plants of East Africa—an illustrated guide. Drongo publishing, Nairobi, Kenya, p 57
Ekunwe S, Thomas M, Luo X, Wang H, Chen Y, Zhang X, Begonia G (2010) Potential cancer-fighting Ocimum gratissimum (OG) leaf extracts: increased anti-proliferation activity of partially purified fractions and their spectral fingerprints. Ethnicity Dis 20:1–16
Ekunwe S, Hall S, Luo X, Wang H, Begonia G (2013) Fractionated Ocimum gratissimum leaf extract inhibit prostate cancer (PC3·AR) cells growth by reducing androgen receptor and survivin levels. J Health Care Poor Underserved 24(4):61–69
El-Beltagi HS, Mohamed HI, Megahed BMH, Gamal M, Safwat G (2018) Evaluation of some chemical constituents, antioxidant, antibacterial and anticancer activities of Beta vulgaris L. Root Fresenius Environ Bull 27(9):6369–6378
Fouche G, Cragg GM, Pillay P, Kolesnikova N, Maharaj VJ, Senabe J (2008) In vitro anticancer screening of South African plants. J Ethnopharmacol 119:455–461
Garcia-Solis P, Yahia EM, Morales-Tlalpan V, Diaz-Munoz M (2009) Screening of antiproliferative effect of aqueous extracts of plant foods consumed in Mexico on the breast cancer cell line MCF-7. Int J Food Sci Nutr 60:32–46
Gathura G (2017) 20 plants studied in Kenya and the cancer(s) they treat. https://www.standardmedia.co.ke/evewoman/article/2001234918/20-plants-studied-in-kenya-and-the-cancer-s-they-treat. Accessed 20 Feb 2022
Gathura G (2019) Local shrub now top candidate for new cancer drug. https://www.standardmedia.co.ke/amp/health-science/article/2001317800/local-shrub-now-top-candidate-for-new-cancer-drug. Accessed 20 Feb 2022
Gavamukulya Y, Abou-Elella F et al (2014) Phytochemical screening, anti-oxidant activity and in vitro anticancer potential of ethanolic and water leaves extracts of Annona muricata (Graviola). Asian Pac J Trop Med 7:S355–S363
George VC, Kumar D, Rajkumar V, Suresh P, Kumar RA (2012) Quantitative assessment of the relative antineoplastic potential of the n-butanolic leaf extract of Annona muricata Linn. in normal and immortalized human cell lines. Asian Pac J Cancer Prevent 13:699–704
Grace OM, Prendergast HDV, Jager AK, Van Staden J (2003) Bark medicines used in traditional healthcare in KwaZulu-Natal, South Africa: an inventory. S Afr J Bot 69:301–363
Guevara AP, Vargas C, Sakurai H, Fujiwara Y, Hashimoto K, Maoka T et al (1999) An antitumor promoter from Moringa oleifera Lam. Mutat Res 440:181–188
Guon T, Chung HS (2016) Induction of apoptosis with Kigelia africana fruits in HCT116 human colon cancer cells via MAPKs signaling pathway. Nat Prod Sci 22:209–215
Hamdi Y, Abdeljaoued-Tej I, Zatchi AA, Abdelhak S, Boubaker S, Brown JS, Benkahla A (2021) Cancer in Africa: the untold story. Front Oncol 11:650117
Hirose M, Yamaguchi T, Kimoto N, Ogawa K, Futakuchi M, Sano M, Shirai T (1998) Strong promoting activity of phenylethyl isothiocyanate and benzyl isothiocyanate on urinary bladder carcinogenesis in F344 male rats. Int J Cancer 77:773–777
Hisiger S, Jolicoeur M (2007) Analysis of Catharanthusroseus alkaloids by HPLC. Phytochem Rev 6:207–234
Hostettmann K, Marston A, Ndjoko K, Wolfender JL (2000) The potential of African plants as a source of drugs. Curr Org Chem 4(10):973–1010
Hu J, Shi X, Chen J, Mao X, Zhu L, Yu L, Shi J (2014) Alkaloids from Toddalia asiatica and their cytotoxic, antimicrobial and antifungal activities. Food Chem 148:437–444
Huang CC, Hwang JM, Tsai JH, Chen JH, Lin H, Lin GJ (2020) Aqueous Ocimum gratissimum extract induces cell apoptosis in human hepatocellular carcinoma cells. Int J Med Sci 17(3):338–346
Iwasaki H, Okabe T, Takara K, Toda T, Shimatani M, Oku H (2009) Tumor-selective cytotoxicity of benzo[c]phenanthridine derivatives from Toddalia asiatica Lam. Cancer Chemothera Pharmacol 65(4):719–726
Jaleny OP (2020) Herbal remedies for cancer by various indigenous kenyan communities: a review of ethnobotanical surveys and anticancer studies. Int J Sci Healthc Res 5(4):292–298
Jayakumar R, Kanthimathi MS (2011) Inhibitory effects of fruit extracts on nitric oxide-induced proliferation in MCF-7 cells. Food Chem 126:956–960
Jena AK, Vasisht K, Sharma N, Kaur R, Dhingra MS, Karan M (2016) Amelioration of testosterone induced benign prostatic hyperplasia by Prunus species. J Ethnopharmacol 190:33–45
Jeruto P, Lukhoba C, Ouma G, Otieno D, Mutai C (2008) Herbal treatments in Aldai and Kaptumo divisions in Nandi District, Rift Valley Province, Kenya. Afr J Tradit Complement Altern Med 5(1):103–105
Jeruto P, Too E, Mwamburia LA, Amukab O (2015) An inventory of medicinal plants used to treat gynaecological-obstetric-urino-genital disorders in South Nandi sub county in Kenya. J Nat Sci Res 5:18
Jones GB (2014) History of anticancer drugs. In: eLS, Wiley, Chichester, pp 1–4
Jung IL, Lee JH, Kang SC (2015) A potential oral anticancer drug candidate, Moringa oleifera leaf extract, induces the apoptosis of human hepatocellular carcinoma cells. Oncol Lett 10:1597–1604
Kaigongi MM, Lukhoba CW, Yaouba S, Makunga NP, Githiomi J, Yenesew A (2020) In Vitro antimicrobial and antiproliferative activities of the root bark extract and isolated chemical constituents of Zanthoxylum paracanthum Kokwaro (Rutaceae). Plants 9:920
Kamau LN, Mbaab PM, Mbaria JM, Gathumbi PK, Kiama SG (2016) Ethnobotanical survey and threats to medicinal plants traditionally used for the management of human diseases in Nyeri County. Kenya Tang 6(3):e21
Kapadia GJ, Azuine MA, Rao GS, Arai T, Iida A, Tokuda H (2011) Cytotoxic effect of the red beetroot (Beta vulgaris L.) extract compared to doxorubicin (adriamycin) in the human prostate (PC-3) and breast (MCF-7) cancer cell lines. Anti-Cancer Agents Med Chem 11:3
Kapingu MC, Moshi MJ, Mbwambo ZH, Nondo RS, Masimba PJ, Kamuhabwa A (2006) Evaluation of ethnomedical claims and brine shrimp toxicity of some plants used in Tanzania as traditional medicines. Afr J Tradit Complement Alternat Med 3:48–58
Kareru PG, Kenji GM, Gachanja AN, Keriko JM, Mungai G (2007) Traditional medicines among the Embu and Mbeere peoples of Kenya. Afr J Tradit Complement Altern Med 4:75–86
Kaur R, Kapoor K, Kaur H (2011) Plants as a source of anticancer agents. J Nat Prod Plant Resour 11(1):119–124
Khalafalla MM, Abdellatef E, Dafalla HM, Nassrallah AA, Aboul-Enein KM, Lightfoot DA et al (2010) Active principle from Moringa oleifera Lam leaves effective against two leukemias and a hepatocarcinoma. Afr J Biotechnol 9:8467–8471
Kigen G, Some F, Kibosia J, Rono H, Kiprop E, Wanjohi B, Kigen P, Kipkore W (2014) Ethnomedicinal plants traditionally used by the Keiyo Community in Elgeyo Marakwet County, Kenya. J Biodiv Bioprospect Dev 1(3):1000132
Kigen G, Kipkore W, Wanjohi B, Haruki B, Kemboi J (2017) Medicinal plants used by traditional healers in Sangurur, Elgeyo Marakwet County, Kenya. Pharmacog Res 9(4):333–347
Kigen G, Kamuren Z, Njiru E, Wanjohi B, Kipkore W (2019) Ethnomedical survey of the plants used by traditional healers in Narok county, Kenya. Evid Based Complement Alternat Med 2019:8976937
Kimani PM (2022) In vitro anti-proliferative activity of selected plant extracts against cervical and prostate cancer cell lines. MSc thesis, Jomo Kenyatta University Of Agriculture and Technology, Nairobi
Ko YM, Wu TY, Wu YC, Chang FR, Guh JY, Chuang LY (2011) Annonacin induces cell cycle-dependent growth arrest and apoptosis in estrogen receptor-a-related pathways in MCF-7 cells. J Ethnopharmacol 137:1283–1290
Kokwaro JO (1976) Medicinal Plants of East Africa. East African Literature Bureau, Nairobi, Kenya.
Kokwaro JO (1993) Medicinal plants of East Africa, 2nd edn. East African Literature Bureau, Nairobi, Kenya, p 416
Krishnamurthy PT, Vardarajalu A, Wadhwani A, Patel V (2015) Identification and characterization of a potent anticancer fraction from the leaf extracts of Moringa oleifera L. Indian J Exp Biol 53(2):98–103
Kumar A, Patil D, Rajamohanan PR, Ahmad A (2013) Isolation, purification and characterization of vinblastine and vincristine from endophytic fungus Fusarium oxysporum isolated from Catharanthus roseus. PLoS ONE 8:e71805
Kuria KAM, De Coster S, Muriuki G, Masengo KI, Hoogmartens LGM (2001) Antimalarial activity of Ajuga remota Benth (Labiatae) and Caesalpinia volkensii Harms (Caesalpiniaceae): in vitro confirmation of ethnopharmacological use. J Ethnopharmacol 74(2):141–148
Kuruppu AI, Paranagama P, Goonasekara CL (2019) Medicinal plants commonly used against cancer in traditional medicine formulae in Sri Lanka. Saudi Pharmaceut J 27:565–573
Lacroix D, Prado S, Deville A, Krief S, Dumontet V, Kasenene J et al (2009) Hydroperoxy-cycloartane triterpenoids from the leaves of Markhamia lutea, a plant ingested by wild chimpanzees. Phytochem 70:1239–1245
Lacroix D, Prado S, Kamoga D, Kasenene J, Namukobe J, Krief S et al (2011) Antiplasmodial and cytotoxic activities of medicinal plants traditionally used in the village of Kiohima, Uganda. J Ethnopharmacol 133:850–855
Lee CT, Huang YW, Yang CH, Huang KS (2015) Drug delivery systems and combination therapy by using vinca alkaloids. Curr Top Med Chem 15:1491–1500
Lichota A, Gwozdzinski K (2018) Anticancer activity of natural compounds from plant and marine environment. Int J Mol Sci 19:3533
Macharia L, Mureithi M, Anzala O (2019) Cancer in Kenya: types and infection-attributable: data from the adult population of two National referral hospitals (2008–2012). AAS Open Res 1:25
Madi N, Dany M, Abdoun S, Usta J (2016) Moringa oleifera’s nutritious aqueous leaf extract has Anticancerous effects by compromising mitochondrial viability in an ROS-dependent manner. J Am Coll Nutr 35(7):604–613
Margalef S, Barzanti PR, Puigjaner RJ, Morote RJ, Okatsu TTM (2003) Antimitogenic effect of Pygeum africanum extracts on human prostatic cancer cell lines and explants from benign prostatic hyperplasia. Archivos Espanoles De Urologıa 56(4):369–378
Matata DZ, Ngassapa OD, Machumi F, Moshi MJ (2018) Screening of plants used as traditional anticancer remedies in mkuranga and same districts, Tanzania, using brine shrimp toxicity bioassay. Evid Based Complem Altern Med 2018:3034612
Mbuni YM, Wang S, Mwangi BN, Mbari NJ, Musili PM, Nyamolo OW et al (2020) Medicinal plants and their traditional uses in local communities around Cherangani Hills, Western Kenya. Plants 9:331
Melariri P, Campbell W, Etusim P, Smith P (2011) Antiplasmodial properties and bioassay-guided fractionation of ethyl acetate extracts from Carica papaya leaves. J Parasitol Res 2011:104954
Ménan H, Banzouzi JT, Hocquette A, Pélissier Y, Blache Y, Koné M et al (2006) Antiplasmodial activity and cytotoxicity of plants used in West African traditional medicine for the treatment of malaria. J Ethnopharmacol 105:131–136
Milugo T, Masila VM, Owuor B, Oyugi J, Ochanda J, Wamunyokoli F (2016) Anti-cancer activities of crude extracts from medicinal plants Moringa oleifera Lam and Rauwolfia caffra against selected cancer cell lines. IOSR J Pharm Biol Sci 11:59–64
Moghadamtousi SZ, Rouhollahi E, Karimian H, Fadaeinasab M, Firoozinia M, Ameen Abdulla M, Abdul Kadir H (2015) The chemopotential effect of Annona muricata leaves against azoxymethane-induced colonic aberrant crypt foci in rats and the apoptotic effect of acetogenin annomuricin E in HT-29 cells: a bioassay-guided approach. PLoS ONE 10:e0122288
Monte LG, Santi-Gadelha T, Reis LB, Braganhol E, Prietsch R, Dellagostin O et al (2014) Lectin of Abelmoschus esculentus (okra) promotes selective antitumor effects in human breast cancer cells. Biotechnol Lett 36(3):461–469
Morimoto C, Dang NH, Dang N (2008) Cancer prevention and treating composition for preventing, ameliorating, or treating solid cancers, e.g. lung, or blood cancers, e.g. lymphoma, comprises components extracted from brewing papaya. Patent WO2006004226-A1, EP1778262-A1, JP2008505887-W, US2008069907-A1, YS Therapeutic Co Ltd (YSTH-Non-standard) Toudai Tlo Ltd (TODNon-standard) Morimoto C (MORI-Individual) Dang NH (DANG-Individual)
Mukavi JW, Mayeku PW, Nyaga JM, Kituyi SN (2020) In vitro anti-cancer efficacy and phyto-chemical screening of solvent extracts of Kigelia africana (Lam.) Benth. Heliyon 6:e04481
Muniafu MM, Kipkore KW, Maima AO, Kwena MO, Kahindi JHP (2014) Survey of medicinal plants used by the Giriama of Basi, Kenya. Pharmaceut J Kenya 21(4):7–15
Muriuki J (2011) Medicinal trees in smallholder agroforestry systems: assessing some factors influencing cultivation by farmers East of Mt Kenya, Dissertation, University of Natural Resources and Applied Life Sciences, Vienna
Mustafa NR, Verpoorte R (2007) Phenolic compounds in Catharanthus roseus. Phytochem Revs 6:243–258
Nair S, Varalakshmi K (2011) Anticancer, cytotoxic potential of Moringa oleifera extracts on HeLa cell line. J Nat Pharmaceut 2:138
Najmuddin SUFS, Romli MF, Hamid M, Alitheen NB, Rahman NMANA (2016) Anti-cancer effect of Annona muricata Linn leaves crude extract on breast cancer cell line. BMC Compl Alternat Med 16:311
Nakamura Y, Yoshimoto M, Murata Y, Shimoishi Y, Asai Y, Park EY et al (2007) Papaya seed represents a rich source of biologically active isothiocyanate. J Agric Food Chem 55:4407–4413
Nangia-Makker P, Raz T, Tait L, Shekha M, Li H, Balan V (2013) Ocimum gratissimum retards breast cancer growth and progression and is a natural inhibitor of matrix metalloproteases. Cancer Biol Ther 14(5):417–427
Nassazi W, K’Owino IO, Makatiani J, Wachira S (2020) Phytochemical composition, antioxidant and antiproliferative activities of African basil (Ocimum gratissimum L.) Leaves. Asian J Appl Chem Res 6(4):1–18
Nawwar M, Ayoub N, Hussein S, Hashim A, El-Sharawy R, Wende K et al (2012) Flavonol triglycoside and investigation of the antioxidant and cell stimulating activities of Annona muricata Linn. Arch Pharmaceut Res 35:761–767
NCI (2022) National Cancer Institute of Kenya. Cancer situation in Kenya. https://www.ncikenya.or.ke/. Accessed 10 Jan 2022
Ngule MC, Ndiku MH, Ramesh F (2014) Chemical constituents screening and in vitro antibacterial assessment of Prunus africana bark hydromethanolic extract. J Nat Sci Res 4(16):85–90
Nguyen T, Parat M, Shaw P, Hewavitharana A, Hodson M (2016) Traditional aboriginal preparation alters the chemical profile of Carica papaya leaves and impacts on cytotoxicity towards human squamous cell carcinoma. PLoS ONE 11:e0147956
Nibret E, Ashour ML, Rubanza CD, Wink M (2010) Screening of some tanzanian medicinal plants for their trypanocidal and cytotoxic activities. Phytother Res 24:945–947
Nisa FZ, Astuti M, Murdiati A, Haryana SM (2017) Anti-proliferation and apoptosis induction of aqueous leaf extract of Carica papaya L. on human breast cancer cells MCF-7. Pak J Biol Sci 20:36–41
Njuguna DK, Mbuthia K, Mutuku C, Jepkorir M et al (2018) Phytochemical composition and in vitro anti-proliferative activity of Oxygonum sinuatum (Meisn.) dammer on selected cancerous cells. J Complement Altern Med Res 6(2):1–9
Noté OP, Mitaine-Offer AC, Miyamoto T, Paululat T, Mirjolet JF, Duchamp O, Pegnyemb DE, Lacaille-Dubois MA (2009) Cytotoxic acacic acid glycosides from the roots of Albizia coriaria. J Nat Prod 72(10):1725–1730
Note OP, Chabert P, Pegnyem DE, Weniger B, Lacaille-Dubois M, Lobstein A (2010) Structure elucidation of new acacic acid-type saponins from Albizia coriaria. Mag Res Chem 48(10):829–836
Nyamai D, Mawia A, Wanbua F, Njoroge A, Matheri F (2015) Phytochemical profile of Prunus africana stem bark from Kenya. J Pharmacog Nat Prod 1:110
Ocheng F, Bwanga F, Boström EA (2016) Essential oils from Ugandan medicinal plants: in vitro cytotoxicity and effects on IL-1β-induced proinflammatory mediators by human gingival fibroblasts. Evid Based Complement Alternat Med 2016:5357689
Ochwang’i DO et al (2014) Medicinal plants used in treatment and management of cancer in Kakamega County, Kenya. J Ethnopharmacol 151:1040–1055
Okello S, Nyunja R, Netondo G, Onyango J (2010) Ethnobotanical study of medicinal plants used by Sabaots of Mt. Elgon Kenya. Afr J Tradit Complement Altern Med 7:1–10
Omara T (2020) Antimalarial plants used across Kenyan communities. Evid Based Complement Alternat Med 2020:4538602
Omara T, Kiprop AK, Ramkat RC, Cherutoi J, Kagoya S, Nyangena DM et al (2020) Medicinal plants used in traditional management of cancer in Uganda: ethnobotanical surveys, phytochemistry and anticancer studies. Evid Based Complement Altern Med 2020:3529081
Omara T, Kiprop A, Wangila P, Wacoo AP, Kagoya S, Nteziyaremye P et al (2021a) The scourge of Aflatoxins in Kenya: A 60-year review (1960 to 2020). J Food Qual 2021:8899839
Omara T, Kiprop AK, Kosgei V (2021b) Intraspecific variation of phytochemicals, antioxidant, and antibacterial activities of different solvent extracts of Albizia coriaria Leaves from some agroecological zones of Uganda. Evid Based Complement Alternat Med 2021:2335454
Omara T, Nakiguli CK, Naiyl RA, Opondo FA, Otieno SB, Ndiege ML et al (2021c) Medicinal plants used as snake venom antidotes in East African Community: review and assessment of scientific evidences. J Med Chem Sci 4:107–144
Omara T, Kiprop AK, Kosgei V (2022) Isolation and characterization of compounds in ethanolic extract of Albizia coriaria (Welw ex. Oliver) leaves: a further evidence of its ethnomedicinal diversity. Bull Natl Res Cent 46:30
Omosa LK, Mbogo GM, Korir E, Omole R, Seo EJ, Yenesew A et al (2019) Cytotoxicity of fagaramide derivative and canthin-6-one from Zanthoxylum (Rutaceae) species against multidrug resistant leukemia cells. Nat Prod Res 7:1–8
Onyancha J, Gikonyo N, Wachira S, Mwitari P, Gicheru M (2018) Anticancer activities and safety evaluation of selected Kenyan plant extracts against breast cancer cell lines. J Pharmacog Phytother 10(2):21–26
Onyancha J, Gikonyo N, Wachira S, Gicheru M (2019) An ethnobotanical survey of plants used for the treatment and management of cancer in Embu County, Kenya. J Med Plants Stud 7(4):39–46
Osorio E, Arango GJ, Jiménez N, Alzate F, Ruiz G, Gutiérrez D et al (2007) Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae. J Ethnopharmacol 111:630–635
Otieno NE, Analo C (2012) Local indigenous knowledge about some medicinal plants in and around Kakamega forest in western Kenya. F1000Res 2:1–40
Otsuki N, Dang N, Kumagai E, Kondo A, Iwata S, Morimoto C (2010) Aqueous extract of Carica papaya leaves exhibits anti-tumour activity and immunomodulatory effects. J Ethnopharmacol 127:760–767
Oviedo V, García M, Díaz C, Marder M, Costa M, Rincón J et al (2009) Extracto y fracción alcaloidal de Annona muricata con actividad de tipo ansiolítica en ratones. Rev Colomb Cienc Quím Farm 38:105–120
Parvathy MVS, Umamaheshwari A (2007) Cytotoxic effect of Moringa oleifera leaf extracts on human multiple myeloma cell lines. Trends Med Res 2:44–50
Pérez AJ, Hassan EM, Pecio L, Omer EA, Kucinska M, Murias M, Stochmal A (2015) Triterpenoid saponins and C-glycosyl flavones from stem bark of Erythrina abyssinica Lam and their cytotoxic effects. Phytochem Lett 13:59–67
Quispe A, Zavala D, Rojas J, Posso M, Vaisberg A (2006) Efecto citotóxico selectivo in vitro de muricin H (acetogenina de Annona muricata) en cultivos celulares de cáncer de pulmón. Rev Peru Med Exp Salud 23:265–269
Rahmat A, Rosli R, Endrini S, Zain WSAH (2002) Antiproliferative activity of pure lycopene compared to both extracted lycopene and juices from watermelon (Citrullus vulgaris) and papaya (Carica papaya) on human breast and liver cancer cell lines. J Med Sci 2:55–58
Rajendran N, Ananthathamula R, Arun K, Brindha P (2014) Anticancer and antioxidant activity of ethanolic extract of markhamia lutea (Benth) K. Schum stem bark. Asian J Chem 26:3741–3744
Rajesh AS, Kiran NSS, Tripathi PC, Verma K (2012) In vitro cytotoxicity of Moringa oleifera against different human cancer cell lines. Asian J Pharmaceut Clin Res 5(4):271–272
Roduan R, Hamid A, Sulaiman H, Mohtarrudin N (2017) Annona muricata leaves extracts prevent DMBA/TPA-induced skin tumorigenesis via modulating antioxidants enzymes system in ICR mice. Biomed Pharmacother 94:481–488
Rosdi MNM, Daud NNNNM, Zulkifli RM, Ya’akob H, (2015) Cytotoxic effect of Annona muricata Linn leaves extract on Capan-1 cells. Pharmmaceut Sci 5:045–048
Rufford TE (2020) Ethnomedicine of Tugen Community, Baringo County, Kenya. https://www.rufford.org/files/19802-1%20Medicinal%20Plants%20of%20Baringo,%20Kenya.pdf. Accessed 20 Jul 2020
Schmelzer GH, Achigan-Dako EG, Bosch CH (2010) Medicinal plants of tropical Africa. Conclusions and recommendations based on plant resources of tropical Africa Foundation, Nairobi, Kenya, pp 121–152
Shaimaa G, Mahmoud M, Mohamed M, Emam A (2016) Phytochemical screening, antioxidant activities and in vitro anticancer potential of Egyptian Capsicum Spp. Biochem Pharmacol 5:2
Shantanu, KH (2015) Anticancer activity of a constituent from Moringa oleifera leaves. J Chem Pharmaceut Res 7:701–705
Shiracko N, Owuor BO, Gakuubi MM, Wanzala W (2016) A survey of ethnobotany of the AbaWanga people in Kakamega county, Western province of Kenya. Indian J Tradit Knowl 15(1):93–102
Sottomayor M, RosBarcelo A (2006) The vinca alkaloids: from biosynthesis and accumulation in plant cells, to uptake, activity and metabolism in animal cells. Stud Nat Prod Chem 33:813–857
Sukieum S, Sang-aroon W, Yenjai C (2017) Coumarins and alkaloids from the roots of Toddalia asiatica. Nat Prod Res 32(8):944–952
Sun S, Liu J, Kadouh H, Sun X, Zhou K (2014) Three new antiproliferative Annonaceous acetogenins with mono-tetrahydrofuran ring from graviola fruit (Annona muricata). Bioorg Med Chem Letts 24:2773–2776
Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F (2021) Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. Science 71(3):209–249
Suphachai C (2014) Antioxidant and anticancer activities of Moringa oleifera leaves. J Med Plants Res 8:318–325
Teng WC, Chan W, Suwanarusk R, Ong A, Ho HK, Russell B et al (2019) In vitro antimalarial evaluations and cytotoxicity investigations of Carica papaya leaves and carpaine. Nat Prod Commun 14:33–36
Tiloke C, Phulukdaree A, Chuturgoon AA (2013) The antiproliferative effect of Moringa oleifera crude aqueous leaf extract on cancerous human alveolar epithelial cells. BMC Complement Altern Med 13:226
Torres MP, Rachagani S, Purohit V, Pandey P, Joshi S, Moore ED et al (2012) Graviola: a novel promising natural-derived drug that inhibits tumorigenicity and metastasis of pancreatic cancer cells in vitro and in vivo through altering cell metabolism. Cancer Lett 323:29–40
Torres R, Casanova L, Carvalho J, Marcondes M, Costa S, Sola-Penna M, Zancan P (2018) Ocimum basilicum but not Ocimum gratissimum present cytotoxic effects on human breast cancer cell line MCF-7, inducing apoptosis and triggering mTOR/Akt/p70S6K pathway. J Bioenerg Biomem 50(2):93–105
Tuasha N, Seifu D, Gadisa E, Petros B, Oredsson S (2019) Cytotoxicity of selected Ethiopian medicinal plants used in traditional breast cancer treatment against breast-derived celllines. J Med Plants Res 13(9):188–198
Valencia L, Muñoz DL, Robledo SM, Echeverri F, Arango GJ, Vélez ID, Triana O (2011) Actividad tripanocida y citotóxica de extractos de plantas colombianas. Biomedica 31:552–559
Vázquez R, Riveiro ME, Vermeulen M, Mondillo C, Coombes PH, Crouch NR et al (2012) Toddaculin, a natural coumarin from Toddalia asiatica, induces differentiation and apoptosis in U-937 leukemic cells. Phytomed 19(8–9):737–746
Wekha G, Ssewante N, Iradukunda A, Jurua M, Nalwoga S, Lanyero S et al (2021) Colorectal cancer in Uganda: A 10-year, facility-based, retrospective study. Cancer Manage Res 13:7697–7707
Welle D (2020) Saving Kenya's anti-cancer tree. https://www.dw.com/en/saving-kenyas-anti-cancer-tree/a-18284972. Acessessed 20 Jan 2022
Wu FE, Gu ZM, Zeng L, Zhao GX, Zhang Y, McLaughlin JL, Sastrodihardjo S (1995) Two new cytotoxic monotetrahydrofuran Annonaceous acetogenins, annomuricins A and B, from the leaves of Annona muricata. J Nat Prod 58:830–836
Yang X, Liu J, Huo Z, Yuwen H, Li Y, Zhang Y (2020) Fluevirines E and F, two new alkaloids from Flueggea virosa. Nat Prod Res 34(14):2001–2006
Yuan SSF, Chang HL, Chen HW, Yeh Y, Kao Y, Lin K et al (2003) Annonacin, a mono-tetrahydrofuran acetogenin, arrests cancer cells at the G1 phase and causes cytotoxicity in a Bax-and caspase-3-related pathway. Life Sci 72:2853–2861
Zayas-Viera MDM, Vivas-Mejia PE, Reyes J (2016) Anticancer effect of Moringa oleifera leaf extract in human cancer cell lines. J Health Disparit Res Pract 9:1
Previous authors are commended for their useful quest for knowledge on medicinal plants in Kenyan cancer phytotherapy, the reports of which instigated this review.
This research received no external funding.
Ethics approval and consent to participate
Consent for publication
The authors declare that there is no conflict of interest regarding the publication of this paper.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Omara, T., Odero, M.P. & Obakiro, S.B. Medicinal plants used for treating cancer in Kenya: an ethnopharmacological overview. Bull Natl Res Cent 46, 148 (2022). https://doi.org/10.1186/s42269-022-00840-x
- Non-communicable diseases
- Medicinal plants
- East African botanical plate