Phytochemical analysis of some selected traditional medicinal plants in Ethiopia

Abstract

Background

This review of relevant medicinal plants is based on the fundamental knowledge accumulated by indigenous people of Ethiopia and to identify which types of selected medicinal plants for phytochemical analysis were analyzed and which one is not analyzed at Ethiopian levels. In this review, the most traditional medicinal plant species found and used in Ethiopia are chosen.

Results

The qualitative phytochemical analysis, some of which are the most important phytochemicals such as phenolic, tannins, alkaloids, saponins, cardiac glycosides, steroids, terpenoids, flavonoids, phlobatannins, anthraquinones, and reducing sugars are studied by the researcher. Most studies have revealed that some phytochemicals are present in some medicinal plants while some are absent. The phytochemical properties of some species were studied like Artemisia afra (Ariti), Aloe Vera (Erret), Yzygium guineense (Dokuma), Ruta chalepensis (Tenadam), Ocimum grattissimum (Damakese), Nigella sativa (Tikur Azmud), Lepidium sativum (Feto), Hagenia abyssinica (Kosso), Croton macrostachyus (Bisana), and Rhamnus prinoides (Gesho).

Conclusions

This review has shown that traditional medicinal plants whose phytochemical properties are not studied have various medicinal purposes like treating mastitis, preventing boils, hemorrhoids, congestion, headache, hepatitis, liver, vertigo, stomatitis, kidneys, liver, and vision for treating anemia, hemorrhoid coughs, fluxes, and stomatitis in most animals and human beings. So that identifying the plants based on the investigation and analysis of phytochemical properties of such plant species are more important than Ethiopian levels.

Background

Medicinal plants still play important roles in the daily lives of people living in developing countries of Asia and Africa, including Ethiopia. Medicinal plants not only serve as complements or substitutes for modern medical treatments, which are often inadequately available but also enhance the health and security of local people. Thus, these plants play indispensable roles in daily life and are deeply connected to diverse social, cultural, and economic events associated with life, aging, illness, and death (JAFICOAF 2008). Medicinal plants are used to treat and diagnose diseases and infections. From ancient times, plants have been rich sources of effective and safe medicines (Russell-Smith et al. 2006).

The world health organization (WHO) defined traditional medicine as the total combination of knowledge and practices that can be formally explained or used in the prevention and elimination of physical, mental, or social imbalance and relying exclusively on practical experience and observation handed down from generation to generation, whether verbally or in writing. About 75–90% of the rural population in the world (excluding western countries) relies on traditional medicines as their only health care system. This is not only because of poverty where people cannot afford to buy expensive modern drugs, but traditional systems are also more culturally acceptable and meet the psychological needs in a way modern medicine does not (Fassil Kibebe 2001).

Ethnomedicinal practices are believed to be one of the potential bases for the development of safe and effective treatments. Ethiopia has a long history of a traditional health care system, but studies on traditional medicinal plants (TMP) have been limited in comparison to the country’s multiethnic, cultural, and flora diversity (Fentahun et al. 2017), Also, the use of medicinal plants to treat infections is an old practice in large parts of Ethiopia to solve health problems for livestock and humans (Redda et al. 2014; Giday et al. 2009; Regassa 2013; Abera 2014; Tamene 2020; Mulatu 2020).

Main text

Increasing traditional medicines and natural plant products

The main phytochemical components, present in medicinal plants are tannins, alkaloids, saponins, cardiac glycosides, steroids, terpenoids, flavonoids, phlobatannins, anthraquinones, and reducing sugars. As proposed by WHO, the primary health care of most population of developing countries depend on traditional medicines and mostly natural plant products (Vines 2004). Like the worldwide countries, populations of Ethiopia use traditional medicines in both rural and urban areas. Traditional practice and activities have a long history in many areas in the Ethiopia and it will continue to give useful and applicable tools for treating disease (Helen et al. 2019).

Different traditional medicinal plant species are studied by different researchers in the world and in the Ethiopian. Ethiopia comprises people with many languages, cultures, and beliefs. This makes for a rich and diverse knowledge and practice of traditional medicine, including herbal remedies (Helen et al. 2019). There are different literature reviews that investigated and studied the Ethnobotanical and Ethnopharmacological evidence of some Ethiopian medicinal plants traditionally used for the Treatment of Cancer, skin problems, leprosy, and external parasites, Evil eye, and wound treatment in the Ethiopia. However, there is no report that could show phytochemical composition and its expanded pharmacological application in the folk medicine of some traditional medicinal plants in the country of Ethiopia. Moreover, this knowledge of identifications of studied and unstudied phytochemical composition of medicinal plants in Ethiopia can serve as the baseline data for researchers and analyzers for the further study of traditional medicinal plants in Ethiopia (Helen et al. 2019).

The medicinal power of traditional plants species lies in phytochemical components that cause definite pharmacological action on the human body (Naseem 2014). Based on their metabolism activity in the plant, phytochemicals components are generally can be mainly divided into two groups, which are primary which has mainly sugars, amino acids, chlorophyll and proteins, and secondary constituents while secondary constituents consist of alkaloids, flavonoids, saponins, tannins, phenolic compounds and many more (Krishnaiah 2007).

The most important components of the medicinal plant were isolated by the extraction methods by using the right solvent. Each researcher in the published articles in this review, different methods of extraction such as ethanol, methanol, chloroform, acetone, hexane, petroleum ether, ethyl acetate, and aqueous (water) were used to the phytochemical composition of plant species. The objective of this review was to collect and summarize the information about the medicinal plant and to classify the plants based on the studies of their phytochemical composition as well as this provides information for the research community to conduct further scientific investigations in Ethiopia’s medicinal plants.

Materials and methods

In this review, the data and information on the traditional medicinal plants in Ethiopia were collected from the published papers, which are available online in different forms such as books, published articles, and research reports. Different online sources such as Google Scholar and gray literature were the source of published articles by browsing the different words or terms like medicinal plants and Ethiopian traditional plants. For this review, scientific name, family name, local name, and important, obtained from the published articles that were obtained online, and the data are shown in Table 23.

There are various traditional medicinal plants used to treat different illnesses and diseases in Ethiopia which did not describe plant species by scientific names; and review articles, are excluded. For this review paper, a total of 53 plant species that are recognized and grown in Ethiopia are documented. From those plant species, the phytochemical composition of some plant species is studied by a researcher and some are not studied. The most important components of the medicinal plant were isolated by the extraction methods by using different solvents. In all reported literature, different solvent such as ethanol, methanol, chloroform, acetone, hexane, petroleum ether, ethyl acetate, and water was used as solvent.

The main aim of this review is to collect and summarize the information about the medicinal plant and to classify the plants based on the studies of their phytochemical composition as well as to provide information for the research community to conduct further scientific investigations on the Ethiopia medicinal plants.

Results and discussions

Phytochemical analysis

Traditional medicine plays a significant role in the healthcare of the people in developing countries, including Ethiopia, and medicinal plants provide a valuable contribution to this practice (Tesfahuneygn and Gebreegziabher 2019). In this review, around 33 medicinal plants species were identified from published articles. The different parts of the plant such as root, leaves, and fruit, in which these different parts have many traditional values, pharmacological uses, and phytochemical constituents were mentioned. From few medication values of plant parts, to treat rheumatism, madness, snakebite, chest pain, jaundice chest pain, malaria, headache, cough, etc. All the medicinal plants are shown in the table form with the scientific name, families, local name, and importance. Most plants were reported and investigated in Ethiopia. As reported by many authors, some medicinal plants with their scientific name, family, local name and their importance are shown in Table 23, and these plant species listed in this review were often used by the people in Ethiopia.

Phytochemicals

Analysis of the phytochemical properties of the medicinal plants used to show and isolate the drug, lead compounds and components from the parts of the plant. The unique biological activity of the plants can be identified by their phytochemicals properties. Most parts of the plants used for the analysis of the phytochemical properties were leaves, roots, stem barks, and fruits. In this review, medicinal plants were investigated for phytochemical constituents of ethanol, methanol, chloroform, acetone, hexane, petroleum ether, ethyl acetate, and aqueous (water) extraction of different phytochemicals.

In this review, the most published articles recognized the presence of phytochemical components in the plants was indicated by the positive sign (+) and the absence of phytochemical components in the plants, by the negative sign (−) as shown in table.

Alkaloids

Alkaloids are one of the main and largest components produced by plants, and they are metabolic byproducts that are derived from the amino acids (Naseem 2014). Based on the published articles in these reviews, alkaloids were extracted from the different parts of the plants using different solvents such as ethanol, methanol, chloroform, acetone, hexane, petroleum ether, ethyl acetate, and aqueous (water). These types of solvents extract phytochemical components from medicinal plants like leaves, roots, stem bark, and fruits.

Flavonoids

Flavonoids consist of a large group of polyphenol compounds having a benzoyl-γ-pyrone structure and are ubiquitously present in plants. They are synthesized by the phenylpropanoid pathway. Available reports tend to show that secondary metabolites of a phenolic nature including flavonoids, are responsible for the variety of pharmacological activities (Mahomoodally et al. 2005; Pandey 2007). Flavonoids are hydroxylated phenolic substances and are known to be synthesized by plants in response to microbial infection (Dixon et al. 1983). In this review, flavonoids were detected in most plant species but in some medicinal plants were not present the same plant but different solvents like eucalyptus and Agenda Abyssinia leaves.

Tannins

The term tannin is widely applied to a complex large biomolecule of polyphenol nature having sufficient hydroxyls and other suitable groups such as carboxyl to form strong complexes with various macromolecules (Navarrete 2013). In this present review, tannins were detected in most plant species like peel and juice of Citrus medica, mango (Mangifera indica L.) leaves, Avocado fruit (Persea Americana), Dioscorea alata leaf, of Leucas aspera L. leaf and root, Ocimum gratissimum Linn leaf, Rhamnus prinoides root, extract of Rhizomes, Zingiber officinale and Curcuma longa and also for different solvent give different response for the same plant species like Bersama abyssinica leaf, Flax seeds, Nigella sativa, Ruta chalepensis leaves, and Syzygium guineense and not totally detected in part of plants like Lepidium sativum seeds and love Gilbetii root. Tannins are generally used in the tanning process and used as healing agents in inflammation, burn, piles, and gonorrhea (Boroushaki et al. 2016).

Saponins

Saponins are an important group of plant secondary metabolites that are widespread throughout the plant kingdom. Saponins are basically phytochemicals that are found in most vegetables, beans, and herbs (Francis et al. 2002; Haralampidis et al. 2002). In this review, saponins were detected in most medicinal plants like citrus fruit juice, of Mango (Mangifera indica L.) leaves, Avocado fruit (Persea americana), Leucas aspera L. leaf, and root, Rhamnus prinoides root, Bitter (Vernonia amygdalina) leaf and Stem bark of Vernonia amygdalina in common plant species and some plants were shown different results, that depends on solvent and also not totally detected in part of the plant such as Bersama abyssinica leaf, Dioscorea alata leaf, love Gilbertii root, and Flax seeds.

Steroids

The word steroid is derived from sterol, which is a natural or synthetic chemically active hormone-like element. A steroid is one of a large group of chemical substances classified by a specific carbon structure. Steroids include drugs used to relieve swelling and inflammation, such as prednisone and cortisone; vitamin D; and some sex hormones, such as testosterone and estradiol (Hill et al. 2007). For this review, Steroids were detected in most plant species like citrus fruit juice, peel and juice of citrus Medica, Flaxseeds, Nigella sativa, Ocimum gratissimum Linn leaf, Syzygium guineans root, and Root and Stem bark of Vernonia amygdalina in common plant species while in some plant species were shown variable result that depends on the given solvents and not totally detected in the part of the plant like Rhamnus prinoides root.

Terpenoids

Terpenoids are small molecular products synthesized by plants and are probably the most widespread group of natural products. Terpenoids show significant pharmacological activities, such as antiviral, antibacterial, antimalarial, anti-inflammatory, inhibition of cholesterol synthesis, and anti-cancer activities (Boroushaki et al. 2016). As mentioned earlier, Terpenoids were detected in most analysis plant species such as citrus fruit juice, Hagenia abyssinica leaves, Leucas aspera L. leaf and root, Flax seeds, Ocimum gratissimum linn leaf, Ruta chalepensis leaves, and Syzygium guineans root while in some plants its result depends on the types of solvents.

Phenolic

Phenolic compounds are secondary metabolites, which are produced in the shikimic acid of plants and pentose phosphate through phenylpropanoid metabolization (Derong Lin et al. 2016). In this review, phenolic was detected in most the medicinal plants like citrus fruit juice, peel and juice of citrus medica, mango (Mangifera indica L.) leaves and Avocado fruit (Persea Americana), eucalyptus leaves, Flax seeds, Rhamnus prinoides root, of Rhizomes, Zingiber officinale, and Curcuma longa but some medicinal plant is given different response and depend on the solvents.

Even though there are so many medicinal plants in Ethiopia, this review of the phytochemical analysis shows that some medicinal plants were studied by the investigator in different areas of Ethiopia, while some traditional plants are not studied. According to the data of published articles, the extraction techniques of the medicinal plants were mainly digestion and aqueous-alcohol extraction. From Tables show that phytochemical investigation results are available in the Ethiopia area levels.

Above the Table 1, phytochemical screening of alkaloids, tannins, saponins, flavonoids, phenols and phytosterols were the secondary metabolites found in the crude extract of Echinops amplexicaulis, Ruta chalepensis, and Salix subserrata. The methanol extracts of Echinops amplexicaulis and Salix subserrata contain most of the secondary metabolites.

Table 1 Phytochemical results of Echinops amplexicaulis, Ruta chalepensis and Salix subserrata (Lencho Megersa Marami et al. 2021)

In terms of the qualitative phytochemical investigation of the medicinal plants, the medicinal plants extract had different phytochemicals constituents such as saponins, tannins, alkaloids, terpenoids, anthraquinones, phenolic compounds, cardiac glycosides, and flavonoids (Table 2).

Table 2 Phytochemical results of medicinal plants (Taye Kebede et al. 2021a, b)

Phytochemical investigations from these medicinal plants have shown a large number of organic complex and biologically active compounds.

The results of the qualitative phytochemicals analysis showed that the leaf extracts of Lippia adonis var. koseret also indicated the presence of tannins, flavonoids, polyphenols, alkaloids and saponins, while in the case of ethyl acetate alkaloids were not detected and tannins were absent in petroleum ether extract (Table 3). Amino acids and carbohydrates were absent in all three extracts.

Table 3 Phytochemical results of Lippia adoensis var. koseret (Yordanos Germam and Tegenu Mekuria 2021)

In this review, phytochemical screening of Bersama abyssinica leaf in Table 4 shown that the most published articles recognized the presences of specific phytochemical components in the plants was indicated by the positive sign (+) and the absence of phytochemical components in the plants, by the negative sign (−). These phytochemical constituents in Bersama abyssinica leaf were shown variable results that depend on the given solvents and are not totally detected in Bersama abyssinica leaf.

Table 4 Phytochemical results of Bersama abyssinica leaf (Mathewos Anza1 et al. 2015)

The results in Table 5 show that there are phytochemical components in Citrus fruit juice concentrates. These phytochemical constituents all are found in citrus fruit juice concentrates except cardiac glycosides were not detected in lemon and they indicated highly medicinal values. It can be suggested that the presence of phenols, alkaloids, flavonoids, saponins, steroids, and reducing sugar in Citrus fruit juice indicates are highly medicinal value.

Table 5 Phytochemical results of Citrus fruit juice concentrates (Ehigbai et al. 2016)

From Table 6, flavonoids, phenols, tannins, steroids, coumarin and cardioactive glycosides: have shown positive tests of ethyl acetate, and methanol extracts of peel and juice of citrus medica, while some phytochemical positive test and totally not detected like (anthraquinones, alkaloids, and terpenoids). These secondary metabolites are known to be biologically active and play significant roles in the bioactivity of medicinal plants because the medicinal values of the medicinal plant lie in these phytochemical compounds which produce a definite and specific action on the human body.

Table 6 Phytochemical results of peel and juice of Citrus medica (Aveen Nozad 2015)

Based on the given data from Table 7, phytochemical screening of ethanol extract of mango (Mangifera indica L.) leaves and Avocado (Persea americana) fruits almost all are were detected but terpenoids were not detected in Mango (Mangifera indica L.). The phytochemical are naturally occurring chemicals in plants which serve as medicinal for the protection of human disease; the phytochemicals are nonnutritive plants chemical that have protection or disease preventive properties.

Table 7 Phytochemical results of mango (Mangefera indica L.) leaves and Avocado (Persea americana) fruits (Lalisa Wakjira Duresa and Daniel Manaye 2017)

In this review, the phytochemical analysis revealed the presence of flavonoids, phenols, and tannins while the terpenoids positive test of methanol extract and the remaining phytochemical components are were not detected. These results show that phytochemical depend on solvents (Table 8).

Table 8 Phytochemical results of Dioscorea alata leaf (Abhishek Das et al. 2014)

Table 9, the presence of flavonoid, tannin, and phenol in methanol extract. The acetone extract obtained from the eucalyptus leaves was screened for phytochemicals. Qualitative phytochemical screening of acetone extract of eucalyptus leaves demonstrated the presence of saponins, carbohydrate, tannin, and phenol, while quinone, fat, protein, and flavonoid were absent.

Table 9 Phytochemical results of Eucalyptus leaves (Shubhreet Kaur et al. 2019)

In this review, the methanol, ethanol, n-hexane, and petroleum ether extract obtained from the Hagenia abyssinica leaves were screened for various phytochemicals from Table 10. Qualitative phytochemical screening of methanol extract of Hagenia abyssinica leaves demonstrated the presence of saponins, flavonoids, phenols, terpenoids, steroids, and glycosides, while tannins, anthraquinones, and alkaloids were absent. Phytochemical analysis of ethanol extract of Hagenia abyssinica leaves demonstrated the presence of saponins, tannins, phenols, terpenoids, and alkaloids, while steroids, glycosides and phlobatannins were absent. A similarity that phytochemical screening of n-hexane extract of Hagenia abyssinica leaves demonstrated the presence of flavonoids, anthraquinones and terpenoids but saponins, tannins, alkaloids, steroids, glycosides, and phlobatannins are not detected and Hagenia abyssinica leaves extracted by petroleum ether were obtained presence of phytochemical only saponins and terpenoids, while other phytochemicals are not detected.

Table 10 Phytochemical screening of results of Hagenia abyssinica leaves (Tesfaye Wolde et a l. 2016)

Phytochemicals screening in the plant extracts revealed the presence of flavonoid, stereol and polyterpenes, and saponified present in both methanol and ethyl acetate extract of Lepidium sativum seeds and also flavonoids were present in petroleum ether extract of Lepidium sativum seeds while other phytochemical components were not detected (Table 11).

Table 11 Phytochemical results of Lepidium sativum seeds (Yasudha et al. 2019)

In this review, phytochemical screening of the aqueous, methanol, and hexane extracts of Leucas aspera L. leaf and root revealed the presence of various medically active constituents from Table 12. Almost all phytochemical compounds present in the aqueous, methanol, and hexane extracts of Leucas aspera L. leaf and root were identified except cholesterol and steroids in the parts of leaf and root by aqueous. These plants indicate highly medicinal values.

Table 12 Phytochemical results of Leucas aspera L. leaf and root (Yasudha et al. 2019)

Phytochemical screening of the love Gilbertii root suggests the presence of major phytochemicals in the root extracts (Table 13). Dichloromethane: methanol of roots showed the presence of alkaloids, anthraquinones, and flavonoids whereas; tannins, saponins, and terpenoids were not presented.

Table 13 Phytochemical results of love Gilbertii root (Milkyas et al. 2016)

As result in Table 14, screening for phytochemicals in the plant extracts almost all presents in both acetone and methanol extracts of Flax seeds, while some phytochemical is not detected like tannins, saponins in acetone extract of Flax seeds and also saponins were presented by methanol extract of flaxseeds. In addition to this phytochemicals screening of ethanol and water extract of flaxseeds almost phytochemical components presents and some phytochemicals not totally detected. These secondary metabolites are known to be biologically active and play significant roles in the bioactivity of medicinal plants because the medicinal values of the medicinal plant lie in these phytochemical compounds which produce a definite and specific action on the human body.

Table 14 Phytochemical results of Flaxseeds (Hanaa et al. 2017)

This review was shown in the (Table 15) phytochemical analysis of petroleum ether and ethyl acetate seed extract of Nigella sativa contains tannins, steroids, terpenoids and alkaloids, flavonoids, phenol, glycosides and steroids were found in the extract and are potent methanol soluble while some phytochemicals were not presented since it depends on the solvents.

Table 15 Phytochemical results of Nigella sativa (Abdurohaman Mengesha Yessuf. 2015)

In the present review, phytochemical screening of methanol and aqueous extracts of Ocimum gratissimum Linn leaf showed that the presence of tannins, phlorotannins, steroids, terpenoids, flavonoids and cardiac glycosides with steroidal ring whereas, saponins and sugar were not present in methanol solvent and also alkaloids were not absent in Table 16. These detected phytochemical compounds are known to have beneficial importance in medicinal as well as physiological activities. In this manner, isolating and identifying these bioactive compounds, new drugs can be formulated to treat various diseases and disorders.

Table 16 Phytochemicals results of Ocimum gratissimum Linn leaf (Akinmoladun et al. 2007)

Table 17 shows the phytochemicals detected in Rhamnus prinoides root extract. Tests for triterpenes, saponins, tannins, phenols, glycosides, cardiac glycosides, and resins were positive in both aqueous and methanol/water extracts. Alkaloids were detected only in the methanol/water extract while steroids, flavonoids, flavones, and anthraquinones were not detected in both aqueous and methanol/water extracts. These phytochemicals may be responsible for the medicinal value of Rhamnus prinoides.

Table 17 Phytochemicals results of Rhamnus prinoides root (Teklit Gebregiorgis Amabye 2015)

Phytochemical screening of ethanol/water (1:1) extract of Rhizomes, Zingiber officinale, and Curcuma longa showed the presence of phenolic, flavonoids, glycosides, and tannins whereas alkaloids were not present (Table 18).

Table 18 Phytochemical results of Rhizomes, Zingiber officinale and Curcuma longa (Alemayehu Mekonnen and Welday Desta 2021)

The phytochemical analysis of Ruta chalepensis leaves extract in methanol showed that phytochemical components include; alkaloids, flavonoids, terpenoids, cardiac glycosides, phenols, saponins, tannins and anthraquinones and steroids were not present. Steroids, terpenoids and saponins were additionally present in both ethyl acetate and acetone extract, and also flavonoids, terpenoids, and anthraquinones were detected in the n-hexane extract, while others were not totally found in Table 19.

Table 19 Phytochemical results of Ruta chalepensis leaves ((Ketema Alemayehu Destaw and Engidaw Seid Mustofa 2019)

In Table 20, the presence of steroids, terpenoids, saponins, flavonoids, flavonoids, tannins, alkaloids, phenol, and glycosides were present in both dichloromethane/methanol and methanol extracts and steroids and terpenoids also were present in n-hexane extract whereas other phytochemicals components were not detected.

Table 20 The phytochemical results of Syzygium guineens root (Ei Ei Aung et al. 2020)

From Table 21, it can be seen that the sample extracts showed positive tests for the presence of alkaloids, saponin, tannins, phlorotannin, glycosides, and flavonoids except for anthraquinones. Therefore, Bitter (Vernonia amygdalina) is the most frequently used for medicinal purposes.

Table 21 Phytochemical results of Bitter (Vernonia amygdalina) leaf (Audu Inusa et al. 2018)

In this review, the results revealed the presence of alkaloids, steroids, glycosides, saponin, and phlorotannin methanol extracts from the root and stem bark of Vernonia amygdalina whereas only tannins and phenols were not detected (Table 22). Therefore, the phytochemical screening results reveals that the presence of these phytochemical constituents supports the use of the Vernonia amygdalina plant in folklore medications and it is probable that these phytochemicals are responsible for the healing properties.

Table 22 Phytochemical results of Root and Stem bark of Vernonia amygdalina (Raimi et al. 2020)

A total of 53 traditional medicinal plants were identified in this review. All of the reviewed plants have direct traditional uses for treating either ailment with cancer-like symptoms (determined by the traditional practitioner) or for laboratory-confirmed cancer cases. Medicinal plants have continued to be the most affordable and easily accessible source for the treatment of several human and livestock ailments in Ethiopia. Besides treating cancer, the plants selected in this review are also cited for their various traditional uses, including for the treatment of eczema, leprosy, rheumatism, gout, ringworm, diabetes, respiratory complaints, warts, hemorrhoids, syphilis, and skin diseases (Table 23). The output calls for the need for further phytochemical and pharmacological investigation giving priority to those plants which have been cited most for their use to treat cancer.

Table 23 Some totally 53 medicinal plant of Ethiopia

In Ethiopia, there are increasing demands for many most popular, more available, and effective plant species by the people. As stated by the different authors in the above Tables, different phytochemicals were investigated in different plant species with different solvent concentrations. Even though different phytochemicals were analyzed for different plant species, their concentration varied from one plant species to another plant species for different parts of the plant. Based on the above information from the Table, one type of phytochemical cannot be detected in all plant species and the concentration of one phytochemical content varies from one part of the plant to another part which mean the concentration of one phytochemical content in leaves can vary from the concentrations of phytochemical contents in root and fruits. Generally, even though there are various medicinal plants in Ethiopia, there are no studies that show enough information about qualitative and quantitative phytochemical contents for most plant species in the country. This may be due to the lack of enough laboratory facilities and modern technology available in the country for improving the synthesis and extraction of phytochemical components for developing the new drug product and drug leading compounds from the different parts of the medicinal plants by the government and private company.

Conclusions

In conclusion, this study showed the wide use of medicinal plants in Ethiopia. Even though there is a wealth of indigenous knowledge transfer is declining from generation to generation as a result of oral transmission. Human beings around the world have spent their lives for a long time to discovering a new drug to diagnose, prevent and treat various diseases. To save their lives from dangerous diseases, a new and powerful drug must be discovered and developed from the different parts of the plant. In order to future promote for development of new drug synthesis and extraction of bioactive components from the parts of the plant, availability, and value of information is very important. From tables, phytochemicals analysis of different medicinal plants revealed the presence of various bioactive compounds such as polyphenols, flavonoids, phenolic compounds alkaloids, saponins, tannins, phlobatannins, glycosides, anthraquinones, steroids, terpenoids, and triterpene. Based on the above data available in the review, most phytochemical components of traditional medicinal plants in Ethiopia are not analyzed. This leads to more traditional plants in Ethiopia are not being recognized by the international scientific organization, not how to use medicinal plants for disease treatment and they do not have scientific names. This review recommended finding further most common medicinal plants to investigate in scientific research and to governing them in the scientific naming system and as well as further studies should focus on green synthesis of heavy metals on different types of medicinal plants in Ethiopia. Based on this review, the studied phytochemical characteristics of medicinal plants in Ethiopia are few, so further study could be needed for examining, and characterizing the properties of unrecognized plant species in Ethiopia.