# Table 4 Threshold Inhibitory concentration (IC50) of crude aqueous and methanolic extracts of leaves, stem and roots of C. dependens and ascorbic acid standard on DPPH radicals

Extracts

Threshold inhibitory concentration (*IC50)

Mathematical model

Equation

R2

CDRM

1.81 ± 0.32

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.941

CDLM

1.44 ± 0.14

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.956

CDSM

1.52 ± 0.10

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.975

CDRA

1.10 ± 0.12

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.939

CDLA

1.81 ± 0.32

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.942

CDSA

1.51 ± 0.14

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.966

AA

0.58 ± 0.05

Sigmoid (a, b, c)

$$y=\frac{a}{1 +\mathrm{exp}\left(-\left(\frac{x-{x}_{0}}{b}\right)\right)}$$

0.934

1. CDRM, C. dependens root methanol; CDLM, C. dependens leaves methanol; CDSM, C. dependens stem methanol; CDRA, C. dependens root aqueous; CDLA, C. dependens leaves aqueous; CDSA, C. dependens stem aqueous; AA, ascorbic acid
2. *IC50 is the concentration of extract or standard that scavenged 50% of the generated free radicals