Phytochemical content, antioxidant activities and androgenic properties of four South African medicinal plants

Introduction: This study aimed to investigate the phytochemical contents, antioxidant activities, and androgenic properties of Peltophorum africanum Sond, Trichilia emetica Vahl, Terminalia sambesiaca, and Ximenia caffra. Methods: The finely powdered leaves of the selected plants were extracted using acetone, aqueous, and methanol as solvents. The total phenolics and flavonoids contents were determined from gallic acid and quercetin standard curves. The antioxidant activities of these extracts were evaluated using ۱, ۱-Diphenyl-۲-picrylhydrazyl ( DPPH) assay. The effect of plant extracts (۱۰۰-۱۰۰۰ µg/mL) on TM۳ Leydig cells was assessed using ۳-(۴,۵-Dimethylthiazol-۲-yl)-۲,۵-diphenyltetrazolium (MTT) assay. Testosterone levels were measured using ELISA kit. Results: The methanol extracts of T. sambesiaca and X. caffra revealed higher total phenolic and flavonoid contents (۱۰۲.۱۳±۲.۳۲ mg/g GAE and ۱.۰۵±۰.۰۴ mg/g QE, respectively) than other plant extracts. The acetone and methanol extracts of P. africanum revealed the best IC۵۰ value (۱۲.۵۰ ± ۰.۰۵۲ µg/mL) against DPPH than the other plant extracts and ascorbic acid. The MTT assay results showed that all varying concentrations of plant extracts maintained cell viability and were not cytotoxic with IC۵۰ values of greater than ۲۰ µg/mL. The methanol extract of T. sambesiaca had the highest testosterone production at ۵۰۰ µg/mL (۰.۳۹۹ ng/mL) when compared with the basal control while at the concentration of ۵۰۰ µg/mL the acetone extracts of P. africanum and T. sambesiaca had significantly high testosterone production ۰.۱۴۷ and ۰.۱۸۸ ng/mL respectively when compared with basal control. Conclusion: The results reveal that these plants possess antioxidants and androgenic property and suggest the potential use for the treatment of male infertility.