Phytochemical Screening and Toxicological Study of Neptunia oleracea Lour. (Mimosaceae) Extracts, Plant Used in Traditional Medicine

Neptunia oleracea (Lourd.) Mimosaceae is a plant commonly used in traditional medicine for the treatment of several pathologies such as dysentery, jaundice, leucorrhoea, troubles of earache, among others.

Aim: The purpose of this study was to carry out preliminary phytochemical screening, acute toxicity studies and to evaluate the effect of the aqueous and hydro-ethanolic extracts of N. oleracea on intestinal motility in vivo.

Methodology: Preliminary qualitative phytochemical screening was conducted using standard procedures while acute toxicity studies was performed using OECD method. The effect of N. oleracea extracts on intestinal motility was evaluated using on normal and acetylcholine-induced transits.

Results: Preliminary qualitative phytochemical screening of aqueous and hydro-ethanolic extracts of N. oleracea revealed the presence of similar constituents including steroids, triterpenoids, saponins, tannins, flavonoids, anthocyanidins, coumarins and carbohydrates. Alkaloids was absent in both the extracts. The oral median lethal dose (LD50) for both extracts was estimated to be 5000 mg/kg.

The effect of extracts on intestinal peristalsis in mice showed that the aqueous and hydro-ethanolic extracts of N. oleracea stimulate normal intestinal transit by 1.29 and 8.54% respectively at the dose of 50 mg/kg body weight, thus there was inhibition at higher doses. These extracts potentiate acetylcholine-induced intestinal transit by 23.9 and 14.39% respectively at 500 mg/kg body weight.

Conclusion: The findings of this study showed that the aqueous and hydro-ethanolic extracts of Neptunia oleracea contain bioactive constituents that have practically no toxic effect. This could justify the many forms of use of this plant in traditional medicine.