THE PHYTOPHARMACOLOGICAL EVALUATION OF THE METHANOL ROOT EXTRACT OFAZANZA GARCKEANA(MALVACEAE) ON ISOLATED WISTAR RAT UTERINE SMOOTH MUSCLES

Ethnopharmacological relevance Pregnant women in Chongwe, Zambia traditionally use the root of Azanza garckeana (F.Hffm.) Exell & Hillc (Malvalceae) to induce or accelerate labour. A previous study on the plant showed the crude root extracts to possesses uterotonic potential on isolated Wistar rat uterine smooth muscles. The methanol crude root extract was found to be the most potent. Aim The aim of the study was to isolated by bioactivity-guided isolation method the compound with the major uterotonic activity in the root of Azanza garckeana . Materials and methods This was a laboratory-based study designed using the uterus isolated from estrogenised adult non-gravid female virgin Wistar rats. The fresh plant materials (leaves and roots) were collected from Chongwe district. The methanol crude extract was obtained by continuous maceration and it was partitioned using hexane, chloroform, ethyl acetate and n-butanol in the increasing order of polarity. The most active fraction was fractionated using column chromatography. One-way ANOVA, Bonferroni post hoc tests were used to analyze data using STATA version 13. Bar charts and dose-response curves were done using Graphpad Prism version 5.00 for Windows (San Diego California USA). Results The final aqueous suspension demonstrated the highest uterotonic potency (EC 50 = 2.49 x 10 −3 mg/ml; 95% CI 1.19 x 10 −3 to 5.23 x 10 −3 mg/ml, p=0.0001), while sub-fraction pool number 2 (subfractions number 41 to 61) demonstrated the highest uterotonic potency (EC 50 at 2.05 x 10 −3 mg/ml; 95% CI 2.09 x 10 −3 to 3.85 x 10 −3 mg/ml, p=0.0001). Sub-fraction pool number 2 was suggested to contain the compound with the major uterotonic activity which was suggested to be related to the family of glycosides after High Performance Liquid Chromatography (HPLC) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Conclusions The study suggests the presence of a major uterotonic phytochemical constituent in the methanol root crude extract of Azanza garckeana , which was suggested to be related to the family of glycosides. The study has provided scientific evidence suggesting the root of Azanza garckeana , a plant used traditionally for inducing or accelerating labor possess uterotonic activity. Further pharmacological and toxicological studies need to be undertaken on the plant.