Effect of Leaf Aqueous Extracts of Vernonia amygdalina Del on Contraction of Mammary Gland and Uterus of Guinea Pig Dams

Abstract

Aims: To determine the effects of aqueous extracts of Vernonia amygdalina on litter-weight gain, milk production and uterine contraction amplitude and mammary gland smooth muscle contraction amplitudes in the guinea pig model. Methodology: The animals were placed in four groups of three animals each with group1 as control, and groups II-IV receiving 5 mg/kg, 10 mg/kg and 100 mg/kg V. amygdalina respectively. Using a chymograph, uterine and mammary gland contraction amplitudes were determined at 5, 10 and 100mg/ml of the extract with ergometrine as the control drug. Results: After 5 weeks, the litter-weight of the control group (1.88 ± 0.68 g) was significantly (P<0.05) less than that in groups III (4.20 ±0.20 g) and IV (13.69 ± 1.53 g) but not different from group III (3.11 ± 0.10 g). All the dams had their highest mean milk production index (g) at week 2. From week 4, all the treatment groups produced more milk than the control group. At concentrations of 5 mg/ml and 10 mg/ml, uterine contraction amplitudes (mm) were 1.22 ± 0.03 and 3.60 ± 0.03, respectively. The contraction amplitude at 100 mg/ml matched that of ergometrine (9.58 ± 0.39 mm). The mammary gland contraction amplitudes (mm) recorded for 5 mg/ml, 10 mg/ml and 100 mg/ml V. amygdalina were 1.2 ± 0.14, 2.70 ± 0.36 and 6.15 ± 0.13 respectively. These values were significantly (P< 0.05) lower than those observed for the equivalent concentrations of ergometrine. Conclusion: The results appear to support the claims of traditional birth attendants who use the plant to induce uterine motility and milk let-down after parturition.