Not a Laughing Matter: Effects of Tawa-tawa

Nigeria. Results ot the study snowed that botn the decoction and extract of E. hirta, at doses of 60. 4 mg/kg and 483. 0 mg/kg have a significant effect on the platelet counts of Sprague-Dawley rats. The RBC and WBC counts were not significantly affected, demonstrating that E. hirta does not affect the circulating RBC or the erythropoietic centers of the experimental animals, and it does not induce production or destruction of the WBC. The mean increases in platelet count in the decoction and ethanolic extract groups did not significantly differ, suggesting that oth preparations can be used for further studies.The difference in the mean platelet counts of subgroups who received the 60. 4 mg/kg and 483. 0 mg/kg doses was not significant as shown in Dunnet's test. This finding indicated that the platelet- increasing activity of E. hirta was not dose-dependent. The platelet-increasing activity of E. hirta was further evaluated by determining the effect of the plant material on stimulati ng platelet production in the bone marrow. In this evaluation, the dose and preparation (483. g/kg of the ethanolic extract) that produced the greatest numerical increase in platelet count during the initial evaluation was used. Anagrelide, a drug which inhibits the maturation of megakaryocytes into platelets, was administered to decrease the platelet counts of the test animals.After exposure to anagrelide, 483. 0 mg/kg of ethanolic extract was administered to 50% of the test population. Results of this further evaluation showed that the mean platelet count did not differ significantly in the group which received both anagrelide (125 pg/day) nd ethanolic extract of E. irta (483. 0 mg/kg) and in the group who were only exposed to anagrelide (control). This suggested that the platelet-increasing activity of E. hirta was not due to stimulation of the platelet production in the bone marrow. 0 In another study conducted by the students of St. Marys School in Davao, E. hirta was also foun d to increase the platelet counts of white mice (Mus musculus). E. hirta was prepared in a teabag form. The results of this study were not published, and therefore, no further information was obtained.In Nigeria, the effects of aqueous and methanolic extracts of E. hirta on platelet count, bleeding time, and clotting time were also investigated. The extracts of E. hirta were administered orally to albino Wistar rats. Platelet count, bleeding time, and clotting time were determined before, and at different time intervals after administration of the extracts. At 60 minutes, the aqueous extract reduced bleeding time by 54% compared to 49. 5% for methanolic extract, and the difference was significant.