Research Article - Asian Journal of Biomedical and Pharmaceutical Sciences (2017) Volume 7, Issue 63

In vitro Effects of Schumanniophyton magnificum, Pseudospondias microcarpa and Rauvolfia vomitoria Stem Barks Extracts, on Free Larval Stages of Heligmosomoides bakeri (Nematoda, Heligmosomatidae)

Purpose: A comparative in vitro study was carried out to evaluate the potential larvicidal effect of aqueous and methanol/methylene chloride extracts of Schumanniophyton magnificum, Pseudospondias microcarpa,and Rauvolfia vomitoria stem barks on different life-cycle stages of Heligmosomoides bakeri. Methods: The organic extracts were diluted in 2.5% dimethylsulphoxide (DMSO) and aqueous extracts in distilled water to obtain stock solutions. Serial dilutions were made to obtain four increasing concentrations of 1250, 2500, 5000 and 10000 µg/ml for incubation in Petri dishes with L1, L2 and L3 larvae of the parasite. Exposure times were 2, 4, 6 and 24 hours for L1 and L2 larvae and 24 and 48 h for the infective L3 larvae. Albendazole was used as the positive control, while 2.5% DMSO and distilled water were used as negative controls for organic and aqueous extracts, respectively. Results: The organic extract of stem bark of R. vomitoria showed significant (p<0.05) mortality on L1 larvae (85%) at the 5000 µg /ml and had a 50% lethal concentration (LC50) of 2404.980 µg/ml. Mortality rates of 100% were recorded at the concentrations higher or equal to 2.5 mg/ml for albendazole and 95.6 % at 5000 µg/ml for R. vomitoria extracts on L2 larvae and the LC50 were 1589.970 and 1272.413 µg/ml, respectively, for these products. The L3 infective larvae of the parasite were not affected by either the plant extracts or albendazole after 24 h and the effect of the products after 48 h of exposure was not significant. Organic extracts in general were more active than aqueous extracts. The larvicidal activity was dose and time dependent. Conclusion: These results show that organic extracts of all three plants possess anti-parasitic properties. Further research, such as in vivo studies, need to be carried out on adult stages of H. bakeri.

Author(s): Jeannette Yondo, Marie- Claire Komtangi, Josue Pone Wabo, C. F. Bilong Bilong, Jules-Roger Kuiate, Mbida Mpoame

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