|Title:||IN VITRO LOUSCIDAL AND ACARICIDAL ACTIVITIES OF ALKALOID OF CALPURNIA AUREA AND FRACTIONS OF RICINUS COMMUNIS EXTRACTS AGAINST LINOGNATHUS OVILLUS AND AMBLYOMMA VARIEGATUM|
|???metadata.dc.contributor.*???:||Dr. Yacob Hailu|
Dr. Getachew Terefe
Dr. Kaleab Asres
|Abstract:||The present study was designed to evaluate the louscidal and acaricidal activities of alkaloids of Calpurnia aurea and fractions of Ricinus communis leaves extracts. Alkaloid of C. aurea and solvent fractions of R. communis leaves extract at concentrations of 200, 100, 50, 25, 12.5 and 6.25 mg/ml were used for in vitro adult immersion test of ticks and lice, which then were monitored for their mortality rates for 24hrs. The activities of test substances were evaluated against Amblyomma variegatum and Linognathus ovillus, and compared with diazinon 60 EC. After 24hrs post exposure, two higher concentrations of 200 and 100 mg/ml of the alkaloid extract caused 100±0.5% and 100±0.6% lice mortality, and 100±0.33 and 93.3±0.33 tick mortality respectively. The alkaloid extract showed an insignificant difference in its acaricidal and louscidal activity when compared to the Diazinon 60EC at the same concentration (P > 0.05). LC50 and LC90 values (with 95% confidence limits) of the alkaloid of C. aurea for lice and tick were estimated 9.08 mg/ml (6.21-13.47), 17.65 mg/ml (11.71-22.49) and mg/ml 16.69 (11.77, 26.64), 31.69 mg/ml (21.25-50.72), respectively. Based on LC50 and LC90 values, alkaloid extract was found to be more effective in killing of lice than ticks. Dose response data of C. aurea alkaloid extract on L. ovillus and A. variegatum indicated the gradual increase in the mortality pattern with slopes of 3.1188, and 3.2321, and R2 values of 0.9702 and 0.9882 suggesting that 97.02, 98.82% data were correlated with log concentration, respectively. Chloroform and petroleum ether fractions of R. communis extracts showed less louscidal and acaricidal effects than the acetone and methanol fractions extracts based on the calculated LC50 and LC90. At higher concentration of 200 mg/ml, the chloroform and petroleum ether fractions extracts showed weaker activity on both A. variegatum and L. ovillus with significant difference (P < 0.05) when compared to that of diazinon after 24hr post exposure. As compared to the alkaloid extract of C. aurea, fractions of R. communis extracts were less lethal both to lice and tick. Alkaloid of C. aurea and fractions of R. communis extract were shown to induce tick and lice mortality in a time and dose-dependent manner. The results obtained in this study indicate that the alkaloid extract of C. aurea and the polar solvent fractions of R. communis have promising louscidal and acaricidal activities, lending support for further investigation of the plants to isolate the active components.|
|Description:||Thesis submitted to College of Veterinary Medicine and Agriculture of Addis Ababa University in partial fulfillment of the requirement for degree of Masters of Science in Tropical Veterinary Parasitology|
|Appears in Collections:||Thesis - Tropical Veternery Medicine|
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