Positive Effects of Aqueous and Ethanolic Extracts of Stem Bark from Trichilia emetica (MELIACEAE) on Cellular Immunity Markers in Rats

Aims: This study was designed to evaluate the effect of aqueous and ethanolic extracts of stem bark from Trichilia emetica on the cellular immunity markers (TCD4+ count, Lymphocytes, WBC, RBC) in rats wistar.

Study Design: Forty-two rats have been divided into seven groups of six and each was administered a single oral dose of the samples for 8 days. Experimental design was as follows: Group I served as control and received distilled water, group II received Isoprinosine at a dose of 50 mg/kg body weight (b.w.), group III was administered Methylprednisolone (15 mg/kg b.w), group IV and group V received aqueous extract at a dose of 100 and 200 mg/kg b.w. respectively, group VI and VII were administered ethanolic extract at a doses of 100 and 200 mg/kg b.w. respectively. At the end of the treatment, some blood was collected in EDTA tubes for the determination of TCD4+ count by flow cytometry and hematological parameters by hemogram.

Results: Concerning TCD4+ count, the results show that there is a significant difference (P<0.05) between the control group and all groups of the treated rats. There is also a significant difference between both extracts. But the ethanolic extract at a dose of 100 mg/kg b.w. showed pronounced activity by TCD4+ increasing in relation with control and all the treated groups. Thus, the haematological parameters show that there is no significant difference (p˃ 0.05) between the control group and the other treated groups by aqueous extract (100 and 200 mg/kg b.w.) and ethanolic extract at a dose of 200 mg/kg b.w. concerning WBC count and total lymphocytes level. However, there is a significant increase (P<0.05) of WBC and total lymphocytes in blood of rats treated by ethanolic extract at a dose of 100 mg/kg b.w. compared with control group.

Conclusion: The present study revealed that both extracts of Trichilia emetica have positive effects on cellular immunity markers such as TCD4+, total lymphocytes, WBC, RBC. However, lower concentration of ethanolic extract showed much positive effects compared to the aqueous extract.

The results of this preliminary study could be used to explore the spleenocyte proliferation and the analysis of spleen cells in order to see the real immunomodultory activity.