In vitro Antitrypanosomal Activity of Aqueous and Ethanolic Leaf Extract of Ocimum sanctum L.

Abstract:

In vitro anti-trypanosomal effects of aqueous and ethanolic leaf extracts of Ocimum sanctum against Trypanosoma brucei brucei was examined. The leaf of Ocimum sanctum was collected and maceration method was used for extraction. Aqueous and ethanolic leaf extract of Ocimum sanctum extract was subjected to qualitative phytochemical screening using the method described by (Trease and Evans). Which revealed the presence and absence of active compounds which includes; alkaloids, phenols, tannins, saponins, cardiac glycosides, carbohydrates, flavonoids, terpenoids, steroids and it further revealed the absence of anthraquinones The in vitro test of anti-trypanosomal activity of aqueous and ethanolic extract of Ocimum sanctum was carried out in a 96 well micro-titre plate. Twenty micro-litres (20µl) of blood were exposed to 10µl of the extract solution concentration of 2.5mg/ml, 5mg/ml and 10mg/ml respectively 10µl of the standard drug Diminazine diaceturate, was used as the positive control; while 10µl of phosphate buffered saline glucose was used as the negative control. At five minutes’ incubation, a drop of the incubated blood sample was placed on a glass slide, covered with a cover slip and mounted on a light microscope. The parasite was monitored every 5 minutes of a total of 60 minute, the parasite motility was observed and tracked under microscope at X400 magnification. It was discovered that the leaf extract of Ocimum sanctum exhibited anti-trypanosomal activity in a concentration and time dependent manner on the parasite. When the parasite was exposed to 2.5mg/ml of aqueous and ethanolic leaf extract of Ocimum sanctum, the parasites were slightly weak in 5 minutes of exposure, under 10 minutes of exposure, motility ceased until 60 minutes. The same procedure applies for 5mg/ml and 10mg/ml of aqueous and ethanolic leaf extract of Ocimum sanctum, the parasite's motility ceased in 5 minutes till 60 minutes of these concentrations. It can be concluded that the aqueous and ethanolic leaf extract of Ocimum sanctum exhibited good anti-trypanosomal activity against Trypanosoma brucei brucei. The bioactive compounds in the plant extract are attributed to the anti-trypanosomal activity. The p-value is < 0.05, here we reject the null hypothesis and concluded that the Ocimum sanctum leaf extract has significant anti-trypanosomal activity.