Preliminary Study on the Effect of Methanolic Extract of Watermelon (Citrullus lanatus) Rind on Prednisolone Suppressed Immunity in Male Wistar Rats

Citrullus lanatus thumb (Cucurbitaceae) commonly called watermelon is widely consumed in this part of the world as food and medicine. This study was carried out to examine the effect of methanolic extract of watermelon (Citrullus lanatus) rind on prednisolone suppressed immunity in male wistar rats. A total of 20 male wistar rats weighing 150-294g were used in 4 groups with five rats each. Group 1, the control group was given distilled water and feed, Group 2 was given 200 mg/kg body weight of methanolic extract of watermelon rind, Group 3 rats were given 2.5 mg/kg body weight of prednisolone and Group 4 rats were given 2.5 mg/kg body weight of prednisolone and 200 mg/kg body weight of methanolic extract of watermelon rind. Prednisolone and the methanolic extract of watermelon rind were administered orally for a period of 30 days. Blood samples were collected by cardio puncture from the rats for white blood cell (WBC), lymphocyte, and granulocyte and monocyte counts at the end of the experiment. The data were statistically analysed using one-way ANOVA (Analysis of variance). Data were considered significant at p<0.05. The results obtained showed that methanolic extract of watermelon rind caused a significant increasen in immune function of rats when compared with the control and immune suppressed rats.