Abstract

Medicinal herbs are commonly used worldwide as immune boosters and immunomodulators in the management of various disease conditions. Many of these herbs commonly used have not been scientifically evaluated for their immune modulating activities. The study investigated the immunomodulatory activity of the total crude leaf extract of Hibiscus sabdariffa in Wistar albino rats. It was an experimental study that was conducted on four groups of animals each with 6 healthy adult rats. Group I was dosed each with 1mL of normal saline. Groups II, III and IV were dosed 1mL of 125, 250 and 500 mg/Kg bwt of total crude extract, daily for 14 days respectively. On the 15^th day, whole blood was collected into a clean ethlenediaminetetracetic acid (EDTA)-vacutainer. The complete blood count (CBC), immune blood cell count, hemagglutination antibody (HA) titers, neutrophil adhesion and delayed-type hypersensitivity (DTH) response were determined. All the doses caused an increase in mean red blood cell (RBC) counts as compared to control group. Similarly, the mean percentage neutrophils, monocytes, basophils and eosinophils increased with dose while the opposite was true for percentage lymphocytes. The mean HA titers for the herb were higher than control though no statistical difference (p≥0.05) was observed. Similar effects were observed with neutrophil adhesions response as that of HA titers. For DTH, the highest footpad thickness (175.2% increment) was observed at a dose of 500 mg/Kg bwt after 12 h and was statistically significant (p≤0.05) as compared to control. H. sabdariffa contain compounds with immunomodulatory activity in Wistar albino rats.

Key words: Immunomodulation, Hibiscus sabdariffa, total crude extracts.