The beneficial effects of
kolaviron, a natural
biflavonoid from the seeds of Garcinia kola, have been attributed mainly to its
antioxidant and anti-inflammatory effects. This study investigated these effects on
dextran sulphate
sodium (DSS)-induced
ulcerative colitis in rats.
Sulfasalazine served as standard reference in this study.
Kolaviron and
sulfasalazine were separately co-administered orally at 200 mg/kg and 500 mg/kg, respectively, to
dextran sulphate
sodium-exposed rats for 5 days. The result indicated that
kolaviron or
sulfasalazine significantly prevented DSS-induced
body weight loss as well as the incidence of diarrhoea and
bleeding in DSS-exposed rats.
Kolaviron suppressed the DSS-mediated increase in colonic
nitric oxide concentration and
myeloperoxidase activity and significantly prevented the increase in inflammatory mediators, interleukin-1β and tumour
necrosis factor alpha, in the colon of DSS-treated rats. The significant depletion in colonic
antioxidant status in rats exposed to DSS alone was evident by marked reduction in colonic
catalase and
glutathione S-transferase activities as well as
glutathione content, leading to elevated
hydrogen peroxide and lipid peroxidation levels. Histopathologically, DSS alone resulted in severe epithelial erosion, total absence of goblet cells, destruction of the crypts, necrotic and distorted glands, accompanied by marked cellular mononuclear cells infiltration. However, administration of
kolaviron and
sulfasalazine ameliorated DSS-induced
colitis by increasing the
antioxidant status decreased
hydrogen peroxide and lipid peroxidation levels and attenuated the adverse effect of DSS on colon architecture. In conclusion, the anti-
colitis effect of
kolaviron is related to its intrinsic anti-inflammatory and anti-oxidative properties.