Protective efficacy of Hippophae rhamnoides L. extract exhibited in rat heart against hypobaric hypoxia is possibly mediated by configurations in JAK/STAT pathway

ABSTRACT

Hypoxia is a condition deprived of oxygen at tissue level, is known to be linked to oxidative stress and inflammatory cytokines. Hippophae rhamnoides L., commonly called Seabuckthorn, being rich in flavonoids, is reported to reduce oxidative stress. It is hypothesized that aqueous extract of H. rhamnoides relieves adverse changes in rat heart induced by continuous sub-acute hypobaric hypoxia. Exposure to continuous hypobaric hypoxia for seven days resulted in elevated levels of malondialdehyde, decrease in reduced glutathione, glutathione peroxidase and superoxide dismutase activities with concomitant increase in NFkB expression in rat heart. The levels of pro-inflammatory cytokines, TNFα and IL6 and TGFβ1, AKT and ERK were found to be decreased. The expression levels of JAK1 were reduced while STAT3 and STAT6 levels were found increased following hypoxia exposure. The treatment of rats with aqueous extract of H. rhamnoides significantly attenuated hypobaric hypoxia induced oxidative stress, increased TNFα and IL6 and deactivated NFҡB activity. H. rhamnoides treatment augmented expressions of JAK1, AKT and ERK proteins. Overall, results of this study indicate that the aqueous extract of Hippophae rhamnoides helps in inducing tolerance to rat heart at extreme altitude faster by optimizing tissue oxidative stress, preventing inflammatory response and configuring JAK1/ERK/AKT and STAT3/STAT6, at least to certain extent.