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

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.

Phytochemical and antimicrobial activities of Himalayan Cordyceps sinensis (Berk.) Sacc.

This study evaluated the phytochemical and antimicrobial activities and also quantified bioactive nucleoside using high performance thin layer chromatography (HPTLC) of five extracts of Indian Himalayan Cordyceps sinensis prepared with different solvents employing accelerated solvent extraction (ASE) technique. The phytochemical potential of these extracts was quantified in terms of total phenolic and total flavonoid content while antioxidant activities were determined by 1,1-diphenyl-2-pycryl-hydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric-reducing antioxidant power (FRAP) assays. Total reducing power (TRP) was determined by converting iron (III) into iron (II) reduction assay. CS50%Alc (15.1+ 0.67mg/g of dry extract) and CS100%Alc (19.3 + 0.33mg/g of dry extract) showed highest phenolic and flavonoid content, respectively while CSAq extract showed maximum antioxidant activity and the highest concentration of the three nucleosides (adenine 12.8±0.49 mg/g, adenosine 0.36±0.28 mg/g and uracil 0.14±0.36 mg/g of dry extract) determined by HPTLC. The evaluation of extracts for antimicrobial activity against gram-negative and gram-positive bacterial strains showed CS25%Alc, CS75%Alc and CS100%Alc extract to be more effective against E. coli, P. aerugenosa and B. subtilis giving 9, 7 and 6.5 mm of zone of inhibition (ZOI) in 93.75, 93.75 and 45 µg concentration, respectively, whereas CSAq extract showed minimal inhibition against these.