Pharmacological screening of Hypericum androsaemum extracts for antioxidant, anti-lipid peroxidation, antiglycation and cytotoxicity activity

Oxidative stress and glycation processes have a combined effect on diabetes related complications. Crude plant extracts and plant derived compounds possessing both antiglycation and antioxidant activities have a high therapeutic potential for treating these complications. Antioxidant, antiglycation, anti-lipid per oxidation and cytotoxic activities of crude methanol extract and solvent fractions of Hypericum androsaemum L. [Hypericaceae] were evaluated and correlated with total content of phenolics and flavonoids. Significant radical scavenging activity was observed for the methanol extract against 2,2-diphenyl-1-picrylhydrazyl [DPPH] free radical used as a basis for antioxidant activity with IC50 value of 92.70 +/- 2.85 micro gmL-1 [96.20 +/- 2.34% inhibition at 500 micro gmL-1]. In case of anion scavenging activity the results were not very significant [33.20 +/- 1.22% inhibition at 500 micro gmL-1]. Anti-lipid per oxidation activity was highest for n-hexane fraction [67.83 +/- 1.33% inhibition at 500 micro gmL-1] while the ethyl acetate fraction had the highest antiglycation activity [62.77 +/- 2.54% inhibition at 500 micro gmL-1]. Statistically significant correlation was determined for antioxidant and antiglycation activity and phenolic and flavonoid contents. In cytotoxicity assay all the extracts had IC50 values >30 microg mL-1 as compared to the standard cycloheximide [IC50 value 0.084 +/- 0.1 micro gmL-1]. The polar extracts of H. androsaemum can be a good source of non-toxic compounds with antioxidant, anti-lipid per oxidation and antiglycation activities

Various fractions of Hypericum x moserianum and Hypericum ericoides possess antiglycation, anti-lipid peroxidation, antioxidative activities and non-toxic effects in vitro

In the present study, two species Hypericum x moserianum and Hypericum ericoides which belong to genus Hypericum were evaluated for their potential antiglycation, antioxidant, anti lipid peroxidation and cytotoxic activities. These species are widely used in folk medicine and to the best of our knowledge there were no previous reports regarding antioxidant, anti-glycation and cytotoxicity studies of these species. Among the crude methanol extracts and fractions of both the species, the ethyl acetate fraction of H. x moserianum exhibited promising antioxidant activity against 1, 1-diphenyl-2-picrylhydrazyl [DPPH] with IC50 129.084+/-1.215µg/ml, followed by methanol extract [IC50=232.083+/-1.215µg/ml] and aqueous fraction [IC50=266.962+/-2.213µg/ml]. The ethyl acetate fraction of Hericoides exhibited IC50 value of 295.088+/-2.320µg/ml. In antiglycation assay, the ethyl acetate fraction of H.x moserianum showed 52.096% inhibition at 500µg/ml. For lipid peroxidation assay, the dichloromethane, aqueous and n-hexane fractions of H. x moserianum showed 67.241, 66.147 and 64.213% inhibition respectively, while aqueous fraction of H. ericoides exhibited 67.404% inhibition at 500µg/ml. In cytotoxicity assay, all fractions of both the species were found to be non-toxic on mouse fibroblast 3T3 cells with IC50 value greater than 30µg/ml as compared to cycloheximide with IC50 value 0.073+/-0.1µg/ml used as a st and ard. It was concluded from the study that among the two species, crude methanolic and ethyl acetate fractions were more active regarding the antioxidant, anti-glycation activities while dichloromethane, aqueous and n-hexane fractions possessed anti-lipid peroxidation activity