ABSTRACT
BACKGROUND AND THE PURPOSE OF THE STUDY: The early stage of diabetes mellitus type 2 is associated with postprandial hyperglycemia. Hyperglycemia is believed to increase the production of free radicals and reactive oxygen species, leading to oxidative tissue damage. In an effort of identifying herbal drugs which may become useful in the prevention or mitigation of diabetes, biochemical activities of Polygonum hyrcanicum and its constituents were studied. METHODS: Hexane, ethylacetate and methanol extracts of P. hyrcanicum were tested for α-glucosidase inhibitory, antioxidant and radical scavenging properties. Active constituents were isolated and identified from the methanolic extract in an activity guided approach. RESULTS: A methanolic extract from flowering aerial parts of the plant showed notable α-glucosidase inhibitory activity (IC50 = 15 µg/ml). Thirteen phenolic compounds involving a cinnamoylphenethyl amide, two flavans, and ten flavonols and flavonol 3-O-glycosides were subsequently isolated from the extract. All constituents showed inhibitory activities while compounds 3, 8 and 11 (IC50 = 0.3, 1.0, and 0.6 µM, respectively) were the most potent ones. The methanol extract also showed antioxidant activities in DPPH (IC50 = 76 µg/ml) and FRAP assays (1.4 mmol ferrous ion equivalent/g extract). A total phenol content of 130 mg/g of the extract was determined by Folin-Ciocalteu reagent. CONCLUSION: This study shows that P. hyrcanicum contains phenolic compounds with in vitro activity that can be useful in the context of preventing or mitigating cellular damages linked to diabetic conditions.
ABSTRACT
Today, there is an increasing interest in the use of metal nanoparticles in health sciences. Amongst all nanoparticles, the gold nanoparticles have been known to kill the cancer cells under hyperthermic condition by near-infrared frequency electromagnetic waves. On the other hand, although there are different physiochemical methods for disinfection of microbial pollution, however applications of irradiated gold nanoparticles against microorganisms have not yet been investigated. In this study, gold nanoparticles were prepared using D-glucose and characterized (particle size <26 nm). In the next step, the enhancing effect of the non toxic level of gold nanoparticles (50 µg/mL) on the antimicrobial activity of 2450 MHz electromagnetic radiation generated at a microwave oven operated at low power (100 W), was investigated by time-kill course assay against Staphylococcus aureus (S.aureus) ATCC 29737. The results showed that application of gold nanoparticles can enhance the lethal effect of low power microwave in a very short exposure time (5 s).
