RP-HPLC-DAD determination of the differences in the polyphenol content of Fucus vesiculosus extracts with similar antioxidant activity.

Significant quantities of bioactive compounds have been found in the chemical composition of seaweeds. This source of natural antioxidants such as polyphenols appears to attenuate lipid peroxidation caused by oxidative stress, preventing the harmful effects of a number of injuries including ischemia-reperfusion (I/R). Conventional extraction (CE) has been used for years as a traditional method for obtaining bioactive components from seaweeds. However, recent studies highlight ultrasonic-assisted extraction (UAE) as an alternative and more eco-friendly technique. Therefore, the two methods were optimised and compared to obtain a Fucus vesiculosus extract (FVE) with high antioxidant activity and polyphenol content. The highest antioxidant activity was obtained after 1 h at 25 °C for conventional extraction, and after 5 min at 35 °C for ultrasonic-assisted extraction. Higher concentrations of polyphenols were obtained with the optimal conditions in conventional extraction (13.61 mg PGE/g seaweed), but no significant differences were observed between the antioxidant activity obtained with UAE (89.33%) and CE (89.74%). The characterization of the polyphenols present in both optimised extracts was carried out and compared with reverse-phase high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD). The following compounds were identified: phloroglucinol, gallic acid, catechin, vanillic acid, epicatechin, protocatechuic acid, rutin, gentisic acid, chlorogenic acid, caffeic acid, coumaric acid and ferulic acid. RP-HPLC-DAD results also showed higher concentrations of polyphenols in optimised extracts with CE. Consequently, CE was found to be more effective than UAE in providing extracts with higher concentrations of polyphenols, but UAE constitutes an efficient and more eco-friendly methodology for obtaining a FVE with the highest antioxidant activity.

Antioxidant potential of Himanthalia elongata for protection against ischemia-reperfusion injury in the small bowel.

BACKGROUND: Seaweed has been associated with the prevention and/or treatment of various diseases related to oxidative stress because of its antioxidant activity. We investigated the protective potential of extract of Himanthalia elongata against ischemia-reperfusion (I/R) injury in the intestine of rats. METHODS: Seventy-two (72) male Wistar albino rats were randomly assigned into 12 groups as follows: sham, I/R only, I/R plus vehicle at 3 time points, and I/R plus extract at 3 time points. The degree of intestinal injury was determined by oxidative stress using lipid peroxidation, superoxide dismutase, catalase, and glutathione peroxidase after mesenteric ischemia-reperfusion. A histological study was also performed. RESULTS: The algae extract helps to maintain normal enzymatic levels because, for all the studied parameters, groups treated with the extract showed significant differences (P < .05) compared with the I/R groups, and there were no differences compared with the sham group. The histological study showed that damage to the intestinal mucosa was less severe in animals treated with extract of H elongata after up to 24 hours of reperfusion compared with the I/R group. CONCLUSION: These results suggest that the extract of H elongata can protect intestinal tissue against ischemia-reperfusion injury.

Allopurinol Protective Effect of Renal Ischemia by Downregulating TNF-α, IL-1ß, and IL-6 Response.

Allopurinol is a well-known antioxidant that protects tissue against ischemia and reperfusion injury, blocking purine catabolism, and possibly reducing TNF-α and other cytokines. It also plays a significant role in reducing the inflammatory processes by inhibiting chemotaxis and other inflammatory mediators. The objective of this study was to define the role of allopurinol regarding kidney ischemic injury particularly as to its effect on inflammatory molecules such as TNF-α, IL-1ß, and IL-6 response. One hundred and twenty five rats were subjected to warm renal ischemia. Five more animals were included as sham. Animal survival and plasma levels of lipid peroxidation, myeloperoxidase, lactate dehydrogenase, glutathione, urea, creatinine, and cytokines were determined. Inflammatory parameters (TNF-α, IL-1ß, and IL-6) were measured in all groups by quantitative immunosorbent assay. Further, immunohistological and histopathological studies were carried out on animals treated prior to, or following reperfusion with 10 and 50 mg/kg of Allopurinol. The statistical analysis included ANOVA and Fisher test as well as χ2 test. Significance was reached at a p < 0.05. The results of this study indicated that Allopurinol protected against kidney ischemia-reperfusion injury since significantly better results of survival, biochemical analysis, and histopathological testing were observed in treated animals as compared to ischemic controls. In conclusion, Allopurinol protected ischemic kidneys through a mechanism associated with downregulation of TNF-α, IL-1 ß, and IL-6, in addition to other well-known effects such as decreased lipid peroxidation and neutrophil activity. It also increased antioxidant capacity and diminished endogenous peroxidase stain in renal ischemic tissue. Therefore, this experiment showed an effectiveness of allopurinol protection against proteomic and morphological damage.