Condensed and Hydrolysable Tannins as Antioxidants Influencing the Health

Abstract

Natural polyphenols are a wide class of secondary plant metabolites and represent an abundant antioxidant component of human diet. An important, but often neglected group of natural polyphenols, are tannins. This review offers a general description of chemistry of both hydrolysable and condensed tannins (proanthocyanidins), the mechanisms of their antioxidation action, like free radical scavenging activity, chelation of transition metals, inhibition of prooxidative enzymes and lipid peroxidation. The mechanisms of action of antibacterial, antiviral, anticarcinogenic, cardiovascular system preventing, and antiinflammatory effects as well as the absorption, metabolic fate and positive in vivo effects of tannins are enclosed.

Antioxidative effects of Brassica juncea and Moringa oliefera prepared by different processing methods

“…This can be explained by the fact that in addition to phenolics, ascorbic acid and hydrolysable tannins contribute to the antioxidant capacity of fresh leafy vegetables. However at higher temperatures (frying) unlike the phenolics these are not stable and do not contribute to the total antioxidant activity (Begum et al 2009;Koleckar et al 2008). So the total antioxidant capacity of fried BJ can be attributed only to the phenolics which are stable at higher temperature (Vallejo et al 2003).…”

The mixture of procyanidins extracted from the lotus seed pod and bilobalide ameliorates scopolamine-induced memory impairment in mice

“…Being a common compound in plants, fruits, vegetables and seeds, procyanidins has been reported to exert strong biological effects on cardiovascular disease, cancer and certain neurodegenerative disorders [3] . Lotus seeds contain abundant procyanidins and exist as both food and medicine.…”

Effect of Sulphur and Selenium on Yield, Selenium Content and Antioxidant Properties in Sunflower (Helianthus annuus L.)

“…Scavenging of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) was assessed by the method of Koleckar et al, (2007) using ascorbic acid as a standard. Absorbance was measured in spectrophotometer at 517 nm (Model ECIL GS 5701).…”