Therapeutic potential of heat-processed Panax ginseng with respect to oxidative tissue damage

Panax ginseng has been reported to exhibit a wide range of pharmacological and physiological actions. A method of heat-processing to enhance the efficacy of ginseng is well established in South Korea based on a long history of ethnopharmacological evidence. We investigated the increase in free radical-scavenging activity of Panax ginseng as a result of heat-processing and its active compounds related to fortified antioxidant activity. In addition, the therapeutic potential of heat-processed ginseng (HPG) with respect to oxidative tissue damage was examined using rat models. Based upon chemical and biological activity tests, the free radical-scavenging active components such as less-polar ginsenosides and maltol in Panax ginseng significantly increased depending on the temperature of heat-processing. According to animal experiments related to oxidative tissue damage, HPG displayed hepatoprotective action by reducing the elevated thiobarbituric acid reactive substance (TBA-RS) level, as well as nuclear factor-kappa B (NF-kappaB) and inducible nitric oxide synthase (iNOS) protein expressions, while increasing heme oxygenase-1 in the lipopolysaccharide-treated rat liver, and HPG also displayed renal protective action by ameliorating physiological abnormalities and reducing elevated TBA-RS, advanced glycation endproduct (AGE) levels, NF-kappaB, cyclooxygenase-2, iNOS, 3-nitrotyrosine, N?-(carboxymethyl)lysine, and receptors for AGE protein expression in the diabetic rat kidney. Therefore, HPG clearly has a therapeutic potential with respect to oxidative tissue damage by inhibiting protein expression related to oxidative stress and AGEs, and further investigations of active compounds are underway. This investigation of specified bioactive constituents is important for the development of scientific ginseng-derived drugs as part of ethnomedicine.