Antioxidant and anti-inflammatory properties of taiwanese yam (Dioscorea japonica Thunb. var. pseudojaponica (Hayata) Yamam.) and its reference compounds

Anti-Inflammatory Effects of Trilinolein from Panax notoginseng Through the Suppression of NF-κB and MAPK Expression and Proinflammatory Cytokine Expression

In this study, we have investigated the anti-inflammatory effects of trilinolein (TL) using a lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) and carrageenan (Carr)-induced mouse paw edema model. When RAW264.7 macrophages were treated with different concentrations of TL together with LPS, a significant concentration-dependent inhibition of nitric oxide (NO), tumor necrosis factor (TNF-α), interleukin-1 (IL-1β), and IL-6 production was detected. Western blotting revealed that TL blocked the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-κB (NF-κB), IκBα, and mitogen-activated protein kinases (MAPKs). In the anti-inflammatory test, TL decreased the paw edema at the 5th h after λ-Carr administration in paw edema. We also demonstrated TL significantly attenuated the malondialdehyde (MDA) level in the edema paw at the 5th h after Carr injection. TL decreased the NO and TNF-α levels on the serum level at the 5th h after Carr injection. Western blotting revealed that TL decreased Carr-induced iNOS and COX-2 expressions at the 5th h in the edema paw. The anti-inflammatory mechanisms of TL might be related to the decrease in the level of iNOS, COX-2, IκBα, and MAPK pathway through the suppression of TNF-α, IL-1β, and IL-6.

Antioxidant and Anti-inflammatory Effects of Yam (Dioscorea batatas Decne.) on Azoxymethane-induced Colonic Aberrant Crypt Foci in F344 Rats

Yam (Dioscorea batatas Decne.) has long been used as a health food and oriental folk medicine because of its nutritional fortification, tonic, anti-diarrheal, anti-inflammatory, antitussive, and expectorant effects. Reactive oxygen species (ROS), which are known to be implicated in a range of diseases, may be important progenitors of carcinogenesis. The aim of this study was to investigate the modulatory effect of yam on antioxidant status and inflammatory conditions during azoxymethane (AOM)-induced colon carcinogenesis in male F344 rats. We measured the formation of aberrant crypt foci (ACF), hemolysate antioxidant enzyme activities, colonic mucosal antioxidant enzyme gene expression, and colonic mucosal inflammatory mediator gene expression. The feeding of yam prior to carcinogenesis significantly inhibited AOM-induced colonic ACF formation. In yam-administered rats, erythrocyte levels of glutathione, glutathione peroxidase (GPx), and catalase were increased and colonic mucosal gene expression of Cu/Zn-superoxide dismutase (SOD), Mn-SOD, and GPx were up-regulated compared to the AOM group. Colonic mucosal gene expression of inflammatory mediators (i.e., nuclear factor kappaB, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, and interleukin-1beta) was suppressed by the yam-supplemented diet. These results suggest that yam could be very useful for the prevention of colon cancer, as they enhance the antioxidant defense system and modulate inflammatory mediators.

Diminution of hepatic response to 7, 12-dimethylbenz(α)anthracene by ethyl acetate fraction of Acacia catechu willd. through modulation of xenobiotic and anti-oxidative enzymes in rats

BACKGROUND

Liver is the primary metabolizing site of body and is prone to damage by exogenous as well as endogenous intoxicants. Polycyclic aromatic hydrocarbons such as 7, 12- dimethylbenz(α)anthracene (DMBA) is an exogenous hepatotoxin, which is well known for modulating phase I, II and anti-oxidative enzymes of liver. Plants contain plethora of polyphenolic compounds which can reverse the damaging effect of various xenobiotics. The present study investigated protective role of the ethyl acetate fraction of Acacia catechu Willd. (EAF) against DMBA induced alteration in hepatic metabolizing and anti-oxidative enzymes in rats.

METHODOLOGY AND PRINCIPAL FINDINGS

The rats were subjected to hepatic damage by treating with DMBA for 7 weeks on alternative days and treatment schedule was terminated at the end of 14 weeks. The rats were euthanized at the end of protocol and livers were homogenized. The liver homogenates were used to analyse phase I (NADPH-cytochrome P450 reducatse, NADH-cytochrome b5 reductase, cytochrome P420, cytochrome b5), phase II (glutathione-S-transferase, DT diaphorase and γ-Glutamyl transpeptidase) and antioxidative enzymes (catalase, superoxide dismutase, ascorbate peroxidase, glutathione reductase, guiacol peroxidase and lactate dehydrogenase). Furthermore, other oxidative stress parameters (thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes and reduced glutathione) and liver marker enzymes (serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and alkaline phosphatase) were also studied. The DMBA induced significant changes in activity of hepatic enzymes that was reversed by treatment with three dose levels of EAF.

CONCLUSION

It is concluded that EAF affords hepato-protection against DMBA in rats through modulation of phase I, II and anti-oxidative enzymes.

Bioassay guided isolation and identification of anti-inflammatory active compounds from the root of Ficus formosana

Activity-directed fractionation and purification processes were employed to identify the anti-inflammatory active compounds using lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) in vitro. Air-dried roots of Ficus formosana were extracted with methanol and separated into n-hexane, chloroform, ethyl acetate, n-butanol, and water layers. Among them, the chloroform layer showed strong activity and was subjected to separation and purification by using various chromatographic techniques. Five compounds showing potent activity were identified by comparing spectral data to be β-sitosterol, stigmasterol, psoralen, kaempferol, carpachromene, and syringic aldehyde. When macrophages were treated with psoralen and kaempferol together with LPS, a concentration-dependent inhibition of nitric oxide (NO) and tumor necrosis factor (TNF-α) productions were detected. Western blotting revealed that kaempferol, psoralen, and carpachromene blocked protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated macrophages. The results confirmed that the traditional use of F. formosana could be a potential anti-inflammatory agent.