Hepatoprotective effect of the flavonoid fraction isolated from the flower of Inula britannica against D-Galactosamine-induced hepatic injury.

The aim of this study was to investigate the mechanism and nature of the protective effect of Inula britannica flower flavonoids (IBFF) on antioxidants and the inhibition of inflammation in liver injury. Liver injury was induced in a mouse model by intraperitoneal injection of D-Galactosamine (D-Gal; 850 mg/kg) and IBFF was administered orally at 125, 250 or 500 mg/kg once a day for 7 days. The results revealed that IBFF reversed the increases in serum aminotransferase levels and lipid peroxidation and also reversed the decreases in hepatic glutathione content. IBFF attenuated the D-Gal-induced increases in tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein levels in the liver. Our data suggest that IBFF ameliorates D-Gal-induced acute liver injury and that this protection may be due to its antioxidative and anti-inflammatory activities.

Protective effect of myricetin in dextran sulphate sodium-induced murine ulcerative colitis.

In the present study, the protective effect of myricetin administered orally at 200, 100 or 50 mg/kg for 10 days was evaluated in a murine model of acute experimental colitis induced by dextran sulphate sodium (DSS). Macroscopic analysis was carried out to determine the effect of myricetin on pro-inflammatory cytokines, inflammatory markers and oxidative damage in biopsies of colonic tissues. The results showed that treatment with myricetin ameliorated body weight loss in a dose-dependent manner and significantly reduced histology scores. Myricetin decreased the production of nitric oxide (NO), myeloperoxidase (MPO) and malondialdehyde (MDA), while increasing the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Furthermore, the levels of the cytokines interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) were significantly decreased. Taken together, the results suggest that the anticolitis effects of myricetin may be attributed to anti-inflammatory and antioxidant actions. Additional investigation is required to determine the detailed mechanisms of action.

Composition and bioactivity of polysaccharides from Inula britannica flower.

In this paper, the composition and biological activities of polysaccharides from Inula britannica flower IBP obtained by water extraction were investigated. The properties and chemical compositions of IBP were analyzed with HPLC and IR methods. The results showed that IBP consisted of two kinds of polysaccharides with the molecular weight of 3500 Da, 700 Da. IBP consisted of mannose, glucuronic acid, rhamnose, galacturonic acid, glucose, galactose, arabinose with a molar ratio of 4.1:1:1.4:2.7:14.6:6.3:7.9. The IR spectrum of IBP revealed the typical characteristics of polysaccharides and protein. IBP was administered orally at three doses [100, 200 and 400 mg/kg body weight] for 14 days to the diabetic mice induced by alloxan. The body weight, plasma glucose, serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and liver glycogen were evaluated in normal and alloxan-induced diabetic mice. IBP could dose-dependently significantly increase the body weight of diabetic mice, and reverse the decrease of plasma glucose, glycogen and the decrease of blood lipid of diabetic mice as compared to those in control group. These results indicated that IBP could be developed to a potential anti-diabetic drug in the future.

Effect of Quercetin in the 1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine-Induced Mouse Model of Parkinson's Disease.

In this paper, the protective effect of the bioflavonoid quercetin on behaviors, antioxidases, and neurotransmitters in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine-(MPTP-) induced Parkinson's disease (PD) was investigated. Quercetin treatment (50 mg/kg, 100 mg/kg and 200 mg/kg body weight) was orally administered for 14 consecutive days. The results show that quercetin treatment markedly improves the motor balance and coordination of MPTP-treated mice. Significant increases were observed in the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and Na(+), K(+)-ATPase, AchE, the content of dopamine (DA) in the quercetin plus MPTP groups compared to those in the MPTP group. Significant reduction the 4-hydroxy-2-nonenal (4-HNE) immunoreactivity in striatum of brains was observed in the quercetin plus MPTP groups in comparison to the MPTP group. Taken together, we propose that quercetin has shown antiparkinsonian properties in our studies. More work is needed to explore detailed mechanisms of action.