METHODS: In the Nrf2 induction study, mice were divided into control, 2000 mg/kg TRF and diethyl maleate treated groups. After acute treatment, mice were sacrificed at specific time points. Liver nuclear extracts were prepared and Nrf2 nuclear translocation was detected through Western blotting. To determine the effect of increasing doses of TRF on the extent of liver nuclear Nrf2 translocation and its implication on the expression levels of several Nrf2-regulated genes, mice were divided into 5 groups (control, 200, 500 and 1000 mg/kg TRF, and butylated hydroxyanisole-treated groups). After 14 days, mice were sacrificed and liver RNA was extracted for qPCR assay.

RESULTS: 2000 mg/kg TRF administration initiated Nrf2 nuclear translocation within 30 min, reached a maximum level of around 1 h and dropped to half-maximal levels by 24 h. Incremental doses of TRF resulted in dose-dependent increases in liver Nrf2 nuclear levels, along with concomitant dosedependent increases in the expressions of Nrf2-regulated genes.

METHODS: Ten healthy volunteers were given four different doses of vitamin E formulations (268 mg α-T, 537 mg α-T, 263 mg TRF or 526 mg TRF) in a cross-over postprandial trial. Blood was sampled at 0, 2, 4, 5, 6 and 8 hours after meal consumption and plasma antioxidant status including total glutathione, superoxide dismutase, malondialdehyde (MDA), ferric reducing antioxidant potential and trolox-equivalent antioxidant capacity, was analyzed.

EXPERIMENTAL PROCEDURE: The microbial limit test (MLT) studies indicated the suitable dosage of minimum and maximum gamma irradiation for leaf extracts as well as dried leaves of all the tested medicinal plants. Quantitative analysis of total phenolic content (TPC) analysis is based on calorimetric measurements determined using the Folin-Ciocalteu reagent with gallic acid (GA) used as the reference. In vitro cytotoxicity assay by using fibroblast (L929) cell lines was performed on each plant to determine the toxicity effect which sodium dodecyl sulfate (SDS) as the positive control. DPPH (2,2-diphenyl-1-picryl-hydrazyl) assay was conducted by using vitamin C and GA as the positive controls to determine the antioxidant property of each plant.

PURPOSE: This study aimed to investigate the anti-aging potential of CC extracts and fractions, particularly their inhibition of collagenase, MMP-1 and MMP-3 activities in human dermal fibroblasts CCD-966SK, followed by isolation, identification and analysis of their bioactive constituents.

STUDY DESIGN AND METHODS: DPPH assay was firstly used to evaluate the antioxidant activity throughout the bioactivity-guided fractionation. Cell viability was determined using MTS assay. Collagenase activity was examined, while MMP-1 and MMP-3 expression were measured using qRT-PCR and western blotting. Then, chemical identification of pure compounds isolated from CC fractions was done by using ESIMS, 1H and 13C NMR spectroscopies. HPLC analyses were carried out for bioactive fractions to quantify the major components.

RESULTS: Throughout the antioxidant activity-guided fractionation, fractions CC-E2 and CC-E3 with antioxidant activity and no toxicity towards CCD-966SK cells were obtained from CC 75% ethanol partitioned layer (CC-E). Both fractions inhibited collagenase activity, MMP-1 and MMP-3 mRNA and protein expression, as well as NF-κB activation induced by TNF-α in CCD-966SK cells. 14 compounds, which mainly consists of flavonoids and their glycosides, were isolated. Quercitrin (14.79% w/w) and quercetin (11.20% w/w) were major compounds in CC-E2 and CC-E3, respectively, as quantified by HPLC. Interestingly, both fractions also inhibited the MMP-3 protein expression synergistically, compared with treatment alone.

METHODS: HFD-fed mice were administered MD (50 mg/kg, 100 mg/kg, and 150 mg/kg) or 2 mg/kg metformin (positive control) orally for 16 weeks. Normal diet and HFD-fed control groups received normal saline.

RESULTS: MD dose of 50 mg/kg was better than 100 mg/kg and 150 mg/kg in significantly reducing weight-gain, glucose intolerance, insulin resistance, lipid accumulation in liver and kidney, and improving the serum lipid profile. Lowered protein carbonyls and lipid hydroperoxides in urine and tissue homogenates and elevated reduced glutathione, ferric reducing antioxidant power (FRAP), and Trolox equivalent antioxidant capacity (TEAC) levels in tissue homogenates indicated amelioration of oxidative stress.