Short-Term Feeding Response in Chicks to Tea Saponin

Application of response surface methodology to optimise the extraction of tea saponin from Camellia oleifera, and their verification by HPLC

Single factor combined with response surface methodology was used to optimise the process parameters of tea saponin extraction from Camellia oleifera. Four factors including material-liquid ratio, extraction temperature, extraction time, and ethanol concentration were selected as the influencing factors on the basis of single factor. The extraction rate of tea saponin was used as the response factor to analyse the response of these four factors and three levels. Results showed that extraction temperature of 81.69°C, material-liquid ratio of 1:11.85 g/mL, time of 6.17 h, and ethanol concentration of 56.69% were the best extraction conditions. The estimated yield of extraction was 7.46%. Analysis of the tea saponin samples by using high performance liquid chromatography showed that the main peak time was 6.668 min, and the absorption peaks and peaks were symmetric.

Teasaponin reduces inflammation and central leptin resistance in diet-induced obese male mice

Chronic inflammation is involved in the pathogenesis of obesity and type 2 diabetes. Recently teasaponin, an extract from tea, has been shown to have antiinflammatory effects. We examined the effect of teasaponin on obesity, inflammation, glucose metabolism, and central leptin sensitivity in obese mice fed a high-fat (HF) diet for 16 weeks. Intraperitoneal injections of teasaponin (10 mg/kg, daily) for 21 days significantly decreased the food intake and body weight of HF diet-induced obese mice. Teasaponin treatment also reduced the protein levels of proinflammatory cytokines (TNF-α, IL-6, and/or IL-1β) and nuclear factor-κB signaling (phosphorylated inhibitory-κB kinase and phosphorylated inhibitory-κBα) in adipose tissue and the liver. The antiinflammatory effects of teasaponin were associated with improved glycemic status in the treated animals, evidenced by improved glucose tolerance, homeostasis model assessment, and fasting plasma insulin. In the hypothalamus, teasaponin decreased both proinflammatory cytokines and inflammatory signaling in the mediobasal hypothalamus. Teasaponin treatment also enhanced the anorexigenic effect of central leptin administration, restored leptin phosphorylated signal transducer and activator of transcription-3 (p-STAT3) signaling in the arcuate nucleus, and increased hypothalamic expression of the anorexigenic peptide proopiomelanocortin. These results identify a potential novel application for teasaponin as an antiobesity and antiinflammatory agent.