The Obesity Paradox

Oolong tea polysaccharide and polyphenols prevent obesity development in Sprague-Dawley rats

Background

Several studies have evaluated the effects of oolong tea extracts on obesity. However, only few studies focused on the anti-obesity effect of specific components of oolong tea.

Objective

This study investigated the specific anti-obesity capabilities of oolong tea polysaccharide (TPS) and tea polyphenols (TPP) in high-fat diet-induced Sprague–Dawley rats.

Methods

Oolong tea water extract, TPS, TPP, and polysaccharide mixed with polyphenol (TPSM) given at doses of 400 or 800 mg/kg were administered to rats fed with high-fat diet for 6 weeks to explore the anti-obesity effects of the treatments.

Results

TPS and TPP were responsible for the suppressive effect on body fat accumulation. TPSM exhibited the highest effect on body weight reduction, and TPS and TPP effectively reduced serum leptin levels and significantly improved blood lipid and antioxidant levels. Moreover, microarray analysis of hepatic and adipose gene expression profiles revealed that TPP and TPS inhibited obesity through effects on the pathways of fatty acid biosynthesis, steroid hormone biosynthesis, unsaturated fatty acid biosynthesis, fatty acid elongation, glycerolipid metabolism, and glycerophospholipid metabolism.

Conclusions

TPSM might be a potential therapy for the treatment of obesity.

Mulberry and cherry anthocyanin consumption prevents oxidative stress and inflammation in diet-induced obese mice

SCOPE

This study aimed to determine whether cherry anthocyanin (CA) and mulberry anthocyanin (MA) can alleviate oxidative stress and inflammation associated with developing obesity in mice fed with high-fat diet (HFD).

METHODS AND RESULTS

CA and MA were added in the daily food of mice throughout the experiment. Sixty mice were randomly divided into two groups: a low-fat diet (LFD, n = 12) group and HFD (n = 48) group. Mice in the HFD group were supplied with a HFD for 8 wks to induce obesity. The HFD-fed mice were then divided into four subgroups for another 8-wk experiment. The subgroups included the control group, HFD plus Orlistat group, and HFD plus CA or MA group, with each group consisting of 12 mice. Consumption of CA and MA at 200 mg/kg food reduced bodyweight gain by 29.6 and 32.7%, respectively, in HFD-fed C57BL/6 mice. CA and MA supplementation could effectively improve the lipid profiles, decrease serum glucose and leptin levels, reduce MDA production, increase SOD and GPX activities, and down-regulate the expression of the TNFα, IL-6, iNOS, and NF-кB genes.

CONCLUSION

Therefore, MA and CA can potentially alter bodyweight by alleviating oxidative stress and inflammation in diet-induced obesity.

The anti-obesity effect of green tea polysaccharides, polyphenols and caffeine in rats fed with a high-fat diet

Beneficial effects of green tea (Camellia sinensis, Theaceae) extracts against obesity have been reported; however, the anti-obesity ability of the major components of green tea, polysaccharides, polyphenols and caffeine is not clear. Therefore, experiments with total green tea extracts, polyphenols, polysaccharides, caffeine, and a complex of polysaccharide and polyphenol at a dose of 400 or 800 mg kg⁻¹ were conducted on high-fat diet fed rats for 6 weeks to investigate their anti-obesity effects. The results indicated that polyphenols and polysaccharides were responsible for the suppressive effect of green tea extracts on body weight increase and fat accumulation. Moreover, polyphenols, polysaccharides, or caffeine can improve blood lipid and antioxidant levels, and effectively reduce rat serum leptin levels, inhibit the absorption of fatty acids, and markedly reduce the expression levels of the IL-6 and TNF-α gene. Furthermore, it was shown that polysaccharides and polyphenols were synergistic in reduction of serum leptin levels and in anti-inflammatory activity. These results suggest that the polysaccharide combination with polyphenols might be a potential therapy against obesity.