Shen Shengrong

Effect of yellow capsicum extract on proliferation and differentiation of 3T3-L1 preadipocytes

OBJECTIVES To evaluate the effect of effect of Yellow Capsicum extract (YCE) that is rich in capsaicin on the proliferation and differentiation of 3T3-L1 preadipocytes in vitro. METHODS 3T3 L1 cells that were exposed to differentiation-inducing medium containing high glucose DMEM (Dulbeccos Modified Eagles Medium) and subsequently were treated with capsaicin and YCE for their effect on adipocyte differentiation, changes in their triglyceride content, leptin secretion, expression of lipoprotein lipase, PPARγ, and CCAAT/enhancer-binding protein alpha (C/EBPα). RESULTS Both YCE and capsaicin inhibited proliferation and differentiation 3T3-L1 preadipocytes and suppressed accumulation of intracellular triglyceride in a dose-dependent manner. In addition, a significant decrease in the expression of lipoprotein lipase (LPL), leptin, PPARγ, and C/EBPα was noted in 3T3-L1 preadipocytes when induced to differentiate by YCE and Capsaicin. CONCLUSIONS The potent inhibitory action of YCE and Capsaicin on the differentiation of 3T3-L1 preadipocyte observed suggests that they (YCE and Capsaicin) have the potential to inhibit obesity that needs to be explored in future studies.

Interaction of catechins with aluminum in vitro

Tea is one of the most popular beverages, consumed by over two thirds of the worlds population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminums known adverse effect on human health. Investigation of the interactions of catechins with Al3+ showed that during the interaction of catechins with Al3+, the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322 nm; EC and Cs at 278 nm changed little. The ratio of Al3+ to EGCG was 1∶1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the Al-EGCG complex was 1∶1. Interestingly, while the ratio reached to over 2, after the complex of Al-EGCG started polymerization, the ratio in the polymer was 2∶1. In pH 6.2 buffer solution, the complex behavior of C with Al3+ was the same as that of EGCG, with a little difference for EC. When the ratio of Al3+ to EC was <1, the complex in ratio was 1∶2, but, the complex polymerized when the ratio of Al3+ to EC was >1. It was found that the ratio of Al3+ to EC in the polymer was 1∶1. Polymerization of Al-catechin complexes might reduce aluminum absorption in the intestine.Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols onKow in buffer solution. Results showed thatKow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminumKow value in acetic buffer, indicating that these compounds may reduce aluminum absorption during tea intake.

Influence of green tea polyphenols on mitochondrial permeability transition pore and Ca2+ transport

The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mitochondria swelling and change of mitochondria membrane potential. The data showed that GTPs had obvious protective effect on the Ca2+-induced PTP opening in a dose-dependent manner detected by mitochondria swelling. The results were obtained by measuring the change of mitochondria membrane potential through Rh 123. Further experiments were conducted to examine the detailed influence of GTPs on Ca2+ import and export of mitochondria. The results showed that GTPs had remarkably inhibitory effect on the Ca2+-induced Ca2+ import in mitochondria; and that they could accelerate Ca2+-release from mitochondria. Our data provide an alternate interpretation of the potent protective function of GTPs on cell against apoptosis.