[Effects of Piper longum L. on chills in Japanese young women: time-dependent changes in skin surface temperature and its recovery rate following the exposure to mild cold stress].

Chills can lead to problems such as insomnia, mental fatigue, and unstable emotions. Increasing evidence shows that young women, as well as menopausal women, suffer from chills. The present study investigated the effect of Piper longum L. on chills in young women. Participants with (n = 16) and without (n = 16) chills were sampled randomly from female university students using reported discriminative criteria (Yamada et al, 2007). Each participant was randomly assigned to low- (15 mg) and high-dose (30 mg) P. longum groups. We determined the severity of complaints related to chills, physical parameters (body mass index, body fat ratio, and blood pressure), the peripheral circulation dynamics using a laser tissue blood flow-meter, and the skin surface temperature in the fingers using a thermograph. Mild cold stress was applied 10 min after taking a capsule containing P. longum or a dextrin placebo. Then, a thermograph was recorded every minute for 11 min. Piper longum significantly facilitated the recovery of skin surface temperature at either low or high dosages in participants with chills. In subjects without chills, neither high- nor low-dosage of P. longum had an effect. Our findings have important implications for the utility of P. longum in women with chills.

Hepatoprotective effect of sesquiterpenes in turmeric.

Hepatoprotective effect of turmeric together with its sesquiterpenes and curcuminoids fractions were examined on D-galactosamine induced liver injury in rats. All the diets individually contained the turmeric extract, the curcuminoids fraction, and the sesquiterpenes fraction suppressed the increase of LDH, ALT, and AST levels caused by D-GalN treatment. Since few anti-oxidative activities are expected in the sesquiterpenes fraction, it is presumed that hepatoprotective mechanism of sesquiterpenes in turmeric is different from that of curuminoids.

Awa (Tokushima) lactate-fermented tea as well as green tea enhance the effect of diet restriction on obesity in rats.

Drinking tea is recommended for promoting health due to its bioactive nutrients, such as catechins and caffeine. In Tokushima area, we have a unique traditional tea, named Awa tea, which are fermented with Lactobacillus pentosus and Lactobacillus plantarum. The present study was designed to investigate anti-obesity effects of the Awa tea and compare with those of non-fermented green tea. Obese male Wistar rats (19 weeks of age) were given by low energy diets containing 3% of Awa and green tea extracts, respectively, or without any tea extracts (control), for 4 weeks. Awa tea contained smaller amount of catechins than green tea, although they contained similar amounts of polyphenols. This finding indicates that there are distinct kinds of polyphenols from catechins. The diets containing Awa and green tea extracts further decreased whole body weight, fat tissue mass and plasma leptin level, compared with control diet. In addition, their diets increased the daily amount of lipid excreted to feces and total 24-h-energy consumption, compared with the control group. However, there is no significant difference in these anti-obesity effects between Awa tea and green tea. Our results indicate that Awa lactate-fermented tea as well as green tea similarly enhance the effect of diet restriction on obesity, at least in part, through the increase in fat energy consumption and the decrease in fat absorption in rats.

Inhibitory effect of ethanol extract of Piper longum L. on rabbit platelet aggregation through antagonizing thromboxane A2 receptor.

Piper longum L. has been used as a crude drug for the treatment of disorders of poor peripheral blood circulation in Asia. However, the detailed mechanism of its action has not been clarified as yet. In the present study, we examined the effects of several extracts of Piper longum L. on rabbit platelet function. Thromboxane A(2) receptor agonist U46619 caused rabbit platelet aggregation, which was potently inhibited by the ethanol or butanol extract of Piper longum L. The ethanol extract inhibited U46619-induced platelet aggregation in a concentration-dependent manner, but only weakly inhibited that induced by thrombin. The maximum response to U46619 was reduced by 100% ethanol extract concentration dependently, suggesting that the inhibitory mode of U46619-induced platelet aggregation by the ethanol extract was non-competitive. The extract also inhibited U46619-induced phosphoinositide hydrolysis with a similar concentration dependency to the platelet aggregation. Furthermore, the extract inhibited binding of [(3)H]SQ29548 to thromboxane A(2) receptor in intact platelets in a concentration-dependent manner. These results suggest that Piper longum L. contains a constituent(s) that inhibits platelet aggregation as a non-competitive thromboxane A(2) receptor antagonist.