Capsaicin ameliorates intermittent high glucose-mediated endothelial senescence via the TRPV1/SIRT1 pathway.

BACKGROUND: Patients with diabetes have accelerated vascular aging when compared with healthy individuals. Hyperglycemia, especially intermittent high glucose (IHG), is the main cause of vascular endothelial senescence. Capsaicin, a major component of chili pepper is thought to contribute to cardiovascular protection by spicy food. OBJECTIVE: To investigate the pathway related with the effects of capsaicin on endothelial cell senescence induced by IHG. METHODS: HUVECs were exposed to IHG (5 mM or 33 mM glucose, alternating every 12 hours for 3 days) and treated with capsaicin at 0.3, 1 and 3 µM. To determine endothelial cell senescence, we examined the senescence-related ß-galactosidase staining, cell cycle arrest, cell viability, as well as production of reactive oxygen species (ROS). To evaluate the involvement of TRPV1/[Ca2+]i/CaMKII/AMPK/SIRT1 pathway in anti- senescence effects of capsaicin, HUVECs were treated with CAPZ (a TRPV1 antagonist), BAPTA-AM (an intracellular calcium chelator), KN62 (a CaMKII antagonist), compound C (an AMPK inhibitor), or EX527 (a SIRT1 inhibitor). To knockdown TRPV1, HUVECs were transfected with shRNA lentivirus targeting TRPV1. The levels of SIRT1, p21, TRPV1, AMPK and phospho-AMPK were evaluated by western blotting. RESULTS: IHG suppressed the levels of SIRT1 and enhanced endothelial senescence. Capsaicin upregulated SIRT1 expression and downregulated the senescence marker, p21, thereby protecting endothelial cells from IHG-induced senescence as indicated by relieved G0/G1 phase arrest, improved cell viabilities, and reduced counts of senescent cells and ROS production. Pre-treatment with CAPZ, BAPTA-AM, KN62 or compound C abrogated the anti-senescence effects of capsaicin. Capsaicin restored AMPK phosphorylation and IHG-inhibited TRPV1 expression. Moreover, TRPV1 silencing suppressed SIRT1 expression and abolished the anti-senescence effects of capsaicin. CONCLUSION: Capsaicin elevates SIRT1 levels through TRPV1/[Ca2+]i/CaMKII/AMPK pathway and suppresses IHG-mediated endothelial cell senescence. This study provides initial evidence that capsaicin is a potential candidate for the prevention of vascular aging in diabetes.

Screening and identification of the metabolites in rat urine and feces after oral administration of Lycopus lucidus Turcz extract by UHPLC-Q-TOF-MS mass spectrometry.

Lycopus lucidus Turcz has been used as a kind of edible and medicinal material in eastern Asian countries. It has various bioactivities, including treatment of menstrual disorder, amenorrhea, menstrual cramps, inflammation, and cardiovascular diseases. However, the in vivo metabolism of L. lucidus Turcz extract is still not well described. In this study, L. lucidus Turcz extracts were administered to rats. Urine and fecal samples were collected at the difference periods (0-12h, 12-24h, and 24-36h). Ultra-high performance liquid chromatography coupled with electrospray ionization tandem quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) method was developed to characterize and identify the metabolites. A total of 17 metabolites in feces and 19 metabolites in urine were tentatively identified by means of accurate mass and characteristic fragment ions. The results show that glucuronidation and sulfation are the major metabolic reactions. This study is the first reported analysis and characterization of the metabolites and the proposed metabolic pathways of bioactive components might provide further understanding of the metabolic fate of the chemical constituents after oral administration of L. lucidus Turcz extract in rats.

[Experimental study on Dendrobium candidum polysaccharides on promotion of hair growth].

OBJECTIVE: To observe the effect and mechanism of Dendrobium candidum polysaccharides (DCP) in promoting hair growth, in order to lay a foundation for the development and utilization of D. candidum. METHOD: The water-extraction and alcohol-precipitation method was adopted to extract DCP, and the phenol-sulphuric acid method was used to determine its content. Thirty C57BL6J mice were collected to establish the hair loss model with hair removal cream. They were randomly divided into the control group, the positive control group and the DCP group, and given 0.2 mL of ultra-pure water, minoxidil tincture and DCP (5.0 g x L(-1)) 21 days. The mice hair growth scoring standard was adopted to evaluate the hair growth of C57BL/6J mice at 7, 14 d. The hairs in unit hair-losing areas of treated C57BL/6J mice at 21 d were weighed to evaluate the effect of DCP on the promotion of hair growth. MTT assay and RT-PCR method were used to evaluate the effect of DCP on the proliferatin of HaCaT cells and the mRNA expression of VEGF in HaCaT cells. RESULT: The extraction percent of DCP was 29.87%, and its content was 79.65%. The average scores for the hair growth and weight of C57BL/6J mice of DCP group were much higher than the control group. The survival rate and mRNA expression of VEGF of HaCaT cells were much higher than the control group. CONCLUSION: DCP has the effect in promoting hair growth. Its mechanism may be related to the up-regulation of the mRNA expression of VEGF.

An intervention study to prevent gastric cancer by micro-selenium and large dose of allitridum.

BACKGROUND: People have more and more concerned about allitridum as studies have shown that taking more raw garlic associated with a lower risk for cancers of the alimentary system. In the present study, we tried to examine whether a large dose of allitridum and a microdose of selenium prevent gastric cancer. METHODS: A double-blind intervention study was performed on the participants aged (35 - 74) years, who had matched at least one of the following criteria: (1) a medical history of stomach disorder, (2) a family history of tumour, or (3) smoking and/or alcohol consumption. A total of 2,526 and 2,507 persons were randomly enrolled into intervention group and control group respectively from 288 natural villages of seven communities in Qixia County, Shandong Province, China. Each person of the intervention group orally took 200 mg synthetic allitridum every day and 100 microg selenium every other day for one month of each year during November 1989 to December 1991. At the same time, people in control group were given 2 placebo capsules containing corn oid with the identical appearance to that in the intervention group. RESULTS: For all subjects the large dose of allitridum was accepted and no harmful side effects were found during the study. In the first follow-up five years (1992 - 1997) after stopping the intervention, the morbidity rates of malignant tumours in the intervention group declined by 22%, in contrast to the control group, declined by 47.3%. After adjusting for age, gender, and other potential confounders, relative risks (RRs) for all tumours and gastric cancer of the whole population were 0.67 (95% CL: 0.43 - 1.03) and 0.48 (95% CL: 0.21 - 1.06), respectively, and for male group they were 0.51 (95% CL: 0.30 - 0.85) and 0.36 (95% CL: 0.14 - 0.92), respectively. No signigicantly protective effect was found for the female subgroup. CONCLUSION: The present study proves that large doses of allitridum and microdorse of selenium may effectively prevent gastric cancer, especially in men.