Effects of Capsaicin on the Hypoglycemic Regulation of Metformin and Gut Microbiota Profiles in Type 2 Diabetic Rats.

Dietary capsaicin (CAP), the main irritant component in pepper, can reduce the incidence of diabetes, while metformin (MET) is a first-line oral hypoglycemic drug. The purpose of this study was to investigate whether CAP on the hypoglycemic effect of MET is pertinent to gut microbiota. The glucose and insulin tolerance of diabetic rats were monitored. The glycolipid metabolism was analyzed by detecting blood biochemical parameters. Liver pathological changes were observed by Hematoxylin eosin (HE) staining. The inflammatory cytokines and intestinal tight junction proteins were detected by RT-qPCR and Western blot. 16S rRNA sequencing was employed to analyze gut microbiota profiles. The results showed that CAP and MET co-treatment could significantly reduce fasting blood glucose, improve glucose tolerance, lessen liver injury and inflammatory infiltration, down-regulate inflammatory cytokines and up-regulate intestinal tight junction proteins in diabetic rats by comparing it with MET monotherapy. Moreover, CAP and MET co-treatment altered gut microbiota profiles by regulating microbials' abundances such as Akkermansia. In conclusion, CAP showed the significant hypoglycemic effect of MET and remodulated gut microbiota profiles in diabetic rats.

Anti-diabetic Role of Adropin in Streptozotocin Induced Diabetic Rats via Alteration of PI3K/Akt and Insulin Signaling Pathway.

Diabetes mellitus (DM) is a hyperglycemia-related multifactorial condition with an elevated risk of microvascular and microvascular complications associated with this disease. The current experimental study was to examine the antidiabetic activity of streptozotocin (STZ)-induced adropin against diabetic rats by altering the PI3K/Akt and insulin signaling pathways. STZ (60 mg/kg) was used for the induction of DM and rats were divided into different groups and received the adropin (20, 40 and 80 mg/kg) and glibenclamide (10 mg/kg) till 28 days. Body weight, plasma insulin, blood glucose and food intake were estimated, respectively. Biochemical enzymes, carbohydrate enzymes, lipid parameters, AMPK and insulin signalling pathway parameters were estimated. GLUT4 and PPARγ expression were also estimated. Oral administration of adropin significantly (p < 0.001) increased the glycogen, glucose-6-phosphatase dehydrogenase, insulin, hexokinase and belittled the blood glucose level, fructose 1-6-biphosphatase, glucose-6-phosphatase at dose dependent manner. Adropin significantly (p < 0.001) reduced the level of triglyceride, cholesterol, low density lipoprotein, very low density lipoprotein and increased the level of high density lipoprotein at dose dependent manner. Adropin significantly (p < 0.001) activated the Akt, IRS-2, IRS-1, IR, p-AKT and PI3k, which are the key modulator molecules of PI3K/Akt, AMPK and insulin signalling pathway in DM rats. The current experimental study confirms the anti-diabetic effect of adropin on DM rats induced by AMPK and insulin signalling pathway against STZ.

[Response Mechanism of Trace Metals in the Bishuiyan Subterranean River to the Rainfall and Their Source Analysis].

High-frequency sampling was conducted at the outlet of Guangxi Bishuiyan karst subterranean river using an automatic sampler during the rainfall events. The hydrochemical drymanic variation characteristics of trace metals (Cu, Pb, Zn, Cd) at the outlet of Guangxi Bishuiyan karst subterranean river were analyzed, and the sources of the trace metals in the subterranean river as well as their response to rainfall were explored. The results showed that the rainfall provoked a sharp decrease in the major elements (Ca²âº, Mg²âº, HCO3⁻, etc.) due to dilution and precipitation, while it also caused an increase in the concentrations of dissolved metals including Al, Mn, Cu, Zn and Cd, due to water-rock reaction, sediment remobilization, and soil erosion. The water-rock reaction was more sensitive to rainfall than the others, while the sediment remobilization and soil erosion took the main responsibility for the chemical change of the heavy metals. The curves of the heavy metal concentrations presented multiple peaks, of which the maximum was reached at 9 hours later after the largest precipitation. Different metal sources and the double-inlet structure of the subterranean river were supposed to be the reasons for the formation of multiple peaks. During the monitoring period, the average speed of the solute in the river reached about 0.47 km · h⁻¹, indicating fast migration of the pollutants. Therefore, monitoring the chemical dynamics of the karst subterranean river, mastering the sources and migration characteristics of trace metal components have great significance for the subterranean river environment pollution treatment.

Spatial variations of dimethylsulfide and dimethylsulfoniopropionate in the surface microlayer and in the subsurface waters of the South China Sea during springtime.

Spatial variations in dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) were surveyed in the surface microlayer and in the subsurface waters of the low productivity South China Sea in May 2005. Overall, average subsurface water concentrations of DMS and DMSP of dissolved (DMSPd) and particulate (DMSPp) fractions were 1.74 (1.00-2.50), 3.92 (2.21-6.54) and 6.06 (3.40-8.68) nM, respectively. No enrichment in DMS and DMSPp was observed in the microlayer. In contrast, the microlayer showed a DMSPd enrichment, with an average enrichment factor (EF, defined as the ratio of the microlayer concentration to subsurface water concentration) of 1.40. In the study area, none of the sulfur components were correlated with chlorophyll a. An important finding in this study was that DMS, DMSP and chlorophyll a concentrations in the surface microlayer were respectively correlated with those in the subsurface water, suggesting a close linkage between these two water bodies. The ratios of DMS:Chl-a and DMSPp:Chl-a showed a gradually increasing trend from North to South. This might be due to changes in the proportion of DMSP producers in the phytoplankton community with the increased surface seawater temperature. A clear diurnal variation in the DMS and DMSP concentrations was observed at an anchor station with the highest concentrations appearing during the day and the lowest concentrations during the night. The higher DMS and DMSP concentrations during daytime might be attributed to the light-induced increase in both algal synthesis and exudation of DMSP and biological production of DMS. The mean flux of DMS from the investigated area to the atmosphere was estimated to be 2.06 micromo lm(-2)d(-1). This low DMS emission flux, together with the low DMS surface concentrations was attributed to the low productivity in this sea.