ABSTRACT
Liver fibrosis is an abnormal wound healing response and a common consequence of chronic liver diseases from infection or alcohol/xenobiotic exposure. At the cellular level, liver fibrosis is mediated by trans-differentiation of hepatic stellate cells (HSCs), which is driven by persistent hepatic and systemic inflammation. However, impaired enterohepatic circulation and gut dysbiosis may indirectly contribute to the liver fibrogenesis. The composition of the gut microbiota depends on diet composition and host factors. In this study, we examined chlorophyllin, derived from green pigment chlorophyll, on gut microbiota, the intestinal mucosal barrier, and liver fibrosis. BALB/c mice received carbon tetrachloride through intraperitoneal injection to induce liver fibrosis and chlorophyllin was administrated in drinking water. The effects of chlorophyllin on liver fibrosis were evaluated for (1) survival rate, (2) hepatic morphologic analysis, (3) inflammatory factors in both the small intestine and liver, and (4) gut microbiota. Our results indicate that oral administration of chlorophyllin could attenuate intestinal and hepatic inflammation and ameliorate liver fibrosis. Importantly, oral administration of chlorophyllin promptly rebalanced the gut microbiota, exhibiting down-regulation of the phylum Firmicutes and up-regulation of the phylum Bacteroidetes. In vitro experiments on intestinal epithelial cells showed that chlorophyllin exposure could inhibit NF-κB pathway via IKK-phosphorylation suppression. In conclusion, this study demonstrates potential application of chlorophyllin to regulate the intestinal microbiota and ameliorate hepatic fibrosis.
ABSTRACT
One-third of the world's population has been infected with Mycobacterium tuberculosis (M. tuberculosis), a primary pathogen of the mammalian respiratory system, while about 10% of latent infections progress to active tuberculosis (TB), indicating that host and environmental factors may determine the outcomes such as infection clearance/persistence and treatment prognosis. The gut microbiota is essential for development of host immunity, defense, nutrition and metabolic homeostasis. Thus, the pattern of gut microbiota may contribute to M. tuberculosis infection and prognosis. In current study we characterized the differences in gut bacterial communities in new tuberculosis patients (NTB), recurrent tuberculosis patients (RTB), and healthy control. The abundance-based coverage estimator (ACE) showed the diversity index of the gut microbiota in the patients with recurrent tuberculosis was increased significantly compared with healthy controls (p < 0.05). At the phyla level, Actinobacteria and Proteobacteria, which contain many pathogenic species, were significantly enriched in the feces RTB patients. Conversely, phylum Bacteroidetes, containing a variety of beneficial commensal organisms, was reduced in the patients with the recurrent tuberculosis compared to healthy controls. The Gram-negative genus Prevotella of oral origin from phylum of Bacteroidetes and genus Lachnospira from phylum of Firmicutes were significantly decreased in both the new and recurrent TB patient groups, compared with the healthy control group (p < 0.05). We also found that there was a positive correlation between the gut microbiota and peripheral CD4+ T cell counts in the patients. This study, for the first time, showed associations between gut microbiota with tuberculosis and its clinical outcomes. Maintaining eubiosis, namely homeostasis of gut microbiota, may be beneficial for host recovery and prevention of recurrence of M. tuberculosis infection.
ABSTRACT
Soils were collected from Shergyla Mountain shade slope and south-facing slope in southeast Tibetan Plateau (TP) in August 2012 and they were measured for polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs)(including HCHs and DDTs). The concentrations of ∑16PAHs ranged from 99.3 to 1984 ng·g-1 dw, with a mean value of 1017 ng·g-1 dw. HCHs and DDTs in soils samples were in the range of 0.37-2.07 ng·g-1 dw (mean 1.15 ng·g-1 dw) and 0.70-43.9 ng·g-1 dw (mean 9.87 ng·g-1 dw), respectively. The concentrations of all measured compounds were much higher than those in central or western TP,and the PAHs concentration was even up to two orders of magnitude. The concentrations of α-HCH and DDTs in south-facing slope increased with altitude, but HCHs and DDTs in shade slope had no significant correlation with altitude. There was no consistent increasing or decreasing trend of PAHs in shade slope with altitude, and the concentrations of PAHs in south-facing slope showed a higher value in lower altitude, indicating the existence of local pollution emissions. The PAHs profile was dominated by lighter constituents (2 & 3-ring accounted for higher than 85%),inferring that the PAHs in the study area were largely influenced by long range atmospheric transport (LRAT) of pollutants. The special diagnostic ratios of PAHs suggested that PAHs were mainly produced by low temperature combustion of biomass and fossil fuels, except that two sampling sites of shade slope had been possibly influenced by oil residue. The relatively low ratios of α/γ-HCH inferred HCHs in the research area was the result of the combined contribution of the historical technical HCHs and Lindan. The ratios of p,p'-DDE/p,p'-DDT and o,p'-DDT/p,p'-DDT indicated DDTs were from the combined contribution of the historical technical DDTs and dicofol. According to the profile of PAHs, HCHs and DDTs and the meteorological conditions of Shergyla Mountain, the transport of PAHs and OCPs in the study area was mainly influenced by the Indian Monsoon.
ABSTRACT
The sediment core was collected in Pumoyum Co, a lake located in southern Tibetan Plateau, in July 2008. Samples were digested using microwave equipment and analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), to determine the content of heavy metals in the sediments. The average concentrations for Cr, Co, Ni, Cu, Zn, Cd, Pb, Mn and Fe were 26.4 µg x g(-1), 6.64 µg x g(-1), 16.2 µg x g(-1), 26.2 µg x g(-1), 50.2 µg x g(-1), 0.363 µg x g(-1), 16.8 µg x g.(-1), 0.302 mg x g(-1) and 9.84 mg x g(-1) , respectively. The concentrations of analysed metals in Pumoyum Co were slightly higher than those in Antarctic, but lower than those from Dianchi in Yunnan, Daihai in Inner Mongolia, the Great lakes in North America and Taihu in China, which were obviously affected by anthropogenic activities. Overall, these metals in sediments from Pumoyum Co represented a low concentration level. Vertical profiles of heavy metals in the sediment core kept stable without large fluctuation and the concentrations in surface slices were relatively higher. Results of principle component analysis and cluster analysis indicated that organic matter and Mn were affected by surface runoff markedly while other metals were mainly correlated to natural diagenetic weathering and atmospheric deposition. Sediment quality guideline and potential ecological risk index were introduced to assess sediment quality and both of their results indicated that the Pumoyum Co as a whole can be ranked as low potential ecological risk.