Protective Effect and Mechanism of Polysaccharides from Cordyceps cicadae on Acute Liver Injury Induced by D-GlaN in Mice

[Objectives]To observe the protective effect of Cordyceps cicadae polysaccharides on acute liver injury induced by D-galactosamine( D-GlaN) in mice,and to explore its mechanism. [Methods] Seventy-five male Kunming mice were randomly and evenly divided into 5 groups according to the digital table method: normal group( CK)( injected intraperitoneally with saline solution),model group( injected intraperitoneally with D-GlaN),low-dose C. cicadae polysaccharides group( administered with 0. 5 g/kg of C. cicadae polysaccharides solution by gavage),middle-dose C. cicadae polysaccharides group( administered with 1. 0 g/kg of C. cicadae polysaccharides solution by gavage) and high-dose C. cicadae polysaccharides group( administered with 2. 0 g/kg of C. cicadae polysaccharides solution by gavage). After 12 d of administration,the liver histopathological score,liver homogenate indexes( superoxide dismutase,SOD; malondialdehyde,MDA; glutathione peroxidase,GSH-Px; nitric oxide,NO) and serum markers( aspartate transaminase,AST; alanine transaminase,ALT; alkaline phosphatase,ALP; cholinesterase,CHE) of mice in each group were detected. The expression levels of nuclear factor-κB( NF-κB) and tumor necrosis factor-α( TNF-α) in liver tissues were detected by immunohistochemistry. [Results]The liver histopathological score and the MDA,NO,AST,ALT,ALP,NF-κB and TNF-α levels were significantly higher( P < 0. 05) and the SOD,GSH-Px and CHE levels were significantly lower( P <0. 05) in the model group compared with the normal group. Compared with those in the model group,the liver tissue histopathological scores in the low-,middle-and high-dose C. cicadae polysaccharides groups were all significantly reduced( P < 0. 05). With the increase of treatment dose,the liver tissue histopathological scores showed a significant decrease( P < 0. 05). Compared with the model group,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α were significantly lower( P < 0. 05),and the levels of SOD,GSH-Px and CHE were significantly higher( P < 0. 05) in the low-,middle-and high-dose C. cicadae polysaccharides groups. With the increase of treatment dose,the levels of MDA,NO,AST,ALT,ALP,NF-κB and TNF-α declined significantly( P < 0. 05),while the levels of SOD,GSH-Px and CHE rose significantly( P < 0. 05). [Conclusions] C. cicadae polysaccharides have a significant protective effect on D-GlaN-induced acute liver injury in mice in a dose-dependent manner,and the mechanism may be related to the inhibition of NF-κB inflammatory signaling pathway.

Male marriage squeeze and a sociodemographic portrait of involuntary bachelors in rural China

This study uses,primarily,the 2020 National Population Census data to comprehensively examine the phenomenon of the“male marriage squeeze”and provide a socio-demographic portrait of involuntary bachelors in rural China.The descriptive findings make clear the pronounced male marriage squeeze in rural China.In 2020,China recorded its highest historical sex ratio of marriageable population,reaching 110.The age-specific proportions of never-married men surpass those of women,particularly in rural areas where a significant proportion of men remain unmarried throughout their lives.Between 2010 and 2020,men in rural areas exhibited a notable trend of delayed marriage.The likelihood of rural men getting married steadily declined during this decade,with rural men significantly less likely to get married than urban men.In China,the concentration of involuntary bachelors is mainly in rural areas,characterized by lower socioeconomic status,and inferior living conditions.While educational qualification among involuntary bachelors in rural areas has improved,it still lags behind that of currently or previously married men.Another problem is that the elderly population in rural areas faces resource scarcity,increasing the reliance on the minimum subsistence allowance.Elderly involuntary bachelors are generally in poorer health than their married peers,and the health disparity is widening.To make matters worse,a high percentage of these men live alone.

The changing trend of life expectancy for the Chinese elderly and its rural-urban disparity

Using data from Population Censuses,1%National Population Sample Surveys of China and the Human Mortality Database,this article adopts robust percentile-based methods to analyze the changing trend of life expectancy of the Chinese elderly especially the young-old and rural-urban disparity from 1989 to 2015,and attempt to explain the disadvantage of old-age mortality improvement in China compared to developed countries.We find that life expectancy at age 65 in China has increased continuously in recent decades,but at a lower speed than in developed countries,leading to a widening gap between China and developed countries,and the increase in e65 has not shown a clear catch-up trend that has been observed in the life expec-tancy at birth.Similar patterns are found when we explore the rural-urban disparity of China.Based on the age-at-death distribution,we find that the old-age deaths in rural areas are more concentrated at relatively younger ages compared to urban areas due to the higher death risks and slower improvement in mortality of the young-old in rural China.Our findings describe the age-patterns underlying the rural-urban disparity in life expectancy of the elderly within China,and also the main reason for the slower improvement of life expectancy among the Chinese elderly compared with those in developed countries.Survival improvement of the young-old and equalization of available health services are key to reducing the rural-urban bias and achieving accelerated increase in life expectancy among the elderly in China.