Hepatoprotective Effect of Tea Composite Solid Beverage on Alcohol-Caused Rat Liver Injury

Alcoholic liver disease (ALD) remains a major cause of liver-related morbidity and mortality worldwide. Tea polyphenols (TPs) possess strong antioxidant activity; cassia seed extract (CSE) has the effect of brightening the eyes; and Ampelopsis grossedentata extract (AGE) has the function of protecting the liver. However, the synergistic hepatoprotective effect of TP, AGE and CSE as a joint formulation is unknown. This study aimed to investigate the role of a tea solid beverage, composed of TP, AGE and CSE, on chronic alcoholic liver injury in rats and its underlying mechanisms via the analysis of transcriptomics and gut microbiota. The histopathological findings revealed that the tea solid beverage could reduce the production of fat vacuoles and inflammatory cell infiltration. Additionally, the tea solid beverage was found to effectively relieve the increase in the AST (from 424.85 U/L to 180.17 U/L), ALT (from 139.95 U/L to 85.88 U/L) and LDH (from 21.16 U/L to 13.35 U/L) enzyme activities and the expression of the inflammatory factors TNF-α (from 394.02 pg/mL to 214.44 pg/mL) and IL-6 (from 208.46 pg/mL to 116.59 pg/mL) caused by alcohol consumption. Further, it significantly enhanced the GSH concentration (from 4.53 pg/mL to 8.08 pg/mL) and SOD activity (from 84.70 U/mL to 156.94 U/mL) and decreased the MDA (from 58.61 mmol/mL to 36.58 mmol/mL) and TG (from 7.07 mmol/L to 3.43 mmol/L)) concentrations in the liver of rats. The analysis and identification of transcriptomics showed that the tea solid beverage intervention primarily protected the liver of rats with chronic alcoholic injury by up-regulating the differential gene Hmgcs1 in order to increase the synthesis of ketone bodies and by down-regulating the differential gene Pfkfb1 for the purpose of decreasing the glucose metabolism. Additionally, it was found that the tea solid beverage could significantly change the composition of intestinal flora in drinking rats by regulating mineral absorption, the pathways of bile secretion, the adipocytokine signaling pathway and the peroxisome balance of the intestinal flora, in order to protect alcohol-drinking rats' livers. In conclusion, the tea solid beverage, consisting of TP, AGE and CSE, is a functional drink that prevents ketone metabolism, glucose metabolism and microbiome disorders induced by alcohol intake.