Protective effects of crocin and gallic acid on the liver damage induced by methylglyoxal in male mice: role of inflammatory factors

Aim

This study aims to evaluate whether biochemical alterations caused by methylglyoxal (MG), improves by the administration of gallic acid (GA), crocin (Cr), and metformin (MT) in the liver.

Background

MG is produced naturally through various physiological processes, but high levels of MG cause inflammation in hepatocytes. Normal liver function is essential for maintaining glucose homeostasis. Gallic acid and crocin can reduce inflammation.

Methods

This experiment was done in 5 weeks. 50 male NMRI mice were randomly divided into 5 groups (n=10): 1) Control, 2) MG (600 mg/Kg/d, p.o.), 3) MG+GA (30 mg/kg/day, p.o.), 4) MG+Cr (60 mg/kg/day, p.o.), 5) MG+MT (150 mg/kg/day, p.o.). After one week of habituation, MG was administered for four weeks. Gallic acid, crocin, and metformin were administered in the last two weeks. Biochemical and histologic evaluations were assessed after plasma collection and tissue sample preparation.

Results

Gallic acid and crocin-received groups significantly reduced fasting blood glucose, total cholesterol, triglyceride levels, and elevated insulin sensitivity. Administration of MG exerted a marked increase in the levels of hepatic enzymes. Treatment with gallic acid, crocin, and metformin significantly decreased them. The altered levels of inflammatory factors in the diabetic group were significantly improved in the diabetic-treated groups. High levels of steatosis and red blood cells (RBCs) accumulation in the MG group markedly recovered in other treated mice.

Conclusion

Harmful effects of accumulated MG in the liver of diabetic mice were effectively attenuated by using gallic acid and crocin.

Diabetic nephropathy induced by methylglyoxal: gallic acid regulates kidney microRNAs and glyoxalase1-Nrf2 in male mice

BACKGROUND

Methylglyoxal (MG) has been reported to be a toxic by-product of glycolysis and intracellular stressor compound. This study investigated the effects of gallic acid (GA) against diabetic nephropathy (DN) induced by MG in male mice.

METHODS

DN was induced by methylglyoxal (600 mg/kg/day, p.o.) treated for 28 consecutive days. The animals received GA (30 mg/kg/day, p.o.) and metformin (MT) (150 mg/kg/day, p.o.) for 7 consecutive days after diabetes induction. Biochemical assays, antioxidant evaluation, microRNAs associated with fibrosis, endoplasmic reticulum stress, and histopathological analysis were examined.

RESULTS

MG increased malondialdehyde, albuminuria, Nrf2, miR-192 and miR-204 expression in diabetic groups and GA decreased them. Superoxide dismutase, catalase, glyoxalase1, and miR-29a expression decreased in diabetic groups and increased in treatment with GA.

CONCLUSION

Our results revealed that GA has improved DN induced by MG via amelioration of biochemical indices, histopathological aspects, oxidative stress and microRNAs associated with endoplasmic reticulum stress and fibrosis.

The anti-inflammatory and anti-apoptotic effects of gallic acid against mucosal inflammation- and erosions-induced by gastric ischemia-reperfusion in rats

The present study aimed to evaluate the protective effect of gallic acid on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rat. Forty male rats were randomly divided into sham, control (I/R injury) and three gallic acid-pretreated groups. To induce I/R lesions, the celiac artery was clamped for 30 min and then the clamp was removed to allow reperfusion for 6 hr. Pretreated rats received gallic acid (15, 30 or 60 mg kg(-1), intraperitoneally) 30 min prior to the induction of I/R injury. Macroscopic and microscopic evaluations of the areas of ulceration were compared. Samples of gastric mucosa were collected to evaluate the protein expression of pro-apoptotic factor, caspase-3, and pro-inflammatory enzyme, inducible nitric oxide synthase (iNOS) using western blot. Pretreatment with gallic acid decreased the total area of gastric lesions. Gallic acid at 30 mg kg(-1) decreased the levels of protein expression of caspase-3 and iNOS induced by I/R injury. Our findings showed the protective effect of gallic acid on gastric mucosa against ischemia-reperfusion injury. This effect of gallic acid was mainly mediated by reducing protein expression of iNOS and caspase-3.