The positive effect of eugenol on acute pancreatic tissue injury: a rat experimental model

Simvastatin and eugenol restore autophagic flux and alleviate oxidative, inflammatory, and fibrotic perturbations in an arginine-induced chronic pancreatitis rat model

Chronic pancreatitis (CP), a progressive inflammatory disease characterized by pancreatic tissue destruction and fibrosis, is considered a challenging health burden due to insufficiencies of current management procedures. Autophagy impairment has emerged as a major triggering event in pancreatitis, raising interest in exploring the potential of targeting autophagy as a possible interventional strategy. This study aimed to evaluate the possible ameliorative effect of two autophagy modulators, simvastatin and eugenol, on CP-related perturbations in an arginine-induced rat model. Repeated l-arginine administration (5 g/kg divided into 2 doses with a 1 h interval, given intraperitoneally every 3rd day for a total of 10 times) provoked CP features, demonstrated by acinar damage, oxidative stress, inflammation, and fibrosis. Arginine-triggered pancreatitis was accompanied by hampered pancreatic autophagic flux, evidenced by overexpression of pancreatic p62 and LC3-Ⅱ and downregulation of pancreatic AMPK and LAMP-1 mRNA expression. Treatment with simvastatin (20 mg/kg, intraperitoneally 24 h, before each arginine dose) and eugenol (50 mg/kg/day orally for 30 days) achieved significant anti-oxidative, anti-inflammatory, and anti-fibrotic effects, and reversed the arginine-instigated autophagic blockade, with superior ameliorative effects attained by eugenol. Altogether, simvastatin and eugenol provide a promising interventional approach for CP, at least partly, by restoring the impaired autophagic flux associated with CP.

Eugenol Reduced ΜPO, CD45 and HMGB1 Expression and Attenuated the Expression of Leukocyte Infiltration Markers in the Intestinal Tissue in Biliopancreatic Duct Ligation-Induced Pancreatitis in Rats

Background and Objectives: Inflammation and dysregulation in the intestinal barrier function in acute pancreatitis (AP) trigger pancreatic lesions, systemic inflammatory response, and multiple organ dysfunction. Eugenol, as the main component of clove (Syzygium aromaticum), is known for its antioxidant and anti-inflammatory properties. We studied the potentially beneficial effect of eugenol in a rodent model of biliopancreatic duct ligation-induced AP. Materials and Methods: Rats were randomly divided into three groups: Sham, AP, and AP + eugenol (15 mg/kg/day). Serum TNFα, IL-6, IL-18, and resistin levels, as well as IL-6, TNFα, MPO, HMGB1, and CD45 tissue expression, were determined at various timepoints after the induction of AP. Results: Eugenol attenuated hyperemia and inflammatory cell infiltration in the intestinal mucosal, submucosal, and muscular layers. IL-6 and resistin serum levels were significantly reduced in the AP + eugenol group, while serum TNFα and IL-18 levels remained unaffected overall. TNFα pancreatic and intestinal expression was attenuated by eugenol at 72 h, while IL-6 expression was affected only in the pancreas. MPO, CD45, and HMGB1 intestinal expression was significantly reduced in eugenol-treated rats. Conclusions: Eugenol managed to attenuate the inflammatory response in the intestine in duct ligation-induced AP in rats.

The effects of eugenol on histological, enzymatic, and oxidative parameters in the major salivary glands and pancreas of healthy male Wistar rats

OBJECTIVE

We evaluated the effects of eugenol on histological, enzymatic, and oxidative parameters in the pancreas, parotid, submandibular, and sublingual glands of healthy male rats.

DESIGN

Twenty-four adult Wistar rats were assigned into four groups (n = 6/group). Control rats received 2% Tween-20 (eugenol vehicle), whereas the other animals received 10, 20, and 40 mg kg-1 eugenol through gavage daily for 60 d. Major salivary and pancreatic glands were weighed and preserved fixed for microscopic analysis and frozen for in vitro assays.

RESULTS

Eugenol did not alter glands' weight and serum amylase activity regardless of the concentration. The highest dose of eugenol caused an increase in pancreatic amylase activity and a reduction of lipase activity from serum and pancreas. Eugenol at 40 mg kg-1 diminished the activity of SOD and FRAP in the submandibular gland and CAT and FRAP in the sublingual gland. However, it did not exert any effect on GST regardless of the gland. Additionally, 40 mg kg-1 eugenol increased MDA levels in pancreatic, parotid, and submandibular glands and NO levels in the sublingual. The concentrations of eugenol induced distinct responses in the glands regarding the activity of Na+/K+, Mg2+, and total ATPase activity. They also affected histomorphometrical and histochemistrical parameters in the submandibular gland only.

CONCLUSIONS

Results indicated that 40 mg kg-1 eugenol altered most of the biochemical and oxidatived parameters of digestive glands. Only submandibular glands presented histological changes after eugenol exposure suggesting potential implications for its function.