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.