Histological and biochemical effects of an ethanolic extract of Myrtus communis leaf on the pancreases of rats fed high fat diets

We investigated the effects of an ethanolic extract of Myrtus communis subsp. communis (MC) leaves on the pancreases of rats fed with a high fat diet (HFD). Wistar albino rats were fed either with standard lab chow (Control group) or with a 45% fat diet (HFD and HFD+MC groups) for 4 months, with the MC extract (100 mg/kg) being administered by orogastric gavage to rats in the HFD+MC group during the last month. Blood and pancreas samples were collected from all experimental groups at the end of the study. Insulin and leptin levels, and the lipid profile, were analyzed in the blood serum. Pancreatic injury was assessed histologically. Insulin, nuclear factor kappa beta (NF-κB), and alpha-smooth muscle actin (α-SMA) were assessed using immunohistochemistry. Apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) immunohistochemistry. In addition, oxidant/antioxidant activity was analyzed by biochemical methods. Increased body weight, serum insulin and leptin levels, blood glucose level and pancreatic tissue malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, myeloperoxidase (MPO) activity and decreased tissue glutathione (GSH) level were observed in the HFD group compared to the Control group, in addition to dyslipidemia. An increased histopathological damage score, pancreatic islet area, insulin, TUNEL, NF-κB and α-SMA immunoreactivity were seen in animals from the HFD group compared to the Control group. However, such pathological changes were reduced in the HFD+MC group. Our data indicate further investigation of MC extract as a therapeutic adjuvant for HFD-induced pancreatic injury, acting via anti-inflammatory and antioxidant mechanisms, is worth carrying out.