Effects of orally-administered melatonin and long-term exposure to light and dark on serum indices and gene expression of insulin and glucagon in male Wistar rats

Protective Effects of Melatonin and Bee Pollen on Hematotoxicity and Hepatorenal Toxicity Induced by Long-Term Intake of Gabapentin in Female Albino Rats

Gabapentin (GBN) is an anti-seizure medication that is also used to treat nerve pain and other diseases. However, its misuse is currently a growing worry, as it may pose a significant health danger. The present study aimed to evaluate the protective effect of melatonin (MEL) and bee pollen (BP) as antioxidants against GBN-induced hematotoxicity and hepatorenal toxicity in female Albino rats. In this study, fifty-six adult female albino rats were divided into seven groups (n = 8 each), served as control, GBN, MEL, BP, MEL + GBN, BP + GBN, and MEL + BP + GBN treated groups. Results showed that oral administration of GBN resulted in a hematological toxicity as confirmed by a significant reduction in RBCs, Hb concentration, Ht%, MCV, MCH, platelets as well as altering of leukocyte profiles, WBCs, neutrophils, lymphocytes, monocytes, eosinophils and basophils. The biochemical results of liver and kidney functions showed a significant decrease in serum glucose, total protein, triglycerides, urea and uric acid. However, a significant increase in albumin, cholesterol, creatinine as well as ALP, AST, and ALT liver enzymes compared to the control was found. The oral administration of MEL and BP 12 h before GBN mostly ameliorates the altered hematological and biochemical parameters as well as hepatic and renal histopathological architecture to normal levels. In conclusion, Pre-treatment with MEL and BP, individually or together provided protection against the GBN induced changes in the blood parameters as well as hepatorenal structure and function.

Histomorphological changes in the pancreas and kidney and histopathological changes in the liver in male Wistar rats on antiretroviral therapy and melatonin treatment

Combination antiretroviral therapy (cART) has shown to cause inflammation, cellular injury and oxidative stress, whereas melatonin has been successful in reducing these effects. The aim of the study was to determine potential morphometric changes caused by cART in combination with melatonin supplementation in human immunodeficiency virus (HIV)-free rats. Tissue samples (N = 40) of the pancreas, liver and kidney from a control (C/ART-/M-), cART group (C/ART + ), melatonin (C/M + ) and experimental group (ART+/M + ) were collected and stained with haematoxylin and eosin (H&E) and evaluated for histopathology. The pancreata were labelled with anti-insulin and anti-glucagon to determine α- and β-cell regions. Kidneys were stained with periodic acid Schiff (PAS) to measure the area, perimeter, diameter and radius of renal corpuscles, glomeruli and proximal convoluted tubules (PCTs). Blood tests were conducted to determine hepatotoxicity. No significant changes in histopathology were seen. Melatonin stimulated pancreatic islet abundance, as the number of islets per mm² was significantly higher in the C/M+ than in the C/ART-/M- and ART+/M+. Parameters of the renal corpuscle, glomeruli, renal space and PCTs were significantly lower in the C/ART+ compared to the other groups, thus cART may have caused tubular dysfunction or cellular damage. A significant increase in serum haemoglobin was observed in the C/ART+ compared to the C/ART-, which showed cART increases serum haemoglobin in the absence of immune deficiency. Serum lipids were significantly decreased in the C/M+ compared to the C/ART-, possibly due to the effect of melatonin on the decrease of lipolysis, decreasing effect on cholesterol absorption and stimulation of lipoprotein lipase (LPL) activity. In conclusion, we have demonstrated that melatonin stimulated α-cell production, increased the number of pancreatic islets and caused a decrease in total lipids, whereas cART increased serum haemoglobin and decreased various parameters of the nephron in an HIV-free rat model, suggestive of tubular dysfunction.