DOI: https://doi.org/10.53350/pjmhs2115103524 ORIGINAL ARTICLE 3524 P J M H S Vol. 15, No.10, OCT 2021 Effect of Metformin on the Kidney Histology of Rats in Gentamicin Induced Toxicity SOHAIL AHMAD 1 , AYESHA AFTAB 2 , FAUZIA SIRAJ 3 , AISHA HAMEED 4 , ZAHID IQBAL 5 , KHALIDA MOEED 6 1 Senior Medical officer, Tehsil Headquarter Hospital, Gujar Khan / District Health Authority, Rawalpindi 2 Assistant Professor Pharmacology, AL Nafees Medical College and Hospital, Islamabad 3 Assistant Professor Anatomy, Wah Medical College, Wah Cantt 4 Assistant Professor Pathology, Gujranwala Medical College / DHQ-Teaching Hospital, Gujranwala 5 Professor and Head of Department Pharmacology, Swat Medical College, Saidu Sharif, Swat 6 Assistant Professor Anatomy, Loralai Medical College, Loralai Corresponding author: Ayesha Aftab, Email: ayeshahaftab28@gmail.com, Cell: +923005001621 ABSTRACT Acknowledgment: We are indebted to Dr. Rashad Hussain from department of animal sciences, Quaid-i-Azam University, Islamabad for his consistent support and guidance for the write up of this manuscript. Study’s background and aim: Metformin, an oral antidiabetic agent has been studied in the past for its protective effects in aminoglycoside induced renal injuries. We hypothesized that the use of metformin may be protective in the aminoglycoside mediated acute renal failure. We thus tried two doses of metformin (M1; 75mg/kg/day) (M2; 150mg/kg/day) to evaluate this preventive potential on gentamicin induced acute renal failure in rats. Study Design: Randomized controlled trial Place of Study: Animal House of National Institute of Health Islamabad/ Department of Pharmacology, AL Nafees Medical College and Hospital, Islamabad, duration was 1 st August 2018 to 31 st January 2019. Materials and Methods: The rats were divided into three main groups (n=10) kept under similar conditions for food and temperature. Renal failure was induced by injecting gentamicin (80mg/kg/day) intraperitonealy (ip) for eight days with simultaneous administration of oral metformin for 28 days.Slides of rats’ kidneys were prepared for histological comparison at the last day of study. Results: In gentamicin induced renal failure and simultaneous administration of metformin, the histological findings of rat kidneys showed remarkable tissue necrosis in control group and prevention in metformin treated groups. Conclusion: Based on the histological results of our study it was concluded that metformin at a dose of 150mg/kg showed a nephroprotective effect in gentamicin induced renal injuries in Sprague-Dawley rats. Keywords: Metformin, Gentamicin, Nephrotoxicty, Renal injuries, Nephroprotective effect INTRODUCTION Medications-induced renal injuries are not rare, and they can range from modest harm to severe and/or complete renal failure [1]. Acute tubular necrosis, acute interstitial nephritis, nephrotic syndrome blockage, electrolyte problems, and chronic renal failure [2] are all possible outcomes in the clinical setting as a result of this condition. On the basis of these observations, several animal models of acute renal failure have been developed by administering supra- pharmacological doses of drugs such as glycerol (single dose 10mg/kg IM) [3], gentamicin (80 mg/kg per day IP) for 7 days [4], non-steroidal anti-inflammatory drugs (NSAIDs) (single dose 3g/kg po) [5-6], ifosfamide (60mg/kg Numerous factors, such as the dose and duration of antibiotic therapy [9], the age of the patient [10], concomitant administration of other nephrotoxic drugs, extracellular volume depletion, potassium depletion [11], excessive diuretic doses, and the renal status prior to initiation of treatment are all associated with aminoglycoside nephrotoxicity. Most cases of renal failure are reversible if the medicine is stopped in the early stages. Creatinine levels, on the other hand, may continue to rise for several days as a result of continuous tubular injury caused by chronically high parenchymal levels of aminoglycosides in the blood. There are several different types of tubular dysfunction conditions, including hypomagnesemia, hypocalcemia, hypokalemia, and full-blown tubular necrosis. Fanconi syndrome has been reported in the context of aminoglycoside poisoning [12]. [13] A large number of studies have been carried out in order to identify herbal extracts and antioxidants that have the ability to decrease or protect kidney damage. There have only been a few experimental studies that have demonstrated that some medications and substances have a preventative and protective role in gentamicin-induced nephropathy in particular. Resveratrol (a natural antioxidant), ROS scavengers, and metformin are the agents involved [14-15]. The use of metformin is frequently restricted due to concerns about lactic acidosis, however the contraindications to metformin have been well studied [16]. It has been discovered that in diabetic individuals with mild to severe renal impairment, there is no influence on their blood lactate levels [17]. Similar to this, serum metformin concentrations rise only when the glomerular filtration rate (GFR) is less than 30ml/min. As a result, it can be administered safely to patients with mild to moderate renal failure [18]. It was our goal with this study to determine the protective effects of metformin on the cellular and histological architecture of gentamicin-induced kidney damage in albino rats, and we were successful. MATERIALS AND METHODS For this study 32 Albino rats weighing 100-150 g were purchased from National Institute of Health (NIH), Islamabad. The rats were kept in the animal house of NIH at the standard room temperature of (25 0 C) under 12h day and night cycles with ad libitum food and water. The rats were given one week to be acclimatized. Animals were divided randomly into 3 groups (n=10) named C (Control) M1 (Metformin 75 mg/kg/day) M2(Metformin 150mg/kg/day) while two additional rats were kept as absolute control for comparative histopathological changes.Control group was given distilled water (1ml) by gavage for 28 days as single morning dose starting from day 0 while M1 and M2groups received respective doses of Metformin dissolved in 1ml distilled water from day 0 to 28.All animals (except absolute control) were given injection gentamicin (80mg/kg/day) intraperitonealy from day 0 to 7 to develop renal failure 4 . On the last day of study, rats were sacrificed and their kidneys were removed and fixed by immersing them in 10% buffered formalin for 24 hours. Afterwards the kidneys were trimmed sagittaly, dehydrated by passing different grades of ethanol (70%, 80%, 90%, 100% followed by xylene treatment and finally embedded in paraffin wax (melting point =56 0 C). Blocks were cut into 5 μm thick paraffin sections and fixed on pre-coated glass slides. Specimen slides were stained with Haris Hematoxylin (BDH) and Eosin (BDH).Prepared slides were examined under