Phytochemical Characterization of Aqueous Garlic (Allium sativum) Extract by FTIR, GC–MS and Assessment of Its Antiglycation, Alpha-amylase and Antidiabetic Activities in Alloxan-induced Diabetic Sprague–Dawley Rats and Molecular Docking Study
Johnson Oshiobugie Momoh *
Department of Chemical Sciences (Biochemistry Unit), College of Basic Sciences, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Matthew Iwada Ekum
Department of Statistics, Federal University of Agriculture Bassambiri, Bayelsa State, Nigeria.
Mark Imhonikhe Ogbiti
Department of Obstetrics and Gynecology, Faculty of Clinical Sciences, Ambrose Alli University, Ekpoma, Nigeria.
Nkechi Perpetua Nwafor
Basic Sciences Unit, School of Science and Technology, Christopher University, Mowe, Ogun State, Nigeria.
Olanrewaju Anthony Damazio
Department of Chemical Sciences (Chemistry Unit), College of Basic Sciences, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Taiwo Toyin Oshin
Department of Chemical Sciences (Chemistry Unit), College of Basic Sciences, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Olawale Jelili Ishola
Department of Animal Production, College of Agriculture, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Cecilia Oyinlade Ogundare
Department of Chemical Sciences (Biochemistry Unit), College of Basic Sciences, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Murisiku Adegbemi Onigemo
Department of Animal Production, College of Agriculture, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Oluwasegun Michael Adekunle
Department of Chemical Sciences (Biochemistry Unit), College of Basic Sciences, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Damilare Stephen Olojede
Department of Biological Sciences (Biochemistry Option), Faculty of Pure and Applied Sciences, Southwestern University of Nigeria. Okun-Owa, Ogun State, Nigeria.
Adenike Omosalewa Babalola
Department of Chemical Sciences (Biochemistry Unit), College of Basic Sciences, Lagos State University of Science and Technology (LASUSTECH), Ikorodu, Lagos State, Nigeria.
Babajide David Kayode
Department of Basic Medical Biochemistry, Faculty of Basic Medical Science, Eko University of Medicine and Health Sciences, Badagry Express way, Lagos State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Garlic (Allium sativum L.) contains phytochemicals of potential relevance to oxidative stress reduction and glucose homeostasis. This study characterised aqueous Allium sativum extract and evaluated its antioxidant, antiglycation and antidiabetic effects in alloxan-induced diabetic Sprague–Dawley rats, together with molecular docking against human alpha-amylase. Mineral composition, FTIR, GC–MS and phytochemical profiles were determined, while antioxidant and antiglycation activities were assessed using established in-vitro assays. Twenty-five rats were allocated to five groups. Diabetic animals received no treatment, glibenclamide (10 mg/kg), or aqueous garlic extract at 250 or 500 mg/kg body weight for 15 days, while a non-diabetic group served as the normal control. GC–MS identified 22 compounds, with 4H-pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl accounting for 22.53% and diallyl disulfide for 17.05%. The extract showed DPPH radical-scavenging activity with an IC₅₀ of 66.67 ± 2.07 µg/mL and inhibited advanced glycation end-product formation with an IC₅₀ of 66.75 ± 0.76 µg/mL. Treatment with the extract was associated with reduced blood glucose, total cholesterol, triglycerides, LDL-cholesterol, atherogenic indices and malondialdehyde, together with increases in HDL-cholesterol and antioxidant parameters compared with untreated diabetic animals. Pancreatic histology also showed better-preserved islet architecture in extract-treated groups. Molecular docking against human alpha-amylase (PDB: 1U2Y) yielded a binding affinity of −5.9 kcal/mol for the highest-ranked garlic-derived ligand (Hydrazine,1,2-dimethyl-), compared with −6.3 kcal/mol for acarbose. Overall, the findings indicate antioxidant, antiglycation and glucose-lowering activity of aqueous garlic extract in this experimental model.
Keywords: Allium sativum, aqueous garlic extract, alloxan-induced diabetes Sprague–Dawley rats, Fourier-transform infrared spectroscopy, gas chromatography–mass spectrometry, antioxidant activities, antiglycation activity, biochemical parameters, α-amylase molecular docking