_____________________________________________________________________________________________________ *Corresponding author: E-mail: msuddin75@yahoo.com; msuddin75@ru.ac.bd; Journal of Pharmaceutical Research International 26(6): 1-12, 2019; Article no.JPRI.48311 ISSN: 2456-9119 (Past name: British Journal of Pharmaceutical Research, Past ISSN: 2231-2919, NLM ID: 101631759) Exploration of Antidiabetic Activity of Stephania japonica Leaf Extract in Alloxan-Induced Swiss Albino Diabetic Mice Md. Dobirul Islam 1 , Syeda Farida Akter 1 , Md. Amirul Islam 1 and Md. Salim Uddin 1* 1 Department of Biochemistry and Molecular Biology, University of Rajshahi, Rajshahi-6205, Bangladesh. Authors’ contributions This work was carried out in collaboration among all authors. Author MDI designed the study, performed the statistical analysis and wrote the first draft of the manuscript. Author SFA managed the literature searches and carried out the tests. Authors MAI and MSU managed the analyses of the study and reviewed the manuscript. All authors read and approved the final manuscript. Article Information DOI: 10.9734/JPRI/2019/v26i630154 Editor(s): (1) Dr. Jongwha Chang, University of Texas, College of Pharmacy, USA. Reviewers: (1) Rajibul Islam, Gono Bishwabidyalay, Bangladesh. (2) Dr. Dennis Amaechi, Veritas University Abuja, Nigeria. Complete Peer review History: http://www.sdiarticle3.com/review-history/48311 Received 24 January 2019 Accepted 07 April 2019 Published 20 April 2019 ABSTRACT Aims: Presently the medicinal world is rapidly turning more on the therapeutic health benefits of natural product and medicinal plants in the management of major crucial disease and their complications. Medicinal plant, Stephania japonica has been studied for exploring antidiabetic potentiality as an alternative source of medicine against the global threat of Diabetes mellitus (DM). Methods: The extraction of S. japonica leaf was carried out by acetone and ethanol. Phytochemical screening and quantitative analysis of S. japonica leaf extracts were evaluated through chemically forming characterized color formation and calibration method respectively, by using standard reference substances (ascorbic acid, gallic acid, and quercetin) to assess the probable compounds present in the extract. Anti-diabetic potentiality of highest phytochemicals containing two extracts were investigated in in vitro as a ⍺-amylase inhibitors and in vivo through alloxan-induced Swiss albino diabetes mice model. Original Research Article