Vo l. 13(3), pp. 82-90, July-Se pte mb e r 2021 DOI: 10.5897/ JPP2021.0609 Artic le Numbe r: 01614D267754 ISSN: 2141-2502 C o p yrig ht©2021 Autho r(s) re ta in the c o p yrig ht o f this a rtic le http :/ / ww w.a c a d e m ic jo urna ls.o rg / JPP Journal of Pharmacognosy and Phytotherapy Full Length Research Paper Laurus nobilis leaves extract protects against high fat diet-induced type 2 Diabetes in rats Costantine F. Daher 1 , Robin I. Taleb 1 , Mohamad A. Mroueh 2 , Bilal Nehmeh 1 , Hachem Araji 1 , Rawan H. Chakas 1 , Aimee M. Daccache 1 , Kamar H. Eid 1 , Maria K. El Khoury 1 , Pamela F. El Hayek 1 , Hala T. Faddoul 1 , Elio Junior Feghali 1 , Ahmad G. Ghanem 1 , Tony P. Haydar 1 , Abir R. Jammoul 1 , Sula H. Nasra 1 , Nouhad Saade 1 , Donna G. Tahan 1 , Joey C. Daher 3 , Esther Tannoury 3 and Wassim N. Shebaby 2* 1 Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, P. O. Box 36, Byblos, Lebanon. 2 Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese American University, P. O. Box 36, Byblos, Lebanon. 3 Gilbert and Rose Marie Chagoury School of Medicine, Lebanese American University, P. O. Box 36, Byblos, Lebanon. Received 27 May, 2021; Accepted 25 August, 2021 Laurus nobilis, commonly known as bay, is used in folk medicine as a remedy for many ailments. The present study investigates the protective effect of L. nobilis leaves extract against high fat diet-induced type 2 diabetes in rats. Animals were divided into group 1 (control), groups 2, 3, and 4 (bay leaves aqueous (AQ) extracts; 50, 100, and 250 mg/kg of body weight, respectively), and groups 5, 6, and 7 (bay leaves methanol/acetone (MeAc) extract; 50, 100, and 250 mg/kg of body weight, respectively). Animals were fed an isocaloric high fat diet for four weeks. The intake of bay leaves extracts was associated with a significant decreases in serum levels of glucose (AQ, 100 and 250 mg/kg; MeAc, 50, 100, and 250 mg/kg) and serum triglyceride (AQ, 250 mg/kg; MeAc, 100, and 250 mg/kg) as well as lower abdominal fat (all AQ and MeAc groups) and body weight gain (MeAc groups only). In conclusion, L. nobilis leaves extract intake provides a protective remedy against high fat diet-induced type 2 diabetes. Key words: Laurus nobilis, type 2 diabetes, bay leaves, high fat diet. INTRODUCTION Diabetes is a major public health problem worldwide with 425 million cases estimated in 2017 (Karurunga et al., 2017). Its global health care expenditure is expected to reach 802 billion US dollars in 2040 (Ogurtsova et al., 2017). Conventional medicinal treatments prescribed for diabetic patients are overpriced and may cause unfavorable side effects (Choudhury et al., 2018). Newer glycemia controlling agents are therefore needed. Herbal medicine is a promising alternative that relies on botanical extracts containing pharmacologically active compounds and substances (Atanasov et al., 2015). Extensive studies are being conducted on herbal supplements due to their potential efficacy, low-cost and low-toxicity (Ota and Ulrih, 2017). Laurus nobilis, also *C o rre sp o nd ing a utho r. E-ma il: wa ssim.she b a b y@ la u.e d u.lb . Te l: +961 9 547 262/ 3147. Fa x: +961 9 546 262. Autho r(s) a g re e tha t this a rtic le re m a in p e rm a ne ntly o p e n a c c e ss und e r the te rm s o f the C re a tive C o m m o ns Attrib utio n Lic e nse 4.0 Inte rna tio na l Lic e nse