Antidiabetic Compounds in Plant Species

Many of the currently available drugs have been directly or indirectly derived from plants. Identification of guanidine and related compounds in French lilac plant (Galega officinalis L.) led to the development of biguanides such as metformin for the treatment of type-2 diabetes. Despite of their plant origin, biguanides have not been reported in plants. The objective of this study was to identify and quantify biguanide and related compounds (BRCs) in experimentally or clinically substantiated antidiabetic medicinal plant foods and potatoes. The results of Voges-Proskauer (V-P) assay after corrections suggest that the highest amounts of BRCs are present in green curry leaves (Murraya koenigii (L.) Sprengel) followed by fenugreek seeds (Trigonella foenum-graecum L.), green bitter gourd (Momordica charantia Descourt.), and potato (Solanum tuberosum L.). Whereas, garlic (Allium sativum L.), and sweet potato (Ipomea batatas (L.) Lam.) contain negligible amounts of BRCs. Liquid chromatography-mass spectrometry (LC-MS) analysis confirmed the presence of biguanide, triguanide, galegine, and other guanidine and urea compounds in these plants with few exceptions.