Aegle marmelos Correa leaf extract prevents secondary complications in streptozotocin-induced diabetic rats and demonstration of limonene as a potent antiglycating agent

Objectives To study the antiglycating, antidiabetic and antioxidant properties of Aegle marmelosCorrea leaf extract and identify the bioactive constituent. Methods The effect of the chloroform extract of Aegle marmelosCorrea was studied in streptozotocin-induced diabetic rats through evaluation of biochemical parameters. Antiglycation activity was assessed in vitro through measurement of total and specific advanced glycation end products, protein carbonyl formation and collagen solubility tests. Antioxidant potential was evaluated using the ferric-reducing antioxidant power assay and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assays. Identification of the bioactive component was attempted through silica gel column chromatography and GC-MS analysis. Results In-vivo studies for 60 days revealed that the extract prevented kidney damage and other secondary complications. The chloroform extract at 16g could inhibit protein glycation by 44.33% and pentosidine formation by 59.31%, and could effectively inhibit protein carbonyl formation. It could scavenge DPPH radicals up to 85.26% (IC50: 26g). Bio-guided fractionation revealed limonene as the bioactive component, which could account for the antiglycating activity shown by the chloroform extract. Conclusion The chloroform extract of Aegle marmelos demonstrated antidiabetic antiglycating and antioxidant activity, effectively preventing kidney damage and establishment of cataracts. Limonene is reported for the first time as possessing potent antiglycating activity and is non-toxic at the concentration used.