Quantitative assessment of tactile allodynia and protective effects of flavonoids of Ficus carica Lam. leaves in diabetic neuropathy

Background: Flavonoids, a group of polyphenols responsible for protective role against many diseased conditions, provide antioxidant activity which is the reason for their medicinal properties. Tactile allodynia is a behavioral biomarker of neuropathy that is well estimated by von Frey filaments and Randall–Selitto test. Objective: Ficus carica Lam. leaves were studied for the conformation of flavonoids in ethyl acetate fraction of methanolic extract (FCEA) using GC-HRMS for the identification of flavonoids. It was analyzed for antioxidant activity by in vitro free radical scavenging activity, performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) followed by blood glucose-level estimation, evaluation of neuropathic pain, and kidney and liver function tests in diabetic rats. Materials and Methods: The shade-dried leaves of F. carica Lam. were extracted with methanol and after that fractionated using ethyl acetate (FCEA). The characterization of FCEA was established using GC-HRMS. In vitro free radical scavenging activity was performed using DPPH assay. Diabetes was induced using streptozotocin (40 mg/kg/intraperitoneally), and effects of FCEA were studied on blood glucose level, neuropathy markers, and liver and kidney functions of diabetic rats. Results: GC-HRMS results highlighted the presence of quercetin, kaempferol, and chrysin in FCEA with free radical scavenging activity of 78.35% and IC50 value of 5.508 μM. FCEA reduces glucose levels and also shows protective effects in case of diabetic neuropathy as it increases the threshold of withdrawal latency in tactile allodynia and also decreases the serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, blood urea nitrogen, and creatinine levels. Conclusion: The protective effects of FCEA against diabetic neuropathy, hepatoprotective and nephroprotective effects might be due to strong antioxidant property of important flavonoids present which is confirmed in the study.