Quantification of quercetin obtained from Allium cepa Lam. leaves and its effects on streptozotocin-induced diabetic neuropathy

Abstract

Objective:Antioxidant potential has protective effects in diabetic neuropathy (DN); hence, the present study was designed with an objective to quantify quercetin from shade-dried leaves of Allium cepa Lam. and to study its effects on streptozotocin (STZ)-induced chronic DN.Materials and Methods:The shade-dried leaves of A. cepa Lam. were extracted with methanol and then fractionated using ethyl acetate (ACEA). The quantification of quercetin in ACEA was evaluated by high-performance thin layer chromatography (HPTLC). The STZ (40 mg/kg) was administered to Sprague-Dawley rats (180–250 g) maintained at normal housing conditions. The STZ was administered once a day for 3 consecutive days. The elevation in blood glucose was monitored for 3 weeks periodically using flavin adenine dinucleotide-glucose dehydrogenase method by Contour TS glucometer. Rats showing blood glucose above 250 mg/dl were selected for the study. Animals were divided into eight groups. ACEA (25, 50, and 100 mg/kg), quercetin (40 mg/kg), metformin (120 mg/kg), and gabapentin (100 mg/kg) were given orally once a day for 2 weeks. The blood glucose level was again measured at the end of treatment to assess DN. Thermal hyperalgesia, cold allodynia, motor incoordination, and neurotoxicity were studied initially and at the end of 2-week treatment. Biochemical parameters were also evaluated after 2-week drug treatment.Results:The quercetin present in ACEA was 4.82% by HPTLC. All the ACEA treatment reduces blood glucose level at the end of the 2-week study and shows a significant neuroprotective effect in STZ-induced DN in the above experimental models.Conclusion:The quercetin present in ACEA proved protective effect in STZ-induced DN.SUMMARY High-performance thin layer chromatography reveals the presence of 4.82% quercetin in Allium cepa ethyl acetate. (ACEA). Its investigation against various diabetic neuropathy biomarkers has proved that ACEA has significant blood glucose reducing action shown neuroprotective action in thermal hyperalgesia, motor incoordination, and biochemical parameters. Abbreviations Used: HPTLC: High-performance thin layer chromatography, TLC: Thin layer chromatography, UV: Ultraviolet, ACEA: Allium cepa ethyl acetate, STZ: Streptozotocin, LDL: Low-density lipids, HDL: High-density lipids.

Exploring the Potent Combination of Quercetin–Boronic Acid, Epalrestat, and Urea Containing Nanoethosomal Keratolytic Gel for the Treatment of Diabetic Neuropathic Pain: In Vitro and In Vivo Studies

“…The cutoff time was 10 s to prevent paw damage. The latency to the first sign of paw licking or a jump response to avoid the heat was used as an index of the pain threshold . The number of foot withdrawal reactions following the application of acetone to the paw’s plantar surface was used to gauge the degree of cold allodynia.…”

“…A syringe attached to a thin polyethylene tube was used to gently inject acetone into the rat’s heel. After spreading acetone over the paw’s plantar surface, a quick foot withdrawal was observed and thought to be a symptom of cold allodynia . The mean SD ( n = 3) for each experiment was carried out in triplicate.…”

“…Blood was taken from the orbital plexus of overnight fasted rats after the course of treatment. After the serum had been separated, the levels of triglycerides, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and cholesterol were assessed using the corresponding techniques …”

“…After the serum had been separated, the levels of triglycerides, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and cholesterol were assessed using the corresponding techniques. 19 Histopathological and Statistical Evaluation. After the skin samples were paraffin-fixed and sections with a thickness of 5 mm were obtained.…”

“…The latency to the first sign of paw licking or a jump response to avoid the heat was used as an index of the pain threshold. 19 The number of foot withdrawal reactions following the application of acetone to the paw's plantar surface was used to gauge the degree of cold allodynia. A syringe attached to a thin polyethylene tube was used to gently inject acetone into the rat's heel.…”