The Activity of Red Ginger Oil in Antioxidant Study In Vitro and Antihyperalgesia Effect in Alloxaninduced Painful Diabetic Neuropathy in Mice

Abstract

Background: Red ginger oil (RGO) contains the highest bioconstituent, especially its essential oil which is important for antioxidant, than the other varieties. Chronic diabetic triggers the increase of reactive oxygen species which responsible for a diabetic complication such as painful diabetic neuropathy (PDN). Aim of the Study: This study was aimed to prove the antioxidant activity of RGO and the activity of RGO as antihyperalgesia in PDN through reducing blood glucose level or direct action in nerves or both. Materials and Methods: Two varieties of ginger which were red ginger and ginger, destilated using water, then calculated the total phenolic content and the antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH). Ginger with the highest antioxidant effect was continued to in vivo study in diabetic mice. In PDN model, mice were induced PDN using alloxan 210 mg/kg body weight (BW) i.p. After 14 days, mice which were showed diabetic followed by hyperalgesia would randomized into 7 groups: Normal, diabetic, glibenclamide and RGO (with dose 100, 200, 400 and 600 mg/kg BW). Treatments were given once daily for 14 days. Hyperalgesia response was evaluated using a hot plate as latency time. The latency time and fasting blood glucose levels were observed at day – 0, 7, 14, 21, and 28. Results: RGO had higher total phenolic content (0.778 ± 0.175 mg GAE/g oil) and antioxidant activity using DPPH (inhibitory concentration 50 3.626 ± 0.357 µl/ml) than GO. In vivo evaluation using mice showed that RGO 600 mg/kg BW had the best activity in reducing hyperalgesia and delaying spinal cord damage after PDN compared to the diabetic group (P < 0.05). RGO also had slightly effect in reducing blood glucose level and postponing the islet pancreas cell breakage. Conclusions: RGO had stronger antioxidant effect compared to GO. RGO also reduced hyperalgesia in PDN mice due to the improvement of spinal cord morphology.