title: Curcumin ameliorated diabetic neuropathy partially by inhibition of NADPH oxidase mediating oxidative stress in the spinal cord.
abstract: Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases are the main enzymes that produce oxidative stress, which plays an important role in painful diabetic neuropathy. Curcumin has been reported to exert an antinociceptive effect in a rat model of diabetic neuropathy by suppressing oxidative stress in the spinal cord. However, it remains unknown whether the mechanism by which curcumin ameliorates diabetic neuropathy can be attributed to spinal NADPH oxidases. This study was designed to determine the effect of curcumin on diabetic neuropathy and to investigate its precise mechanism in relation to NADPH oxidase-mediating oxidative stress in the spinal cord. Diabetic neuropathy was induced in Sprague-Dawley rats by intraperitoneal injection with 1% streptozotocin (STZ; 60 mg/kg). After the onset of diabetic neuropathy, a subset of the diabetic rats received daily intragastric administrations of curcumin (200mg/kg) or intraperitoneal injections of apocynin (2.5mg/kg) for 14 consecutive days, whereas other diabetic rats received equivalent volumes of normal saline (NS). STZ resulted in diabetic neuropathy with hyperglycemia and a lower paw withdrawal threshold (PWT), accompanied by elevations in the expression of the NADPH oxidase subunits p47(phox) and gp91(phox) and in the levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA) and a reduction in superoxide dismutase (SOD) activity (P<0.05) in the spinal cord. Both curcumin and apocynin ameliorated diabetic neuropathy. In conclusion, curcumin attenuated neuropathic pain in diabetic rats, at least partly by inhibiting NADPH oxidase-mediating oxidative stress in the spinal cord.
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China.
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Zhao
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China.
authors.forename: Mei-Juan
authors.initials: MJ
authors.lastname: Liao
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China.
authors.forename: Wen-Xuan
authors.initials: WX
authors.lastname: Zhang
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China.
authors.forename: Wan-You
authors.initials: WY
authors.lastname: He
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China.
authors.forename: Han-Bing
authors.initials: HB
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First People's Hospital of Foshan, 81# North of Rinlan Road, Foshan 528000, China. Electronic address: ycxiang2530@126.com.
authors.forename: Cheng-Xiang
authors.initials: CX
authors.lastname: Yang
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D001835:Body Weight / Q000187:drug effects; D003474:Curcumin / Q000494:pharmacology* / Q000627:therapeutic use; D003929:Diabetic Neuropathies / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D006861:Hydrogen Peroxide / Q000378:metabolism; D006930:Hyperalgesia / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism; D013311:Streptozocin; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000098:Acetophenones; D000975:Antioxidants; D008315:Malondialdehyde; D013311:Streptozocin; C056165:acetovanillone; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D019255:NADPH Oxidases; D003474:Curcumin
keywords: Apocynin; Curcumin; Diabetes; H(2)O(2); MDA; NADPH; NADPH oxidase; NOX2; NS; Neuropathy; ROS; SOD; STZ; Spinal cord; hydrogen peroxide; malondialdehyde; nicotinamide adenine dinucleotide phosphate; nicotinamide adenine dinucleotide phosphate oxidase 2; normal saline; reactive oxygen species; streptozotocin; superoxide dismutase