title: Protective effect of thymoquinone on glucose or methylglyoxal-induced glycation of superoxide dismutase.
abstract: Glycation plays an important role in various oxidative stress related diseases. Superoxide dismutase (SOD) constitutes an essential defense against oxidative stress. The damage caused by oxidative stress is exacerbated if the antioxidant enzymes themselves are inactivated by glycation. Thymoquinone (TQ) has been reported to have various pharmacological activities. Therefore, the glycation of SOD by glucose or methylglyoxal (MG) and its protection by TQ has been investigated. Incubation of SOD with glucose, MG or both at 37 °C resulted in a progressive decrease in the activity of the enzyme, and a parallel decrease in the amount of protein on SDS-PAGE gels for glucose incubated SOD and formation of high molecular weight aggregates for MG or both glucose and MG incubated enzyme. TQ offered protection against glucose or MG induced loss in SOD activity and fragmentation/cross-linking. The antiglycating activity of TQ appears to be better for mild glycating agents. It is also effective in protecting against strong glycating agents, more when the exposure time to the glycating agent is short. TQ has also earlier been reported to have anti-diabetic effects, and this along with the observed antiglycating effect makes it an effective compound against diabetes and its complications.
authors.affiliation: College of Pharmacy, Qassim University, Buraidah, Saudi Arabia; College of Applied Medical Sciences, Buraidah, Saudi Arabia.
authors.forename: Masood A
authors.initials: MA
authors.lastname: Khan
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Shehwaz
authors.initials: S
authors.lastname: Anwar
authors.affiliation: College of Pharmacy, Qassim University, Buraidah, Saudi Arabia; College of Pharmacy, Al-Ghat College of Health Sciences, Buraidah, Saudi Arabia.
authors.forename: Ahmad N
authors.initials: AN
authors.lastname: Aljarbou
authors.affiliation: College of Medicine, Qassim University, Buraidah, Saudi Arabia.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Al-Orainy
authors.affiliation: College of Applied Medical Sciences, Buraidah, Saudi Arabia.
authors.forename: Yosef H
authors.initials: YH
authors.lastname: Aldebasi
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
authors.forename: Sehbanul
authors.initials: S
authors.lastname: Islam
authors.affiliation: Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India. Electronic address: hinayounus@rediffmail.com.
authors.forename: Hina
authors.initials: H
authors.lastname: Younus
mesh_terms: D000818:Animals; D016227:Benzoquinones / Q000494:pharmacology*; D002417:Cattle; D004347:Drug Interactions; D005947:Glucose / Q000494:pharmacology*; D006031:Glycosylation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D011765:Pyruvaldehyde / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D016227:Benzoquinones; D011765:Pyruvaldehyde; D013482:Superoxide Dismutase; D005947:Glucose; C003466:thymoquinone
keywords: Glycation; Superoxide dismutase; Thymoquinone