L-arginine augments the antioxidant effect of garlic against acetic acid-induced ulcerative colitis in rats.
Garlic contains many sulfhydryl compounds that act as antioxidants. However, the role of nitric oxide (NO) in inflammation is controversial. The aim of the present study is to investigate the possible protective effect of garlic against acetic acid-induced ulcerative colitis in rats, as well as the probable modulatory effect of L-arginine (NO precursor) on garlic activity. Intra-rectal inoculation of rats with 4% acetic acid for 3 consecutive days caused a significant increase in the colon weight and marked decrease in the colon length. In addition, acetic acid induced a significant increase in serum levels of nitrate as well as colonic tissue content of malondialdehyde (MDA). Moreover, colonic tissue contents of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were markedly reduced. On the other hand, pre-treatment of rats with garlic (0.25 g/kgbwt, orally) for 4 consecutive weeks and 3 days during induction of colitis significantly reduced the increase in the colon weight induced by acetic acid and ameliorated alterations in oxidant and antioxidant parameters. Interestingly, oral co-administration of garlic (0.25 g/kgbwt) and L-arginine (625 mg/kgbwt) for the same period of garlic administration mitigated the changes in both colon weight and length induced by acetic acid and increased garlic effect on colon tissue contents of MDA and GSH. In conclusion, L-arginine can augment the protective effect of garlic against ulcerative colitis; an effect that might be mainly attributed to its NO donating property resulting in enhancement of garlic antioxidant effect. Further studies will be needed to determine which one of the active ingredients of garlic has the main antioxidant effect to be used with L-arginine.
Biochemistry Department, Faculty of Pharmacy (boys), Al-Azhar University, Nasr City, Cairo, Egypt.
Gamal Eldin I
GE
Harisa
Osama M
OM
Abo-Salem
El-Sayed M
el-SM
El-Sayed
Ehab I
EI
Taha
Nermin
N
El-Halawany
D019342:Acetic Acid; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001120:Arginine / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D002626:Chemistry, Pharmaceutical; D003093:Colitis, Ulcerative / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D003106:Colon / Q000187:drug effects / Q000473:pathology; D004357:Drug Synergism; D005737:Garlic / Q000737:chemistry*; D005978:Glutathione / Q000378:metabolism; D008297:Male; D009573:Nitrites / Q000097:blood; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D009573:Nitrites; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; D001120:Arginine; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D019342:Acetic Acid