Amelioration of acetic acid-induced colitis in rats by nano zinc oxide.

Amany A. E. Ahmed*, Hala A. Attia, Nouf M. Al-Rasheed, Nawal M. Al-Rasheed.

Department of Pharmacology, Faculty of Pharmacy, King Saud University, Riyadh, Saudi Arabia.

E-mail:  ampharmacol2008@yahoo.com

ABSTRACT

Zinc is an essential trace element which is strongly implicated in cell turnover and repair systems. The decrease in zinc content was observed in the mucosa of patients affected by ulcerative colitis. This condition is associated with the increase in reactive oxygen intermediates and inflammation. Nano molecules are characterized by the small particle size which may offer greater penetration into the target cells and consequently higher bioavailability.

In this study we investigate the effect of administration nano zinc oxide (5 mg/kg body weight) to rats suffering from acetic acid-induced colitis. 24 hours after drugs administration the rats were sacrificed and the lesions in distal colon were scored. Colon mucosal malondialdehyde (MDA), catalase,  reduced glutathione, myeloperoxidase,  total protein, TNF-?, DNA fragmentation as well as barrier mucus contents were estimated in control (saline treated), nano zinc oxide treated, and sulfasalazine (the reference anti-colitis drug) treated rats. The results indicated that, treatment with nano zinc oxide reduces the colon lesion scores of colitis and significantly increases the adherent mucus contents. Meanwhile, the elevated levels of colon MDA, DNA fragmentation, TNF-?, myeloperoxidase induced by acetic acid are significantly reduced upon nano zinc oxide treatment. Moreover, the reduction in glutathione and catalase activities induced by acetic acid is completely reversed in nano zinc oxide treated rats. The results were comparable with the reference drug sulfasalazine with better anti-inflammatory and antioxidant effects.

Conclusion, nano zinc oxide seemed to be beneficial in protecting the colon from acetic acid induced colitis model in rats. This may occur through inhibition of the mucosal inflammatory responses associated with colitis and preservation of the antioxidant defensive status and preservation of the integrity of the colon mucosa.

Key words: nano-zinc oxide, colitis, antioxidant enzymes, mucus contents, myeloperoxidase, DNA fragmentation, TNF-?.

Corresponding author contact: Department of pharmacology, Faculty of Pharmacy, King Saud University, Riyadh, 11495. P.O. Box 22452 Saudi Arabia.

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