Dietary nicotinic acid supplementation improves hepatic zinc uptake and offers hepatoprotection against oxidative damage.
We examined the effect of dietary nicotinic acid (NA) variations before and after oxidative stress (OS) treatment on the antioxidant defence system, function and morphology of the liver along with Zn status in rats. OS was generated by three intraperitoneal injections of tert-butyl hydroperoxide in the first week for the pre-exposure group and in the third week for the post-exposure group, respectively. These groups were further divided into subgroups and fed on a diet with marginally deficient Zn (10 mg Zn/kg diet) and NA variations as NA deficient, normal and excess with 10, 30 and 1000 mg NA/kg diet, respectively. Aspartate aminotransferase and alanine aminotransferase levels were elevated in rats with OS coupled with the Zn- and NA-deficient diet, which decreased towards normal with excess dietary NA. Excess NA supplementation in the OS pre-exposure group resulted in nearly preserved hepatic architecture with normal hepatocytes, whereas maximum tissue destruction was evident in the post-exposure group with NA deficiency. Dose-dependent improvement in the antioxidant defence system, enhanced reduced glutathione levels, lowered lipid peroxidation and higher hepatic Zn levels were observed with NA supplementation. The effect was more prominent in the pre-exposure group. In conclusion, dietary NA supplementation improves hepatic Zn uptake and results in hepatoprotection against OS-induced damage in rats.
Agharkar Research Institute, G. G. Agarkar Road, Pune 411 004, India.
Rashmi S
RS
Tupe
Agharkar Research Institute, G. G. Agarkar Road, Pune 411 004, India.
Santosh G
SG
Tupe
Agharkar Research Institute, G. G. Agarkar Road, Pune 411 004, India.
Vaishali V
VV
Agte
D000410:Alanine Transaminase / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001219:Aspartate Aminotransferases / Q000097:blood; D019587:Dietary Supplements; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D009525:Niacin / Q000172:deficiency / Q000494:pharmacology*; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D014803:Vitamin B Complex / Q000494:pharmacology*; D015032:Zinc / Q000172:deficiency / Q000493:pharmacokinetics*
D000975:Antioxidants; D014803:Vitamin B Complex; D009525:Niacin; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D005978:Glutathione; D015032:Zinc