Effect of chitobiose and chitotriose on carbon tetrachloride-induced acute hepatotoxicity in rats.

The purpose of the present study was to examine whether chitobiose and chitotriose can protect rats from CCl4-induced hepatic toxicity when given orally. We studied the effects of the 2 chitooligosaccharides given orally to rats on the acute hepatotoxicity induced by CCl4-dependent lipid peroxidation. The increase in the sum of malondialdehyde and 4-hydroxy-2-alkenals, a marker of lipid peroxidation, in both plasma and liver of CCl4-treated rats was suppressed by oral administration of chitobiose or chitotriose.

Pharmacokinetics of chitobiose and chitotriose administered intravenously or orally to rats.

Chitooligosaccharides have attracted much attention as new biomedical materials. The biologic availability of each of these chitooligosaccharides, however, has not yet been studied. In the present study, we found that chitobiose and chitotriose appeared in the blood of rats with maximum plasma concentrations at around 1 h after administration when given orally at a dose of 30 mg/kg.

Antioxidant activity of a Schiff base of pyridoxal and aminoguanidine.

We recently reported that PL-AG, a Schiff base of pyridoxal and aminoguanidine, was more effective than aminoguanidine (AG), a well-known anti-diabetic-complication compound, in preventing nephropathy in diabetic mice and presented brief data indicating the antioxidant activity of the adduct. In the present study, we additionally investigated the inhibitory activity of PL-AG in comparison with that of AG against in vitro and in vivo oxidation. PL-AG was more potent than AG and reference compounds such as pyridoxal and pyridoxamine in any of the five antioxidant activities examined in vitro, i.

Antioxidant activities of chitobiose and chitotriose.

Chitooligosaccharides, the oligomers made up of beta-1,4-linked D-glucosamine, are obtained by partial hydrolysis of chitosan, a deacetylation product of chitin. The antioxidant activity of various chitooligosaccharides was tested in vitro with aminoguanidine, pyridoxamine, and Trolox as reference compounds. Hydroxylation of benzoate to salicylate by H2O2 in the presence of Cu(2+) was effectively inhibited by chitobiose, chitotriose, aminoguanidine, pyridoxamine, and Trolox (their IC(50) values=18, 80, 85, 10, and 95 microM, respectively), whereas glucosamine and N-acetylchito-oligosaccharides (di-N-acetylchitobiose and tri-N-acetylchitotriose) did not show any inhibitory activity.