Anticarcinogenic activity of meso-zeaxanthin in rodents and its possible mechanism of action.

Anticarcinogenic activity of meso-zeaxanthin (MZ), a xanthophyll carotenoid with profound antioxidant activity, was evaluated against 3-methylcholanthrene (3-MC)-induced sarcoma in mice. Oral administration of MZ at different doses significantly increased tumor latency period. In 3-MC control group, animals started developing sarcoma on 6th week.

Effect of carotenoid lutein on N-nitrosodiethylamine-induced hepatocellular carcinoma and its mechanism of action.

Oxycarotenoid lutein (3,3'-dihydroxy-β,ε-carotene) was checked for anticarcinogenic activity against N-nitrosodiethylamine-induced hepatocellular carcinoma (HCC) in rats. Lutein could significantly reduce the altered morphological and pathological changes in the liver induced by N-nitrosodiethylamine. Biochemical analysis of serum and tissues indicated that alanine transaminase, aspartate transaminase, and alkaline phosphatase were significantly elevated in the control group and significantly reduced in the lutein-treated groups.

Amelioration of radiation-induced damages in mice by carotenoid meso-zeaxanthin.

Purpose: The present study was undertaken to evaluate the radioprotective effect of meso-zeaxanthin, a xanthophyll carotenoid with profound antioxidant activity.

Materials And Methods: Swiss albino mice were treated with different doses of meso-zeaxanthin (50 and 250 mg/kg body weight, orally) five days before irradiation and sacrificed at different time points. The protective effects of meso-zeaxanthin on mortality, haematological parameters, bone marrow cellularity and gastrointestinal system of irradiated mice were studied.

Antimutagenic activity of Lutein--an oxycarotenoid present in the macula and its inhibition of cytochrome P 450 enzymes in vitro.

Carotenoid lutein was investigated for its antimutagenic activity in vitro by Ames test using Salmonella typhimurium strains TA 98, TA 100, TA 102 and TA 1535. Mutagens used were direct acting mutagens such as sodiumazide (NaN3) (5μg/ plate), nitro-o- phenylendiamine (NPDA) (20μg/ plate), N-methyl- N'-nitro-N-nitrosoguanidine(MNNG) (1μg/ plate), tobacco extract (50mg/ plate) and acetamidofluorene (AAF) (20μg/ plate) which needed microsomal activation. Lutein significantly inhibited the mutagenicity produced by direct acting mutagens as well as mutagens needing activation by cytochrome P450 enzymes at very low concentration (IC50 < 50 μg/plate).

Anti-mutagenic and anti-carcinogenic potential of the carotenoid meso-zeaxanthin.

Meso-zeaxanthin was investigated for antimutagenic and anticarcinogenic activity, using the Ames test (Salmonella typhimurium strains TA 98, TA 100, TA 102 and TA 1535) with direct acting mutagens like sodium azide (NaN3) (5 μg/ plate), nitro-o-phenylendiamin (NPD) (20 μg/ plate), N-methyl- N'-nitro-N-nitrosoguanidine (MNNG) (1μg/ plate) and tobacco extract 50 mg/ plate) and with a mutagen needing microsomal activation, acetamidofluorene (AAF) ( 20 μg/ plate). The carotenoid was found to inhibit the mutagenicity induced by NaN3, NPD and MNNG in a concentration dependent manner, as well as that with AAF and the tobacco extract. Concentrations needed for 50 % inhibiton was found to be 50 μg/ plate for the chemical mutagens and 100 μg/ plate for tobacco extract.