Free Radical Mediated Oxidative Degradation of Carotenes and Xanthophylls.

This article reviews the excited-state quenching, pro-vitamin A activity and anticarcinogenicity of carotenes and xanthophylls in relation to their chemical structures. Excited-state quenching improved with the length of the conjugated chain structure. Pro-vitamin A activity was dependent on the presence of at least one beta-ionyl ring structure. The effectiveness of carotenoids as antioxidants depended on their ability to trap peroxyl radicals with production of resonance-stabilized carotenyl radicals. The products identified from oxidations of carotenes and xanthophylls with molecular oxygen and other oxidizing agents are presented. The free radical-mediated mechanisms that have been proposed to account for the different classes of products are reviewed.

Factors influencing maternal mortality among rural communities in southwestern Nigeria.

BACKGROUND: Maternal mortality and morbidity reflect the status of population health and quality of life across nations. Poor understanding of the interplay of many antecedent factors, including sociocultural, economic and logistic factors, combined with an overwhelming poor health services delivery, is a basic challenge in several countries, particularly in rural settings where functional health care services are relatively scarce. There are still uncertainties as to the extent of this burden, owing to current challenges with information and data collation. This study aimed at identifying nonmedical factors associated with maternal mortality in rural and semiurban communities of southwestern Nigeria. METHODOLOGY: The study was carried out in Ado-Odo/Ota Local Government Area of Ogun State. A multistage sampling technique and an informant survey approach were used in the study. A total sample of 360 eligible respondents were selected randomly from 11 out of 16 political wards in the study area and interviewed through the administration of questionnaires. The data were processed using descriptive statistics and regression analyses. RESULTS: Place of consultation (P=0.000), who pays the treatment costs (P=0.000), awareness of pregnancy complications (P=0.002) and knowledge of the place of antenatal care treatment (P=0.000) significantly influenced maternal mortality (proxy by place of delivery of last birth). The F-statistic (15.100) confirmed the hypothesis that nonmedical factors influence maternal mortality. The correlation of predictor variables was significant at both the 0.01 level and the 0.05 level (2-tailed). CONCLUSION: Our findings suggest that in a rural community setting with a depleted health care system, health education tailored toward community culture, subsidized maternal health care services by the government and operators of private clinics, as well as empowering and improving the status of women may reduce maternal mortality and prompt better utilization and survival chances of women in the study area as well as in all of Nigeria.

Identification of products from canthaxanthin oxidation.

Canthaxanthin is a carotenoid that lacks pro-vitamin A activity but is known to have antioxidant activity. The products of its oxidation in oxygen were found to be mainly substituted apo-carotenals and apo-carotenones. The product profile resembles that obtained in the oxidation of ß-carotene, except that with canthaxanthin these products are the 4-oxo-ß-apo-carotenals and 4-oxo-ß-apo-carotenones. Epoxides and diepoxides were clearly identified from ß-carotene oxidation but in contrast, with canthaxanthin, apart from 5,6-epoxy-canthaxanthin, which was detected at the early stage of oxidation and minor quantities of 5,6-epoxy-ß-ionone and 5,6-epoxy-4-oxo-ß-apo-11-carotenal, no other epoxides were detected. The identities of these products lead us to suggest that the mechanism of canthaxanthin oxidation bears significant similarity to that of ß-carotene.