• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3335-3340
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• 2016

Background: Oral submucous fibrosis (OSF) is a precancerous condition with a 4 to13% malignant transformation rate. Related to the habit of areca nut chewing it is mainly prevalent in South-east Asian countries where the habit of betel quid chewing is frequently practised. On chewing, alkaloids and polyphenols are released which undergo nitrosation and give rise to N-nitrosamines which are cytotoxic agents. CYP450 is a microsomal enzyme group which metabolizes various endogenous and exogenous chemicals including those released by areca nut chewing. CYP1A1 plays a central role in metabolic activation of these xenobiotics, whereas CYP2E1 metabolizes nitrosamines and tannins. Polymorphisms in genes that code for these enzymes may alter their expression or function and may therefore affect an individuals susceptibility regarding OSF and oral cancer. The present study was therefore undertaken to investigate the association of polymorphisms in CYP1A1 m2 and CYP2E1 (RsaI/PstI) sites with risk of OSF among areca nut chewers in the Northern India population. A total of 95 histopathologically confirmed cases of OSF with history of areca nut chewing not less than 1 year and 80, age and sex matched controls without any clinical signs and symptoms of OSF with areca nut chewing habit not less than 1 year were enrolled. DNA was extracted from peripheral blood samples and polymorphisms were analyzed by PCR-RFLP method. Gene polymorphism of CYP1A1 at NcoI site was observed to be significantly higher (p = 0.016) in cases of OSF when compared to controls. Association of CYP1A1 gene polymorphism at NcoI site and the risk of OSF (Odd's Ratio = 2.275) was also observed to be significant. However, no such association was observed for the CYP2E1 gene polymorphism (Odd's Ratio = 0.815). Our results suggest that the CYP1A1 gene polymorphism at the NcoI site confers an increased risk for OSF.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.232-239
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• 1996

Phenolic compounds are known to inhibit the nitrosation or oxidation reaction. In the present work, the effects of phenolic compounds including phenolic acids and flavonoids on the nitrite-scavenging and electron donating ability were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds and investigated as electron donator. The nitrite scavenging ability appeared in all the phenolic acids and showed the highest value at PH 1.2. Among the Phenolic compounds, phenolic acids showed higher nitrite-scavenging action than some flavonoids. Futhermore, the nitrite scavenging action of phenolic compounds was pH dependent highest at pH 1.2 and lowest at pH 6.0. The electron donating ability (EDA) by reduction of ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) among hydroxybenzoic acids was in the decreasing order of gallic acid, gentisic acid, syringic acid, protocatechuic acid, salicylic acid, vanillic acid, benzoic acid and p-hydroxybenzoic acid. EDA of hydroxycinnamic acids was in the decreasing order of hydrocaffeic acid, caffeic acid, ferulic acid, p-coumaric acid and trans-cinnamic acid. EDA of flavonoids was in the decreasing order of (+)catechin, rutin, quercetin, naringin and hesperidin. Other phenolic compounds were significantly high in electron donating abilities.