Detail of "84-60-6"

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Inhibition of epidermal xenobiotic metabolism in SENCAR mice by naturally occurring plant phenols

Inhibition of epidermal xenobiotic metabolism in SENCAR mice by naturally occurring plant phenols.Some chemicals with cas registry numbers like 50-32-8 and 61443-57-0 are also used. Das, Mukul; Mukhtar, Hasan; Bik, Daniel P.; Bickers, David R. (Univ. Hosp. Cleveland, Case West. Reserve Univ., Cleveland, OH 44106, USA). Cancer Res., 47(3), 760-6 (English) 1987. CODEN: CNREA8. ISSN: 0008-5472. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Section cross-reference(s): 1 In vitro addn. of tannic acid, quercetin [117-39-5], myricetin [529-44-2], and anthraflavic acid [84-60-6] to mouse epidermal microsomal prepns. inhibited aryl hydrocarbon hydroxylase (AHH) [9037-52-9] activity in a concn.-dependent manner. The 50% inhibitory concns. for tannic acid, myricetin, quercetin, and anthraflavic acid ranged from 4.4 ′ 10-5M to 12.4 ′ 10-5M in microsomes prepd. from control and 3-methylcholanthrene-pretreated animals. Of the plant phenols studied tannic acid was the most potent inhibitor of epidermal AHH activity. Tannic acid, quercetin, myricetin, and anthraflavic acid exhibited a mixed type of inhibitory effect with Ki values of 81, 63, 135, and 165 mM, resp. In vitro addn. of these plant phenols (240 mM) to the incubation mixt. prepd. from control and 3-methylcholanthrene-treated animals resulted in varying degrees of inhibition of epidermal microsomal AHH (57-92%), ethoxycoumarin O-deethylase [42613-26-3] (19-58%), and ethoxyresorufin O-deethylase [59793-97-4] (33-85%) activities. HPLC anal. of the org. solvent-sol. metabolites of benzo[a]pyrene (BP) [50-32-8] produced by epidermal microsomes indicated a substantial decrease in the formation of BP-diols (23-67%) and BP-phenols (29-57%) by each of the plant phenols. The formation of BP-7,8-diol (I) [61443-57-0] was substantially inhibited (29-52%) by each of the plant phenols. Further in vivo studies showed that a single topical application of tannic acid, quercetin, and myricetin greatly diminished epidermal AHH (53-65%), ethoxycoumarin O-deethylase (30-68%), and ethoxyresorufin O-deethylase (66-97%) activities whereas anthraflavic acid was ineffective in this regard even when repeatedly applied. Thus plant phenols have substantial though variable inhibitory effects on epidermal monooxygenase activities and BP metab. suggesting that these compds. may be capable of inhibiting the carcinogenic effects of polycyclic arom. hydrocarbons in the skin. .

Inhibition of polycyclic aromatic hydrocarbon-DNA adduct formation in epidermis and lungs of SENCAR mice by naturally occurring plant phenols

Inhibition of polycyclic aromatic hydrocarbon-DNA adduct formation in epidermis and lungs of SENCAR mice by naturally occurring plant phenols. Das, Mukul; Khan, Wasiuddin A.; Asokan, Parthasarathy; Bickers, David R.; Mukhtar, Hasan (Univ. Hosp. Cleveland, Case West. 117-39-5 and 529-44-2 are also occured in this study. Reserve Univ., Cleveland, OH 44106, USA). Cancer Res., 47(3), 767-73 (English) 1987. CODEN: CNREA8. ISSN: 0008-5472. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 4 Naturally occurring plant phenols such as tannic acid, quercetin [117-39-5], myricetin [529-44-2] and anthraflavic acid [84-60-6] are known to inhibit the mutagenicity of several bay-region diol-epoxides of polycyclic arom. hydrocarbons (PAHs). The binding of bay-region diol epoxides of PAHs to target tissue DNA is thought to be essential for the initiation of cancer by these compds. Thus, the effect of these plant phenols on PAH-DNA adduct formation in the epidermis and lung of SENCAR mice was studied. In vitro addn. of tannic acid, quercetin, myricetin, and anthraflavic acid (25 mM) to an incubation system contg. epidermal microsomes prepd. from either control or 3-methylcholanthrene-pretreated mice inhibited benzo[a]pyrene binding to calf thymus DNA by 63-64, 38-43, 36-37. and 27-33%, resp. A single topical application of tannic acid, quercetin, myricetin, and anthraflavic acid at a dose of 400 mmol/kg body wt. resulted in the inhibition of [3H]benzo(a)pyrene binding to epidermal DNA (48-73%) and protein (51-63%). The same dose of these plant phenols (400 mmol/kg) caused even greater inhibition of (±)-7b,8a-dihydroxy-7,8-dihydrobenzo(a)pyrene and 7,12-dimethylbenz(a)anthracene binding to epidermal DNA and protein. The formation of (+)-7b,8a-dihydroxy-9a,10a-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene- deoxyguanosine adduct [66141-82-0] was substantially diminished in both epidermis (62-86%) and lungs (38-84%). Thus, tannic acid, quercetin, myricetin, ad anthraflavic acid are potent inhibitors of carcinogen binding to epidermal and lung DNA, and these plant phenols could prove useful in modifying the risk of tumor induction by PAHs such as benzo(a)pyrene and 7,12-dimethylbenz(a)anthracene in these 2 tissues. .