m-Tolualdehyde

m-Tolualdehyde (3-Methylbenzaldehyde) is an aldehyde metabolite produced by m-xylene metabolism, and it bidirectionally regulates the CYP 2B1, CYP 2E1, and CYP 4B1 isoenzymes in the respiratory tract of rats. m-Tolualdehyde serves as an oxidation substrate and carbon source for Pseudomonas Pxy, and it can be oxidized to m-toluic acid in an NAD⁺ -dependent manner. m-Tolualdehyde exerts a dose-dependent inhibitory effect on CYP 2B1 and CYP 2E1 in the nasal mucosa and lungs of rats, and a dose-dependent activating effect on pulmonary CYP 4B1. m-Tolualdehyde can form aldehyde-heme adducts with the heme group of cytochrome P450. m-Tolualdehyde can be used in studies related to metabolic enzymes in the respiratory tract of rats^[1][2]. In Vitro:m-Tolualdehyde is oxidized to m-toluic acid in an NAD⁺-dependent manner under the catalysis of crude cell extracts of Pseudomonas Pxy cultured with m-xylene or p-xylene^[1].
m-Tolualdehyde can serve as the sole carbon and energy source to support the growth of Pseudomonas Pxy^[1]. In Vivo:m-Tolualdehyde (m-ALD) (50-100 ppm; inhalation; single exposure; 6 hours) causes dose-dependent inhibition of CYP 2B1 and CYP 2E1 in rat lung (at 100 ppm) and nasal mucosa (at 50 and 100 ppm), dose-dependent induction of pulmonary CYP 4B1, and no effect on hepatic CYP 2B1 or CYP 2E1, with the highest tissue m-tolualdehyde levels measured in nasal mucosa and lung^[2].