Stimulatory and inhibitory effects of dimethyl sulfoxide on microsomal aniline hydroxylase activity

Biotransformation enzymes inCunninghamella blakesleeana (NCIM-687)

Presence of higher enzyme levels of aminopyrine N-demethylase, aniline hydroxylase and 11-beta hydroxylase activities were observed in Cunninghamella blakesleeana grown in potato-dextrose medium for 96 h. The enzyme activity preferred NADPH as a cofactor and showed inhibition with CO, indicating cytochrome P450 mediated reactions. A significant increase in aniline hydroxylase enzyme activity was observed when mycelia incubated in incubation medium containing different inducers (viz. camphor, cholesterol, naphthalene, veratrole, phenobarbital, n -hexadecane and ethyl alcohol) when compared with mycelia incubated in same way but in absence of inducers. Cunninghamella blakesleeana (NCIM 687) have shown the ability to degrade cholesterol, camphor and naphthalene when 96 h grown mycelia incubated in incubation medium containing these organic compounds.

Effects of aflatoxin B1 on liver microsomal enzymes in different strains of chickens

Administration of Aflatoxin B1 (AFB1) with safflower seed oil to hubbard chickens caused a significant increase in liver microsomal protein, electron transport components, and drug metabolizing enzymes. No alteration was observed in the activity of alanine and aspartate aminotransferases. AFB1 treatment with dimethylsulfoxide (DMSO) as a vehicle caused a significant decrease in electron transport components, drug metabolizing enzymes, and a significant increase in the activity of aspartate aminotransferase. Higher inhibition was observed at 1.5 mg/kg dose level of AFB1. Inhibition by AFB1 was maximal after 24 hr of treatment and decreased thereafter. AFB1 treatment with DMSO caused no significant change in electron transport components and drug metabolizing enzymes in Rhode Red Island (RRI) strain. Vancob male chickens showed significant decrease in electron transport components and drug metabolizing enzymes, while a significant increase was observed in vancob females. Results suggest that the effects of AFB1 depend on treatment vehicle, strain and sex of chickens.