Potent antitumor and antineoplastic efficacy of baicalein on benzo(a)pyrene-induced experimental pulmonary tumorigenesis

Current study aims to evaluate the efficacy of baicalein (BE), a naturally occurring bioactive flavanoid (5,6,7-trihydroxy-flavone), at a dose of 12mg/kg body wt in Swiss albino mice exposed to tobacco-specific carcinogen benzo(a)pyrene [B(a)P] (50mg/kg body wt) for its ability to mitigate pulmonary adenoma formation and growth. Under coarse observation, B(a)P-administered mice, after 16weeks, developed macroscopically detectable tumors, whereas oral treatment with BE to the lung cancer-induced mice significantly reduced tumor incidence in 16-week pre- and posttreated groups. A detailed histopathological examination of lung was conducted to determine the degree of cancer progression. Incidence of anaplasia, hyperplasia, dysplasia, severe dysplasia, and adenocarcinoma were evident in carcinogen-administrated group in 6, 10, 12, 14, and 16th weeks, respectively, whereas these anomalies were effectively reduced after pre- and posttreatment with BE. In the pretreatment group, BE significantly arrested tumor multiplicity by approximately 65% and tumor load by approximately 88%, while in the posttreatment, the compound significantly reduced the tumor multiplicity by approximately 48% and tumor load by approximately 61%. Further analysis of serum tumor markers like carcinoembryonic antigen, CK 19 fragments (CYFRA 21-1), and tissue marker enzymes like aryl hydrocarbon hydroxylase, adenosine deaminase, γ-glutamyl transpeptidase, 5′-nucleotidase, and lactate dehydrogenase in serum and lung homogenate was carried out to substantiate the anticarcinogenic effect of BE. The overall data from our experiments suggested that BE significantly inhibited pulmonary adenoma formation and growth, thus revealing its potent antitumorigenic effect.