Abstract
The modifying effects of naturally occurring plant products such as neem leaf and turmeric extracts on 4-nitroquinoline-1-oxide (4NQO)-induced oral carcinoma were investigated in male Wistar strain rats. All the animals painted with 4NQO on their cheek mucosa for 20 weeks developed oral neoplasms identified histologically as squamous cell carcinoma. The oral tumor tissue showed a decrease in lipid peroxidation with concomitant changes in antioxidant activity. In groups of animals painted with 4NQO and simultaneous oral administration of neem leaf and turmeric extract, respectively, no tumors were observed; and the lipid peroxidation and antioxidant levels showed a pattern similar to that of untreated controls. Thus, the anticarcinogenic effect of neem leaf and turmeric extract appears to be related to their antioxidant function. We envisage that measurement of lipid peroxidation and antioxidant status with histological changes could be used to biomonitor tumor progression and evaluate the therapeutic response.
