The use of some plant oils for inhibiting the carcinogenic effect of some chemical carcinogens using BALB/c mice as biological test animals

Abstract

In the present work, it was aimed to investigate the possible preventive & therapeutic effects of two kinds of oils designated C.D.(chemically extracted oil) & N.D. (naturally extracted oil) extracted from the seeds of the Egyptian plant Nige!la sativa L. (the Black Seed), and applied during the promotion phase of DMBNcroton oil two-stage skin carcinogenesis ,as it was done in the prevention experiments which included skin painting as well as feeding experiments, or applied after the termination of promotion, as it was done in the chemotherapy experiments. The ;•esults of the present work are summarized as follows: regarding skin painting experiments, DMBNcroton oil produced skin papillomas and carcinomas in mice.The first tumor appeared 5 weeks after the start of the experiments. The tumors which appeared in mice were permanent and persisted until the end of the experiments. The topical application of C.D. and N.D. highly prevented the appearance of skin tumors in experimental animals. This can be deduced from the complete absence of skin tumors in group 3 (painted with N.D.) and the significant decrease in number of mice bearing tumors, number of tumors per mouse(tumor yield), multiplicity, and the significant increase of latency in group 2 (painted with C.O.) (Table 1). When these oil extracts (both C.O. and N.O.) were suppplemented in diets they did not exert a remarkable prevenrive effect against skin tumorigenesis: Actually,the result of these experiments show that there was a slight decrease in the number of mice bearing tumors, and a slight increase in latency in groups 2 and 3 which were fed on C.O: and N.O., respectively(Table 2). These results indicate that both oils may have a slight inhibitory effects on skin tumorigenesis. [n the chemotherapy experiments, hoth C.O.and N.O. were topically applied to the well-developed tumors (Experiment #1) and the newly-developed skin tumors (Experiment #2).The results of these experriments indicate that both oils -)•.. have a slight therapeutic effect. [n Experiment #1, N.O. caused regression and complete disappearance to two papillomas(Table3,Fig.27-30), whereas, in Experiment #2, C.O. prevented the appearance of any new papillomas throughout the period of application (Table 4).