Chemopreventive and anticarcinogenic effects of Momordica charantia extract.

The aim of the study was to examine whether Momordica fruit extract (MFE) and Momordica leaves extract (MLE) might exert any chemopreventive effect in a two stage protocol in skin carcinogenesis with Swiss albino mice. The tumour incidence, tumour yield, tumour burden and cumulative no. of papillomas were found to be higher in the controls (without either extract) as compared to the MFE or MLE treated experimental groups. In a melanoma model, the mice which received fruit and leaf extracts of Momordica at the doses of 500 and 1000 mg/kg body weight for 30 days showed increase in life span of animals and tumour volume was significantly reduced as compared to control values. In cytogenetic studies, a single application of Momordica extracts at doses of 500, 1000 and 1500 mg/kg body weight, 24 hours prior the i.p. administration of cyclophosphamide, significantly prevented micronucleus formation and chromosomal aberrations in a dose dependent manner in bone marrow cells of mice. The present study demonstrate chemopreventive potential of Momordica fruit and leaf extracts on DMBA induced skin tumorigenesis, melanoma tumour and cytogenicity.

Anticarcinogenic effects of Solanum lycopersicum fruit extract on Swiss albino and C57 Bl mice.

In the present studies, the effect of Solanum lycopersicum extract on DMBA induced skin papillomas and B6 F10 melanomas was studied. Topical single application of DMBA at the dose of 4 mg/kg b.wt. followed by 1 % croton oil for 16 weeks produced a 100% incidence of skin papillomas which started appearing from the 6th week onwards. The mice which additionally received S. lycopersicum extract at 0.6 g/kg 2 day/week for 16 weeks showed a significant decrease in the number and incidence of tumors (p<0.05), with a delay in their appearance to week 10. Histopathological examination showed well and poorly differentiated squamous cell carcinomas in the group which received DMBA + Croton oil treatment whereas hyperkeratosis and hyperplasia were more prevalent in DMBA + Croton oil + Lycopersicum extract treated animals. In a second experiment the effect of cyclophosphamide alone and in combination with S. lycopersicum extract was studied in B16F10 melanoma tumour bearing mice. The inhibition rate was 25.9% in the cyclophosphamide treated group but this increased to 37.7% with S. lycopersicum. The life span of tumour bearing animals was also increased. Thus in two models, S. lycopersicum extract exerted protective potential against skin tumors.

Evaluation of anticarcinogenic and antimutagenic potential of Bauhinia variegata extract in Swiss albino mice.

BACKGROUND: Infusions from the bark of Bauhinia is used to treat various diseases in the traditional medical system of India and decoction of the roots is used in dyspepsia and act as an antidote to snake poison. Its chemopreventive potential for cancer was the subject of the present study. MATERIALS AND METHODS: To evaluate the anticarcinogenicity and antimutagenicity of Kachanar extract a skin carcinogenesis and melanoma tumour model was used, along with micronucleus and chromosomal aberration tests, in Swiss albino mice. RESULTS: In the skin papilloma model, significant prevention, with delayed appearance and reduction in the cumulative no. of papillomas was observed in the DMBA + Kachanar + croton oil treated group as compared to the DMBA + Croton Oil group. C57 Bl mice which received a 50 % methanolic extract of Kachanar extract at the doses of 500 and 1,000 mg/ kg body weight for 30 days showed increase in life span and tumour size was significantly reduced as compared to controls. In antimutagenicity studies, a single application of Kachanar extract at doses of 300, 600 and 900 mg/kg dry weight, 24 hours prior the i.p. administration of cyclophosphamide (at 50 mg/kg) significantly prevented micronucleus formation and chromosomal aberrations in bone marrow cells of mice, in a dose dependent manner. CONCLUSIONS: Our results suggest that Kachanar extract exerts anticarcinogenic and antimutagenic activity.

Tumour-promoting effect of chilli extract in BALB/c mice.

In 50% of BALB/c mice pretreated with atropine, tongue tumours were induced by fortnightly application of DMN-OAc (2 mg/kg) on the tongue. When DMN-OAc + TPA was used for the initiation-promotion protocol, tumours were observed on the tongue, the site of application, in only 10% of animals. In the same group, stomach tumours were obtained in 63% of mice, denoting that initiation-promotion could be successfully used to induce stomach tumours. Using a protocol of DMN-OAc + chilli as a promoter, we observed induction of stomach tumours. The promoter effect of chilli extract was also seen in the BHC-induced hepato-carcinogenesis system. It thus appears that, in BALB/c mice, chilli acts as a promoter in stomach and liver carcinogenesis.

Chilli extract treatment and induction of eye lesions in hamsters.

On chronic administration of 20 microliter of chilli extract to the cheek pouch of hamsters till death, 23% of the hamsters developed shrunken eye balls and closing of the eyelids. This effect was not observed in hamsters which received a single application of the potent carcinogen methylacetoxymethyl nitrosamine (DMN-OAC) (2 mg/kg body wt.) prior to repeated treatment with chilli extract. Vitamin A levels decreased significantly in the liver tissue of chilli-treated and carcinogen + chilli-treated groups compared to absolute alcohol-treated and untreated groups, while serum Vitamin A values decreased only in the DMN-OAC + chilli-treated group. However, Vitamin A levels do not seem to be linked causally with the effect on the eyes of chilli-treated hamsters, because these hamsters had circulating levels of Vitamin A comparable to those observed in untreated and alcohol-treated groups.