Colored fruits, particularly berries, are emerging as highly chemoprotective because of their antioxidant, anti-proliferative and anti-inflammatory activities. In this study, we investigated chemoprotective potential of Eugenia jambolana Lam., commonly known as ‘jamun’ or Indian blackberry. Jamun is widely used as a fruit in India and several other Asian countries, besides its use in the treatment of various ailments, including diabetes mellitus. Anthocyanin pigments in the jamun were extracted with acidic ethanol, and the crude anthocyanin extract was purified by ethyl acetate partitioning, amberlite XAD7/HP20 column chromatography, followed by Sephadex LH-20 column Chromatography. Anthocyanin content in jamun pulp powder was found to be 0.08% by HPLC-PDA (at 520nm). Upon hydrolysis, the jamun extract yielded five anthocyanidins, namely delphinidin (20.3%), cyanidin (6.6%), petunidin (24.6%), peonidin (2.8%) and malvidin (44.2%) as detected by HPLC and confirmed by mass spectral analysis. The jamun extract had high antioxidant potential as reflected by ABTS scavenging (IC50, 12 µg/ml), DPPH scavenging (IC50, 110 µg/ml), and ferrous ions-chelating activities (IC50, 50 µg/ml). In vivo chemopreventive effect of jamun was investigated using the estrogen-mediated ACI rat mammary tumorigenesis model. Groups of female rats were given control (AIN 93M) diet or diet supplemented with jamun pulp powder (5%, w/w). Two weeks later, one half of the animals from each group were treated with subcutaneous silastic implants of 17β-estradiol (1.2 cm; 9 mg). Diet and water were provided ad libitum. Twelve weeks later immediately before the appearance of mammary tumors, all groups were euthanized and blood and mammary tissue were collected. No significant difference was observed in body weight gain and diet intake when compared with control, suggesting that jamun diet was well tolerated. Estrogen treatment resulted in substantial (30-fold) elevation of the plasma prolactin, a key factor in mammary tumorigenesis. The plasma prolactin levels were significantly offset by jamun-supplemented diet. To determine molecular mechanisms of its chemopreventive effects, mammary tissues were analyzed for the expression of cyclin D1 and estrogen receptor alpha (ERα). Western blot analysis showed that jamun diet significantly down-regulated the levels of both cyclin D1 and ERα. Together, these data suggest that jamun contains compounds with high antioxidant and antiproliferative activities, suggesting that consumption of jamun fruit may be useful in the prevention/treatment of breast cancer (Supported from CA-125152 and Agnes Brown Duggan Endowment).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5688.