Quercetin and rutin as inhibitors of azoxymethanol-induced colonic neoplasia

Abstract

Dietary quercetin (QU) and rutin (RU), phenolic flavonoids commonly found in many fruits and vegetables, were provided to CF1 female mice for 50 weeks to assess the ability of these compounds to inhibit azoxymethanol (AOM)-induced colonic neoplasia. In addition to a control group fed an AIN 76A diet, five other groups received that diet to which was added either 0.1, 0.5 or 2.0% QU and 1.0 or 4.0% RU. Acute studies revealed that, among saline controls, no alteration of any proliferative parameters of colonic epithelial cells was observed among those groups receiving any dose of QU or RU. However, among the AOM-treated mice, both 2% QU and 4% RU significantly reduced hyperproliferation and inhibited the shift of S-phase cells to the middle and upper portion of crypts. Moreover, mice fed these concentrations of QU and RU had significantly fewer AOM-induced focal areas of dysplasia (FADs) than those fed the control diet (0.2 +/- 0.4 and 0.4 +/- 0.5 versus 3.6 +/- 2.3 respectively). Tumors occurred more frequently in the distal half of the colon, regardless of treatment. Compared with controls, mice fed 2% QU had a significantly reduced tumor incidence (25.0% versus 5.9%, P = 0.03). Those fed 4% RU showed only a trend toward inhibition (25% versus 9.7%, P = 0.11). Nevertheless, both 2% QU and 4% RU suppressed tumor multiplicity, i.e. fewer tumors/animal arose in these groups than in the AOM-treated control mice (1.2 versus 2.3, P = 0.005; 1.1 versus 2.3, P = 0.003 respectively). Clearly, QU and RU exhibit significant activity in reducing AOM-induced hyperproliferation of colonic epithelial cells and FAD incidence. This behavior successfully forecast the ability of both flavonoids to suppress tumor multiplicity and ultimately tumor development.

Platycodin D induces mitotic arrest in vitro, leading to endoreduplication, inhibition of proliferation and apoptosis in leukemia cells

“…Recently, several flavonoids, such as quercetin and genistein, and isothiocyanates have inhibited tumor growth and induced apoptosis in cancer cells by interrupting cell cycle progression in the G 2 /M phase. [33][34][35][36][37] It is also known that the Cdc2/ cyclin B1 kinase complex is a known regulator of the G 2 /M transition. 38,39 The Cdc2 activity is significantly reduced and decreases the interaction with cyclin B1 for the exit from mitosis.…”

Oxidative Stress and Skin Cancer: An Overview

“…Quercetin has anti-inflammatory and antioxidant effects and act as a immunomodulator [58]. A diet rich in quercetin has been reported to inhibit the development of carcinogeninduced rat mammary cancer [59], colonic neoplasia [60], oral carcinogenesis [61], and skin tumor formation in three models of skin carcinogenesis in mice when administered by topical application [62]. Quercetin may account for the beneficial effects of dietary fruits and vegetables on mutagens and carcinogens, including metals [63].…”

A sensitive microextraction by packed sorbent-based methodology combined with ultra-high pressure liquid chromatography as a powerful technique for analysis of biologically active flavonols in wines

“…Their results showed that flavonols exhibit distinctive antioxidant and anti-inflammatory potentials and that the structures, required to strengthen these activities, vary with sorts of free radicals and mechanisms. Quercetin blocked the aggregation of human platelets by ADP and thrombin, and this compound has gained considerable prominence as an inhibitor of carcinogens and of cancer cell growth in many experimental and human tumors [27,28].…”