Protective action of propolis on the rat colon carcinogenesis

Abstract

Propolis is a honeybee product with several biological and therapeutical properties. Its effect on the process of colon carcinogenesis and DNA damage were evaluated in the male Wistar rats using the aberrant crypt foci (ACF) assay and the comet assay, respectively. For both tests, animals were treated with the colon carcinogen 1,2 dimethylhydrazine (DMH, 40 mg/kg, s.c.) for 2 weeks (two injections/week) in order to induce both DNA damage and ACF. The animals were divided into groups that received propolis (ethanolic extract) at three different doses (10, 30, and 90 mg/kg b.w., by gavage), either simultaneously or after DMH treatment. For the comet assay, peripheral blood samples were collected 4 h after the last DMH treatment. All animals were sacrificed at the 5th week for evaluation of ACF. The results show that only the intermediate dose (30 mg/kg) of propolis, administered after DMH initiation, is significantly associated to a smaller number of aberrant crypts in the distal colon. No effect on DNA damage in peripheral blood cells, however, was verified by the comet assay. These data suggest that propolis has a protective influence on the process of colon carcinogenesis, suppressing the development of preneoplastic lesions, and probably exerts no protection against the initiation of carcinogenesis.

Preparation of Propolis Nanofood and Application to Human Cancer

“…In addition to a potential application for propolis in cancer therapy, studies in numerous experimental (chemical) carcinogenesis models [8][9][10][11][12][13][14][15] and in a clinical trial performed in patients with familial adenomatous polyposis 16,17) have confirmed that propolis can also ameliorate the progression to cancer in a variety of organ sites, reiterating the potential of propolis as a chemopreventive agent.…”

Cytotoxic constituents of propolis inducing anticancer effects: a review

“…[68] The protective action of Brazilian EEP was evaluated on 1,2 dimethylhydrazine (DMH) induced colon carcinogenesis in rats. [69] EEP administration after DMH initiation led to a smaller number of aberrant crypts in the distal colon, suppressing the development of preneoplastic lesions. It has been reported that Brazilian AEP significantly reduced DMHinduced DNA damage in colon cells, but it did not suppress the development of aberrant crypt foci in rats.…”

“…The mechanisms involved in the chemoprevention by propolis are not fully understood, but one may suppose that the interference by one or more propolis components in mutagenic/carcinogenic metabolic pathways or its putative antioxidant activity could explain its effects on DMH genotoxicity. [69] Although some studies have demonstrated the mechanisms of action of propolis and its constituents, further investigations are needed to understand how they exert antitumour effects in humans and animals.…”

Preliminary Studies of the Immunomodulator Effect of the Propolis Trigona spp. Extract in a Mouse Model

“…[2,3,4,5,6]. This product has attracted the interest of researchers in recent decades because of the properties of biological and pharmacological, among others such as antimicrobial [7,8,9], antitumor [10], immunomodulator [11], anti-inflammatory [12], an antioxidant [13].…”