Anticancer activity of quercetin, naringenin, and morin Acetoxy DMU in the therapeutic treatment of rats inoculated with Walker 256 carcinosarcoma

Author(s)

Camila de Andrade Camargo

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2011-08-08

Examining board members

Hiroshi Aoyama; Paulo Afonso Granjeiro; Vera Lucia Scherholz Salgado de Castro; Daniel Martins de Souza; Cíntia Maria Saia Cereda

• Advisor: Hiroshi Aoyama

Abstract

Currently, cancer is a public health problem worldwide in virtue of the increase in incidence. Anorexia and involuntary weight loss are common in cancer patients. This condition, also known as cachexia, affects the functional capacity, response to treatment, quality of life and patient survival. It is estimated that approximately two million people worldwide die annually because of cancer cachexia consequences. In this work the Walker 256 carcinosarcoma (W256) is used as an experimental model to establish cancer cachexia in infected animals. Furthermore, it presents an aggressive biological behavior, local invasive growth and high metastasis potential. Flavonoids are polyphenolic compounds with several biological activities mainly due to its antioxidant properties and ability to modulate several enzymes or cellular receptors. These characteristics are associated with the protective effect attributed to these compounds against cardiovascular system diseases, some causes of cancer, diseases caused by photosensitivity and aging, among other. The aim of this study was to evaluate the effects of the flavonoids quercetin, naringin and morin and the compound acetoxy DMU (a synthetic derivative of resveratrol and DMU-212) in the cachexia prevention/attenuation and inhibition of tumor growth in rats bearing W256, in a preclinical study. Healthy male rats were inoculated with tumor cells and treated with different doses of quercetin, naringin, morin and acetoxy DMU (10, 25 and 35mg/kg) intraperitoneally administered, 5 consecutive times a week, during 50 days or until death. The administration of 10 mg/kg quercetin and 25mg/kg naringin, morin and acetoxy DMU inhibited about 50% of tumor growth (ED50) compared with Tumor group (untreated). The ED50 values for the treatment with quercetin, naringin, morin and acetoxy DMU were responsible for a survival increase about 30, 50, 40 and 60%, respectively, in contrast to 100% mortality observed in the tumor group. Another consequence of the ED50 administration was the tumor regression in 2, 5, 2 and 3 animals, respectively, for treatment with quercetin, naringin, morin and acetoxy DMU (n=10). The effect of treatment with these compounds on cytokines mediators of the cachectic process (in liver and tumor tissue) was efficient in maintaining the TNF-? and IL-6 levels similar to those found in control rats (Control group). Tumor group presented high levels of these cytokines in both liver and tumor samples. The treatments also promoted a high potential anti-angiogenic, shown by the decrease in VEGF expression and MMP-2 activity of liver and tumor samples. The VEGF levels found in Tumor group (liver samples) were significantly higher than the Control group. Another effect of treatment with the compounds was a significant decrease in the low molecular weight protein tyrosine phosphatase expression (in liver and tumor tissue), which had been over-expressed in Tumor group. Analyses of testes and accessory reproductive organs weights (epididymis, seminal vesicle, coagulating gland and prostate) were made for animals treated with narigina and acetoxy DMU. The results indicated a significant reduction in Tumor group organs compared with the Control group. On the other hand, the naringin and acetoxi DMU therapeutic treatments of rats with tumor have been proven effective in protecting the morphology of these organs and inhibiting its reduction. According to the results, the best treatment was obtained with the acetoxy DMU. The results of this work confirm the effect of these flavonoids and acetoxi DMU on reducing the cachexia symptoms and tumor growth inhibition, contributing to a better understanding of the action of these compounds in vivo, both in healthy and in tumor organisms (AU)