Green Tea, Phytic Acid, and Inositol in Combination Reduced the Incidence of Azoxymethane-Induced Colon Tumors in Fisher 344 Male Rats

Abstract

Experimental as well as epidemiologic studies in human populations provide evidence that consumption of phytochemicals reduces the incidence of degenerative diseases. Green tea (GT) catechins are known for their antioxidative potential. Phytic acid (PA) also acts as a natural antioxidant and may have numerous health benefits. This experiment was designed to investigate the inhibitory effects of combinations of 1% and 2% GT, PA, and inositol (I) in reducing the incidence of azoxymethane-induced colon tumors in Fisher 344 male rats. After an acclimatization period of 1 week, nine groups of rats (15 rats per group) were initially assigned to consume AIN 93 G diet and later AIN 93 M diet after 20 weeks of age. Treatments were given in drinking water. All rats received azoxymethane injections (16 mg/kg of body weight) subcutaneously at 7 and 8 weeks of age. Rats were killed at 45 weeks of age by CO(2) euthanasia. Tumor incidence (93.76%) and the number of tumors per tumor-bearing rat ratio (2.25) were significantly (P<.05) higher in the control group compared with treatment groups. Glutathione S-transferase activity was significantly (P<.05) higher in rats fed combinations of 2% GT+PA+I and GT+PA (33.25 ± 1.23 and 29.83 ± 1.10 μmol/mL, respectively) compared with other groups. These findings suggest that the synergistic effect of the 2% level of GT, PA, and I may reduce the incidence of colon tumors and therefore have potential as a chemopreventive agent.

Effects of Water Solutions on Extracting Green Tea Leaves

“…As a popular drink favoured by Asians, in particular Chinese, green tea has received much global attention for its promotion of human health. A number of studies have shown that green tea possesses a wide range of biological activities [3], including antioxidant activity [4–9], anti-inflammatory activity [10], antimutagenic as well as anticarcinogenic activities [11–14], and neuroprotective effects [15]. The major functional constituents of green tea, catechins, account for 8–15% of the dry leaf weight [16].…”

Acid-Base and Antioxidant Properties of Complexes of Phytic Acid-Xymedone in Solution

“…This scheme has been studied using the Fenton reagent in vitro in homogenates of large intestinal mucosa from Wistar rats [5].…”

Cancer Preventive Effects of Green Tea Polyphenols

“…For example, a combination of green tea with phytic acid and inositol (all 2% in drinking water) enhanced the anticancer activity of green tea against colorectal cancer in azoxymethane-treated rats after 41 weeks. 112 Combination with folic acid treatment could also increase the anticancer activity of EGCG against gastrointestinal cancer in vivo. For example, EGCG (12.5 mg/day) combined with folic acid (1 mg/day) for 28 weeks was shown to significantly decrease the number of rats with N-methyl-N 0 -nitro-N-nitrosoguanidine (MNNG)-induced gastrointestinal tumors compared to controls or single treatments (p 5 0.011, compared to control).…”