Evaluation of the Chemo-Preventive Effects of Camellia sinensis Silver Nanoparticles and Synergistic Effects with 5-fluorouracil in Colorectal Cancer Induced Rats

In the present study, the chemopreven-tive effect of green tea nanoparticles (GTNP) and synergistic effect between GTNP and 5-Fluorouracil (5FU) on 1, 2-Dimethylhydrazine (DMH) induced colorectal carcinogenesis was studied in Wistar albino rats. GTNP synthesized and characterized by transmission electron mi-croscope (TEM) and Fourier-transform infrared spectroscopy (FTIR) and tested for their acute toxicity. All groups except for normal group received subcutaneous injections of DMH once a week for 5 weeks. GT group was treated daily with GTNP alone, GTFU group received both GTNP and intraperitoneal injection of 5FU once a week and 5FU group was treated with 5FU once a week for 16 weeks. In the GT group, a significant reduction in the number of aberrant crypt foci (ACF) was observed suggesting the inhibitory effect of green tea in attenuating colorectal cancer progression. By comparing GTNP and GTFU treatment, there was a significant decrease in total ACF number in combined treatment of GT and 5FU compared to GT alone (13.33 ± 0.88 vs 25.00 ± 2.31, p <0.05). The total number of ACF in 5FU treatment alone was significantly reduced when compared to combined GTFU treatment (5.67 ± 2.19 vs 13.33 ± 0.88, p < 0.05). These results suggested that green tea nanoparticles significantly inhibited ACF formation on DMH-induced colorectal cancer which has led to no tumor formation. The large ACF only significantly reduced by this combined therapy compared to small ACF. In overall, it does not exert the synergistic effect between the combination therapy of GTNP and 5FU on colorectal cancer.