Correlation between antioxidant activity of garlic extracts and WEHI-164 fibrosarcoma tumor growth in BALB/c mice.

The biological activities of garlic may be affected by different processing methods. This study, therefore, aimed to evaluate potential anticancer effects of different type of processed garlic extracts on WEHI-164 tumor cells in inbred BALB/c mice and correlate the tumor growth rates with some garlic constituents. In a preclinical trial 60 BALB/c mice were injected with WEHI-164 tumor cells and divided into six groups of 10 animals. Group 1 mice received 200 μL of saline, and groups 2-6 were injected intraperitoneally with fresh, microwaved, 3-month-old, leaves, and boiled garlic extracts, respectively, at 20 mg/kg/0.2 mL. Three weeks following tumor inoculation, the mean tumor size in garlic extract-treated groups was reduced with significant reductions observed in the fresh and microwaved extract groups compared with the control group (P<.05). The antioxidant capacity and the amounts of allicin, flavonoids, and phenolic compounds in differentially processed garlic were evaluated and correlated with their anticancer activities. There was a linear correlation between the amounts of allicin, flavonoids, or phenolic components derived from fresh, microwaved, 3-month-old, leaves, and boiled garlic and cancer growth prevention. In conclusion, garlic has anticancer activity against WEHI-164 tumor cells, and processing such as heating reduces its effect dramatically. The anticancer activities of different kinds of garlic are related to the level of allicin, flavonoids, and phenolic components. Therefore, fresh garlic has the highest content of bioactive components and the greatest anticancer efficacy.