摘要：Colon cancer is the third leading cause of death in the US. Herbal teas and spices may reduce the incidence of chronic diseases, including colon cancer. The objectives of this study were to determine the chemopreventive effects of herbal teas and cinnamon in an in-vitro cell model and to evaluate the inhibitory effects of selected extracts on enzymes associated with inflammatory disease. Effects of raspberry leaf (0.5 - 2.0 mg/mL), strawberry leaf (0.4 - 1.0 mg/mL), hibiscus flower (4.0 - 10.0 mg/mL) and cinnamon (400 - 1500 μg/mL) were evaluated for cytotoxicity, induction of caspase and DNA fragmentation in colon cancer (Caco-2) cells to determine possible chemopreventive effects. Effects of extracts on inhibition of cyclooxygenase-2 (COX-2) were also measured to determine possible anti-inflammatory potential. Caco-2 cells were obtained from American Type Culture Collection (ATCC) and maintained in Dulbecco’s Modified Eagle’s Medium with 10% fetal bovine serum. As concentrations of tea increased, LDH release from Caco-2 cells increased, with cytotoxicity ranging from 1% - 80% (hibiscus flower 1.0 mg/mL and strawberry leaf (1.0 mg/mL) for teas. All extract concentrations of herbal teas and cinnamon were able to enhance caspase-3 activity with lowest activity (4.4 mmol/ min/mL) observed in the lowest concentration of cinnamon (400 μg/mL) and highest activity (6.0 mmol/min/mL) seen in the highest concentration of raspberry leaf (2 mg/mL). Tea and spice extracts were able to induce apoptosis in Caco-2 cells exhibited by increased DNA fragmentation (expressed as enrichment factor). Enrichment factor ranged from 1.0 - 1.5 (raspberry leaf 1.0 mg/mL and hibiscus 10.0 mg/mL). Teas and cinnamon exhibited anti-inflammatory potential by inhibiting COX-2 by 0.6% - 8.0% (raspberry leaf 1.0 mg/mL and strawberry leaf 0.8 mg/mL). The results suggest that herbal teas and cinnamon may have significant benefits in chemoprevention.
