TITLE:
Chemopreventive and Anti-Inflammatory Potential of Select Herbal Teas and Cinnamon in an In-Vitro Cell Model
AUTHORS:
Shantrell Willis, Rajitha Sunkara, Fredreana Hester, Louis Shackelford, Lloyd T. Walker, Martha Verghese
KEYWORDS:
Colon Cancer, Inflammation, Herbal Tea, Cell Culture
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.10 No.9,
September
29,
2019
ABSTRACT: 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.