Anticancer effects of maple syrup phenolics and extracts on proliferation, apoptosis, and cell cycle arrest of human colon cells

The antiproliferative effects of Canadian maple syrup (grades C and D) extracts and fifty-one purified phenolic constituents were evaluated against human tumourigenic (HT-29, HCT-116, and CaCo-2) and non-tumourigenic (CCD-18Co) colon cells. Overall, maple syrup ethyl acetate (MS-EtOAc), butanol (MS-BuOH), and methanol (MS-MeOH) extracts were more active against the tumourigenic versus non-tumourigenic colon cells. At equivalent phenolic levels, the antiproliferative activities of grade D > C maple syrup, and MS-BuOH > MS-MeOH > MS-EtOAc. Among the isolates, gallic acid, catechaldehyde, syringaldehyde, and catechol were most active and their higher levels in grade D MS-BuOH extract could account for the highest observed anticancer effects of that extract. Moreover, the maple syrup extracts did not induce apoptosis of the colon cancer cells but induced cell cycle arrest which was also associated with a decrease in cyclins A and D1 levels. These results suggest that phenolics may impart potential biological effects to maple syrup.

► Maple syrup phenolic-enriched extracts were prepared and 50 phenolics isolated.
► Extracts and compounds inhibited growth of colon cancer more than normal colon cells.
► Antiproliferative effects were mediated through cell cycle arrest.