Anthocyanins extracted from Chinese blueberry (Vaccinium uliginosum L.) and its anticancer effects on DLD-1 and COLO205 cells

Abstract

Background: Vaccinium uliginosum L. is a type of blueberry found in the Chinese Changbai Mountains. We extracted Vaccinium uliginosum Anthocyanins (A(V.uli)) to investigate its bioactivity on suppressing cancer cells.

Methods: A(V.uli) was extracted under different conditions of temperature (10°C - 35°C), pH 1.0 - 3.0, and diatomaceous earth (1.0 g - 3.0 g), followed by a HPLC analysis for the determination of the ingredients. Its anticancer bioactivities on human colon and colorectal cancer cells (DLD-1 and COLO205) were compared with those on Lonicera caerulea Anthocyanins (A(L.cae)) and Vaccinium myrtillus Anthocyanins (A(V.myr)), using cell viability assays, DNA electrophoresis and nuclear morphology assays.

Results: The optimum process of A(V.uli) extraction involved conditions of temperature 20°C, pH 2.0, and diatomaceous earth 1.0 g/50 g of fruit weight. A(V.uli) contained 5 main components: delphinidin (40.70 ± 1.72)%, cyanidin (3.40 ± 0.68)%, petunidin (17.70 ± 0.54)%, peonidin (2.90 ± 0.63)% and malvidin (35.50 ± 1.11)%. The malvidin percentage was significantly higher (P < 0.05) than it in A(V.myr). A(V.uli) complied with a dose-dependent repression of cancer cell proliferation with an IC(50) (50% inhibitory concentration) value of 50 µg/ml, and showed greater anticancer efficiency than A(L.cae) and A(V.myr) under the same cell treatment conditions. These observations were further supported by the results of nuclear assays.

Conclusions: The extraction protocol and conditions we used were effective for anthocyanin extraction. A(V.uli) could be a feasible practical research tool and a promising therapeutic source to suppress human colon or colorectal cancers.