HPLC analysis of phenolic acids, antioxidant activity and in vitro effectiveness of green and roasted Caffea arabica bean extracts: a comparative study.

Coffee is a popular drink; it is one of the most commercialized food products and a rich source of biologically active compounds that are important for human health. This study aimed to prove the anticancer activity of green coffee (GC) and roasted coffee (RC) bean aqueous extracts (Coffea arabica) on breast cancer adenocarcinoma cell line (MCF-7) and the safety of both extracts on normal human peripheral blood lymphocytes culture (HPBL). Total phenolic content for GC and RC extracts was measured and result of both extracts were (0.308±0.016 & 0.233±0.013mg/g) respectively. The phenolic acids were screened by HPLC at the wavelength of 254& 278 and 300 nm and 5-caffeoylquinic acids (Chlorogenic acid), the predominant form of phenolic acids, was identified in GC and RC samples. Ferric reducing antioxidant power (FRAP) as well as the free radical scavenging activity (DPPH) proved the antioxidant properties of both extracts. The DPPH IC50 mean values of GC and RC extracts were (2.4±0.08, 2.3±0.16 μg/ml) respectively. Cytotoxicity of both extracts on MCF-7 cells were evaluated by neutral red uptake assay which showed the IC50 mean values (377±5.7,500±8.1 μg/ml) for GC and RC extracts respectively. The safety of both extracts (0, 125, 250, 500 μg/ml) on HPBL was evaluated in vitro using trypan blue exclusion method and DNA single strand breaks (alkaline comet assay). Result revealed non-significant cytotoxic difference (P<0.001) between cultures especially at lower doses of GC and RC extracts except the highest dose of BC and GC extract which showed slightly significant damage (P<0.001). In conclusion, this study proved that GC and RC aqueous extracts were found to be selectively cytotoxic in vitro to cancerous cells (MCF-7 cell line) causing cell death with no cytotoxicity on normal human lymphocytes especially at lower doses.