Zamzam water protects cancer cells from chemotherapy-induced apoptosis via mitogen-activated protein kinase-dependent pathway

Background: Many Muslims believe that water from the Zamzam well is the cure for every disease. Zamzam water (ZW) is naturally alkaline water consumed by millions of people worldwide. The current study investigated the effect of ZW on cell viability and apoptosis in breast, colorectal and ovarian cancer cell lines and compared the effect with that of drinking water (DW). Methods: Three different ZW samples collected from different sources at different periods were used. To balance the tonicity, ZW and DW were buffered using PBS and the pH was adjusted to 7.4. For the treatment, ZW and DW were diluted to 50% with RPMI medium (10% FBS). Cancer cell lines were treated with ZW or DW, with and without chemotherapeutic agents, for 24 h. Apoptosis was measured using flow cytometry whilst the level of protein expression was determined by Western blotting. Results: The results showed that treatment with ZW significantly increased cell proliferation compared to DW control. Treatment with ZW significantly suppressed the effect of chemotherapeutic agents on decreasing cell viability and inducing apoptosis in all the cancer cell lines compared to chemotherapeutic agents alone treated in DW. Furthermore, ZW treatment increased the phosphorylation of CRAF, MEK1/2, ERK1/2 and P38 proteins in these cell lines. Notably, treatment with ZW suppressed the effect of chemotherapy-induced reduction of CRAF, MEK1/2, ERK1/2 and P38 phosphorylation in breast and ovarian cancer cell lines. We also showed that silencing of ERK1/2 significantly increased the chemotherapy-induced apoptosis in breast and colorectal cancer cell lines. These data suggest that MAPK proteins; especially activated ERK1/2 may play a role in ZW mediated suppression of chemotherapy-induced cell death. Conclusions: These findings clearly demonstrate that ZW protects cancer cells from chemotherapy-induced apoptosis through activation of the ERK1/2-MAPK signaling pathway.