The Effects of Spirulina on Proliferation, Apoptosis, Nitric Oxide Release, and the Expression of Ras/MAPK Pathway Genes in Cervical Cancer Cells (CC1-PI 19)

Introduction: Spirulina is a popular dietary supplement and its anticancer properties have been reported. Considering the significant increase in the number of cervical cancer patients in the last 30 years, the lack of efficiency of common treatments, and the need to identify treatment methods with fewer side effects, this study aimed to determine the effects of spirulina on proliferation, apoptosis, and nitric oxide secretion, as well as the expression of Ras/MAPK pathway genes on cervical cancer cells. Method: After the preparation of hydroalcoholic extract of spirulina and treatment of cells with different concentrations of extract, survival was measured using the MTT method. The Diphenylamine test was used to measure apoptosis, and the Griess reaction was used to measure nitric oxide. Gene expression was measured and quantified by real-time PCR. Finally, the data were analyzed using SPSS software (version 16). The significance level of statistical tests was considered to be P≤0.05 for all tests. Results: The cytotoxic effect of spirulina on cancer cells was dependent on concentration and time. The IC50 value of spirulina for cancer cells was lower than that of non-cancerous fibroblast cells. Treatment with the IC50 concentration of spirulina after 24 hours induced a significant increase in apoptosis (P≤0.05) and significant decrease in the expression of Ras (HRAS, KRAS, and NRAS), Raf (ARAF, BRAF, and CRAF), MEK (MEK1, MEK2, MEK3, MEK4 and MEK5), and ERK (ERK1 and ERK2) family genes (P≤0.05). Moreover, IC50 concentration of spirulina significantly reduced nitric oxide production (P≤0.05). Conclusion: Spirulina may have anticancer effects through stimulation of apoptosis and inhibition of the Ras/MAPK signaling pathway.