Synergistic anti-cancer activity of combined 5-fuorouracil and gallic acid-stearylamine conjugate in a431 human squamous carcinoma cell line

Abstract

Purpose: To evaluate the individual and synergistic anti-cancer effects of 5-fuorouracil (5-FU) and synthesized gallic acid-stearylamine (GA-SA) conjugate in A431 human squamous cancer cell line. Methods: Characterisation of the synthesised conjugate was performed using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS). The synergistic effect of the combination therapy (5-FU/GA-SA) was assessed by determining their inhibitory concentration (IC30) whereby A431 cells were treated with 5-FU:GA–SA conjugate at various ratios ranging from 5:1 to 1:5. Results: The cytotoxicity of 5-FU was 29 %, while that of the combination of 5-FU with GA–SA conjugate was as high as 60 %. Thus, this combination showed significant synergistic enhancement in cytotoxicity (p < 0.05). The results obtained also revealed that the IC30 values of 5-FU and the GA–SA conjugate were 1 and 10 μg/mL, respectively. The IC30 values of the combination ratios indicated that the dosages used in the study were safe in HaCaT normal cell line. Conclusion: These results indicate that 5-FU/GA–SA conjugate at a ratio of 1:1 is effective against A431 cell line (cancer cells)) but safe in HaCaT cell lines (normal cells).