Antioxidant potential and low-density lipoprotein cholesterol (LDL-c) uptake of
the black seed and honey mixture on human hepatocellular carcinoma (HepG2)
cells
High lipid levels especially low-density-lipoprotein cholesterol (LDL-c) are associated with increased risk of cardiovascular (CVD) and coronary heart disease (CHD). Both black seed (Nigella sativa L.) and honey are well-known in the hypolipidemic potential and have CVD protective effects. In the present study, LDL-c uptake of the black seed and honey mixture was tested on HepG2 cells. Antioxidant activities of black seed and honey mixtures were determined through the 2, 2’-diphenyl-1-picrylhydrazyl (DPPH) assay. The anticancer potential of black seed and honey mixtures in HepG2 cells was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay. Black seed possessed the highest antioxidant activities with EC50 6.54 mg/mL as compared to honey with EC50 value 9.56 mg/mL while the black seed and honey mixture have EC50 between black seed and honey. From the results obtained, no synergistic effect was observed in the mixtures as the EC50 values were within the range of black seed and honey. Furthermore, no significant difference (p>0.05) among ratios (1:1, 2:1 and 1:2). However, the decrease in cell proliferation was the highest in black seed and honey mixture at 1:1 ratio (p<0.05) than individually treated black seed and honey. Thus, the black seed and honey mixture at ratio 1:1 was the most potent anticancer agent with an IC50 value of 7.44 μg/mL. The present study illustrated that black seed and honey mixtures possess a lipid-lowering effect via LDL-c uptake in HepG2 cells (p<0.05). The highest LDL-c uptake was observed at 15 μg/mL with the treatment of black seed and honey mixture at 1:2 ratio which was 294.4%. Further studies should be conducted on primary human liver cells to further justify the correlation between the antioxidant level and LDLc uptake mechanism of black seed and honey mixtures.