Liver diseases remain a significant global health concern, despite advancements in antiviral agents and vaccines. Factors such as extended life expectancy and over-nutrition are expected to contribute to the increasing prevalence of liver diseases (22). The use of herbal products raises concerns about hepatotoxicity, although conclusive evidence is often lacking (23). To assess the impact of moringa extract on liver cells, the HepG2 cell line was employed, enabling the evaluation of toxicity through various parameters such as cell viability and proliferation (24).
The results from this study demonstrate that moringa methanolic and ethanol extracts exhibit concentration-dependent and time-dependent effects on cell viability. Lower concentrations of the methanolic extract generally showed comparable or slightly higher viability, while the highest concentration had a detrimental effect. The ethanol extract initially showed an increase in viability with increasing concentrations but subsequently led to decreased viability over time, except at the lowest concentration. Previous studies have shown that Moringa extracts reduce cell viability of HepG2 cells, suggesting potential anticancer activity (25, 26).
The total phenolic content assay is a commonly used method to determine the presence and concentration of phenolic compounds in plant extracts. In this study, the optical density (OD) values were measured for Moringa Methanol Extract, Moringa Ethanol Extract, and the positive control Vanillic acid. The optical density of the methanol was found to be 0.3269, while ethanol extract exhibited a higher optical density of 0.5487. In comparison, the positive control vanillic acid had an optical density of 0.2797. These results indicate that both extracts contain phenolic compounds, as evidenced by their higher optical density values compared to the control. To determine the concentration of phenolic compounds in the extracts, the optical density values were converted to catechin equivalents. Catechin, a well-known phenolic compound, is often used as a reference standard for the quantification of phenolics. The calculated catechin equivalents for MME and MEE were 0.01307 and 0.02195, respectively. The obtained results demonstrate that both extracts contain phenolic compounds, with the ethanol extract exhibiting a higher concentration compared to the methanol extract. The presence of phenolic compounds in the extracts are of significant interest due to their potential health benefits. Phenolic compounds are known for their antioxidant and anti-inflammatory properties, which have been associated with various health-promoting effects, including reduced risk of chronic diseases (27).
The antioxidant assay results indicate that both methanol and ethanolic extracts of the sample exhibit antioxidant activity at different concentrations and time points. Figures 3b and 3c highlights that the methanol extract exhibit higher antioxidant capacity than the ethanolic extract. At 24 hours, all concentrations (50 mg/l, 100 mg/l, 200 mg/l, and 400 mg/l) of the methanol extract show higher antioxidant capacity compared to the control group, with the highest capacity observed at the 200 mg/l concentration. However, at 48 hours and 72 hours, the antioxidant capacity varies across concentrations without a clear trend. In contrast, the ethanolic extract shows different patterns of antioxidant capacity. At 24 hours, the antioxidant capacity varies among the concentrations, with the control group and 50 mg/l concentration exhibiting the highest capacity. However, at 200 mg/l and 400 mg/l concentrations, the antioxidant capacity decreases. At 48 hours and 72 hours, the antioxidant capacity continues to vary across concentrations, with the highest capacity observed at the 200 mg/l concentration.
Overall, these findings suggest that the choice of solvent for extraction may influence the antioxidant potential of the extracts. The methanol extract, especially at higher concentrations, demonstrates strong antioxidant properties, while the ethanolic extract shows more variable antioxidant capacity across concentrations and time points. The results suggest that both the methanol and ethanolic extracts possess antioxidant activity, but their effects vary depending on the concentration and time point. The methanol extract shows consistent antioxidant capacity, especially at higher concentrations, while the ethanolic extract exhibits more complex patterns. These findings indicate that the choice of solvent for extraction and the concentration of the extract can significantly influence the antioxidant potential of the sample. Previous studies have found that Moringa oleifera extract possess antioxidant capacity (28, 29, 30, 31).
The liver enzyme activity assay results show that moringa extracts can reduce liver function markers, including aspartate aminotransferase (AST) and alkaline phosphatase (ALP). The methanol extract, at 24 hours, demonstrates decreased AST levels at concentrations of 200 mg/l and 100 mg/l, indicating potential liver cell protection. However, at 48 hours, AST levels decrease across all concentrations, suggesting temporary suppression of liver function, followed by an increase after 72 hours, indicating a regenerative response. For ALP levels, reductions are observed at the 200 mg/l concentration after 24 hours, and at 200 mg/l and 50 mg/l after 48 hours and 72 hours. These findings suggest that the moringa extract, particularly at 200 mg/l, may benefit liver function by lowering ALP levels and potentially reducing hepatocellular damage.
The ethanol extract exhibits varying effects on AST levels at different concentrations and time points. At 24 hours, the 200 mg/l concentration shows the highest AST level, followed by 400 mg/l, while the lowest level is observed at 50 mg/l. At 48 hours, AST levels continue to fluctuate, with the 200 mg/l concentration having the highest level. At 72 hours, the relationship between AST levels and concentrations becomes less distinct. Regarding ALP levels, at 24 hours, the 50 mg/l and 200 mg/l concentrations of the moringa extract reduce ALP levels. At 48 hours, the 50 mg/l and 400 mg/l concentrations decrease ALP levels, while the 100 mg/l and 200 mg/l concentrations show little change. After 72 hours, most concentrations exhibit a slight decrease in ALP levels compared to the control group, except for the 200 mg/l concentration.
Overall, both methanol and ethanol extracts of moringa have the potential to improve liver cell health and reduce hepatocellular damage, as indicated by the decrease in AST and ALP levels. However, the effects vary depending on the concentration and time of treatment.