Fig 1.
Effects of different concentrations of MCF (A), MCP (B) and charantin (C) on the formation of crosslinked AGEs.
A representative SDS-PAGE gel showing lysozyme (10 mg/ml) incubated alone (lane 1) or in the presence of 0.1 M methylglyoxal (lane 2) in 0.1 M sodium phosphate buffer of pH 7.4 for 3 days at 37°C. The dimer formation resulting from protein crosslinking was determined using different concentrations of the MCF (A1) and MCP (B1) extracts or charantin (C1): 5 mg/ml (lane 3), 10 mg/ml (lane 4) and 15 mg/ml (lane 5). Lane 0 contains the marker proteins. The bar charts show the effects of different concentrations of MCF (A2), MCP (B2) and charantin (C2) on the formation of crosslinked AGEs relative to the control. The results are presented as means ± SDs (n = 3). *: p < 0.05, **: p < 0.01, ***: p < 0.001 vs control.
Fig 2.
Effects of different concentrations of MCP, MCF and charantin on CML formation.
The bar graph shows the effect of different concentrations (5 and 15 mg/ml) of the MCP, MCF and charantin extracts on production of CML following glycoxidation of BSA (300 mg) in 0.2 M phosphate buffer, pH 7.8 at 37°C over a period of 24-hours. The positive control was the amount of CML-modified BSA produced in the absence of extracts. The results are presented as mean ± SD (n = 3), **: p < 0.01 vs control.
Fig 3.
Radical scavenging activity of different concentrations of MCP, MCF and charantin.
(A) The hydroxyl radical scavenging activity of 5–15 mg/ml extracts of MCP, MCF and charantin was assessed by monitoring the hydroxylation of salicylate by the Fe3+-salicylate-H2O2 system over a period of 30 minutes at 37°C. Mannitol was used as a positive control. (B) The DPPH radical scavenging activity of 15 mg/ml extracts of MCP, MCF and charantin at 37°C over a period of 30 minutes was also assessed. Ascorbic acid was used as a positive control. All results are presented as mean ± SD (n = 3). ***: p <0.001 vs control.
Fig 4.
Metal chelating activity of different concentrations of MCP, MCF and charantin.
Chelating effects of 5–15 mg/ml of MCP, MCF and charantin extracts were determined over a period of 10 minutes at room temperature using the ferrozine method. EDTA was used as a positive control. The results are presented as mean ± SD (n = 3). ***: p <0.001 vs control.
Fig 5.
The reducing power of 15 mg/ml extracts of MCP, MCF and charantin.
Reducing power of MCP, MCF and charantin (15 mg/ml) extracts were determined over a period of 30 minutes at 50°C using the potassium ferricyanide method. Ascorbic acid was used as a positive control. The results are presented as mean ± SD (n = 3). There was no significant difference between the extracts and ascorbic acid.
Fig 6.
Total phenolic, flavonol and flavonoid contents of 10 mg/ml solutions of MCP, MCF and charantin.
(A) phenolic content was determined using the Folin-Ciocalteau method calibrated using gallic acid standards with the results expressed as mg/g of gallic acid equivalents, (B) flavonol content was determined using the AlCl3 method where the method was calibrated using rutin and results expressed as mg of rutin per g of extract and (C) flavonoid contents of the ethanolic MCP, MCF and charantin extracts determined by a colorimetric method calibrated using rutin and the results expressed as mg of rutin per g of extract. The results are presented as mean ± SD (n = 3). *: p < 0.05, **: p < 0.01.