Elastase Inhibition by Helianthus Extracts

The capacity of the aromatic extracts from H. coronarium to inhibit the elastase activity was evaluated when the substrate was AAAVPN through the assay modified from Thring et al. (2009) and Laothaweerungsawat et al. (2020) [36 (link),43 (link)]. Concisely, 10 μL of the sample solutions, comprising H. coronarium aromatic extracts dissolved in DMSO at a concentration of 1 mg/mL, was mixed with 40 µL of 0.03 unit/mL elastase with the enzyme activity greater than 90%. The resulting mixture was incubated for 15 min at ambient temperature, and 100 μL of 1.6 mM AAAVPN in tris HCl buffer pH 8.0 was added to start the reaction. Immediately, the absorbance was then kinetically measured at 410 nm for 20 min utilizing a multimode microplate reader (BMG Labtech GmbH, Ortenberg, Germany). The outcomes were expressed as the percentage of elastase inhibition, calculated using the subsequent equation:
where a represented the absorbance of the combination without aromatic extracts from H. Coronarium and b represented the absorbance of the combination with aromatic extracts from H. Coronarium. Oleanolic acid was used as the positive control. The test was performed three times.