Antioxidant and Enzyme Inhibition Assays

A total of 5 g of IA and WA was measured and 200 mL of ethanol added. The mixture was boiled for 60 min after waiting for 60 min, filtered, and the process repeated twice. Then, the filtrates were combined and concentrated under reduced pressure and dried for 24 h to obtain the agarwood extracts for the bioactivity measurements.
For the DPPH and ABTS⁺ radical scavenging experiments, various quantities of alcohol-soluble extracts were utilized in accordance with the approach used by Silva et al. [35 (link)]. Meanwhile, different ascorbic acid concentrations were used as positive controls (Appendix A).
The method of Wang et al. [36 (link)] was used with modification. Following the preparation of the sample solutions using various concentrations from the alcohol-soluble extracts, an assay for the inhibition of anti-acetylcholine ester activity was conducted. Tacrine was utilized as a positive control (Appendix A).
The method of Ting et al. was used, with modification [37 (link)], to test the various concentrations of alcohol-soluble extracts of IA and WA for anti-α-glucosidase activity. A positive control was performed with an acarbose solution of the same concentration (Appendix A).
A triple experiment was conducted and the mean and standard deviation (SD) were calculated. In addition, GraphPad Prism software was utilized to compute the IC₅₀ values and create the charts. Additionally, independent samples t-tests were run on the data using SPSS software, with p < 0.05 indicating a significant difference between the samples and p > 0.05 indicating no significant difference between the samples.