Phytochemical and Pharmacological Properties of a Traditional Herb, Strobilanthes Cusia (Nees) Kuntze

The present investigation aimed to determine the effectiveness of bioactive components extracted from Hom herbs (Strobilanthes cusia (Nees) Kuntze) using the solvent-free microwave-assisted extraction (MAE) method. The obtained bioactive components were analyzed for total phenolic content (TPC) and active ingredient content. The Hom extracts were examined for antioxidant, antibacterial, anti-inflammatory, cytotoxic, and anticancer activities. The comparative analysis of extraction methods MAE was studied by using different solvents such as ethanol (EtOH), 50% ethanol (50EtOH) and distilled water (DW). The results obtained by the MAE method with DW as solvent show the TPC of 104.41±1.36 mg GAE/g crude and tryptanthrin 0.1138±0.0014 mg/g crude and indigo 0.0622±0.0015 mg/g crude. Comparatively, values ​​detected in the 50% EtOH extract were not significantly different at the 95% confidence level. At the same time, levels of indirubin were detected at levels equivalent to that of ethanol extracts. The DW extract from MAE had an IC₅₀ value against the DPPH scavenging assay of 0.1927±0.0756 mg/ml, comparable to the test results of extracts of ethanol and 50% ethanol. The bioactive extracted using the MAE with water as solvent had minimum inhibitory concentration (MIC) and could suppress infection at 10 mg/disc. It was also observed that the extracts from the conventional extraction technique using ethanol as the solvent continued to be highly effective against Bacillus cereus even after employing the EtOH or 50% EtOH. Hom extract's MIC value representing inhibiting B. cereus was 0.625 mg/disc. Still, EtOH-extracted Hom demonstrated the highest cytotoxicity against 16HBEo- by reducing cell survival rate by less than 50% while the others did not. Interestingly, Hom that had been extracted using 50EtOH and DW with MAE had an anticancer impact on A549 by reducing the survival rate in a dose-dependent manner.