Effect of temperature and pressure on antimycobacterial activity of Curcuma caesia extract by supercritical fluid extraction method

Supercritical fluid extraction (SFE) is an advanced technique using CO₂as a solvent and plant-based drug exploration is a topic of growing interest. Curcuma caesia is a medicinal herb with many medicinal potential. Hence, in the present study, the effect of temperature (40°C-60°C) and pressure (10-20 MPa) on extraction yield and antimycobacterium potential of C. caesia Roxb. dry rhizome powder using supercritical fluid extraction method were evaluated.

The extract of C. caesia by SFE was accomplished using temperature range (40°C-60°C) and pressure range (10-20 MPa). The chemical profile of the extracts were investigated by Gas Chromatography Mass Spectrometry (GCMS) and the antimycobacterial activity of the extracts were analyzed against Mycobacterium smegmatis strains MTCC06 and MTCC994. Compounds found in the extract were further checked by in silico analyses with two protein target 4DRE and 3UCI.

Extraction yield ranged from 3.0 to 5.6 g/25g dry substrate, with the highest value being achieved at 50°C and 15 MPa. The results of GCMS analyses revealed the presence of beta-elemene, curzerenone, boldenone, and 2-cyclohexen-1-one, 4-ethynyl-4-hydroxy-3, 5, 5-trimethyl in the extracts. The extract obtained at 50°C temperature and 15 MPa pressure showed the highest zone of inhibition against M. smegmatis strains MTCC06 and MTCC994, that is, 15.6 mm and 13.6 mm, respectively. Active constituents present in the extracts showed good binding energy with 4DRE and 3UCI by in silico analysis.

This study identified the effect of temperature and pressure on yield C. caesia extract by SFE method. Furthermore, the effect of different extracts on antimycobacterial potential and docking study validated the antimycobacterial potential.