Mutivariate optimization strategy for the sonication-based extraction of Nardostachys jatamansi roots and analysis for chemical composition, anti-oxidant and acetylcholinesterase inhibitory potential

Extracts from medicinal plants are generally obtained by conventional methods like percolation and maceration. Owing to limitations of traditional methods and to meet the rising demand of extracts, the development of new green approaches is need of hour. In the present research, we have developed an ultrasound-assisted extraction (UAE) method for the Nardostachys jatamansi (NJ) D. Don, DC roots and optimized the extraction parameters for possible improved extract yield. A multivariate optimization strategy using the Centre Composite Design coupled with response surface methodology was applied. A numerical optimization approach accurately predicted the extraction conditions (sonication time ∼ 20 min, ethanol ∼ 70 % and a liquid/solid ratio of about 21:1). Scanning electron microscopy of the plant samples after UAE also indicated the cavitation effect due to sound waves. GC–MS analysis of the optimized ultrasound extract (OUNJ) confirmed improvement in the concentration of various secondary metabolites like jatamansone (91.8 % increase), spirojatamol (42.3 % increase), globulol (130.4 % increase), sitosterol (84.6 % increase) as compared to the soxhlet extract (SXNJ). Different anti-oxidant parameters (DPPH, Glutathione, Catalase SOD and NO) were also significantly altered (p < 0.05) in the optimized extracts. The IC(50) to inhibit acetylcholinesterase activity (AChE) in vitro and its concentration in brain homogenates were significantly (p < 0.05) improved by OUNJ extract as compared to the SXNJ ones. To conclude, we can say that established optimized conditions for UAE of N. jatamansi roots not only reduce the extraction time but also improved the pharmacological potential of the extracts.