Design Based Ultrasound-Assisted Extraction of Marrubium vulgare Linn and Comparative Evaluation of Extracts for Furan Labdane Diterpene (Marrubiin) Concentration and Antihypertensive Potential

Background: Improvement in extract quality in terms of concentration of secondary metabolites and pharmacological activity has always been the need of the hour. In the present research, the target was to extract the selected medicinal herb using the ultrasound waves and to optimize the extraction conditions for the improvement in the quality of extract with respect to furan labdane diterpene (marrubiin) concentration and antihypertensive potential. Methods: The whole plant of Marrubium vulgare Linn. was collected from the fields of Pulwama district of Jammu and Kashmir state in India and extracted by cold maceration (MVM) and ultrasound assisted extraction techniques (MVU). The response surface methodology coupled with the central composite design was employed to optimize the selected extraction parameters in UAE method. The marrubiin concentration in different extracts was determined by HPTLC. The extracts were also evaluated for the antihypertensive potential by non-invasive blood pressure monitoring (NIBPM) method. Results: The extract yield (14.2 ± 0.9%) and concentration of marrubiin (0.91 ± 0.04%) were significantly improved at the optimized UAE conditions (Ultrasound power 467 W, sonication time of 47 minutes and solvent concentration of 33 mL per g of drug) as compared to the conventional method. Furthermore, the MVU extract (200 mg/kg) along with ethanol significantly (p<0.01) prevented the rise in mean systolic blood pressure (MSBP) of animals and also the GSH was significantly (p<0.05) enhanced as compared to ethanol-treated animals. Conclusion: The elevation in MSBP and decrease in reduced glutathione concentration (GSH) by the chronic ethanol consumption were significantly altered by MVU extract as compared to MVM extract. The enhanced antihypertensive effect of selected herb may be attributed to the improved concentration of secondary metabolites (marrubiin) in MVU extract obtained at optimized conditions.