Process optimization and bioactive compounds quantification from Dactylorhiza hatagirea tuber for alleviating glycemic and oxidative stress

Abstract

Dactylorhiza hatagirea, an important source of ‘Salep,’ is a highly valued but underutilized medicinal plant of the Himalayan region. Health benefits of the species are associated with the presence of natural antioxidant that alleviates glycemic activity and oxidative stress. The present study aimed to optimize and propose an effective ultrasound-assisted extraction (UAE) method to extract glycoside (Dactylorhin E) and other polyphenol compounds using response surface methodology (RSM). Under optimal extraction conditions, total phenolics (11.42 ± 0.48 mg GAE/g DW), flavonoids content (11.46 ± 0.28 mg QE/g DW), and antioxidant activity, i.e., DPPH (1.37 ± 0.008 mM AAE/g DW) and ABTS (1.06 ± 0.008 mM AAE/g DW) and anti-glycemic, i.e., alpha-amylase (42.81 ± 0.22 % inhibition) and alpha-glucosidase (27.97 ± 0.40 % inhibition) inhibition activity were found near the model predicted values. HPLC-PDA recorded six bioactive compounds in UAE, of which Dactylorhin E (14.14 mg/g DW) and o-coumaric (3.22 mg/g DW) were most prominent. This study prepared optimized glycoside, polyphenol-rich extracts aimed to be used for the formulation of foodstuffs and phytomedicines. Furthermore, the method is reliable, simple, and an alternative to various other extraction techniques.