Differential solvent extraction, qualitative phytochemical analysis, isolation of secondary metabolites, antioxidant, enzymes inhibitory, antimicrobial, and phytotoxic potentials of Jurinea himalaica R.R.Stewart

Jurinea himalaica, a medicinal plant native to the Western Himalayas, was comprehensively studied for its phytochemical composition and pharmacological potentials. Qualitative phytochemical studies, polarity directed extraction of various fractions, and column chromatography based isolation of compounds were performed. Crude samples including crude methanolic extract (Jh.Cme), n-hexane (Jh.Hex), and chloroform (Jh.Chf) were tested against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and urease enzymes. Samples were also tested for their free radicals scavenging potentials using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydrogen peroxide (H2O2) assays. The antimicrobial potentials of the crude samples were appraised against bacterial and fungal strains, and phytotoxic studies were also performed following standard procedures. Qualitative phytochemical studies identified the presence of alkaloids, flavonoids, terpenoids, glycosides, saponins, and anthraquinones with terpenoids found in particularly high abundance. Column chromatographic separation led to tentative identification of a bioactive compound. The Jh.Chf was found highly potent and inhibited considerable AChE and BChE inhibitory potentials with IC50 values of 85 and 43 μg/mL, respectively. Notably, the Jh.Chf showed strong urease inhibitory activity (IC50 = 63 μg mL−1) which was comparable to the control drug thiourea. The Jh.Chf revealed considerable radical scavenging potentials against DPPH, ABTS and H2O2 radicals with IC50 values of 30, 25, and 19 μg mL−1, respectively. The tested samples also revealed gastroprotective potentials by inhibition of urease enzyme and inhibition of Proteus mirabilis with a diameter of inhibitory zone (DIZ) of 22.8 mm. A considerable antibacterial activity against Escherichia coli (MIC 0.91 mg mL−1) and strong antifungal potentials against Aspergillus flavus with minimum fungicidal concentrations (MFCc) as low as 1.11 µg mL−1 signify its potential antimicrobial effects. The phytotoxic assay also demonstrated that Jh.Cme and Jh.Chf significantly suppressed radish seed germination (up to 88%) and root elongation (up to 91%) at 1000 μg mL−1 concentrations. In conclusion, our findings validate the traditional medicinal use of J. himalaica in various diseases and highlight its significant potential as a source of cholinesterase, urease inhibitory, neuroprotective, antimicrobial, antioxidant, and bio-herbicides. Further purification and mechanistic studies are required to completely explore the therapeutic and agrochemical uses of this plant.