Pharmacognostic, Phytochemical, Antioxidant and In-vitro Anti-diabetic Investigations of Picea smithiana (Wall.) Boiss.
The present study was designed to evaluate the pharmacognostical characteristics, phytochemical potential, antioxidant activity, and anti-diabetic enzyme inhibitory activity of Picea smithiana (Wall.) Boiss., with particular emphasis on its bark extracts. Pharmacognostical investigations, including microscopic examination, revealed characteristic gymnosperm features such as thick cuticular epidermis, well-developed sclerenchymatous hypodermis, resin canals, tracheid-based xylem, and distinct medullary rays, confirming the authenticity of the plant material. Extractive value analysis indicated a higher yield of polar constituents, with aqueous and ethanolic extracts showing maximum extractive values under both cold maceration and hot extraction methods. Antioxidant activity was evaluated using the DPPH radical scavenging assay. The extracts exhibited concentration-dependent antioxidant activity, with polar extracts showing comparatively higher radical scavenging potential. The standard antioxidant rutin demonstrated strong activity with an IC50 value of 1.38 mg/mL. Furthermore, the bark extracts were assessed for α-glucosidase and α-amylase inhibitory activities to explore their anti-diabetic potential. The ethanolic and aqueous extracts showed significant enzyme inhibition in a dose-dependent manner, with comparatively lower IC50 values than non-polar extracts, though less potent than the standard drug acarbose. The findings of present study suggests that Picea smithiana bark is a rich source of bioactive phytoconstituents possessing notable antioxidant and carbohydrate-digesting enzyme inhibitory activities, supporting its potential therapeutic application in oxidative stress–related disorders and diabetes management.