Pharmacognostic Standardization and in Vitro Antidiabetic Evaluation of Cyperus Rotundus Rhizome, Rhodiola Rosea Root and Zostera Marina Leaf Extracts and Their 1:1:1 Polyherbal Combination in Insulin-Resistant 3T3-L1 Adipocytes
Keywords:
Cyperus rotundus; Rhodiola rosea; Zostera marina; polyherbal formulation; 3T3-L1 adipocytes; 2-NBDG glucose uptake; α-amylase; α-glucosidase; HPTLC fingerprinting; pharmacognostic standardization.Abstract
Purpose: The main objective of the current research work was to standardise three plant materials from different ecological habitats, Cyperus rotundus rhizome (tropical sedge), Rhodiola rosea root (high-altitude adaptogen) and Zostera marina leaf (marine seagrass), and to evaluate their methanolic extracts individually and as a 1:1:1 combined polyherbal extract (CPE) for in vitro antidiabetic activity. To our knowledge, this combination of a terrestrial sedge, an alpine adaptogen and a marine angiosperm has not been evaluated earlier.
Methods: The plant materials were authenticated by macroscopy, microscopy, UV-Visible spectroscopy and high-performance thin-layer chromatography (HPTLC), and physicochemical parameters were determined as per IP/WHO guidelines. Cytotoxicity was determined by MTT assay in 3T3-L1 cells (7.8125–1000 µg/mL, 24 h), and glucose uptake was measured by 2-NBDG in insulin-resistant differentiated 3T3-L1 adipocytes at 62.5, 125 and 250 µg/mL with insulin (100 nM) as standard. α-Amylase and α-glucosidase inhibition were determined against acarbose (15.625–500 µg/mL) and IC50 values were obtained by logistic non-linear regression.
Results: All parameters were within the specified limits, and HPTLC confirmed salidroside (Rf 0.43) and rosavin (Rf 0.60) in R. rosea, an α-cyperone-type sesquiterpenoid band (Rf 0.45) in C. rotundus and rosmarinic acid (Rf 0.71) in Z. marina. Viability remained ≥ 80% up to 250 µg/mL for all four materials (CR 86.69%, RR 90.41%, ZM 81.28% and CPE 86.00%). CPE at 250 µg/mL restored glucose uptake to 89.36% of normal control against 46.95% in the insulin-resistant control (Dunnett, p < 0.001), which was close to insulin (92.31%). CPE showed the lowest IC50 for α-amylase (86.28 µg/mL) and α-glucosidase (68.25 µg/mL) among the extracts, followed by CR, RR and ZM, while acarbose gave 58.26 and 44.63 µg/mL.
Conclusion: It can be concluded that the 1:1:1 combination of C. rotundus, R. rosea and Z. marina acts on peripheral glucose uptake and on both carbohydrate-hydrolysing enzymes, and the combined extract was more active than each single extract even though it carried one-third the dose of each component.
