In Vitro and In Vivo Assessment of Antidiabetic Activity of Cupressus torulosa D. Don Needles, Their LCQTOFMS Assisted Metabolite Profiling, and Implications for Diabetes Management

Abstract

Diabetes mellitus (DM) is a prevalent metabolic disorder attributed to insulin secretion and action defects, affecting a growing adult population with hyperglycemia expected to reach 578 million by 2030. This study explores the antidiabetic potential of 25% aqueous methanol extract of Cupressus torulosa needles, utilizing in vitro and in vivo assays. In the α-glucosidase inhibition assay, the extract exhibited significant in vitro antidiabetic activity with an IC₅₀, 123.45 ± 1.8 μg/mL, comparable to the standard drug acarbose (IC₅₀, 58.21 ± 3.1 μg/mL). Toxicity assessment indicated non-toxic nature of the extract at 2000 mg/kg b.w. In STZ-induced diabetic mice, it displayed dose-dependent antihyperglycemic effects, evident at the fourth hour and 14th day, paralleling the positive control glibenclamide. In the chemical profiling of the extract using UPLC-QTOF-MS, the mobile phases consisted of 0.1% formic acid in water (Solvent A) and 100% methanol (Solvent B). The gradient elution started with 5% B (0 to 2 min) and gradually increased to 95% B by 25 min, followed by a post-run time of 2 min. Preliminarily, 50 constituents were identified, predominantly phenolics, with hypoglycemic effects attributed to flavonoids like (−)-epicatechin, amentoflavone, and cupressuflavone, as well as iridoid O-glycoside, exemplified by haprpagoside. Further studies are needed to assess the long-term efficacy, safety, and molecular mechanisms of the extract of C. torulosa needles in diabetes management.