Evaluation of antidiabetic effect of Cistus salviifolius L. (Cistaceae) in streptozotocin-nicotinamide induced diabetic mice

Phytochemistry and Antihyperglycemic Potential of Cistus salviifolius L., Cistaceae

Cistus salviifolius has been previously reported as a traditional remedy for hyperglycemia. However, the plant has been scarcely investigated from scientific point of view. Thus, the aim was to examine the chemical composition and to evaluate its antioxidant and antihyperglycemic potential in vitro. Aqueous and ethanolic extracts were evaluated for total phenolic, tannin, and flavonoid content using spectrophotometric methods. Detailed chemical characterization was performed by high-performance liquid chromatography (HPLC-DAD). The volatile organic compounds (VOCs) profile was assessed by gas chromatography technique. The potential in diabetes treatment was evaluated through tests of free radicals neutralization, inhibition of lipid peroxidation process, and test of ferric ion reduction; activity in tests of inhibition of α-amylase, α-glucosidase and dipeptidyl peptidase-4 was also evaluated. High content of phenolics (majority being tannins) was detected; detailed HPLC analysis revealed high content of gallic acid, followed by rutin, chlorogenic and caffeic acids. The VOCs analysis determined sesquiterpene hydrocarbons and oxygenated sesquiterpenes as the main groups of compounds. The assays classified extracts as potent neutralizers of 2,2-diphenyl-1-picrylhydrazil and nitroso radicals formation and potent inhibitors of α-amylase and α-glucosidase. In conclusion, Cistus salviifolius represents a rich source of phenolics and essential oil with sesquiterpenes. The established results suggested its promising antioxidant and antihyperglycemic activities.

Comparative effects of metformin and Cistus laurifolius L. extract in streptozotocin-induced diabetic rat model: oxidative, inflammatory, apoptotic, and histopathological analyzes

Interest in phytochemical therapy methods in the treatment of diabetes is increasing day by day. Although the antidiabetic and antioxidant effects of Cistus laurifolius L. (CL) have been mentioned, the systemic effects remain unknown. The present study aims at evaluating the antidiabetic effects of the CL aqueous extract via metformin on streptozotocin (STZ)-induced diabetic rats. Forty male Wistar albino rats were divided into five groups of eight animals each: control, diabetic group (55mg/kg STZ), STZ+125mg/kg CL, STZ+250mg/kg CL, and STZ+100mg/kg metformin. The effects of CL and metformin on oxidative, apoptotic, and inflammatory pathways were comparatively investigated. In addition, nuclear factor-κB (NFκB), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-1β expressions analysis were carried out. CL treatment resulted in a significant improvement in blood glucose levels, lipid profile, pancreatic markers, and liver and kidney function tests. A 250mg/kg CL treatment decreased by 67.9%, 31.6%, 66.8%, 28.3%, and 31.4% in the total oxidant capacity, NFκB, TNF-α, IL-1β, caspase3, and cytochrome c levels, respectively, compared to the diabetic group. Additionally, CL treatments showed a dose-dependent reduction in NFκB, TNF-α, and IL-1β expression levels. A 250mg/kg CL treatment exhibited a greater increase (by 9.6%) in total antioxidant capacity than metformin. CL treatment provided histologically more improvement in the brain, heart, pancreas, spleen, liver, kidney, and testicular tissues compared to the metformin group. Our results suggest that the single treatment of CL aqueous extract at the low doses may have stronger short-term anti-diabetic effects than metformin. Therefore, further studies are needed regarding the long-term hypoglycemic effect or treatment of CL aqueous extract.