Abdullah Dalar

Sempervivum davisii: phytochemical composition, antioxidant and lipase-inhibitory activities

Abstract Context: Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research. Objective: This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties. Materials and methods: Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 °C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin–Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined. Results: Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2–5973.3 μM Fe2+/g DW; ORAC values of 1858.5–4208.7 μM Trolox Eq./g DW) and moderate lipase inhibitory (IC50: 11.6–2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found. Conclusions: Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.

Plant Taxa Used in the Treatment of Diabetes in Van Province, Turkey

Despite the richness of local flora and medicinal plant utilization, there is no any report on documentation of antidiabetic botanicals used in Van province. Therefore, the present study aimed to record accumulation of the traditional antidiabetic medicinal plants of Van province in order to preserve the valuable local medicines knowledge, which has been threatened by urbanization. Antidiabetic folk medicines were determined via field surveys conducted in 1065 settlements during the period of 2014-2017 through medicinal plants questionnaire and structured face-to-face interviews (600 informants) with local people who are well known in the province for their long practice in traditional medicine. 69 plant taxa (35 species with undocumented antidiabetic medicinal use in scientific literature for Turkey) including five endemic and one rare to Turkey belong to 16 families (principally Asteraceae and Lamiaceae) were recorded for their traditional antidiabetic use. 52 different vernacular names were detected which were mainly indicate morphological characteristics. Infusion prepared from leaf and flower organs were found as the most common preparation method of local medicines in the province. Use value analysis showed that Rheum ribes, Urtica dioica, Scutelleria orientalis subsp. pichleri, Diplotenia cachrydifolia, Teucrium polium, Rosa canina, Campanula glomerata subsp. hispida, Rumex scutatus, Helichrysum plicatum subsp. plicatum and Tanacetum balsamita subsp. balsamita might serve promising pharmaceutical agents for diabetes treatment.