Chemical compositions by using LC-MS/MS and GC-MS and antioxidant activities of methanolic extracts from leaf and flower parts of Scabiosa columbaria subsp. columbaria var. columbaria L

Hormonal response to recurrent seasonal stress in coastal and mountain scabiouses growing in their natural habitat: linking ABA and jasmonates with photoprotection

Plant species distribution across ecosystems is influenced by multiple environmental factors, and recurrent seasonal stress events can act as natural selection agents for specific plant traits and limit species distribution. For that, studies aiming at understanding how environmental constraints affect adaptive mechanisms of taxonomically closely related species are of great interest. We chose two Scabiosa species inhabiting contrasting environments: the coastal scabious S. atropurpurea, typically coping with hot-dry summers in a Mediterranean climate, and the mountain scabious S. columbaria facing cold winters in an oceanic climate. A set of functional traits was examined to assess plant performance in these congeneric species from contrasting natural habitats. Both S. atropurpurea and S. columbaria appeared to be perfectly adapted to their environment in terms of adjustments in stomatal closure, CO2 assimilation rate and water use efficiency over the seasons. However, an unexpected dry period during winter followed by the typical Mediterranean hot-dry summer forced S. atropurpurea plants to deploy a set of photoprotective responses during summer. Aside from reductions in leaf water content and Fv/Fm, photoprotective molecules (carotenoids, α-tocopherol and anthocyanins) per unit of chlorophyll increased, mostly as a consequence of a severe chlorophyll loss. The profiling of stress-related hormones (ABA, salicylic acid and jasmonates) revealed associations between ABA and the bioactive jasmonoyl-isoleucine with the underlying photoprotective response to recurrent seasonal stress in S. atropurpurea. We conclude that jasmonates may be used together with ABA as a functional trait that may, at least in part, help understand plant responses to recurrent seasonal stress in the current frame of global climate change.

Investigation of Phytochemical, Antioxidant and Antidiabetic Potentials of Scabiosa L. (Caprifoliaceae) Species with Chemometric Methods

In this research, the total phenolic and flavonoid amounts, phenolic compositions, in vitro antioxidant, antibacterial and antidiabetic properties of the methanol extracts obtained from Scabiosa L. (Caprifoliaceae) species distributed in the flora of Türkiye were investigated using chemometric methods. For this purpose, principal component (PCA) and agglomerative hierarchical clustering analysis were performed as chemometric methods. Chlorogenic acid, quinic acid and cyranoside were determined in the extracts. According to chemometric analysis, S. columbaria subsp. ochroleuca var. ochroleuca and S. triniifolia species were found to be valuable in terms of methanol extract yields, total phenolic and flavonoid contents, antioxidant and antidiabetic activities while S. columbaria subsp. ochroleuca var. webbiana species were found to be valuable in terms of phenolic composition. The methanol extracts of Scabiosa species showed high antioxidant activity, with high phenolic and flavonoid contents. Among the tested 13 bacteria, Scabiosa extracts showed only low activity against Klebsiella pneumoniae, Streptococcus pneumoniae and Pseudomonas aeruginosa. The extracts showed high α-amylase and α-glucosidase inhibitory activity. The results show that Scabiosa methanol extracts may be a source of alternative antioxidants that may be beneficial in slowing or preventing the progression of various oxidative stress-related diseases.

Dipsacus and Scabiosa Species-The Source of Specialized Metabolites with High Biological Relevance: A Review

The genera Dipsacus L. and Scabiosa L. of the Caprifoliaceae family are widely distributed in Europe, Asia, and Africa. This work reviews the available literature on the phytochemical profiles, ethnomedicinal uses, and biological activities of the most popular species. These plants are rich sources of many valuable specialized metabolites with beneficial medicinal properties, such as triterpenoid derivatives, iridoids, phenolic acids, and flavonoids. They are also sources of essential oils. The genus Dipsacus has been used for centuries in Chinese and Korean folk medicines to treat bone (osteoporosis) and joint problems (rheumatic arthritis). The Korean Herbal Pharmacopoeia and Chinese Pharmacopoeia include Dipsaci radix, the dried roots of D. asperoides C.Y.Cheng & T.M.Ai. In addition, S. comosa Fisch. ex Roem & Schult. and S. tschiliiensis Grunning are used in traditional Mongolian medicine to treat liver diseases. The current scientific literature data indicate that these plants and their constituents have various biological properties, including inter alia antiarthritic, anti-neurodegenerative, anti-inflammatory, antioxidant, anticancer, and antimicrobial activities; they have also been found to strengthen tendon and bone tissue and protect the liver, heart, and kidney. The essential oils possess antibacterial, antifungal, and insecticidal properties. This paper reviews the key biological values of Dipsacus and Scabiosa species, as identified by in vitro and in vivo studies, and presents their potential pharmacological applications.

Scabiosa atropurpurea: A rich source of iridoids with α-glucosidase inhibitory activity evaluated by in vitro and in silico studies

Scabiosa atropurpurea L. subsp. maritima (L.) Arc. (Caprifoliaceae) is a plant widely distributed in the Mediterranean region and represented by 32 taxa in the flora of Turkey. In the present study, an in-depth phytochemical investigation of S. atropurpurea methanol extract of the whole plant was carried out using a combination of LC-ESI-FT-MS and NMR analysis. This approach allowed the isolation and structural elucidation of 28 compounds: 17 iridoids, 7 flavonoids, and 4 phenolic acids. Among these compounds, three previously unreported iridoids named secologanin-methyl-hemiacetal, atropurpurin A, and atropurpurin B were identified. The methanol extract of S. atropurpurea was assayed for its antioxidant and antihyperglycemic activity, showing a potent α-glucosidase inhibitory activity (IC₅₀ = 100 μg/mL), higher than that exerted by acarbose (IC₅₀ = 196 μg/mL), used as the positive control. Thus, the most abundant iridoids were selected to be tested for their antihyperglycemic activity, and molecular docking experiments were carried out to assess the possibility for selected compounds to form complexes with α-glucosidase enzyme active site.

Electrophysiological and Behavioral Responses of Apis mellifera and Bombusterrestris to Melon Flower Volatiles

As important pollinators, honeybees and bumblebees present a pollination behavior that is influenced by flower volatiles through the olfactory system. In this study, volatile compounds from melon flowers were isolated and identified by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), and their effects on Apis mellifera and Bombus terrestris were investigated by electroantennogram (EAG) and behavior tests (Y-tube olfactometer). The results showed that 77 volatile compounds were detected in melon flowers, among which the relative content of aldehydes was the highest (61.34%; 82.09%). A. mellifera showed a strong EAG response to e-2-hexenal, e-2-octenal, and 1-nonanal. B. terrestris showed a strong EAG response to e-2-hexenal, e-2-octenal, 2,5-dimethyl-benzaldehyde, benzaldehyde and benzenepropanal. In behavior tests, the volatiles with the highest attractive rate to A. mellifera were e-2-hexenal (200 μg/μL, 33.33%) and e-2-octenal (300 μg/μL, 33.33%), and those to B. terrestris were e-2-hexenal (10 μg/μL, 53.33%) and 2,5-dimethyl-benzaldehyde (100 μg/μL, 43.33%). E-2-hexenal and e-2-octenal were more attractive to A. mellifera than B. terrestris, respectively (10 μg/μL, 10 μg/μL, 200 μg/μL). In conclusion, the volatiles of melon flowers in facilities have certain effects on the electrophysiology and behavior of bees, which is expected to provide theoretical and technical support for the pollination of A. mellifera and B. terrestris in facilities.

Evaluation of the wound healing properties of South African medicinal plants using zebrafish and in vitro bioassays

ETHNOPHARMACOLOGICAL RELEVANCE

In South Africa, medicinal plants have a history of traditional use, with many species used for treating wounds. The scientific basis of such uses remains largely unexplored.

AIM OF THE STUDY

To screen South African plants used ethnomedicinally for wound healing based on their pro-angiogenic and wound healing activity, using transgenic zebrafish larvae and cell culture assays.

MATERIALS AND METHODS

South African medicinal plants used for wound healing were chosen according to literature. Dried plant material was extracted using six solvents of varying polarities. Pro-angiogenesis was assessed in vivo by observing morphological changes in sub-intestinal vessels after crude extract treatment of transgenic zebrafish larvae with vasculature-specific expression of a green fluorescent protein. Subsequently, the in vitro anti-inflammatory, fibroblast proliferation and collagen production effects of the plant extracts that were active in the zebrafish angiogenesis assay were investigated using murine macrophage (RAW 264.7) and human fibroblast (MRHF) cell lines.

RESULTS

Fourteen plants were extracted using six different solvents to yield 84 extracts and the non-toxic (n=72) were initially screened for pro-angiogenic activity in the zebrafish assay. Of these plant species, extracts of Lobostemon fruticosus, Scabiosa columbaria and Cotyledon orbiculata exhibited good activity in a concentration-dependent manner. All active extracts showed negligible in vitro toxicity using the MTT assay. Lobostemon fruticosus and Scabiosa columbaria extracts showed noteworthy anti-inflammatory activity in RAW 264.7 macrophages. The acetone extract of Lobostemon fruticosus stimulated the most collagen production at 122% above control values using the MRHF cell line, while all four of the selected extracts significantly stimulated cellular proliferation in vitro in the MRHF cell line.

CONCLUSIONS

The screening of the selected plant species provided valuable preliminary information validating the use of some of the plants in traditional medicine used for wound healing in South Africa. This study is the first to discover through an evidence-based pharmacology approach the wound healing properties of such plant species using the zebrafish as an in vivo model.