Phytochemical profiling and bioactivity assessment of underutilized Symphytum species in comparison with Symphytum officinale.

BACKGROUND: Symphytum (comfrey) genus, particularly Symphytum officinale, has been empirically used in folk medicine mainly for its potent anti-inflammatory properties. In an attempt to shed light on the valorization of less known taxa, the current study evaluated the metabolite profile and antioxidant and enzyme inhibitory effects of nine Symphytum species. RESULTS: Phenolic acids, flavonoids and pyrrolizidine alkaloids were the most representative compounds in all comfrey samples. Hierarchical cluster analysis revealed that, within the roots, S. grandiflorum was slightly different from S. ibericum, S. caucasicum and the remaining species. Within the aerial parts, S. caucasicum and S. asperum differed from the other samples. All Symphytum species showed good antioxidant and enzyme inhibitory activities, as evaluated in DPPH (up to 50.17 mg Trolox equivalents (TE) g-1), ABTS (up to 49.92 mg TE g-1), cupric reducing antioxidant capacity (CUPRAC, up to 92.93 mg TE g-1), ferric reducing antioxidant power (FRAP, up to 53.63 mg TE g-1), acetylcholinesterase (AChE, up to 0.52 mg galanthamine equivalents (GALAE) g-1), butyrylcholinesterase (BChE, up to 0.96 mg GALAE g-1), tyrosinase (up to 13.58 mg kojic acid equivalents g-1) and glucosidase (up to 0.28 mmol acarbose equivalents g-1) tests. Pearson correlation analysis revealed potential links between danshensu and ABTS/FRAP/CUPRAC, quercetin-O-hexoside and DPPH/CUPRAC, or rabdosiin and anti-BChE activity. CONCLUSIONS: By assessing for the first time in a comparative manner the phytochemical-biological profile of a considerably high number of Symphytum samples, this study unveils the potential use of less common comfrey species as novel phytopharmaceutical or agricultural raw materials. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Liquid-liquid chromatography isolation of Petasites hybridus sesquiterpenes and their LC-HR-MS/MS and NMR characterization.

Petasites hybridus L. (butterbur, Asteraceae) is a well-known medicinal plant traditionally used as a remedy for neurological, respiratory, cardiovascular, and gastrointestinal disorders. Eremophilane-type sesquiterpenes (petasins) are considered to be the major bioactive constituents of butterbur. However, efficient methods to isolate high-purity petasins in sufficient amounts for further analytical and biological testing are lacking. In this study, various sesquiterpenes were separated from a methanol rootstock extract of P. hybridus with liquid-liquid chromatography (LLC). The appropriate biphasic solvent system was selected using the predictive thermodynamic model COSMO-RS and shake-flask experiments. After the selection of the feed (extract) concentration and operating flow rate, a batch LLC experiment was performed with n-hexane/ethyl acetate/methanol/water 5/1/5/1 (v/v/v/v). For those LLC fractions containing petasin derivatives with purities < 95%, a preparative high-performance liquid chromatography purification step followed. All isolated compounds were identified by state-of-the-art spectroscopic methods, i.e., liquid chromatography coupled with high-resolution tandem mass spectrometry and nuclear magnetic resonance techniques. As a result, six compounds were obtained, namely 8ß-hydroxyeremophil-7(11)-en-12,8-olide, 2-[(angeloyl)oxy]eremophil-7(11)-en-12,8-olide, 8α/ß-H-eremophil-7(11)-en-12,8-olide, neopetasin, petasin, and isopetasin. The isolated petasins can be further used as reference materials for standardization and pharmacological evaluation.

A review on the ethnobotany, phytochemistry, pharmacology and toxicology of butterbur species (Petasites L.).

ETHNOPHARMACOLOGICAL RELEVANCE: Petasites (butterbur, Asteraceae) species have been used since Ancient times in the traditional medicine of Asian and European countries to treat central nervous system (migraine), respiratory (asthma, allergic rhinitis, bronchitis, spastic cough), cardiovascular (hypertension), gastrointestinal (ulcers) and genitourinary (dysmenorrhea) disorders. AIM OF THE REVIEW: This study summarized and discussed the traditional uses, phytochemical, pharmacological and toxicological aspects of Petasites genus. MATERIALS AND METHODS: A systematic search of Petasites in online databases (Scopus, PubMed, ScienceDirect, Google Scholar) was performed, with the aim to find the phytochemical, toxicological and bioactivity studies. The Global Biodiversity Information Facility, Plants of the World Online, World Flora Online and The Plant List databases were used to describe the taxonomy and geographical distribution. RESULTS: The detailed phytochemistry of the potentially active compounds of Petasites genus (e.g. sesquiterpenes, pyrrolizidine alkaloids, polyphenols and essential oils components) was presented. The bioactivity studies (cell-free, cell-based, animal, and clinical) including the traditional uses of Petasites (e.g. anti-spasmolytic, hypotensive, anti-asthmatic activities) were addressed and followed by discussion of the main pharmacokinetical and toxicological issues related to the administration of butterbur-based formulations. CONCLUSIONS: This review provides a complete overview of the Petasites geographical distribution, traditional use, phytochemistry, bioactivity, and toxicity. More than 200 different sesquiterpenes (eremophilanes, furanoeremophilanes, bakkenolides), 50 phenolic compounds (phenolic acids, flavonoids, lignans) and volatile compounds (monoterpenes, sesquiterpenes) have been reported within the genus. Considering the phytochemical complexity and the polypharmacological potential, there is a growing research interest to extend the current therapeutical applications of Petasites preparations (anti-migraine, anti-allergic) to other human ailments, such as central nervous system, cardiovascular, malignant or microbial diseases. This research pathway is extremely important, especially in the recent context of the pandemic situation, when there is an imperious need for novel drug candidates.