Characterization and NO inhibitory activities of chemical constituents from an edible plant Petasites tatewakianus

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.

New tirucallane-type triterpenoids from the resin of Boswellia carteriiand their NO inhibitory activities

Six new tirucallane-type triterpenoids (1-6), along with ten known triterpenoids, were isolated from methylene chloride extract of the resin of Boswellia carterii Birdw. By the application of the comprehensive spectroscopic data, the structures of the compounds were clarified. The experimental electronic circular dichroism spectra were compared with those calculated, which allowed to assign the absolute configurations. Compounds 5 and 6 possesed a 2, 3-seco tirucallane-type triterpenoid skeleton, which were first reported. Their inhibitory activity against NO formation in LPS-activated BV-2 cells were evaluated. Compound 9 showed appreciable inhibitory effect, with an IC₅₀ value of 7.58 ± 0.87 μmol·L^-1.

Natural Terpenoids as Neuroinflammatory Inhibitors in LPS-stimulated BV-2 Microglia

Neuroinflammation is a typical feature of many neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Microglia, the resident immune cells of the brain, readily become activated in response to an infection or an injury. Uncontrolled and overactivated microglia can release pro-inflammatory and cytotoxic factors and are the major culprits in neuroinflammation. Hence, research on novel neuroinflammatory inhibitors is of paramount importance for the treatment of neurodegenerative diseases. Bacterial lipopolysaccharide, widely used in the studies of brain inflammation, initiates several major cellular activities that critically contribute to the pathogenesis of neuroinflammation. This review will highlight the progress on terpenoids, an important and structurally diverse group of natural compounds, as neuroinflammatory inhibitors in lipopolysaccharidestimulated BV-2 microglial cells over the last 20 years.

S-petasin inhibits lipid accumulation in oleic acid-induced HepG2 cells through activation of the AMPK signaling pathway

S-petasin inhibits lipid accumulation in oleic acid-induced HepG2 cells.

Vitexnegheteroin M, a new phenolic glycoside from Vitex negundo var. heterophylla

The investigation of chemical constituents from the leaves and seeds of Vitex negundo var. heterophylla resulted in the isolation of one new phenolic glycoside, vitexnegheteroin M (1), together with eleven known compounds (2-12). Their structures were elucidated through extensive spectroscopic analyses including 1D, 2D NMR, HR-ESI-MS, and by comparison with the literature. Among them, compound 3 was obtained from the Vitex genus for the first time, and compounds 4-8, and 10-12 were isolated from this plant for the first time. Their anti-inflammatory activities were investigated by measuring nitric oxide (NO) production in lipopolysaccharide (LPS)-induced murine microglial BV-2 cells. As the obtained results, compound 9 showed the strongest inhibitory activity against LPS-stimulated NO production in BV-2 cells with IC₅₀ value ranging from 8.65 ± 0.67 μM.

Lignans and triterpenoids from Vitex negundo var. heterophylla and their biological evaluation

Three new phenylnaphthalene-type lignans, vitexnegheteroins E-G (1-3), and a new polyoxygenated ursane-type triterpene, vitexnegheteroin H (9), were isolated from the seeds of Vitex negundo var. heterophylla, together with ten known compounds. Their structures were established on the basis of extensive 1D and 2D NMR experiments, as well as their mass spectroscopic data. The absolute configurations of compounds 1 and 2 were determined by comparing their experimental ECD spectra with that calculated by the time-dependent density functional theory (TDDFT) method. The isolates were evaluated for their cytotoxicities against three human cancer cell lines, inhibitory activities on lipopolysaccharide-induced NO production in murine microglial BV-2 cells, and antioxidant activities for ABTS radical scavenging.

Isolation, Characterization, and Antiproliferative Activities of Eudesmanolide Derivatives from the Flowers of Inula japonica

Inula japonica belongs to the family Asteraceae, and its flowers have been used as dietary supplements and health tea in China. The study aimed to identify the bioactive components with the antiproliferative property. Ten 1,10-seco-eudesmanolide derivatives, including four new compounds (1-4), were isolated from the flowers of I. japonica. Their structures were established on the basis of the interpretation of spectroscopic data and electronic circular dichroism (ECD) calculations. All of these isolates were evaluated for their antiproliferative activities against MCF-7 and MDA-MB-231 human breast cancer cells. Compound 4 possessed the most potent effects, with the IC50 values of 0.20 ± 0.04 and 6.22 ± 1.30 μM against MCF-7 and MDA-MB-231 cells, respectively. The present investigation indicated that eudesmanolide derivatives from the flowers of I. japonica, especially compound 4, might be used as potential antitumor chemotherapy agent candidates.

Characterization of Diterpenes from Euphorbia prolifera and Their Antifungal Activities against Phytopathogenic Fungi

Euphorbia prolifera is a poisonous plant belonging to the Euphorbiaceae family. In this survey on plant secondary metabolites to obtain bioactive substances for the development of new antifungal agents for agriculture, the chemical constituents of the plant E. prolifera were investigated. This procedure led to the isolation of six new and two known diterpenes. Their structures, including absolute configurations, were elucidated on the basis of extensive NMR spectroscopic data analyses and time-dependent density functional theory ECD calculations. Biological screenings revealed that these diterpenes possessed antifungal activities against three phytopathogenic fungi. The results of the phytochemical investigation further revealed the chemical components of the poisonous plant E. prolifera, and biological screenings implied the extract or bioactive diterpenes from this plant may be regarded as candidate agents of antifungal agrochemicals for crop protection products.

Absolute Configurations and NO Inhibitory Activities of Terpenoids from Curcuma longa

Curcuma longa L., belonging to the Zingiberaceae family, is a perennial herb and has been used as a spice and a pigment in the food industry. In the ongoing search for inhibitory reagents of NO production and survey of the chemical composition of natural vegetable foods, the chemical constituents of C. longa used as spice were investigated. This investigation resulted in the isolation of 2 new terpenoids and 14 known analogues. Their structures were established on the basis of the extensive analyses of 1D and 2D NMR spectroscopic data, and the absolute configurations of 1-4 were elucidated by comparison of the calculated and experimental ECD spectra. Among them, compound 1 is a rare norditerpene with an ent-labdane skeleton, and 2 is a skeletally novel sesquiterpene having an eight-membered ring. All of the compounds were found to possess NO inhibitory activities in murine microglial BV-2 cells. The discovery of two new compounds in this chemical investigation further disclosed the chemical composition of C. longa used a food spice, and the bioassay implied that the natural food spice C. longa, containing terpenoids with NO inhibitory activities, may be potentially promotive to human health.

Isolation and characterization of sesquiterpenes from Celastrus orbiculatus and their antifungal activities against phytopathogenic fungi

Celastrus orbiculatus is an insecticidal plant belonging to the Celastraceae family. In this survey on the secondary metabolites of plants for obtaining bioactive substances to serve agriculture, the chemical constituents of the fruits of C. orbiculatus were investigated. This phytochemical investigation resulted in the isolation of nine new and one known sesquiterpene. Their structures, especially the complicated stereochemical features, were elucidated on the basis of extensive NMR spectroscopic data analyses, time-dependent density functional theory CD calculations, and the CD exciton chirality method. Biological screenings disclosed that these sesquiterpenes showed antifungal activities against six phytopathogenic fungi. The results of our phytochemical investigation further disclosed the chemical components of C. orbiculatus, and biological screening implied that it may be potentially useful to protect crops against phytopathogenic fungi and the bioactive compounds may be regarded as candidate agents of antifungal agrochemicals for crop protection products.