Metabolomics profiling and biological properties of root extracts from two Asphodelus species: A. albus and A. aestivus

Bioguided Identification of Active Antimicrobial Compounds from Asphodelus bento-rainhae and Asphodelus macrocarpus Root Tubers

Root tubers of Asphodelus bento-rainhae subsp. bento-rainhae (AbR), a vulnerable endemic species, and Asphodelus macrocarpus subsp. macrocarpus (AmR) have traditionally been used in Portugal to treat inflammatory and infectious skin disorders. The present study aims to evaluate the in vitro antimicrobial activity of crude 70% and 96% hydroethanolic extracts of both medicinal plants, specifically against multidrug-resistant skin-related pathogens, to identify the involved marker secondary metabolites and also to assess the pre-clinical toxicity of these medicinal plant extracts. Bioguided fractionation of the 70% hydroethanolic extracts of both species using solvents of increasing polarity, namely diethyl ether (DEE: AbR-1, AmR-1), ethyl acetate (AbR-2, AmR-2) and aqueous (AbR-3, AmR-3) fractions, enabled the identification of the DEE fractions as the most active against all the tested Gram-positive microorganisms (MIC: 16 to 1000 µg/mL). Furthermore, phytochemical analyses using TLC and LC-UV/DAD-ESI/MS techniques revealed the presence of anthracene derivatives as the main constituents of DEE fractions, and five known compounds, namely 7'-(chrysophanol-4-yl)-chrysophanol-10'-C-beta-D-xylopyranosyl-anthrone (p), 10,7'-bichrysophanol (q), chrysophanol (r), 10-(chrysophanol-7'-yl)-10-hydroxychrysophanol-9-anthrone (s) and asphodelin (t), were identified as the main marker compounds. All these compounds showed high antimicrobial activity, particularly against Staphylococcus epidermidis (MIC: 3.2 to 100 µg/mL). Importantly, no cytotoxicity against HepG2 and HaCaT cells (up to 125 µg/mL) for crude extracts of both species and genotoxicity (up to 5000 µg/mL, with and without metabolic activation) for AbR 96% hydroethanolic extract was detected using the MTT and Ames tests, respectively. Overall, the obtained results contribute to the concrete validation of the use of these medicinal plants as potential sources of antimicrobial agents in the treatment of skin diseases.

Monographic Quality Parameters and Genotoxicity Assessment of Asphodelus bento-rainhae and Asphodelus macrocarpus Root Tubers as Herbal Medicines

Root tubers of Asphodelus bento-rainhae subsp. bento-rainhae (AbR), an endemic species with relevant interest due to conservation concerns, and Asphodelus macrocarpus subsp. macrocarpus (AmR) have been traditionally used for culinary and medicinal purposes, mainly associated with skin infection and inflammation. The present study aims to establish the quality control criteria for the proper characterization of dried root tubers of both species as herbal substances, together with their preclinical safety assessments. Botanical identification using macroscopic and microscopic techniques and phytochemical evaluation/quantification of the main classes of marker secondary metabolites, including phenolic compounds (flavonoid, anthraquinone, condensed and hydrolysable tannin) and terpenoids were performed. Additionally, in vitro genotoxicity/mutagenicity was evaluated by Ames test. Evident morphological differences in the development of tubercles (3.5 × 1 cm in AbR and 8.7 × 1.4 cm in AmR) and microscopicly in the arrangements and characteristics of the vascular cylinder (metaxylem and protoxylems) were found. Anatomical similarities such as multiple-layered epidermis (velamen) and the cortex area with thin-walled idioblasts (134 ± 2.9 µm and 150 ± 27.6 µm) containing raphide crystals (37.2 ± 14.2 µm and 87.7 ± 15.3 µm) were observed between AbR and AmR, respectively. Terpenoids (173.88 ± 29.82 and 180.55 ± 10.57 mg OAE/g dried weight) and condensed tannins (128.64 ± 14.05 and 108.35 ± 20.37 mg CAE/g dried weight) were found to be the main class of marker secondary metabolites of AbR and AmR extracts, respectively. No genotoxicity (up to 5 mg/plate, without metabolic activation) was detected in these medicinal plants' tested extracts. The obtained results will contribute to the knowledge of the value of the Portuguese flora and their future commercial cultivation utilization as raw materials for industrial and pharmaceutical use.

Phytochemical Screening, Antioxidant, and Enzyme Inhibitory Properties of Three Prangos Species (P. heyniae, P. meliocarpoides var. meliocarpoides, and P. uechtritzii) Depicted by Comprehensive LC-MS and Multivariate Data Analysis

The aim of the present study was to identify/quantify bioactive compounds and determine the antioxidant activity and enzyme inhibitory effects of various solvent extracts (n-hexane, ethyl acetate, methanol, and water) of Prangos heyniae H. Duman and M.F. Watson, Prangos meliocarpoides var. meliocarpoides, and Prangos uechtritzii Boiss. and Hausskn. This is the first time such a report has been designed to validate the phytochemical composition and bioactivity (especially enzyme inhibitory properties) of these plants. A combined approach of liquid chromatography (LC) with mass spectrometry (HR-MS and MSⁿ) allowed to identify that P. heyniae contains condensed tannins; P. meliocarpoides is rich in hydrolysable tannins; and P. uechtritzii possesses coumarins, flavonoids, and hydroxycinnamic acids. Different extracts were tested for antioxidant activities using a battery of assays, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), total antioxidant capacity (TAC) (phosphomolybdenum), and metal chelating. Enzyme inhibitory effects were investigated using acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, α-amylase, and α-glucosidase as target enzymes. The obtained results depended on the extraction solvents used for each Prangos species. The methanol extract of P. meliocarpoides var. meliocarpoides exhibited significant radical scavenging activity (DPPH: 52.27 mg Trolox equivalent (TE)/g; ABTS: 92.84 mg TE/g), the most potent-reducing potential (CUPRAC: 154.04 mg TE/g; FRAP: 104.34 mg TE/g), and high TAC (2.52 mmol TE/g). Moreover, the strongest BChE (7.97 mg galantamine equivalent/g), α-amylase (0.46 mmol acarbose equivalent/g), and tyrosinase (81.15 mg kojic acid equivalent/g) inhibitory effects were observed for the hexane extract of P. meliocarpoides var. meliocarpoides. Correlation analysis showed a significant positive correlation between hydrolysable tannins and antioxidant activities. The same trend was also observed between the same class of compounds and the inhibitory effects on enzymatic activities. These results suggest a principal role of hydrolysable tannins in the observed bioactivities of Prangos. Our results suggested that the tested Prangos species could be valuable as sources of natural agents in the development of health-promoting applications.

Role of polyphenols from Polygonum multiflorum Caulis in obesity-related disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Polygoni Multiflori Caulis (PMC) has been widely consumed as folk medicine in China for anti-obesity, sleep-enhancing and many other pharmacological effects. However, the material basis and underlying mechanism of PMC on obesity-related disorders were still not clear.

AIM OF THE STUDY

To screen active constituents from PMC and explore their multitarget mechanisms in the treatment of obesity and its associated disorders.

MATERIALS AND METHODS

Several major constituents were extracted from PMC and LC-MS assay were used to identify the compounds. The lipase inhibitory activity and lipid accumulation in 3T3-L1 preadipocytes were determined. Furthermore, Caenorhabditis elegans (C. elegans) and high-fat diet (HFD)-induced mice were established to explore the potential pharmacological functions and related mechanisms using kits, RT-qPCR and biochemical analysis.

RESULTS

Regarding the lipase inhibitory activity, the inhibition rate of EA and n-Bu extracts at 4 mg/mL reached over 80%. Effects on 3T3-L1 preadipocytes proliferation and differentiation were also obvious, indicating that EA and n-Bu extracts might exert potential anti-obesity functions. LC-MS assay further showed that polyphenols including emodin and physcion comprised majority of EA and n-Bu extracts. EA and n-Bu extracts treatment could significantly modulate the antioxidant response and lipid accumulation in C. elegans, as evidenced by increased SOD and CAT contents, reduced MDA levels, higher TG contents and changes of related mRNA expression levels. In HFD-induced mice, the inhibition ratio of body weight as well as the histological and biochemical indexes of liver, plasma and epididymal adipose tissues were also reversed by EA and n-Bu extracts treatment. Moreover, EA and n-Bu extracts administration increased the microbial diversity, reshaped the microbiota structure and enhanced the relative abundance of Bifidobacterium.

CONCLUSIONS

This study demonstrated the multicomponent and multitarget characteristics of PMC in preventing obesity related disorders. The results provided novel insights for the development and utilization of PMC.

Making a Virtue of Necessity: The Use of Wild Edible Plant Species (Also Toxic) in Bread Making in Times of Famine According to Giovanni Targioni Tozzetti (1766)

In 1766, the agricultural scientist Giovanni Targioni Tozzetti described for the Grand Duchy of Tuscany, the wild and cultivated plant species that could be used, in times of famine, to increase the quantity of flour or vegetable mass in bread making. These wild plants can be defined as wild edible plants (WEPs) or "alimurgic species", a concept usually traced back to Giovanni Targioni Tozzetti himself. The 342 plant names mentioned in the text are in the Tuscan vernacular, so a research work was done on bibliographic sources from the 1800s in order to match them with their current nomenclature. This process led to an "alimurgic flora" repertoire based on the writing of Targioni Tozzetti; and a comparison with our AlimurgITA database of 1103 wild edible plants used in Italy. It is particularly interesting that in his short treatise, Giovanni Targioni Tozzetti identified eight toxic plants (corresponding to 14 species), indicating how to eliminate the poisonous substances from their useful roots. We treat them in detail, examining their current and past use, their geographical distribution in Italy, and their eventual toxicity. We obtained 343 matches, of which 198 were reliable (certain matches) and 145 possessed some degree of uncertainty (due to generic or collective vernacular names). Among the 198 certain identifications, 140 species are present in the AlimurgITA database (92 mentioned for Tuscany) and 58 are not; for bread-making there are only documentary traces of 53 species for Italy and 7 for Tuscany. Moreover, among the total 198 species, 84 showed some degree of hazard. Researching edible toxic spontaneous species allows: (1) investigation, from an unusual perspective, of a historical period in which the poor conditions of some social strata led to finding unusual solutions to food provision; (2) idea generation to re-enable potentially useful WEPs whose use has been lost. Making a virtue of necessity!

New Natural Products from Asphodelus albus MILL. Essential Oil

A detailed chemical analysis of the essential oil of Asphodelus albus roots performed in this work, in combination with a chemical synthesis approach - the synthesis of selected compounds and their detailed spectral analysis - has led to the identification of a series of new natural products, the esters of furan-3-ylmethanol: furan-3-ylmethyl 2-methylpropanoate, furan-3-ylmethyl butanoate, furan-3-ylmethyl 2-methylbutanoate, furan-3-ylmethyl 3-methylbutanoate, furan-3-ylmethyl pentanoate, furan-3-ylmethyl 4-methylpentanoate, and furan-3-ylmethyl hexanoate.

Chromatographic Separation of Breynia retusa (Dennst.) Alston Bark, Fruit and Leaf Constituents from Bioactive Extracts

Breynia retusa (Dennst.) Alston (also known as Cup Saucer plant) is a food plant with wide applications in traditional medicine, particularly in Ayurveda. Extracts obtained with four solvents (dichloromethane, methanol, ethyl acetate and water), from three plant parts, (fruit, leaf and bark) were obtained. Extracts were tested for total phenolic, flavonoid content and antioxidant activities using a battery of assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), total antioxidant capacity (TAC) (phosphomolybdenum) and metal chelating. Enzyme inhibitory effects were investigated using acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase as target enzymes. Results showed that the methanolic bark extract exhibited significant radical scavenging activity (DPPH: 202.09 ± 0.15; ABTS: 490.12 ± 0.18 mg Trolox equivalent (TE)/g), reducing potential (FRAP: 325.86 ± 4.36: CUPRAC: 661.82 ± 0.40 mg TE/g) and possessed the highest TAC (3.33 ± 0.13 mmol TE/g). The methanolic extracts were subjected to LC-DAD-MSⁿ and NMR analysis. A two-column LC method was developed to separate constituents, allowing to identify and quantify forty-four and fifteen constituents in bark and fruits, respectively. Main compound in bark was epicatechin-3-O-sulphate and isolation of compound was performed to confirm its identity. Bark extract contained catechins, procyanidins, gallic acid derivatives and the sulfur containing spiroketal named breynins. Aerial parts mostly contained flavonoid glycosides. Considering the bioassays, the methanolic bark extract resulted a potent tyrosinase (152.79 ± 0.27 mg kojic acid equivalent/g), α-amylase (0.99 ± 0.01 mmol acarbose equivalent ACAE/g) and α-glucosidase (2.16 ± 0.01 mmol ACAE/g) inhibitor. In conclusion, methanol is able to extract the efficiently the phytoconstituents of B. retusa and the bark is the most valuable source of compounds.