Characterisation of polyphenols by HPLC-PAD-ESI/MS and antioxidant activity in Equisetum telmateia

Biological Activities of Ceratonia siliqua Pod and Seed Extracts: A Comparative Analysis of Two Cretan Cultivars

Ceratonia siliqua L., commonly known as the carob tree, appears in most Mediterranean countries, often cultivated for the collection of its fruits to be used as food for humans and animals. This study was aimed at the phytochemical characterization of two common Cretan C. siliqua cultivars and the biological evaluation of deseeded pod and seed extracts regarding their putative use in cosmetics. Gas and liquid chromatographic techniques were used to assess their essential oil, fatty acid, and carbohydrate profiles. Cell-free assays, including free-radical scavenging; the inhibition of tyrosinase and collagenase; the blocking of advanced glycation end product (AGE) formation; along with assays in human skin fibroblast cultures, i.e., reactive oxygen species suppression, glutathione stimulation, and protection from oxidative stress and from ultraviolet (UVB) radiation, were also used. Extracts from both cultivars were found to possess antioxidant capacity, tyrosinase- and collagenase-inhibitory activities, an ability to block glucose-induced AGEs, and in certain cases, UVB absorbance and photoprotective activities. Seed extracts were in general more active, while the use of 30% aqueous methanol seemed to be more efficient than n-hexane for extraction. Serial partition of the most active extracts resulted in fractions with enriched biological activities. These properties make Cretan carob extracts and their fractions suitable candidates for use in cosmetics.

Genus Equisetum L: Taxonomy, toxicology, phytochemistry and pharmacology

INTRODUCTION

The genus Equisetum (Equisetaceae) is cosmopolitan in distribution, with 41 recognized species. Several species of Equisetum are widely used in treating genitourinary and related diseases, inflammatory and rheumatic problems, hypertension, and wound healing in traditional medicine practices worldwide. This review intends to present information on the traditional uses, phytochemical components, pharmacological activities, and toxicity of Equisetum spp. and to analyze the new insights for further study.

METHODS

Relevant literature has been scanned and collected via various electronic repositories, including PubMed, Science Direct, Google Scholar, Springer Connect, and Science Online, from 1960 to 2022.

RESULTS

Sixteen Equisetum spp. were documented as widely used in traditional medicine practices by different ethnic groups throughout the world. A total of 229 chemical compounds were identified from Equisetum spp. with the major group of constituents being flavonol glycosides and flavonoids. The crude extracts and phytochemicals of Equisetum spp. exhibited significant antioxidant, antimicrobial, anti-inflammatory, antiulcerogenic, antidiabetic, hepatoprotective, and diuretic properties. A wide range of studies have also demonstrated the safety of Equisetum spp.

CONCLUSION

The reported pharmacological properties of Equisetum spp. support its use in traditional medicine, though there are gaps in understanding the traditional usage of these plants for clinical experiments. The documented information revealed that the genus is not only a great herbal remedy but also has several bioactives with the potential to be discovered as novel drugs. Detailed scientific investigation is still needed to fully understand the efficacy of this genus; hence, very few Equisetum spp. were studied in detail for phytochemical and pharmacological investigation. Moreover, its bioactives, structure-activity connection, in vivo activity, and associated mechanism of action ought to be explored further.

Phytochemistry and Pharmacology of the Genus Equisetum (Equisetaceae): A Narrative Review of the Species with Therapeutic Potential for Kidney Diseases

The Equisetum genus, Equisetaceae family, is widely distributed worldwide and may be the oldest nonextinct genus on Earth. There are about 30 known species, which are very often used in traditional medicine with diverse applications. This review aimed to compile scientific reports about Equisetum species with relevant pharmacological properties and/or therapeutic potential for kidney diseases. Our bibliographic survey demonstrates that the most widespread traditional use of Equisetum is as a diuretic, followed by the treatment of genitourinary diseases (kidney diseases, urethritis, kidney stones, and others), inflammation, wound healing, rheumatic diseases, prostatitis, and hypertension. The most popular species from the Equisetum genus with medicinal use is E. arvense L., whose diuretic effect was confirmed in animal models and clinical trials. The species E. bogotense Kunth also demonstrated the beneficial effect of inducing diuresis in both experimental and clinical assays. Several other species have also been studied regarding their therapeutic potential, showing different biological actions. Regarding the chemical composition, it contains many active constituents, such as alkaloids, flavonoids, phenol, phytosterols, saponins, sterols, silicic acid, tannin, triterpenoids, and volatile oils. However, despite the widespread traditional use, many species need to be explored in detail for scientific validation of popular use. Indeed, the species of the Equisetum genus have great potential in the management of kidney disorders.

Hepatic and gastroprotective activity of Serjania marginata leaf aqueous extract in Nile tilapia (Oreochromis niloticus)

The aim of this study was to assess the leaf aqueous extract composition of Serjania marginata and the effects of its inclusion on the diet of Nile tilapia (Oreochromis niloticus), with respect to the activity of digestive enzymes and enzymes associated with the metabolism of the liver and intestine and liver histopathology. Fish (initial mean weight, 54.36 ± 17.04 g) were divided into groups: fasting (without feeding), control (commercial feed), and treatment (commercial feed with leaf aqueous extract of Serjania marginata), and in each aquarium, there were five individuals and the fish fed ad libitum for 15 days. Treatment fish had ingested on average 224.3 mg of extract/kg of fish/day. In the extract analysis by mass spectrometry, quercitrin, isoquercitrin, A-type proanthocyanidin trimer, and quinic acid were identified. In the enzymatic activity, fish from the treatment group showed higher level of alkaline phosphatase, while the hepatotoxic markers (AST and ALT) and levels of lipase, amylase, and nonspecific protease did not differ (p > 0.05). In liver histopathological analysis, it was observed that fish from the treatment showed normal structure, while abnormalities were associated with control (fibrosis, loss of cordonal architecture, vacuolated hepatocytes with nucleus displaced to the periphery) and fasting (reduction in hepatocyte size and sinusoidal space). The intestine histopathology evidenced that the extract favored the development of goblet cells and intestinal fold height. The results indicated that the leaf aqueous extract of S. marginata assists in the structural maintenance of the liver and intestine and stimulates intestinal alkaline phosphatase production in Nile tilapia, suggesting that the identified compounds act on the liver and intestine, showing hepatoprotective effects and stimulating intestinal digestion.

Toxicological safety evaluation in acute and 28-day studies of aqueous extract from Serjania marginata Casar. (Sapindaceae) leaves in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Serjania marginata Casar. (Sapindaceae) is a species traditionally known to be used for the treatment of gastric pain and inflammatory symptoms.

AIM OF THIS STUDY

Due to the therapeutic importance of this species, this study investigated the toxicological effects of S. marginata leaves (AESM), after a single and a repeated exposure in rats.

MATERIALS AND METHODS

For the acute toxicity test, 2000 mg/kg of AESM was administered to male and female rats by gavage, whereas for subacute toxicity test, 30, 150, or 750 mg/kg of AESM were used.

RESULTS

No evidence of toxicity was observed in the animals acutely exposed to the extract, indicating that the LD₅₀ is higher than 2000 mg/kg. After the repeated administration of AESM the hematological and biochemical parameters were unaltered, except the erythrocytes number and albumin levels in the exposed animals. Moreover, daily administration of this extract caused alteration on kidney histology. AESM also induced an increase of abnormal sperm, however the other reproductive parameters analyzed, in both sexes, were not altered by the treatment.

CONCLUSION

Although AESM was not toxic after a single exposure, its use after prolonged periods affected some analyzed parameters, indicating that precautions should be taken when it is given over longer periods.

Equisetum telmateia extracts: Chemical compositions, antioxidant activity and antimicrobial effect on the growth of some pathogenic strain causing poisoning and infection

The aerial parts of Equisetum telmateia have been used as a source of biologically active compounds to treat inflammatory, diarrhea, stomach-ache, eczema and mouth infections in traditional medicine. The aim of this work is to evaluate the extraction yield, chemical compositions, antioxidant activity and antimicrobial activity of E. telmateia extracts on Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella typhi and Candida albicans. Chemical compositions E. telmateia was analyzed by high performance liquid chromatography (HPLC) using a C18 column. Analysis of E. telmateia extract by HPLC allowed the identification of Kaempferol 3-O-(6″-O-acetylglucoside) as major compound. The antioxidant activity of extracts was examined by measuring their ability to sequestrate 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. The results showed that the DPPH (IC₅₀ = 70.83 ± 0.2 μg/ml) were obtained in the case of supercritical fluid extraction (SFE) extract. MIC microdilution assay were used to determine the antimicrobial activities. Contrary to lower extraction yield (9.6 ± 0.5), the SFE extract exhibited the highest antimicrobial potency with MIC and MBC values of 32 mg/ml against S. aureus compared to the other extracts. The results suggest that SFE method is more appropriate for extraction of E. telmateia biologically active substances with antimicrobial and antioxidant activity than conventional solvent extraction methods.

Inhibition of 5α-Reductase, IL-6 Secretion, and Oxidation Process of Equisetum debile Roxb. ex Vaucher Extract as Functional Food and Nutraceuticals Ingredients

This study aims to investigate the biological activities related to hair loss of Equisetum debile extracts, including 5α-reductase inhibition, interleukin-6 (IL-6) secretion reduction, and anti-oxidation. E. debile extracts were obtained by maceration in various solvents. Crude extract (CE) was obtained by maceration in 95% ethanol. Chlorophyll-free extract (CF) was the CE which of the chlorophyll has been removed by electrocoagulation. Hexane extract (HE), ethyl acetate extract (EA), and ethanolic extract (ET) were fraction extracts obtained from maceration in hexane, ethyl acetate, and 95% ethanol, respectively. The extracts were investigated for inhibitory activity against 5α-reductase and IL-6 secretion. Total phenolic contents (TPC) were investigated and antioxidant activities were determined by means of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2′-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The inhibition of lipid peroxidation was determined by the ferric thiocyanate method. The cytotoxicity of the extracts on dermal papilla cells and irritation test by hen's egg test chorioallantoic membrane assay were also investigated. All extracts could inhibit 5α-reductase and decrease IL-6 secretion in lipopolysaccharide-stimulated macrophage. The antioxidant activity of E. debile extracts was directly related to their TPC. ET which contained the highest TPC (68.8 ± 6.7 mg GA/g) showed the highest equivalent concentration (EC₁) of 289.1 ± 26.4 mM FeSO₄/g, TEAC of 156.6 ± 34.6 mM Trolox/g, and 20.0 ± 6.0% DPPH inhibition. However, EA exhibited the highest inhibition against lipid peroxidation (57.2 ± 0.4%). In addition, EA showed no cytotoxicity on dermal papilla cell line and no irritation on chorioallantoic membrane of hen’s eggs. In conclusion, EA was suggested as the most attractive ingredients for functional food and nutraceuticals because of the high inhibitory activity against 5α-reductase, IL-6 secretion, and lipid peroxidation inhibition.

Contribution of the phenolic composition to the antioxidant, anti-inflammatory and antitumor potential of Equisetum giganteum L. and Tilia platyphyllos Scop

Naturally-occurring phytochemicals have received pivotal attention in the last few years, due to the increasing evidence of biological activities. Thus, in the present study, the antioxidant, anti-inflammatory and antitumor potentials of hydroethanolic extracts rich in phenolic compounds obtained from Equisetum giganteum L. and Tilia platyphyllos Scop. were assessed and directly correlated with their content of phenolic compounds, by using HPLC-DAD-ESI/MS analysis. T. platyphyllos showed the higher bioactive potential, evaluated in terms of antioxidant (radical scavenging effects - 105 μg mL^-1, reducing power - 123 μg mL^-1, β-carotene bleaching inhibition - 167 μg mL^-1, and lipid peroxidation inhibition - 56 μg mL^-1), anti-inflammatory (225 μg mL^-1 inhibited 50% of nitric oxide production) and antitumor (breast - 224 μg mL^-1; lung - 247 μg mL^-1; cervical - 195 μg mL^-1 and hepatocellular - 173 μg mL^-1 carcinoma cells) activity, without having cytotoxic effects (>400 μg mL^-1). These biological properties were positively correlated with its content and composition of phenolic compounds. Flavonoid contents were markedly higher than the content of phenolic acids, in both samples, being respectively 50.4 mg g^-1 and 11.65 mg g^-1 for T. platyphyllos, and 21.7 mg g^-1 and 4.98 mg g^-1 for E. giganteum. Moreover, while in E. giganteum extract, kaempferol-O-glucoside-O-rutinoside was the most abundant flavonoid, in T. platyphyllos extract protocatechuic acid and (-)-epicatechin were the most abundant phenolic acid and flavonoid, respectively. In relation to their content of phenolic acids, protocatechuic and caffeic acids existed in higher abundance in T. platyphyllos and E. giganteum hydroethanolic extracts, respectively. However, it would be interesting to evaluate the in vivo efficacy of both plant extracts to unveil the involved modes of action and to establish effective therapeutic doses.

Bioactive properties and functional constituents of Hypericum androsaemum L.: A focus on the phenolic profile

Hypericum androsaemum L. ethanol:water extract acted as a lipid peroxidation inhibitor and free radical scavenger. A marked inhibition of the growth of breast, lung, cervical and hepatocellular human carcinoma cell lines was also observed, whereas no toxicity was shown against non-tumor porcine liver cells (>400μg/mL). The extract was also effective in inhibiting nitric oxide production, as an indicator of the anti-inflammatory potential. The anti-Candida effects varied among different strains of the same species, C. glabrata and C. tropicalis being the most sensible species with an effect directly related with the extract concentrations tested. A significant anti-biofilm formation potential was also observed, namely for C. glabrata and C. tropicalis (biofilm reduction >90%). 5-O-Caffeoylquinic and 3-O-caffeoylquinic acids were the most abundant phenolic compounds identified in the extract, and might be related with the observed bioactive effects. Nevertheless, future studies should be carried out to obtain dose-response curves of the isolated active compounds, in order to perform further pre-clinically testing to quantify the presence of the most active compounds in the extract.

Medicinal plants used for cardiovascular diseases in Navarra and their validation from official sources

ETHNOPHARMACOLOGICAL RELEVANCE

This paper provides significant ethnopharmacological information on plants used to treat cardiovascular diseases in Navarra, Spain.

MATERIAL AND METHODS

Information was collected using semi-structured ethnobotanical interviews with 667 informants (mean age 72; 55.47% women, 44.53% men) in 265 locations. Official sources such as the European Scientific Cooperative on Phytotherapy (ESCOP), German Commission E, World Health Organization (WHO), European Medicines Agency (EMA), European Pharmacopoeia (Ph. Eur.) and Real Farmacopea Española (RFE) monographs were consulted in order to establish the therapeutic efficacy of the reported uses and to obtain further details about quality and safety aspects. A literature review was carried out on the plants that were most frequently cited and were not the subject of a monograph, using a new tool developed by the University of Navarra, UNIKA.

RESULTS

A total of 460 pharmaceutical uses were reported by the informants, belonging to 90 plant species and 39 families, mainly represented by Urticaceae, Rosaceae, Asteraceae, and Equisetaceae. The most frequently used parts of the plants were the aerial parts followed by leaves and flowers. Seventeen out of 90 plants (19%) and 208 out of 460 popular uses (45%) had already been pharmacologically validated in relation to their therapeutic efficacy and safety aspects.

CONCLUSIONS

The authors propose to validate five species for their use in cardiovascular diseases: Rhamnus alaternus L., Potentilla reptans L., Equisetum telmateia Ehrh., Centaurium erythraea Rafn and Parietaria judaica L.

Protective Effect of Standardized Extract of Ginkgo biloba against Cisplatin-Induced Nephrotoxicity

Cisplatin (CDDP) is a potent antitumor compound widely used with a notably side effect of nephrotoxicity inducing oxidative stress and apoptosis in kidneys. Standardized extract from the leaves of the Ginkgo biloba trees, labeled EGb761 (EGb), has been available on the market for its beneficial effects. The purpose of this study was to investigate the ability of EGb to prevent the nephrotoxic effect of CDDP and the mechanisms involved. Our results showed that EGb treatment restored the levels of creatinine, BUN, MDA, NO, SOD, CAT, GPx, and GSSG/GSH ratio in kidneys after CDDP injection. EGb also exhibited a tendency to decrease the elevated NF-κB translocation and caspase-3 protein levels in CDDP-treated kidneys. We further used a porcine kidney proximal tubular epithelial (LLC-PK1) cell line, finding that EGb accordingly inhibited ROS accumulation and iNOS increase induced by CDDP in vitro. EGb also attenuated IκB degradation and p65 NF-κB phosphorylation triggered by CDDP in LLC-PK1 cells. But EGb failed to influence CDDP-stimulated caspase cascade. These findings suggested that EGb's renoprotective effect might be mediated by not only its well-known antioxidant activity but also the anti-inflammatory activity.

Volatile Composition of Six Horsetails: Prospects and Perspectives

Six horsetails were investigated for volatile organic compounds (VOC) by GC-MS using organic solvent extraction. Seventy-five VOC biosynthesized from the shikimic, lipidic and terpenic pathways including isoprenoid derivatives were detected from these putative natural resources. E. palustre var. americana contained mainly lipidic derivatives, i.e., 1-octen-3-ol (mushroom-like odor), ( E)-2-hexenoic acid (fruity odor) and ( E)-2-hexenal (green odor). Many isoprenoid flavour precursors, i.e., 3-oxo-α-ionol (spicy odor) and ( E, E)-pseudoionone (balsamic odor), as well as odorous benzenic derivatives, i.e, phenylethanal (hyacinth, lilac note) and 2-phenylethanol (rose odor) contributed to the odor of E. arvense. The volatile pattern of E. telmateia is dominated by high amounts of isoprenoids and benzenic derivatives. The complex volatile profiles of E. hyemale and E. ramosissimum are based on ferulic acid isomers, along with either ( E)-2-heptenal (green vegetable-like odor) or 4-vinylguaiacol (spicy clove smoky odor) for E. hyemale and E ramosissimum, respectively. The broad spectrum of E. scirpioides shows the lowest VOC content with high amount of isoprenoids (46.9%), mainly ionone derivatives. Equisetum resources are of great interest as bioactive litter and new potential functional feed ingredients.

Cinnamtannin B-1 as an antioxidant and platelet aggregation inhibitor

Cinnamtannin B-1 is a naturally occurring trimeric A-type proanthocyanidin, present in a limited number of plants, which exhibits a large number of cellular actions mostly derived from its antioxidant properties. Cinnamtannin B-1 modulates several biological processes such as changes in cytosolic free Ca(2+) concentration, endogenous reactive oxygen species generation, protein tyrosine phosphorylation and platelet aggregation. Proanthocyanidins, such as cinnamtannin B-1, have been reported to exert antitumoral activity mediated by a selective proapoptotic action in a number of tumoral cell lines associated with antiapoptotic activity in normal cells. The opposite effects of proanthocyanidins in normal and tumoral cells suggest that these compounds might be the base for therapeutic strategies directed selectively against tumoral cells. In addition, cinnamtannin B-1 shows antithrombotic actions through inhibition, in platelets, of endogenous ROS generation, Ca(2+) mobilization and, subsequently, aggregation. This has been reported to be especially relevant in platelets from diabetic patients, where cinnamtannin B-1 reverses both platelet hypersensitivity and hyperactivity. Considering the large number of cellular effects of cinnamtannin B-1 the development of therapeutic strategies for thrombotic disorders or certain types of cancer deserves further studies. This review summarizes the current knowledge on the actions and relevance of the signalling pathways modulated by cinnamtannin B-1.

Antioxidant, antimicrobial and genotoxicity screening of hydro-alcoholic extracts of five serbian Equisetum species

The hydro-alcoholic extracts of five Equisetum species, E. arvense L., E. sylvaticum L., E. fluviatile L., E. palustre L. and E. telmateia Ehrh., growing-wild in Serbia were evaluated for their genotoxicity, antimicrobial activity, antioxidant capacity and the results related to the total phenol content and HPLC flavonoid profiles. The total phenol content was 92-349 micromol expressed as equivalents of chlorogenic acid per g of dried plant material. Main identified compounds were kaempferol-, quercetin- glycosides and caffeic acid derivatives. E. telmateia extract showed the greatest antioxidant capacity. Almost all tested microorganisms demonstrated some degree of sensitivity to the examined extracts. All tested extracts at 62.5 microg/ml showed higher incidence of micronucleus formation than in the control sample. The obtained data allowed mutual comparison of examined species and their assessment as possible sources of antioxidants, antimicrobials and/or genotoxic substances.

Liquid chromatography/electrospray ionization tandem mass spectrometry profiling of compounds from the infusion of Byrsonima fagifolia Niedenzu

A rapid analytical approach suitable to achieve a comprehensive characterization of the compounds present in the infusion prepared from the leaves of Byrsonima fagifolia Niedenzu (Malpighiaceae), a Brazilian plant used as an infusion to treat gastric disorders, was developed. The method was based on high-performance liquid chromatography coupled to electrospray negative ionisation multistage ion trap mass spectrometry (HPLC/ESI-ITMSn). The main ions in the ESI-ITMS spectra were attributed to a quinic acid core containing from one to five galloyl units. Quercetin derivatives containing one and two sugar moieties as well as galloyl esterification were also detected. These results indicated that HPLC/ESI-ITMSn is easily applicable to infusions of this plant and allows the rapid and direct identification of these compounds in crude plant extracts.

Identification of phenolic constituents in Radix Salvia miltiorrhizae by liquid chromatography/electrospray ionization mass spectrometry

The phenolic components from Radix Salvia miltiorrhizae Bunge, a well-known herbal medicine (Dan-Shen in Chinese), have been investigated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI-MS/MS). HPLC analyses were performed on a reversed-phase C18 column using gradient elution. In the ESI mass spectra a predominant [M-H]- ion was observed in negative mode and provided molecular mass information. ESI-MS/MS spectra of the [M-H]- ions were used for structural analysis, based on the spectra of standards. It was found that caffeic acid and its monomeric analogs containing a carboxyl group readily lost CO2, while dimers, trimers and tetramers of caffeic acid expelled successively danshensu or caffeic acid or their esters. Twenty-eight phenolic compounds in S. miltiorrhizae were characterized, of which eight compounds were positively identified by comparison with standards. The remaining twenty phenolics for which standards were not available were tentatively identified based on their UV spectra and MS/MS fragmentation characteristics.