Genus Equisetum L: Taxonomy, toxicology, phytochemistry and pharmacology

Antioxidant and anti-inflammatory effects of Equisetum arvense L. on acid-induced ulcerative colitis in rats

Equisetum arvense L. (EAL) has a long history in traditional medicine for its ability to address various digestive and inflammatory conditions. Here, we aimed to evaluate the therapeutic potential of the EAL hydroalcoholic extract (HAEA) compared with the standard medications in a rat model of ulcerative colitis (UC) caused by acetic acid. Eighty-one male Sprague Dawley rats were acquired and randomly allocated into nine equal groups: healthy control group, negative control groups (receiving normal saline and carboxymethyl cellulose gel base), positive control groups (receiving asacol rectally and mesalazine orally), and test groups treated with different amounts of HAEA. At the end of the experiment (7 days), colonic injury was evaluated by macroscopic, biochemical, and stereological assessments. The effectiveness of HAEA on colonic tissue was proved by significantly decreasing the malondialdehyde (MDA) and interleukin-1β (IL-1β) concentrations as well as myeloperoxidase (MPO) activity and increasing the superoxide dismutase (SOD) activities and glutathione peroxidase (GPx) in comparison to negative control groups. Particularly, the HAEA gel 10% rectal enema was significantly effective in decreasing MDA and IL-1β, as well as increasing GPx and SOD activities in comparison to positive control groups (P < 0.05). According to the stereological evaluations, HAEA 600 mg/kg orally and gel 10% rectal enema-treated groups, as well as the positive control groups, had significantly higher epithelium, submucosa, and muscularis mucosa volume density in comparison to the negative control groups (P < 0.001). This study showed promising therapeutic effects in all HAEA-treated groups, particularly HAEA gel 10% rectal enema in the induced UC rat model compared to conventional treatments. Both in vivo and in vitro findings indicate that EAL has the potential to be used as an additive therapeutic strategy in UC patients.

A unique Equisetum enzyme, hetero-trans-β-glucanase (HTG), enhances industrially and environmentally important cellulose-rich materials

Gigatons of cellulose are synthesised and degraded annually. Under-utilised cellulose, e.g. from sugar-beet pulp ('Curran') and recycled paper, could be valorised by Equisetum hetero-trans-β-glucanase (HTG), the only known enzyme modifying cellulose non-destructively. It catalyses hetero-transglycosylation, with cellulose as donor substrate and xyloglucan oligosaccharides (XGOs) as acceptor, creating cellulose-XGO covalent bonds. Interestingly, XGOs participate in this reaction even if linked to a biotechnologically-valuable 'cargo', e.g. a dye, fluorophore, cation, anion, hydrophobic compound or antibiotic, beneficially functionalising the cellulose. Here, we tested whether HTG acts on intransigent agricultural/industrial celluloses. Curran was found to be pectin- and hemicellulose-poor, but cellulose-rich product, thus potentially enhanceable by HTG technology. To generate industrial quantities of HTG, we explored Equisetum extraction methods, comparing extractants (buffers versus tap-water), extractant ratios, homogenisation technique, work-up (centrifugation versus filtration) and salting out. Pleasingly, simplified 'industrial' methods were 75-85% as effective as laboratory methods. Up-scaled heterologous expression in Pichia also yielded plentiful EfHTG. Thus diverse methods enabled bulk HTG production. All HTG preparations tested acted on pure cellulose (Whatman filter-paper; donor substrate) and radioactive or fluorescent cargo-bearing XGOs ([3H]XXXGol or XXXGol-sulphorhodamine respectively; model acceptor substrates). Diverse HTG preparations acted on potentially 'intractable' celluloses, e.g. Curran and crude recycled brown card, at rates comparable to those on pure celluloses (filter-paper and virgin white never-dried pulp). Where necessary, coarse industrial celluloses were H2SO4-hydrolysed to expose underestimated signal from incorporated but 'masked' radioactive substrate. Unlike surface-finish modifications, HTG-catalysed bonding of cargoes to cellulose is covalent (thus highly stable) and environmentally friendly (green sustainable technology).

Bioaccessibility and Functional Food Potential of Equisetum telmateia Ehrh. Against Diabetes-Induced Kidney Disorders

Various species from the genus Equisetum are recorded as food and folk medicine against both kidney complications and diabetes. Equisetum telmateia Ehrh. is documented as a folk remedy in Türkiye against several kidney disorders. This study was designed to evaluate the possible protective mechanisms of E. telmateia EtOH extract (ETE) against kidney disorders and diabetes through different routes, such as the prevention of ROS formation, inhibitory potential against various DM-related enzymes, and a reduction in the amount of the mediators leading to disorders in both systems at the cellular level. The objective was to achieve advanced precision for in vitro results while considering the effect of GIS on oral consumption. Both phytochemical and bioactivity studies were conducted before and after simulated digestion. The results showed that ETE is a rich source of flavonoids and phenolic acids. In addition, it has significant antioxidant and enzyme inhibitory potential. Treatment also yielded promising results at the cellular level for both antioxidative and inhibitor proteins, which may play a role in the pathogenesis of kidney disorders and diabetes. Following the in vitro digestion procedure, both the number of phytochemical ingredients and bioactivity parameters showed a considerable decreasing trend; however, the results are still significant enough to justify the traditional utilization of the genus Equisetum. This investigation demonstrated that ETE has noteworthy potential as a functional food for protection against diabetic kidney disease.

From Stem to Spectrum: Phytochemical Characterization of Five Equisetum Species and Evaluation of Their Antioxidant Potential

The Equisetaceae family, commonly known as horsetails, has been of scientific interest for decades due to its status as one of the most ancient extant vascular plant families. Notably, the corresponding species have found their place in traditional medicine, offering a wide array of applications. This study presents a comprehensive phytochemical analysis of polar secondary metabolites within the sterile stems of five distinct Equisetum species using HPLC-DAD-ESI-MSn. For this purpose, fresh plant material was extracted with acetone/water, and the resulting crude extracts were fractionated using dichloromethane, ethyl acetate, and n-butanol, respectively. The results reveal a complex array of compounds, including hydroxycinnamic acids, hydroxybenzoic acids, flavonoids, and other phenolic compounds. In addition, total phenolic contents (Folin-Ciocalteu assay) and antioxidant activities (DPPH assay) of the plant extracts were evaluated using spectrophotometric methods. The present comparative analysis across the five species highlights both shared and species-specific metabolites, providing valuable insights into their chemical diversity and potential pharmacological properties.

Distinction and quantification of Panax polysaccharide extracts via attenuated total reflectance-Fourier transform infrared spectroscopy with first-order derivative processing

Derivative spectroscopy is used to separate the small absorption peaks superimposed on the main absorption band, which is widely adopted in modern spectral analysis to increase both the valid spectral information and the identification accuracy. In this study, a method based on attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) with first-order derivative (FD) processing combined with chemometrics is proposed for rapid qualitative and quantitative analysis of Panax ginseng polysaccharides (PGP), Panax notoginseng polysaccharides (PNP), and Panax quinquefolius polysaccharides (PQP). First, ATR-FTIR with FD processing was used to establish the discriminant model combined with principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and linear discriminant analysis (LDA). After that, two-dimensional ATR-FTIR based on single-characteristic temperature as external interference (2D-sATR-FTIR) was established using ATR-FTIR with FD processing. Then, ATR-FTIR with FD processing was combined with PLS to establish and optimize the quantitative regression model. Finally, the established discriminant model and 2D-sATR-FTIR successfully distinguished PGP, PNP and PQP, and the optimal PLS regression model had a good prediction ability for the Panax polysaccharide extracts content. This strategy provides an efficient, economical and nondestructive method for the distinction and quantification of PGP, PNP and PQP in a short detection time.

Ibuprofen-Loaded Silver Nanoparticle-Doped PVA Gels: Green Synthesis, In Vitro Cytotoxicity, and Antibacterial Analyses

In contrast to conventional drug delivery systems, controlled drug release systems employ distinct methodologies. These systems facilitate the release of active substances in predetermined quantities and for specified durations. Polymer hydrogels have gained prominence in controlled drug delivery because of their unique swelling-shrinkage behavior and ability to regulate drug release. In this investigation, films with a hydrogel structure were crafted using polyvinyl alcohol, a biocompatible polymer, and silver nanoparticles. Following characterization, ibuprofen was loaded into the hydrogels to evaluate their drug release capacity. The particle sizes of silver nanoparticles synthesized using a green approach were determined. This study comprehensively examined the structural properties, morphological features, mechanical strength, and cumulative release patterns of the prepared films. In vitro cytotoxicity analysis was employed to assess the cell viability of drug-loaded hydrogel films, and their antibacterial effects were examined. The results indicated that hydrogel films containing 5% and 10% polyvinyl alcohol released 89% and 97% of the loaded drug, respectively, by day 14. The release kinetics fits the Korsmeyer-Peppas model. This study, which describes nanoparticle-enhanced polyvinyl alcohol hydrogel systems prepared through a cost-effective and environmentally friendly approach, is anticipated to contribute to the existing literature and serve as a foundational study for future research.