Vescalagin and Castalagin Present Bactericidal Activity toward Methicillin-Resistant Bacteria

Assessing Therapeutic Value and Side Effects of Key Botanical Compounds for Optimized Medical Treatments

Due to the significance of variable chemical groups across a wide spectrum of modern medicine, it is imperative to determine what is the most widely used group in medical applications with the fewest side effects. Ten compounds from ten chemical groups that are most commonly known for their medical uses were compared in terms of their therapeutic potential and side effects. The comparison among the selected compounds indicated the superiority of the flavonoids over other groups in the multitude of their utilizations and the lower side effects. Kaempferol and quercetin showed higher medical utilization with lower side effects. Whereas alkaloid compounds showed the lowest levels of medical use and the highest levels of side effects. Based on the comparison conducted, it is concluded to give priority to flavonoid compounds being used in medical applications because they exhibit the highest medical uses with the lowest side effects. Within flavonoids, kaempferol and quercetin are the two compounds that are highly recommended to be used in the widest range of medical applications. Serious caution should be considered before applying alkaloids to any medical service. Understanding the characteristics of these compounds can aid in developing safer and more effective treatments for medicinal plants.

Biotransformation of camu-camu galloylated ellagitannins by Lactiplantibacillus plantarum with extracellular tannase activity

Some strains of Lactiplantibacillus plantarum produce specific tannases that could enable the metabolism of ellagitannins into more bioavailable phenolic metabolites, thereby promoting the health effects of these polyphenols. However, the metabolic ability of these strains remains poorly understood. In this study, we analyzed the ability of broad esterase-producing (Est_1092+) and extracellular tannase-producing (TanA+) strains to convert a wide assortment of ellagitannins from camu-camu (Myrciaria dubia) fruit. To this end, forty-three strains were screened to identify and sequence (WGS) those producing Est_1092. In addition, six previously reported TanA+ strains were included in the study. Each strain (Est_1092+ or TanA+) was inoculated into a minimal culture medium supplemented with an aqueous camu-camu extract. After fermentation, supernatants were collected for semi-quantification of ellagitannins and their metabolites by mass spectrometry. For analysis, the strains were grouped according to their enzyme type and compared with an Est_1092 and TanA-lacking strain. Out of the forty-three isolates, three showed Est_1092 activity. Of the Est_1092+ and TanA+ strains, only the latter hydrolyzed the tri-galloyl-HHDP-glucose and various isomers of HHDP-galloyl-glucose, releasing HHDP-glucose and gallic acid. TanA+ strains also transformed three isomers of di-HHDP-galloyl-glucose, liberating di-HHDP-glucose and gallic acid. Overall, TanA+ strains released 3.6-4.9 times more gallic acid than the lacking strain. In addition, those exhibiting gallate decarboxylase activity pursued gallic acid metabolism to release pyrogallol. Neither Est_1092+ nor TanA+ strains transformed ellagitannin-core structures. In summary, TanA+ L. plantarum strains have the unique ability to hydrolyze a wide range of galloylated ellagitannins, releasing phenolic metabolites with additional health benefits.

Chelation of iron(II) ions by ellagitannins-Effects of hexahydroxydiphenoyl and nonahydroxytriphenoyl groups

Tannins represent secondary plant metabolites that are used to control bacterial populations by chelation of essential metal ions. Their presence in food also affects the bioavailability of iron. This study investigates the influence of ellagitannins (vescalin, castalin, vescalagin, castalagin) structure and pH on the stoichiometry and formation constants of ellagitannin-Fe(II) coordination compounds. We demonstrated that ellagitannins are stable for at least one hour at pH values lower than 7.25. The spectra of neutral compounds were measured and explained with the help of TDDFT calculations. Furthermore, the pH-dependence of the ellagitannins UV-Vis spectra was examined to obtain insight into their protolytic equilibrium. Using Job's method in the pH range 3.50-5.51, the stoichiometry of the formed ellagitannin-Fe(II) ions complexes was determined. A model explaining interactions between ellagitannins and Fe(II) ions, that took into account the protolytic equilibrium of ellagitannins, was fitted globally to all four Job plots, whereby the corresponding formation constants were obtained.

Polyphenol-enriched extracts of Sarcopoterium spinosum fruits for counteracting lipid accumulation and oxidative stress in an in vitro model of hepatic steatosis

Sarcopoterium spinosum (L.) Spach is a Rosaceae shrub employed in the folk medicine in the Eastern Mediterranean basin. The previous few studies have focused on the S. spinosum roots, while the fruits have been poorly investigated. The present study aims to assess the biological properties of S. spinosum fruits collected in Lebanon and subjected to ethanolic, water or boiling water extraction. The extracts were compared for the phenol and flavonoid contents, and for the in vitro radical scavenging ability. The ethanolic extract (SEE) was selected and characterized by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) showing a phenolome rich in tannins (ellagitannins), flavonoids (quercetin derivatives), and triterpenes. The biological activity of SEE was tested on a cellular model of moderate steatosis consisting of lipid-loaded hepatic cells treated with increasing concentrations of SEE (1-25 μg/mL), or with corilagin or quercetin as comparison. In steatotic hepatocytes the SEE was able (i) to ameliorate the hepatosteatosis; (ii) to counteract the excess ROS and lipid peroxidation; (iii) to restore the impaired catalase activity. The results indicate that the ethanolic extract from S. spinosum fruits is endowed with relevant antisteatotic and antioxidant activities and might find application as nutraceutical product.

Therapeutic Effects of Oral Application of Menthol and Extracts from Tormentil (Potentilla erecta), Raspberry Leaves (Rubus idaeus), and Loosestrife (Lythrum salicaria) during Acute Murine Campylobacteriosis

Human food-borne infections with the enteropathogen Campylobacter jejuni are becoming increasingly prevalent worldwide. Since antibiotics are usually not indicated in campylobacteriosis, alternative treatment regimens are important. We here investigated potential disease-alleviating effects of menthol and of extracts from tormentil, raspberry leaves, and loosestrife in acute murine campylobacteriosis. Therefore, C. jejuni-infected microbiota-depleted IL-10-/- mice were orally treated with the compounds alone or all in combination from day 2 until day 6 post-infection. Whereas neither treatment regimen affected gastrointestinal pathogen loads, the combination of compounds alleviated C. jejuni-induced diarrheal symptoms in diseased mice on day 6 post-infection. Furthermore, the therapeutic application of tormentil and menthol alone and the combination of the four compounds resulted in lower colonic T cell numbers in infected mice when compared to placebo counterparts. Notably, pro-inflammatory cytokines measured in mesenteric lymph nodes taken from C. jejuni-infected mice following tormentil, menthol, and combination treatment did not differ from basal concentrations. However, neither treatment regimen could dampen extra-intestinal immune responses, including systemic pro-inflammatory cytokine secretion on day 6 post-infection. In conclusion, the combination of menthol and of extracts from tormentil, raspberry leaves, and loosestrife constitutes an antibiotic-independent approach to alleviate campylobacteriosis symptoms.

Elaeagnus umbellata: A miraculous shrub with potent health-promoting benefits from Northwest Himalaya

Medicinal plants encompassing a series of bioactive compounds have gained significant importance for use in the treatment of different diseases. Of them, Elaeagnus umbellata Thunb. (Deciduous shrub found in dappled shade, and sunny hedge) exhibits high medicinal value, with a widespread distribution across the Pir Panjal region of the Himalayas. Fruits serve as an excellent source of vitamins, minerals, and other essential compounds that exhibits hypolipidemic, hepatoprotective, and nephroprotective effects. The phytochemical fingerprint of berries revealed them to have a high content of polyphenols (with major proportion of anthocyanins), followed by monoterpenes and vitamin C. Extract of fruits help in regulating the digestion and absorption of glucose and reduces inflammation and oxidative stress. The phytosterols upholding anticoagulant activity serve the purpose of causing decrease in angina and the blood cholesterol levels. Phytochemicals such as eugenol, palmitic acid, and methyl palmitate exhibit potent antibacterial activity against broad range of disease-causing agents. Additionally, a high percentage of essential oils attribute it with the property of being effective against heart ailments. The present study highlights the importance of E. umbellata in traditional medicinal practices, and summarizes the knowledge of its bioactive constituents and a snapshot vision of remarkable biological activities like antimicrobial, antidiabetic, antioxidant, etc towards understanding its role in the development of efficient drug regimens for use in the treatment of different diseases. It also underlines the need to explore the plant on nutritional aspects to strengthen the existing knowledge pertaining to health promoting potential of E. umbellata.

The Influence of Chestnut Extract and Its Components on Antibacterial Activity against Staphylococcus aureus

Increasing antimicrobial resistance has caused a great interest in natural products as alternatives or potentiators of antibiotics. The objective of this study was to isolate individual tannins from crude chestnut extract as well as to determine the influence of both crude extracts (tannic acid extract, chestnut extract) and individual pure tannins (gallic acid, vescalin, vescalagin, castalin, castalagin) on the growth of Gram-positive Staphylococcus aureus bacteria. Their antibacterial activity was monitored by measuring the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) as well as the duration of the lag phase, growth rate and generation time. The effect of growth medium strength on the MIC of different tannins was also investigated. Bacterial growth was followed spectrophotometrically, and MIC values were determined by the microdilution method. The MIC values of various isolated compounds allowed us to determine the bioactive compounds and their contribution to antimicrobial activity. It was found that MIC values increase with increasing growth medium strength and that the lag phase lengthens with increasing tannin concentrations, while the growth rates decrease. Comparing the results of the two studies, the antimicrobial activity of tannins against S. aureus was not as pronounced as in the case of E. coli, which may indicate that a different mechanism of action is responsible for the antimicrobial effects of tannins on Gram-positive than on Gram-negative bacteria, or that a different mechanism is more pronounced.

Combined -omics framework reveals how ant symbionts benefit the Neotropical ant-plant Tococa quadrialata at different levels

Ant-plant defensive mutualism is a widely studied phenomenon, where ants protect their host plants (myrmecophytes) against herbivores in return for the provision of nesting sites and food. However, few studies addressed the influence of ant colonization and herbivory on the plant's metabolism. We chose the Amazonian plant Tococa quadrialata, living in association with Azteca cf. tonduzi ants for an ant-exclusion study to reveal the chemistry behind this symbiosis. We found that colonized plants did not only benefit from protection but also from increased amino acid and nitrogen content, enabling better performance even in an herbivore-free environment. In contrast, ant-deprived T. quadrialata plants accumulated more ellagitannins, a major class of constitutive defense compounds. Moreover, herbivory-induced jasmonate-mediated defense responses, including the upregulation of signaling and defense genes and the emission of volatiles irrespective of colonization status. Altogether, we show how ant-colonization can influence the general and defense-related metabolism and performance of myrmecophytes.

Hydrolyzable tannins (ellagitannins), flavonoids, pentacyclic triterpenes and their glycosides in antimycobacterial extracts of the ethnopharmacologically selected Sudanese medicinal plant Combretum hartmannianum Schweinf

In Sudanese traditional medicine, decoctions, macerations, and tonics of the stem and root of Combretum hartmannianum are used for the treatment of persistent cough, a symptom that could be related to tuberculosis (TB). To verify these traditional uses, extracts from the stem wood, stem bark, and roots of C. hartmannianum were screened for their growth inhibitory effects against Mycobacterium smegmatis ATCC 14468. Methanol Soxhlet and ethyl acetate extracts of the root gave the strongest effects (MIC 312.5 and 625 µg/ml, respectively). HPLC-UV/DAD and UHPLC/QTOF-MS analysis of the ethyl acetate extract of the root led to the detection of 54 compounds, of which most were polyphenols and many characterized for the first time in C. hartmannianum. Among the major compounds were terflavin B and its two isomers, castalagin, corilagin, tellimagrandin I and its derivative, (S)-flavogallonic acid dilactone, punicalagin, and methyl-ellagic acid xylopyranoside. In addition, di-, tri- and tetra-galloyl glucose, combregenin, terminolic acid, cordifoliside D, luteolin, and quercetin-3-O-galactoside-7-O-rhamnoside-(2→1)-O-β-D-arabinopyranoside were characterized. Luteolin gave better growth inhibition against M. smegmatis (MIC 250 µg/ml) than corilagin, ellagic acid, and gallic acid (MIC 500-1000 µg/ml). Our study justifies the use of C. hartmannianum in Sudanese folk medicine against prolonged cough that could be related to TB infection. This study demonstrates that C. hartmannianum should be explored further for new anti-TB drug scaffolds and antibiotic adjuvants.