"Cladonia uncialis" as a valuable raw material of biosynthetic compounds against clinical strains of bacteria and fungi

Cladonia uncialis is a lichen species with confirmed antibacterial activity and whose genome has been recently sequenced, enabling first attempts in its functional characterization. In this work, we investigated activity of the C. uncialis acetone extract (CUE) and usnic acid (UA) enantiomers against ten clinical microbial strains causing skin infections. The results showed that CUE, containing (–)-UA and squamatic acid, assayed at the same concentrations as UA, was noticeably more active than (–)-UA alone, in its pure form. The studied CUE displayed an activity that was comparable to that of (+)-UA observed for Staphylococcus epidermidis and Enterococcus faecium (18–24 mm zone of growth inhibition), but did not display any activity against fungal strains. The CUE demonstrated low cytotoxicity against HaCaT cells, in comparison to UA enantiomers, which is important for its therapeutic use. Results of the antioxidant assay (DPPH) indicated low antioxidant activity (IC50>200 µg/mL) of CUE, while the total phenolic content was 70.36 mg Gallic Acid Equivalent/g of the dry extrac

Lichens as a source of chemical compounds with anti-inflammatory activity

Symptoms of inflammation accompany a number of diseases. In order to mitigate them, folk medicine has used a variety of medicinal substances, including herbs and mushrooms. Lichens are less known organisms, containing specific secondary metabolites with interesting biological properties. One of their biological actions is the anti-inflammatory activity that has been confirmed by in vitro and animal studies. It has been proven that compounds and extracts from lichens inhibit the enzymes involved in the inflammatory process. The following paper is a review of research on the little-known anti-inflammatory properties of lichens

Horse chestnut – efficacy and safety in chronic venous insufficiency: an overview

The extract from horse chestnut seeds (Aesculus hippocastanum L., Sapindaceae), standardised for the content of aescin, is used as the treatment for chronic venous insufficiency. It has anti-inflammatory and anti-oedematous properties and indicates a positive effect on the venous tone, rheological properties, and blood coagulability. The mechanism of horse chestnut seed extract/aescin activity was proposed on the basis of in vitro and in vivo studies, and its effectiveness was documented with numerous randomised clinical trials. The results of the studies have proven that horse chestnut seed extract not only significantly improves subjective symptoms in patients with chronic venous insufficiency like calf spasm, leg pain, pruritus, fatigue, but it also reduced leg volume, the ankle and calf circumference. The preparations containing horse chestnut seed extract are very popular and they have similar effectiveness as compression therapy and a preparation with O-(β-hydroxyethyl)-rutosides. Moreover, horse chestnut seed extract has been proven to be safe and very well tolerated. The study was to present the results of the studies that have been conducted so far and that have confirmed the effectiveness of use of horse chestnut seed extract or aescin as the treatment for chronic venous insufficiency. Keywords: Aescin, Chronic venous insufficiency, Horse chestnut seed

BIOLOGICAL ACTIVITY AND POLYPHENOL CONTENT IN SELECTED HERBAL TEA BLENDS USED IN DIABETES

This study aimed to evaluate the antioxidant properties, α -glucosidase inhibitory activity, and the total content of polyphenols and flavonoids in the selected antidiabetic herbal blends (1-6), used traditionally in diabetes. The strongest antioxidant activity (DPPH and CUPRAC) was observed in extracts from blends 1 and 6 (IC50 40 mg GAE/g), had a high content of flavonoids (6 - 10.96 mg QE/g, 1 - 7.51 mg QE/g) and the highest α-glucosidase inhibiting capacity (for 1 >90%, for 6 >90% and 5,55%, while for acarbose 1.76% and 0.93% at the 100 μg/ml and 10 μg/ml, respectively).The antioxidant activity of 1 and 6 correlated with the content of polyphenols and α-glucosidase inhibitory properties and indicates the existence of this mechanism in supporting the treatment of type 2 diabetes and diabetic complications by the above preparations

(+)-Usnic acid as a promising candidate for a safe and stable topical photoprotective agent

The study aimed to examine whether usnic acid—a lichen compound with UV-absorbing properties—can be considered as a prospective photoprotective agent in cosmetic products. Moreover, a comparison of two usnic acid enantiomers was performed to preselect the more effective compound. To meet this aim, an in vitro model was created, comprising the determination of skin-penetrating properties via skin-PAMPA assay, safety assessment to normal human skin cells (keratinocytes, melanocytes, fibroblasts), and examination of photostability and photoprotective properties. Both enantiomers revealed comparable good skin-penetrating properties. Left-handed usnic acid was slightly more toxic to keratinocytes (IC50 80.82 and 40.12 µg/mL, after 48 and 72 h, respectively) than its right-handed counterpart. The latter enantiomer, in a cosmetic formulation, was characterized by good photoprotective properties and photostability, comparable to the UV filter octocrylene. Perhaps most interestingly, (+)-usnic acid combined with octocrylene in one formulation revealed enhanced photoprotection and photostability. Thus, the strategy can be considered for the potential use of (+)-usnic acid as a UV filter in cosmetic products. Moreover, the proposed model may be useful for the evaluation of candidates for UV filters

Effect of elicitation with (+)-usnic acid on accumulation of phenolic acids and flavonoids in agitated microshoots of Eryngium alpinum L

The present work was aimed at studying the potential of elicitation on the accumulation of phenolic compounds in in vitro shoot cultures of Eryngium alpinum L., a protected plant from the Apiaceae family. The study examined the influence of (+)-usnic acid on the biomass growth as well as on the biosynthesis of the desired flavonoids and phenolic acids in the cultured microshoots. The phenolic compound content was determined by HPLC-DAD. The flavonoid of the highest concentration was isoquercetin, and the phenolic acids of the highest amount were rosmarinic acid, caffeic acid and 3,4-dihydroxyphenylacetic acid, both in the non-elicited and elicited biomass. Isoquercetin accumulation was efficiently increased by a longer elicitation with a lower concentration of lichenic compound (107.17 ± 4.67 mg/100 g DW) or a shorter elicitation with a higher concentration of acid (127.54 ± 11.34 and 108.37 ± 12.1 mg/100 g DW). Rosmarinic acid production generally remained high in all elicited and non-elicited microshoots. The highest content of this acid was recorded at 24 h of elicitation with 3.125 µM usnic acid (512.69 ± 4.89 mg/100 g DW). The process of elicitation with (+)-usnic acid, a well-known lichenic compound with allelopathic nature, may therefore be an effective technique of enhancing phenolic compound accumulation in alpine eryngo microshoot biomass

<i>In vitro</i> antimicrobial activity of extracts and compounds isolated from <i>Cladonia uncialis</i>

<div><p>Heptane (Hep), diethyl ether (Et₂O), acetone (Me₂CO) and methanolic (MeOH) extracts, as well as ( − )-usnic acid and squamatic acid, were obtained from thallus of <i>Cladonia uncialis</i> (Cladoniaceae). The antimicrobial activities of these extracts, ( − )-usnic acid and squamatic acid, were tested against reference strains: <i>Staphylococcus aureus</i>, <i>Escherichia coli</i> and <i>Candida albicans</i>. In addition, Me₂CO extract was analysed against 10 strains of Methicillin-resistant <i>S. aureus</i> (MRSA) isolated from patients. All extracts exerted antibacterial activity against the reference strain <i>S. aureus</i>, comparably to chloramphenicol [minimum inhibitory concentration (MIC) = 5.0 μg/mL]. The Me₂CO extract exhibited the strongest activity against <i>S. aureus</i> (MIC = 0.5 μg/mL), higher than ( − )-usnic acid, whereas squamatic acid proved inactive. The Me₂CO extract showed potent antimicrobial activity against MRSA (MIC 2.5–7.5 μg/mL). Also no activity of <i>C. uncialis</i> extracts against <i>E. coli</i> and <i>C. albicans</i> was observed.</p></div

Herbal infusions as a valuable functional food

Herbal infusions are an underestimated and easy to intake a source of biologically active natural compounds (polyphenols), which, in the dissolved form, are more easily absorbed. Therefore, this study aimed to assess the potential of herbal infusions as a functional food to reduce postprandial hyperglycemia (inhibition of α-amylase and α-glucosidase) and to reduce the effects of increased blood glucose level (antioxidant effect-DPPH, CUPRAC, and Fe2+ chelating assays, as well as anti-inflammatory activity-inhibition of collagenase). We showed that polyphenols are present in the examined aqueous herbal infusions (including chlorogenic and gallic acids). Subsequently, our research has shown that herbal infusions containing cinnamon bark, mulberry leaves, and blackberry fruits most strongly inhibit glucose release from complex carbohydrates, and that all herbal infusions can, to different degrees, reduce the effects of elevated blood sugar. In conclusion, infusions prepared from herbal blends could be recommended to prevent type II diabetes