Investigation of chemical constituents and cytotoxic activity of the lichen Usnea undulata

Evaluating Phytochemical Profiles, Cytotoxicity, Antiviral Activity, Antioxidant Potential, and Enzyme Inhibition of Vepris boiviniana Extracts

In the present study, we performed comprehensive LC-MS chemical profiling and biological tests of Vepris boiviniana leaves and stem bark extracts of different polarities. In total, 60 bioactive compounds were tentatively identified in all extracts. The 80% ethanolic stem bark extract exhibited the highest activity in the ABTS assay, equal to 551.82 mg TE/g. The infusion extract of stem bark consistently demonstrated elevated antioxidant activity in all assays, with values ranging from 137.39 mg TE/g to 218.46 mg TE/g. Regarding the enzyme inhibitory assay, aqueous extracts from both bark and leaves exhibited substantial inhibition of AChE, with EC50 values of 2.41 mg GALAE/g and 2.25 mg GALAE/g, respectively. The 80% ethanolic leaf extract exhibited the lowest cytotoxicity in VERO cells (CC50: 613.27 µg/mL) and demonstrated selective cytotoxicity against cancer cells, particularly against H1HeLa cells, indicating potential therapeutic specificity. The 80% ethanolic bark extract exhibited elevated toxicity in VERO cells but had reduced anticancer selectivity. The n-hexane extracts, notably the leaves' n-hexane extract, displayed the highest toxicity towards non-cancerous cells with selectivity towards H1HeLa and RKO cells. In viral load assessment, all extracts reduced HHV-1 load by 0.14-0.54 log and HRV-14 viral load by 0.13-0.72 log, indicating limited antiviral activity. In conclusion, our research underscores the diverse bioactive properties of Vepris boiviniana extracts, exhibiting potent antioxidant, enzyme inhibitory, and cytotoxicity potential against cancer cells.

Prodigiosin-Functionalized Probiotic Ghosts as a Bioinspired Combination Against Colorectal Cancer Cells

Lactobacillus acidophilus ghosts (LAGs) with the unique safety of a probiotic, inherent tropism for colon cells, and multiple bioactivities offer promise as drug carriers for colon targeting. Our objective was to evaluate LAGs functionalized with prodigiosin (PG), apoptotic secondary bacterial metabolite, as a bioinspired formulation against colorectal cancer (CRC). LAGs were prepared by a chemical method and highly purified by density gradient centrifugation. LAGs were characterized by microscopic and staining techniques as relatively small-sized uniform vesicles (≈1.6 µm), nearly devoid of cytoplasmic and genetic materials and having a negatively charged intact envelope. PG was highly bound to LAGs envelope, generating a physiologically stable bioactive entity (PG-LAGs), as verified by multiple microscopic techniques and lack of PG release under physiological conditions. PG-LAGs were active against HCT116 CRC cells at both the cellular and molecular levels. Cell viability data highlighted the cytotoxicity of PG and LAGs and LAGs-induced enhancement of PG selectivity for HCT116 cells, anticipating dose reduction for PG and LAGs. Molecularly, expression of the apoptotic caspase 3 and P53 biomarkers in HCT116 intracellular proteins was significantly upregulated while that of the anti-apoptotic Bcl-2 (B-cell lymphoma 2) was downregulated by PG-LAGs relative to PG and 5-fluorouracil. PG-LAGs provide a novel bacteria-based combination for anticancer biomedicine.

Neogrisphenol A, a Potential Ovarian Cancer Inhibitor from a New Record Fungus Neohelicosporium griseum

From the rice fermentation product of a new record fungus, Neohelicosporium griseum, two new polyketides, neogrisphenol A (1) and neogrisphenol B (2), one new isochroman-1-one, (S)-6-hydroxy-7-methoxy-3,5-dimethylisochroman-1-one (3), and four known compounds (4–7) were isolated. Their structures were determined using 1D- and 2D-NMR, mass spectrometry, and chemical calculations. The C-3~C-2′ polymerization mode between the two α-naphthalenone derivative moieties is uncommon in compounds 1 and 2. Meanwhile, compounds 1–2 and 5 exhibited antibacterial activity against Bacillus subtilis, Clostridium perfringens, Staphylococcus aureus, and Staphylococcus aureus, with MIC values ranging between 16 and 31 µg/mL. In addition, compound 5 showed antifungal activity against Sclerotinia sclerotiorum and Phytophthora nicotianae var. nicotianae, with respective IC50 values of 88.14 ± 2.21 µg/mL and 52.36 ± 1.38 µg/mL. Compound 1 showed significant cytotoxicity against A2780, PC-3, and MBA-MD-231 cell lines with respective IC50 values of 3.20, 10.68, and 16.30 µM, and the cytotoxicity against A2780 cells was even higher than that of cisplatin (CDDP). With an IC50 value of 10.13 µM, compound 2 also exhibited cytotoxicity against A2780. The in vitro results showed that compound 1 inhibited A2780 cell proliferation, induced apoptosis, and arrested the cell cycle at the S-phase in a concentration-dependent manner.

Design, Characterization, and Anticancer and Antimicrobial Activities of Mucoadhesive Oral Patches Loaded with Usnea barbata (L.) F. H. Wigg Ethanol Extract F-UBE-HPMC

The oral cavity's common pathologies are tooth decay, periodontal disease, and oral cancer; oral squamous cell carcinoma (OSCC) is the most frequent oral malignancy, with a high mortality rate. Our study aims to formulate, develop, characterize, and pharmacologically investigate the oral mucoadhesive patches (F-UBE-HPMC) loaded with Usnea barbata (L.) F.H. Wigg dry ethanol extract (UBE), using HPMC K100 as a film-forming polymer. Each patch contains 312 µg UBE, with a total phenolic content (TPC) of 178.849 µg and 33.924 µg usnic acid. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed for their morphological characterization, followed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Pharmacotechnical evaluation involved the measurement of the specific parameters for mucoadhesive oral patches as follows: weight uniformity, thickness, folding endurance, tensile strength, elongation, moisture content, pH, disintegration time, swelling rate, and ex vivo mucoadhesion time. Thus, each F-UBE-HPMC has 104 ± 4.31 mg, a pH = 7.05 ± 0.04, a disintegration time of 130 ± 4.14 s, a swelling ratio of 272 ± 6.31% after 6 h, and a mucoadhesion time of 102 ± 3.22 min. Then, F-UBE-HPMCs pharmacological effects were investigated using brine shrimp lethality assay (BSL assay) as a cytotoxicity prescreening test, followed by complex flow cytometry analyses on blood cell cultures and oral epithelial squamous cell carcinoma CLS-354 cell line. The results revealed significant anticancer effects by considerably increasing oxidative stress and blocking DNA synthesis in CLS-354 cancer cells. The antimicrobial potential against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27353, Candida albicans ATCC 10231, and Candida parapsilosis ATCC 22019 was assessed by a Resazurin-based 96-well plate microdilution method. The patches moderately inhibited both bacteria strains growing and displayed a significant antifungal effect, higher on C. albicans than on C. parapsilosis. All these properties lead to considering F-UBE-HPMC suitable for oral disease prevention and therapy.

Evaluation of Usnea barbata (L.) Weber ex F.H. Wigg Extract in Canola Oil Loaded in Bioadhesive Oral Films for Potential Applications in Oral Cavity Infections and Malignancy

Usnea lichens are known for their beneficial pharmacological effects with potential applications in oral medicine. This study aims to investigate the extract of Usnea barbata (L.) Weber ex F.H. Wigg from the Călimani Mountains in canola oil as an oral pharmaceutical formulation. In the present work, bioadhesive oral films (F-UBO) with U. barbata extract in canola oil (UBO) were formulated, characterized, and evaluated, evidencing their pharmacological potential. The UBO-loaded films were analyzed using standard methods regarding physicochemical and pharmacotechnical characteristics to verify their suitability for topical administration on the oral mucosa. F-UBO suitability confirmation allowed for the investigation of antimicrobial and anticancer potential. The antimicrobial properties against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27353, Candida albicans ATCC 10231, and Candida parapsilosis ATCC 22019 were evaluated by a resazurin-based 96-well plate microdilution method. The brine shrimp lethality assay (BSL assay) was the animal model cytotoxicity prescreen, followed by flow cytometry analyses on normal blood cells and oral epithelial squamous cell carcinoma CLS-354 cell line, determining cellular apoptosis, caspase-3/7 activity, nuclear condensation and lysosomal activity, oxidative stress, cell cycle, and cell proliferation. The results indicate that a UBO-loaded bioadhesive film’s weight is 63 ± 1.79 mg. It contains 315 µg UBO, has a pH = 6.97 ± 0.01, a disintegration time of 124 ± 3.67 s, and a bioadhesion time of 86 ± 4.12 min, being suitable for topical administration on the oral mucosa. F-UBO showed moderate dose-dependent inhibitory effects on the growth of both bacterial and fungal strains. Moreover, in CLS-354 tumor cells, F-UBO increased oxidative stress, diminished DNA synthesis, and induced cell cycle arrest in G0/G1. All these properties led to considering UBO-loaded bioadhesive oral films as a suitable phytotherapeutic formulation with potential application in oral infections and neoplasia.

Exploring in vitro anti-proliferative and anti-inflammatory activities of Prasachandaeng remedy, and its bioactive compounds

Background

Prasachandaeng (PSD) remedy has been empirically used in Thai traditional medicine to treat fever in bile duct and liver and cancer patients through Thai folk doctors. However, there have been no scientific reports on the bioactive compounds and bioactivities related to inflammation-associated carcinogenesis or cytotoxicity against cancer cell lines. In this study, we investigated the chemical content of the remedy, and evaluated its cytotoxic activity against two cancer cell lines in comparison with a non-cancerous cell line and determined tumor necrosis factor-alpha (TNF-α) production in a murine macrophage cell line (RAW 264.7) to evaluate anti-inflammatory activity. A novel HPLC method was used for quality control of its chemical content.

Methods

Pure compounds from the EtOH extract of D. cochinchinensis were isolated using bioassay-guided fractionation and chemical content of the PSD remedy was determined using HPLC. The cytotoxic activity against the hepatocarcinoma cell line (HepG2) and cholangiocarcinoma cell line (KKU-M156), in comparison with non-cancerous cell line (HaCaT), were investigated using antiproliferative assay (SRB). The anti-inflammatory activity measured by TNF-α production in RAW 264.7 was determined using ELISA.

Results

All crude extracts and isolated compounds exhibited significant differences from vincristine sulfate (^****p < 0.0001) in their cytotoxic activity against HepG2, KKU-M156, and HaCaT. The PSD remedy exhibited cytotoxic activity against HepG2 and KKU-M156 with IC₅₀ values of 10.45 ± 1.98 (SI = 5.3) and 4.53 ± 0.74 (SI = 12.2) µg/mL, respectively. Some constituents from C. sappan, D. cochinchinensis, M. siamensis, and M. fragrans also exhibited cytotoxic activity against HepG2 and KKU-M156, with IC₅₀ values less than 10 µg/mL. The isolated compounds, i.e., Loureirin B (1), 4-Hydroxy-2,4’-dimethoxydihydrochalcone (2), and Eucomol (3) exhibited moderate cytotoxicity against two cancer cell lines. None of the crude extracts and isolated compounds showed cytotoxicity against HaCaT. D. cochinchinensis and PSD remedy exhibited higher anti-inflammatory activity measured as TNF-α production than acetaminophen.

Conclusion

The findings provide evidence of bioactivity for EtOH extracts of PSD remedy and the isolated compounds of D. Cochinchinensis. The results consistent the use clinical activity and use of PSD remedy as a antipyretic treatment for liver and bile duct cancer patients by Thai traditional practitioners.

Growth Inhibition and Apoptotic Effect of Pine Extract and Abietic Acid on MCF-7 Breast Cancer Cells via Alteration of Multiple Gene Expressions Using In Vitro Approach

In vitro anti-proliferative activity of Pinus palustris extract and its purified abietic acid was assessed against different human cancer cell lines (HepG-2, MCF-7 and HCT-116) compared to normal WI-38 cell line. Abietic acid showed more promising IC50 values against MCF-7 cells than pine extract (0.06 µg/mL and 0.11 µM, respectively), with insignificant cytotoxicity toward normal fibroblast WI-38 cells. Abietic acid triggered both G2/M cell arrest and subG0-G1 subpopulation in MCF-7, compared to SubG0-G1 subpopulation arrest only for the extract. It also induced overexpression of key apoptotic genes (Fas, FasL, Casp3, Casp8, Cyt-C and Bax) and downregulation of both proliferation (VEGF, IGFR1, TGF-β) and oncogenic (C-myc and NF-κB) genes. Additionally, abietic acid induced overexpression of cytochrome-C protein. Furthermore, it increased levels of total antioxidants to diminish carcinogenesis and chemotherapy resistance. P. palustris is a valuable source of active abietic acid, an antiproliferative agent to MCF-7 cells through induction of apoptosis with promising future anticancer agency in breast cancer therapy.

Usnic Acid and Usnea barbata (L.) F.H. Wigg. Dry Extracts Promote Apoptosis and DNA Damage in Human Blood Cells through Enhancing ROS Levels

Nowadays, numerous biomedical studies performed on natural compounds and plant extracts aim to obtain highly selective pharmacological activities without unwanted toxic effects. In the big world of medicinal plants, Usnea barbata (L) F.H. Wigg (U. barbata) and usnic acid (UA) are well-known for their therapeutical properties. One of the most studied properties is their cytotoxicity on various tumor cells. This work aims to evaluate their cytotoxic potential on normal blood cells. Three dry U. barbata extracts in various solvents: ethyl acetate (UBEA), acetone (UBA), and ethanol (UBE) were prepared. From UBEA we isolated usnic acid with high purity by semipreparative chromatography. Then, UA, UBA, and UBE dissolved in 1% dimethyl sulfoxide (DMSO) and diluted in four concentrations were tested for their toxicity on human blood cells. The blood samples were collected from a healthy non-smoker donor; the obtained blood cell cultures were treated with the tested samples. After 24 h, the cytotoxic effect was analyzed through the mechanisms that can cause cell death: early and late apoptosis, caspase 3/7 activity, nuclear apoptosis, autophagy, reactive oxygen species (ROS) level and DNA damage. Generally, the cytotoxic effect was directly proportional to the increase of concentrations, usnic acid inducing the most significant response. At high concentrations, usnic acid and U. barbata extracts induced apoptosis and DNA damage in human blood cells, increasing ROS levels. Our study reveals the importance of prior natural products toxicity evaluation on normal cells to anticipate their limits and benefits as potential anticancer drugs.

In Vitro Anticancer Activity and Oxidative Stress Biomarkers Status Determined by Usnea barbata (L.) F.H. Wigg. Dry Extracts

Lichens represent an important resource for common traditional medicines due to their numerous metabolites that can exert diverse pharmacological activities including anticancer effects. To find new anticancer compounds with fewer side effects and low tumor resistance, a bioprospective study of Usnea barbata (L.) F.H. Wigg. (U. barbata), a lichen from the Călimani Mountains (Suceava county, Romania) was performed. The aim of this research was to investigate the anticancer potential, morphologic changes, wound healing property, clonogenesis, and oxidative stress biomarker status of four extracts of U. barbata in different solvents (methanol, ethanol, acetone, and ethyl acetate), and also of usnic acid (UA) as a positive control on the CAL-27 (ATCC^® CRL-2095™) oral squamous carcinoma (OSCC) cell line and V79 (ATCC^® CCL-93™) lung fibroblasts as normal cells. Using the MTT assay and according to IC₅₀ values, it was found that the most potent anticancer property was displayed by acetone and ethyl acetate extracts. All U. barbata extracts determined morphological modifications (losing adhesion capacity, membrane shrinkage, formation of abnormal cellular wrinkles, and vacuolization) with higher intensity in tumor cells than in normal ones. The most intense anti-migration effect was established in the acetone extract treatment. The clonogenic assay showed that some U. barbata extracts decreased the ability of cancer cells to form colonies compared to untreated cells, suggesting a potential anti-tumorigenic property of the tested extracts. Therefore, all the U. barbata extracts manifest anticancer activity of different intensity, based, at least partially, on an imbalance in antioxidant defense mechanisms, causing oxidative stress.

Usnea sp.: Antimicrobial potential, bioactive compounds, ethnopharmacological uses and other pharmacological properties; a review article

ETHNOPHARMACOLOGICAL RELEVANCE

Usnea sp. is a fruticose thalli lichen with interesting medicinal properties. Since ancient times, Usnea sp. has been used in traditional medicine worldwide to treat various diseases. The broad scientific studies on this lichen have proved its multidirectional biological effect, such as antimicrobial activity, which is attributed to its usnic acid content.

PURPOSE

The main aim of this review is to provide an up-to-date overview of the antimicrobial activities of Usnea sp., including the traditional and medicinal uses, and a critical evaluation of the presented data. Also, the mechanism of this type of action will be explained.

METHODS

To prepare this manuscript, the information was extracted from scientific databases (Pubmed, ScienceDirect, Wiley, Springer, and Google Scholar), books, and theses. The available scientific information was critically analysed.

RESULTS

Analysis of the scientific literature regarding traditional uses and bioactivity research showed that Usnea sp. extracts exhibit high antibacterial activity. The Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, and Mycobacterium tuberculosis) and aquatic oomycetous fungi were the most sensitive Usnea sp. extracts. Moderate activity against Malassezia furfur and dermatophytes was observed, as well. Gram-negative bacteria, yeast, and fungi were more frequently resistant to Usnea sp. extracts (included Escherichia coli, Candida sp., Saccharomyces cerevisiae, and Aspergillus sp.). The antiviral activity of Usnea sp. was limited.

CONCLUSION

The results show that the use of Usnea sp. in traditional medicine can be scientifically documented. Studies show that usnic acid is the active compound present in Usnea sp. extracts. This compound, which has a high antibacterial and cytotoxic activity, exists in large quantities in low-polarity extracts, and low concentration in these of high-polarity. Usnea sp. extracts contain compounds other than usnic acid as well with biological effects. Usnea barbata is a species that has been employed in modern-day cosmetic and pharmaceutical preparations. The information presented in the review can be considered as a source of knowledge about the Usnea sp. It presents research on biological properties reported for different species of Usnea genus and thus can facilitate their use in medicine.

A Review of Anti-Cancer and Related Properties of Lichen-Extracts and Metabolites

BACKGROUND

Lichens are a composite consortium of fungus and alga. The symbiotic organisms are naturally equipped with distinct characteristics as compared to constituting organisms separately. Lichens due to their peculiar anatomy and physiology, are the reservoir of more than 600 unique secondary metabolites, also known as 'lichen substances'. Since ancient times, many ethnic groups from various parts of the world had knowledge about the applications of lichens as major provenance of food/fodder, medicine, dyes, spices, perfumes, etc. Lichen substances have shown impressive antioxidant, antimicrobial, antiviral, antitumor, and anti-inflammatory activities under experimental conditions. Usnic acid, a well-known metabolite, found in several species of lichens, possesses potent antioxidant and anti-inflammatory activities. It also has significant anti-proliferative potential as revealed through testing in different cancer cell lines. Atranorin, Lecanoric acid, Norstictic acid, Lobaric acid, Stictic acid, Ramalin, Gyrophoric acid, Salazinic acid, Protolichesterinic, and Fumarprotocetraric acid are some of the other purified lichen metabolites with potent anti-cancer activities.

OBJECTIVE

This study presents an overview of lichen derived extracts/compounds augmenting the anti-cancer (related) properties.

METHOD

The review comprehends different studies (in vivo and in vitro) backing up the possibility of lichen extracts and metabolites towards their use as antioxidant, anti-proliferative, anti-inflammatory and EMT-inhibiting agents.

RESULTS

The review focuses on anti-cancer and related properties of lichen extracts and metabolites that include their anti-oxidative, anti-inflammatory, anti-proliferative and pro-apoptotic, cancer stemness reduction, activities and, the potential of inhibition of cancer-associated Epithelial-mesenchymal transition (EMT) that is responsible for multiple drug-resistance and metastasis of cancer cells in a large proportion of cases.

CONCLUSION

Lichens can be the repertoire of a plethora of lichen metabolites with putative bioactive potential, which is needed to be explored in order to find out novel anti-cancer drugs.

Two new phenolic compounds from the lichen Parmotrema cristiferum growing in Vietnam

Two new phenolic compounds, cristiferides A-B (1-2) together with six known compounds, 2,4-dihydroxyphthalide (3), lecanoric acid (4), orsellinic acid (5), 5-chloroorsellinic acid (6), methyl haematommate (7), and methyl β-orsellinate (8) were isolated from the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae). The structures of isolated compounds were identified from its spectroscopic data and by comparison with the literatures. Compounds 1-3 and 6-8 were evaluated for alpha-glucosidase inhibition. Compounds 2 and 7 revealed potent activity with IC₅₀ values of 72.66 μM and 48.73 μM, respectively.