The Amoebicidal Effect of Ergosterol Peroxide Isolated from Pleurotus ostreatus

Food and human health applications of edible mushroom by-products

Mushroom waste can account for up to 50% of the total mushroom mass. Spent mushroom substrate, misshapen mushrooms, and mushroom stems are examples of mushroom byproducts. In ancient cultures, fungi were prized for their medicinal properties. Aqueous extracts containing high levels of β-glucans as functional components capable of providing prebiotic polysaccharides and improved texture to foods have been widely used and new methods have been tested to improve extraction yields. Similarly, the addition of insoluble polysaccharides controls the glycemic index, counteracting the effects of increasingly high-calorie diets. Numerous studies support these benefits in vitro, but evidence in vivo is scarce. Nonetheless, many authors have created a variety of functional foods, ranging from yogurt to noodles. In this review, we focus on the pharmacological properties of edible mushroom by-products, and the possible risks derived from its consumption. By incorporating these by-products into human or animal feed formulations, mushroom producers will be able to fully optimize crop use and pave the way for the industry to move toward a zero-waste paradigm.

Bioprospecting of endophytes associated with Solanum species: a mini review

Endophytes are considered the repository of bioactive compounds as they contain a wide variety of chemically and structurally diverse secondary metabolites. The endophytes associated with Solanum species have been studied for the last few years. Therefore, the present study aimed to discuss the bioactive compounds produced by endophytes associated with Solanum species and their biological activities. Our study reveals that among the Solanum species, only 13 species have been studied in the context of endophytes so far. Overall, a total number of 98 bioactive compounds have been reported from endophytes associated with Solanum species, of which 64 compounds are from fungi and 34 compounds from bacteria. These bioactive compounds belong to different chemical groups such as sterols, flavonoids, volatiles, and many others and exhibited diverse biological activities including antimicrobial, anticancer, antiparasitic, antioxidants, and plant growth-promoting activity. Moreover, the endophytic fungi were reported to produce two compounds that are often present in the host plants. These condensed data may open the door for further research and provide details on potent endophytes associated with Solanum species.

Anti-Toxoplasma gondii activity of Trametes versicolor (Turkey tail) mushroom extract

Toxoplasma gondii (T. gondii) infection continues to rise globally in humans and animals with high socioeconomic and public health challenges. Current medications used against T. gondii infection are limited in efficacy, safety, and affordability. This research was conducted to assess the higher fungi extract effect on T. gondii tachyzoites growth in vitro and possibly decipher its mechanism of action. Furthermore, we evaluated the extract's effect on human foreskin fibroblast viability. The methanol extracts of Turkey tail (TT) mushroom was tested against T. gondii tachyzoites growth using an RH-RFP type I strain that expresses red fluorescent protein throughout culture in a dose-dependent manner using a fluorescent plate reader. Similarly, we tested the effect of the extract on host cell viability. We observed that TT extract inhibited tachyzoites growth with a 50% minimum inhibitory concentration (IC_50s), IC₅₀ = 5.98 ± 1.22 µg/mL, and 50% cytotoxic concentration (CC_50s), CC₅₀ ≥ 100 µg/mL. It was discovered that TT extract induced strong mitochondria superoxide and  reactive oxygen species production and disrupted mitochondria membrane potential in T. gondii tachyzoites. Additionally, scanning electron microscopy depicted that TT extract and pyrimethamine (PY) caused a morphological deformation of tachyzoites in vitro. In conclusion, TT methanol extract made up of phytosterols, bioactive sphingolipids, peptides, phenolic acids, and lactones could be a promising source of new compounds for the future development of anti-Toxoplasma gondii drugs. Extracts were non-cytotoxic, even at higher concentrations.

Antiparasitic Activity of Compounds Isolated from Ganoderma tuberculosum (Agaricomycetes) from Mexico

The genus Ganoderma has a long history of use in traditional Asiatic medicine due to its different nutritional and medicinal properties. In Mexico, the species G. tuberculosum is used in indigenous communities, for example, the Wixaritari and mestizos of Villa Guerrero Jalisco for the treatment of diseases that may be related to parasitic infections; however, few chemical studies corroborate its traditional medicinal potential. Thereby, the objective of this study was to isolate and identify anti-parasitic activity compounds from a strain of G. tuberculosum native to Mexico. From the fruiting bodies of G. tuberculosum (GVL-21) a hexane extract was obtained which was subjected to guided fractioning to isolate pure compounds. The in vitro anti-parasitic activity of the pure compound (IC50) was assayed against Leishmania amazonensis, Trypanosoma cruzi, Acanthamoeba castellanii Neff, and Naegleria fowleri. Furthermore, the cytotoxicity (CC50) of the isolated compounds was determined against murine macrophages. The guided fractioning produced 5 compounds: ergosterol (1), ergosta-4,6,8(14),22-tetraen-3-one (2), ergosta-7,22-dien-3β-ol (3), 3,5-dihydroxy-ergosta-7,22-dien-6-one (4), and ganoderic acid DM (5). Compounds 2 and 5 showed the best anti-parasitic activity in an IC50 range of 54.34 ± 8.02 to 12.38 ± 2.72 µM against all the parasites assayed and low cytotoxicity against murine macrophages. The present study showed for the first time the in vitro anti-parasitic activity of compounds 1-5 against L. amazonensis, T. cruzi, A. castellanii Neff, and N. fowleri, corroborating the medicinal potential of Ganoderma and its traditional applications.

Chemical Defence by Sterols in the Freshwater Ciliate Stentor polymorphus

Heterotrich ciliates typically retain toxic substances in specialized ejectable organelles, called extrusomes, which are used in predator-prey interactions. In this study, we analysed the chemical defence strategy of the freshwater heterotrich ciliate Stentor polymorphus against the predatory ciliate Coleps hirtus, and the microturbellarian flatworm Stenostomum sphagnetorum. The results showed that S. polymorphus is able to defend itself against these two predators by deploying a mix of bioactive sterols contained in its extrusomes. Sterols were isolated in vivo and characterized by liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR), as ergosterol, 7-dehydroporiferasterol, and their two peroxidized analogues. The assessment of the toxicity of ergosterol and ergosterol peroxide against various organisms, indicated that these sterols are essential for the effectiveness of the chemical defence in S. polymorphus.

Elucidating Molecular Interactions of Ten Natural Compounds Targeting E6 HPV High Risk Oncoproteins Using Microsecond Molecular Dynamics Simulations

BACKGROUND

Cervical cancer is a major public health issue worldwide, occurring in the vast majority of cases (85%) in low-income countries. Human papillomavirus (HPV) mainly infects the mucosal epithelium, and a small portion causes over 600,000 cases every year worldwide at various anatomical spots, mainly leading to anogenital and head and neck.

INTRODUCTION

The E6 oncoprotein encoded by cancer-associated alpha HPV can transform epithelial cells into tumorigenic tissue. Therapy for this infection and blocking of the HPV E6 oncoprotein could be provided with cost-effective and abundant natural products which are an exponentially growing topic in the literature. Finding an active natural compound that readily blocks HPV E6 oncoprotein which could be available for developing countries without expensive extraction processes or costly synthetic pathways is of major interest.

METHODS

Molecular dynamics simulation was performed using the most up-to-date AMBER protein force field ff14SB and a GPU enabled high performance computing cluster.

RESULTS

In this research, we present a study of the binding properties between 10 selected natural compounds that are readily available with two variants of the E6 oncoprotein types (HPV-16 and HPV-18) using 10+ microsecond molecular dynamics simulations.

CONCLUSION

Our results suggest that crocetin, ergosterol peroxide and κ-carrageenan natural products bind strongly to both HPV-16 and HPV-18 and could potentially serve as a scaffolding for further drug development.

A sensitive, precise and rapid LC-MS/MS method for determination of ergosterol peroxide in Paecilomyces cicadae mycelium

Ergosterol peroxide (EP) has considerable potential effect against the proliferation of tumor cells. Here, we established a new approach for EP content detection through liquid chromatography-tandem mass spectrometry. The specificity, limit of detection (LOD)/quantitative (LOQ), linearity and range, accuracy, repeatability, and intermediate precision were tested. The EP retention time was 7.18 min. The linear relationship between the mass concentration of nonylphenol and the chromatographic peak area was good within the EP concentration range of 0.1-2.0 μg/mL. The correlation coefficient was 0.994, the regression equation was Y = 27 409.8 × X - 1114.67, the average recovery rate was 82.77%, the relative standard deviation was 11.1%, the LOQ was 50 ng/mL, and the LOD was 20 ng/mL. The detection technique was convenient, accurate, reproducible, and rapid. Therefore, this method could be used for deep liquid fermentation, providing a basis for EP to serve as a quality standard for the fermentation of Paecilomyces cicadae.

Insights into Ergosterol Peroxide's Trypanocidal Activity

Trypanosoma cruzi, which causes Chagas disease, is a significant health threat in many countries and affects millions of people. Given the magnitude of this disease, a broader understanding of trypanocidal mechanisms is needed to prevent and treat infection. Natural endoperoxides, such as ergosterol peroxide, have been shown to be toxic to parasites without causing harm to human cells or tissues. Although prior studies have demonstrated the trypanocidal activity of ergosterol peroxide, the cellular and molecular mechanisms remain unknown. The results of this study indicate that a free-radical reaction occurs in T. cruzi following ergosterol peroxide exposure, leading to cell death. Using a combination of biochemical, microscopic and in silico experimental approaches, we have identified, for the first time, the cellular and molecular cytotoxic mechanism of an ergosterol peroxide obtained from Pleurotus ostreatus (Jacq) P. Kumm. f. sp. Florida.

Antiplasmodial Activity of the n-Hexane Extract from Pleurotus ostreatus (Jacq. ex. Fr) P. Kumm

Objectives

Several mushrooms species have been reported to be nematophagous and antiprotozoan. This study reported the antiplasmodial and cytotoxic properties of the n-hexane extract from the edible mushroom Pleurotus ostreatus and the isolation of a sterol from the extract.

Materials and Methods

Antiplasmodial and cytotoxicity assays were done in vitro using the plasmodium lactate dehydrogenase assay and human HeLa cervical cell lines, respectively. The structure of the isolated compound from the n-hexane extract was elucidated using spectroscopic techniques.

Results

The n-hexane extract (yield: 0.93% w/w) showed dose dependent antiplasmodial activity with the trend in parasite inhibition of: chloroquine (IC₅₀=0.016 μg/mL) > n-hexane extract (IC₅₀=25.18 μg/mL). It also showed mild cytotoxicity (IC₅₀>100 μg/mL; selectivity index >4) compared to the reference drug emetine (IC₅₀=0.013 μg/mL). The known sterol, ergostan-5,7,22-trien-3-ol, was isolated and characterized from the extract.

Conclusion

This study reporting for the first time the antiplasmodial activity of P. ostreatus revealed its nutraceutical potential in the management of malaria.