Two New Secondary Metabolites from the Endophytic Fungus Endomelanconiopsis endophytica

Engineered Microorganisms for Advancing Tumor Therapy

Engineered microorganisms have attracted significant interest as a unique therapeutic platform in tumor treatment. Compared with conventional cancer treatment strategies, engineering microorganism-based systems provide various distinct advantages, such as the intrinsic capability in targeting tumors, their inherent immunogenicity, in situ production of antitumor agents, and multiple synergistic functions to fight against tumors. Herein, the design, preparation, and application of the engineered microorganisms for advanced tumor therapy are thoroughly reviewed. This review presents a comprehensive survey of innovative tumor therapeutic strategies based on a series of representative engineered microorganisms, including bacteria, viruses, microalgae, and fungi. Specifically, it offers extensive analyses of the design principles, engineering strategies, and tumor therapeutic mechanisms, as well as the advantages and limitations of different engineered microorganism-based systems. Finally, the current challenges and future research prospects in this field, which can inspire new ideas for the design of creative tumor therapy paradigms utilizing engineered microorganisms and facilitate their clinical applications, are discussed.

Molecular and morphological diversity, qualitative chemical profile and antioxidant activity of filamentous fungi of the digestive tract of Phylloicus sp. (Trichoptera: Calamoceratidae)

Abstract This study aimed to identify by molecular analysis, morphology, chemistry and antioxidant extracts of filamentous fungi isolated from the digestive tract of Phylloicus sp, an aquatic insect that lives on leaf packages in tropical streams and participates together with fungi of the decomposition of plant substrates in aquatic habitats. Insect larvae of Phylloicus sp. were collected in streams in the state of Tocantins, Brazil. Fungi were isolated from the digestive tract of larvae after disinfection and dissection, then described and purified for identification purposes and testing for antioxidant activity. Molecular identity was performed of ITS1 and ITS4, TUB e TEF sequencing. Fungal extracts were produced in 70% ethanol solution and later lyophilized. For analysis of chemical groups of extracts, thin layer chromatography (TLC) was performed in two mobile phases and different developers. Morphology was performed by optical microscopy stained with Toluidine Blue and measurement performed using the ImageJ program. Antioxidant activity performed in TLC and by quantitative method for DPPH and hydrogen peroxide (H2O2) radicals. Four fungi were identified: Endomelanconiopsis endophytica, Myxospora musae, Neopestalotiopsis cubana and Fusarium pseudocircinatum. The TLC showed several spots with acetone/chloroform mobile phase and UV 254 nm developers and I2 vapor. Fungal extracts demonstrate antioxidant action to reduce the DPPH free radical and especially for H2O2 above 50%, E. endophytica 91.6%, M. musae 87.8%, N. cubana 89.5% and 92.3% for F. pseudocircinatum. This study demonstrated that the molecular technique by PCR was satisfactory for identifying fungi, and extracts with numerous chemical groups and potent reducing agents. Thus future work, should be carried out evaluating these four species for industrial use.

Antioxidant activity of mycelia methanolic extracts of endophytic fungi BvFV and BvFIX isolated from leaves of Bauhinia variegata

Endophytes are considered an essential source of natural products. Skin is the body's largest organ; its primary function is the protection of other organs, and aging is one of the most relevant problems associated with this organ. UV radiation generates reactive oxygen species (ROS), which lead to skin degeneration and consequent aging. The main endogenous antioxidants that neutralize ROS are enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase, and glutathione reductase, and non-enzymatic antioxidants, such as glutathione and α-tocopherol. Nuclear receptors are involved in molecular mechanisms that control the aging process, especially peroxisome proliferator-activated receptors (PPAR), which regulate the function and expression of genes that modulate the balance between matrix metalloproteinases (MMP) activity and the expression of collagen. Some natural compounds, such as polyphenols, can activate PPAR and reduce the activation of MMP and collagen degradation. In this work, the antioxidant activity of the mycelia methanolic extracts of two endophytic fungi isolated from leaves of Bauhinia variegata, named BvFV and BvFIX, their action as PPAR agonists, and their effect on the activity of antioxidant defense system enzymes were evaluated. The mycelia methanolic extract of BvFV showed a weak agonist effect on PPARβ/δ, a high capability to inhibit lipid peroxidation, increased catalase activity, and increased superoxide dismutase activity by approximately 64%. In contrast, BvFIX increased catalase activity and increased superoxide dismutase activity in a dose-dependent manner, with an increase of 49.62% ± 7.87%, 56.64% ± 12.27%, and 240.46% ± 26.11% at concentrations of 25 µg/mL, 50 µg/mL and 100 µg/mL, respectively, in human dermal fibroblasts submitted to oxidative stress. These results suggest that the metabolites of the mycelia of endophytic fungi studied are promising to act in the chemoprevention of skin aging.

Bioprospecting of South African Plants as a Unique Resource for Bioactive Endophytic Microbes

South Africa has a long history and strong belief in traditional herbal medicines. Using ethnobotanical knowledge as a lead, a large number of South African medicinal plants have been discovered to possess a wide spectrum of pharmacological properties. In this review, bioprospecting of endophytes is highlighted by following the advantages of the ethnomedicinal approach together with identifying unique medicinal plants where biological activity may be due to endophytes. This review focuses on the current status of South African medicinal plants to motivate the research community to harness the benefits of ethnobotanical knowledge to investigate the presence of endophytic microbes from the most potent South African medicinal plants. The potential chemical diversity and subsequent putative medicinal value of endophytes is deserving of further research. A timely and comprehensive review of literature on recently isolated endophytes and their metabolites was conducted. Worldwide literature from the last 2 years demonstrating the importance of ethnobotanical knowledge as a useful approach to discover endophytic microbes was documented. Information was obtained from scientific databases such as Pubmed, Scopus, Scirus, Google Scholar, Dictionary of Natural Products, Chemical Abstracts Services, official websites, and scientific databases on ethnomedicines. Primary sources such as books, reports, dissertations, and thesises were accessed where available. Recently published information on isolated endophytes with promising bioactivity and their bioactive natural products worldwide (2015-2017) was summarized. The potential value of South African medicinal plants as sources of endophytes is discussed. The insights provided through this study indicate that medicinal plants in South Africa are highly under-investigated sources of potentially useful endophytic microbes. New approaches may be used by medicinal plant scientists for further exploration of natural products from endophytic fungi and bacteria in southern Africa.

Two New Metabolites from the Endophytic Fungus Alternaria sp. A744 Derived from Morinda officinalis

Two new compounds isobenzofuranone A (1) and indandione B (2), together with eleven known compounds (3-13) were isolated from liquid cultures of an endophytic fungus Alternaria sp., which was obtained from the medicinal plant Morinda officinalis. Among them, the indandione (2) showed a rarely occurring indanone skeleton in natural products. Their structures were elucidated mainly on the basis of extensive spectroscopic data analysis. All of the compounds were evaluated with cytotoxic and α-glucosidase inhibitory activity assays. Compounds 11 and 12 showed significant inhibitory activities against four tumor cell lines; MCF-7, HepG-2, NCI-H460 and SF-268, with IC₅₀ values in the range of 1.91-9.67 μM, and compounds 4, 5, 9, 10, 12 and 13 showed excellent inhibitory activities against α-glucosidase with IC₅₀ values in the range of 12.05-166.13 μM.