Keratinophilic fungi from the feathers of Emu (Dromaius novaehollandiae) in Maharastra India.

A total of 70 feathers samples of Emu (Dromaius novaehollandiae) were collected from 7 Emu farms situated at two districts (Raigad and Thane) of Maharashtra (India) and screened for resident keratinophilic fungi. Among them, 44 isolates were recovered and identified by evaluating characteristic macro- and micro-morphological features. Further gene products corresponding to the ITS1-5.8S-ITS2 rDNA region from all isolates were amplified and sequenced. Homology search was performed using BLAST program against non-redundant nucleotide database, and significantly matched DNA sequences deposited to the NCBI Gene Bank for reference purposes. Eight identified fungal species belongs to 7 different genera named as Aphanoascus terreus Ac_MW577456 (21.43%), Microsporum gypseum Ac_MW580920 (14.29%), Ctenomyces serratus Ac_MW577459 (10.0%), Uncinocarpus orissi Ac_MW577461 (5.17%), Aphanoascus verrucosus Ac_MW577458 (4.29%), Gymnascella dankaliensis Ac_MW577460 (2.86%), Gymnoascoideus petalosporus Ac_MW577462 (2.86%) and Arthroderma tuberculatum Ac_MW577457 (1.43%).

Exophiarin, an isocoumarin from the fungus Exophiala sp. with antihyperglycemic activity.

Chemical characterization of ethyl acetate extract of Exophiala sp. has afforded the isolation of three compounds including a new isocoumarin named exophiarin (1). Exophiala sp. was obtained from the soil containing dumped organic waste (litter). Initially, LC-UV-MS analysis of the extract of Exophiala sp. revealed the presence of a new compound having molecular weight 438 (1) and previously reported TPI-2 and TPI-5. The novelty was established using advanced database search comprising of biological source, molecular weight and UV profile. 1D, 2D NMR and HRMS data have been used for structure elucidation. Exophiarin with TPI-2 and TPI-5 have displayed moderate improvement in glucose uptake activity when tested in rat skeletal muscle cell line L6.

Radicicol rescues yeast cell death triggered by expression of human α-synuclein and its A53T mutant, but not by human ßA4 peptide and proapoptotic protein bax.

Aggregation/misfolding of α-synuclein and ßA4 proteins cause neuronal cell death (NCD) associated with Parkinson's and Alzheimer's disease. It has been suggested that a heat shock protein-90 (Hsp90) inhibitor can prevent NCD by activating the heat shock transcription factor-1 which, in turn, upregulates molecular chaperones such as Hsp70 that targets aggregated/misfolded proteins for refolding/degradation. We have isolated radicicol, an Hsp90 inhibitor, from a fungus occurring in the crevices of marble rocks of Central India. Radicicol, which was found to be a strong antioxidant, was tested for its ability to rescue yeast cells from death induced by expression of wild-type α-synuclein, its more toxic A53T mutant, and ßA4. It effectively overcomes wild-type/mutant α-synuclein mediated yeast cell death, concomitantly diminishes ROS levels, reverses mitochondrial dysfunction and prevents nuclear DNA-fragmentation, a hallmark of apoptosis. Surprisingly however, radicicol is unable to rescue yeast cells from death triggered by expression of secreted ßA4. Moreover, although radicicol acts as an antioxidant it fails to prevent yeast cell death inflicted by the proapoptotic protein, Bax. Our results indicate that radicicol specifically targets aggregated/misfolded α-synuclein's toxicity and opens up the possibility of using multiple yeast assays to screen natural product libraries for compounds that would unambiguously target α-synuclein aggregation/misfolding.

Incidence of Keratinophilic Fungi from the Selected Soils of Kaziranga National Park, Assam (India).

Seventy-eight soil samples were collected from the various locations in the vicinity of Kaziranga National Park (Assam), India, during April to October 2009 and screened for the presence of keratinophilic fungi using the hair baiting techniques for isolation. Thirty-nine isolates were recovered and identified by recognition of their macro- and micromorphological features. Their identification was also confirmed by the BLAST search of sequences of the ITS1-5.8S-ITS2 rDNA region against the NCBI/GenBank data and compared with deposited sequences for identification purpose. Eleven species related to seven genera were recorded viz. Aphanoascus durus (1.28%), Arthroderma tuberculatum (3.84%), Arthroderma corniculatum (1.28%), Chrysosporium indicum (16.66%), C. tropicum (3.84%), Ctenomyces serratus (5.12%), Keratinophyton punsolae (1.28%), Microsporum appendiculatum (1.28%), Microsporum gypseum complex (11.53%), Trichophyton mentagrophytes (11.28%) and T. terrestre (2.56%).

Anticancer activity of Ophiobolin A, isolated from the endophytic fungus Bipolaris setariae.

The present work describes the anticancer activity of Ophiobolin A isolated from the endophytic fungus Bipolaris setariae. Ophiobolin A was isolated using preparative HPLC and its structure was confirmed by HRMS, (1)H NMR, (13)C NMR, COSY, DEPT, HSQC and HMBC. It inhibited solid and haematological cancer cell proliferation with IC50 of 0.4-4.3 µM. In comparison, IC50 against normal cells was 20.9 µM. It was found to inhibit the phosphorylation of S6 (IC50 = 1.9 ± 0.2 µM), ERK (IC50 = 0.28 ± 0.02 µM) and RB (IC50 = 1.42 ± 0.1 µM), the effector proteins of PI3K/mTOR, Ras/Raf/ERK and CDK/RB pathways, respectively. It induced apoptosis and inhibited cell cycle progression in MDA-MB-231 cancer cells with concomitant inhibition of signalling proteins. Thus, this study reveals that anticancer activity of Ophiobolin A is associated with simultaneous inhibition of multiple oncogenic signalling pathways namely PI3K/mTOR, Ras/Raf/ERK and CDK/RB.

Anti-inflammatory properties of mutolide isolated from the fungus Lepidosphaeria species (PM0651419).

Mutolide an anti-inflammatory compound was isolated from the coprophilous fungus Lepidosphaeria sp. (PM0651419). The compound mitigated LPS-induced secretion of pro-inflammatory cytokines TNF-α and IL-6 from THP-1 cells as well as human peripheral blood mononuclear cells (hPBMCs). Mutolide also inhibited secretion of another pro-inflammatory cytokine IL-17 from anti-hCD3/anti-hCD28 stimulated hPBMCs. NF-κB is the major transcription factor involved in the secretion of pro-inflammatory cytokines including IL-17. Mechanistic evaluations revealed that mutolide inhibited induced NF-κB activation and translocation from cytoplasm into the nucleus. However, mutolide did not significantly affect activity of p38 MAPK enzyme, a serine/threonine kinase involved in cell cycle proliferation and cytokine secretion. These results indicate that mutolide may exert its anti-inflammatory effect via NF-κB inhibition. Oral administration of mutolide at 100 mg/kg showed significant inhibition of LPS-induced release of TNF-α from Balb/c mice in an acute model of inflammation. Our results highlight the anti-inflammatory properties of mutolide and suggest that further evaluation in a chronic model of inflammation is required to confirm the potential of mutolide as a druggable candidate for the treatment of inflammatory diseases.

Anticancer activity of koningic acid and semisynthetic derivatives.

A screening program aimed at discovering novel anticancer agents based on natural products led to the selection of koningic acid (KA), known as a potent inhibitor of glycolysis. A method was set up to produce this fungal sesquiterpene lactone in large quantities by fermentation, thus allowing (i) an extensive analysis of its anticancer potential in vitro and in vivo and (ii) the semi-synthesis of analogues to delineate structure-activity relationships. KA was characterized as a potent, but non-selective cytotoxic agent, active under both normoxic and hypoxic conditions and inactive in the A549 lung cancer xenograft model. According to our SAR, the acidic group could be replaced to keep bioactivity but an intact epoxide is essential.

Antiproliferative activity of hamigerone and radicinol isolated from Bipolaris papendorfii.

Secondary metabolites from fungi organisms have extensive past and present use in the treatment of many diseases and serve as compounds of interest both in their natural form and as templates for synthetic modification. Through high throughput screening (HTS) and bioassay-guided isolation, we isolated two bioactive compounds hamigerone (1) and radicinol (2). These compounds were isolated from fungus Bipolaris papendorfii, isolated from the rice fields of Dera, Himachal Pradesh, India. The structures of the compounds were established on the basis of spectroscopic data, namely, NMR ((1)H, (13)C, mass, and UV). Both compounds were found to be antiproliferative against different cancer cells. Furthermore we have also noted that both compounds showed increase in apoptosis by favorably modulating both tumor suppressor protein (p53) and antiapoptic protein (BCL-2), and in turn increase caspase-3 expression in cancer cells. This is the first report of these compounds from fungus Bipolaris papendorfii and their anticancer activity.

Anticancer activity of new depsipeptide compound isolated from an endophytic fungus.

A novel depsipeptide (PM181110) was purified from an endophytic fungus Phomopsis glabrae isolated from the leaves of Pongamia pinnata (family Fabaceae). The chemical structure of PM181110 was elucidated using physiochemical properties, 2D NMR and other spectroscopic methods. PM181110 is very close in structure to FE399. The compound exhibited in vitro anticancer activity against 40 human cancer cell lines with a mean IC50 value of 0.089 µM and ex vivo efficacy towards 24 human tumor xenografts (mean IC50=0.245 µM).

Endophytic fungi: a reservoir of antibacterials.

Multidrug drug resistant bacteria are becoming increasingly problematic particularly in the under developed countries of the world. The most important microorganisms that have seen a geometric rise in numbers are Methicillin resistant Staphylococcus aureus, Vancomycin resistant Enterococcus faecium, Penicillin resistant Streptococcus pneumonia and multiple drug resistant tubercule bacteria to name a just few. New drug scaffolds are essential to tackle this every increasing problem. These scaffolds can be sourced from nature itself. Endophytic fungi are an important reservoir of therapeutically active compounds. This review attempts to present some data relevant to the problem. New, very specific and effective antibiotics are needed but also at an affordable price! A Herculean task for researchers all over the world! In the Asian subcontinent indigenous therapeutics that has been practiced over the centuries such as Ayurveda have been effective as "handed down data" in family generations. May need a second, third and more "in-depth investigations?"

Anticancer activity of sclerotiorin, isolated from an endophytic fungus Cephalotheca faveolata Yaguchi, Nishim. & Udagawa.

Biodiversity provides critical support for drug discovery. A significant proportion of drugs are derived, directly or indirectly, from biological sources. Through high throughput screening (HTS) and bioassay-guided isolation, bioactive compound sclerotiorin has been isolated from an endophytic fungus Cephalotheca faveolata. Sclerotiorin was found to be potent anti-proliferative against different cancer cells. In this study sclerotiorin has been found to induce apoptosis in colon cancer (HCT-116) cells through the activation of BAX, and down-regulation of BCL-2, those further activated cleaved caspase-3 causing apoptosis of cancer cells.

Fungal endophytes: a potential source of antifungal compounds.

The prevalence of invasive fungal infections has increased significantly during organ transplantation, cancer chemotherapy and allogeneic bone marrow transplantation. However, only a limited number of antifungal agents are currently available for the treatment of life-threatening fungal infections. Although new antifungal agents have been introduced in the market, the development of resistance to antifungal drugs has become increasingly apparent, especially in patients with long term treatment. Microbial natural products have always been an alternative natural source for the isolation of novel molecules for various therapeutic applications. Endophytes are the microorganisms that colonize internal tissues of all plant species and represent an abundant and dependable source of bioactive and chemically novel compounds with potential for exploitation in a wide variety of medical, agricultural and industrial arenas. In the present review several metabolites obtained from endophytic fungi with a potential as antifungal agents are mentioned with bioactivity including volatile organic compounds. The compounds reported here with a diverse scaffold can be a potential starting point for new antifungal agents either as such or after chemical modification.

Incidence of keratinophilic fungi from the soils of Vedanthangal Water Bird Sanctuary (India).

Fifty-three soil samples were collected from various sites in the vicinity of Vedanthangal Water Bird Sanctuary and screened for the presence of keratinophilic fungi using the hair baiting techniques for isolation. Twenty-eight isolates were recovered and identified by recognition of their macro- and micromorphological features. Seven species related to five genera were recorded viz. Auxarthron conjugatum (1.89%), Chrysosporium fluviale (3.77%), Chrysosporium indicum (20.75%), Chrysosporium tropicum (7.55%), Chrysosporium state of Ctenomyces serratus (5.66%), Gymnoascus petalosporus (1.89%) and Microsporum gypseum complex (11.32%). The study shows that migratory birds harbour a variety of keratinophiles and may be a potential source of transfer of these fungi from one location to another.

Anti-inflammatory and anticancer activity of ergoflavin isolated from an endophytic fungus.

Biodiversity is a major resource for identification of new molecules with specific therapeutic activities. To identify such an active resource, high throughput screening (HTS) of the extracts prepared from such diversity are examined on specific functional assays. Based on such HTS studies and bioactivity-based fractionation, we have isolated ergoflavin, a pigment from an endophytic fungus, growing on the leaves of an Indian medicinal plant Mimosops elengi (bakul). We report here the isolation, structure elucidation, and biological properties of this compound, which showed good anti-inflammatory and anticancer activities.