Diversity of Marine Macro-Algicolous Endophytic Fungi and Cytotoxic Potential of Biscogniauxia petrensis Metabolites Against Cancer Cell Lines

Abstract

Hypersaline environments are known to support diverse fungal species from various orders. The production of secondary metabolites is one of the strategies that fungi adopt to thrive under such extreme environments, bringing up the stress tolerance response. Some such unique secondary metabolites also exhibit clinical significance. The increasing prevalence of drug resistance in cancer therapy demands further exploration of these novel bioactive compounds as cancer therapeutics. In the present study, a total of 31 endophytic fungi harboring inside red, green, and brown marine algae have been isolated and identified. The maximum likelihood analysis and diversity indices of fungal endophytes revealed the phylogenetic relationship and species richness. The genus Aspergillus was found to be the dominating fungus, followed by Cladosporium spp. All the isolated endophytic fungal extracts were tested for their cytotoxicity against HeLa and A431 cancer cell lines. Nine isolates were further analyzed for their cytotoxic activity from the culture filtrate and mycelia extract. Among these isolates, Biscogniauxia petrensis showed potential cytotoxicity with CC50 values of 18.04 and 24.85 μg/ml against HeLa and A431 cells, respectively. Furthermore, the media and solvent extraction optimization revealed the highest cytotoxic active compounds in ethyl acetate extract from the potato dextrose yeast extract broth medium. The compound-induced cell death via apoptosis was 50–60 and 45% when assayed using propidium iodide-live/dead and loss of mitochondrial membrane potential assay, respectively, in HeLa cells. Four bioactive fractions (bioassay-based) were obtained and analyzed using chromatography and spectroscopy. This study reports, for the first time, the cytotoxic activity of an endophytic fungal community that was isolated from marine macro-algae in the Rameswaram coastal region of Tamil Nadu, India. In addition, B. petrensis is a prominent apoptotic agent, which can be used in pharmaceutical applications as a therapeutic.

Fungal diversity notes 1512–1610: taxonomic and phylogenetic contributions on genera and species of fungal taxa

“…Known hosts and distribution : On asymptomatic twig of Artocarpus heterophyllus (Moraceae) in Chiang Mai Province, Thailand (Trakunyingcharoen et al 2015 ); on asymptomatic leaves of Stoechospermum marginatum (Dictyotaceae) and Caulerpa taxifolia (Caulerpaceae) in India (Sahoo et al 2021 ); on dead branches of Mangifera indica (Anacardiaceae) in China (Yang et al 2022 ); on dead stems of Chromolaena odorata (Asteraceae) in Chiang Rai Province, Thailand (this study)…”

“…artocarpi (CPC 22791) show one base pair difference (0.18%) across 531 nucleotides. Aplosporella species can be found on a wide range of hosts such as Anacardiaceae, Asteraceae, Caulerpaceae, Cupressaceae, Dictyotaceae, Fabaceae, Gingkoaceae, Moraceae, Myrtaceae, Proteaceae, and Rosaceae (Du et al 2017 ; Mapook et al 2020 ; Sahoo et al 2021 ; Yang et al 2021 ). We collected Aplosporella artocarpi (MFLU 22-0108) from Thailand and reported here as a new host record associated with Chromolaena odorata .…”

Fungal endophytes from saline-adapted shrubs induce salinity stress tolerance in tomato seedlings

“…Fungal endophyte communities are shaped by various factors, including host genotype, nutrient status around the plant and other environmental factors, although the plant is largely responsible for shaping the association (Bulgarelli et al 2012 , Wehner et al 2014 , Cheng et al 2019 ). Certain fungal phyla have been more frequently found as endophytes and in the soil rhizosphere than others, especially in abiotically stressed environments (Maciá-Vicente et al 2012 , Hamzah et al 2018 , Zhou et al 2018 , Khalil et al 2021 , Sahoo et al 2021 ). The ubiquity of Ascomycetes in soil can probably explain their abundance as endophytes.…”

Metabolites Produced by Fungi against Fungal Phytopathogens: Review, Implementation and Perspectives

“…Fungi, especially fungal endophytes, have been identified as a prolific source of secondary metabolites with very interesting properties in a broad range of applications for different industries, such as pharmacy, the wood and food industry and agronomy [ 72 ]. Within the pharmaceutical industry, a clear example of this prolificacy has been shown by endophytic fungi isolated from marine plants, which were found to produce a great number of secondary metabolites of a diverse nature, perhaps derived from the fact that they live under extreme environmental conditions of salinity stress [ 74 ]. Thus, as an example, secondary metabolites obtained from Fusarium equiseti isolated from marine seaweed have shown activity against cancer cells [ 75 ].…”