Leishmanicidal and antitumoral activities of endophytic fungi associated with the Antarctic angiosperms Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl.

Abstract

A total of 564 isolates of endophytic fungi were recovered from the plants Deschampsia antarctica and Colobanthus quitensis collected from Antarctica. The isolates were screened against parasites Leishmania amazonensis and Trypanosoma cruzi and against the human tumour cell lines. Of the 313 fungal isolates obtained from D. antarctica and 251 from C. quitensis, 25 displayed biological activity. Nineteen extracts displayed leishmanicidal activity, and six inhibited the growth of at least one tumour cell line. These fungi belong to 19 taxa of the genera Alternaria, Antarctomyces, Cadophora, Davidiella, Helgardia, Herpotrichia, Microdochium, Oculimacula, Phaeosphaeria and one unidentified fungus. Extracts of 12 fungal isolates inhibited the proliferation of L. amazonesis at a low IC(50) of between 0.2 and 12.5 μg ml(-1). The fungus Phaeosphaeria herpotrichoides displayed only leishmanicidal activity with an IC(50) of 0.2 μg ml(-1), which is equivalent to the inhibitory value of amphotericin B. The extract of Microdochium phragmitis displayed specific cytotoxic activity against the UACC-62 cell line with an IC(50) value of 12.5 μg ml(-1). Our results indicate that the unique angiosperms living in Antarctica shelter an interesting bioactive fungal community that is able to produce antiprotozoal and antitumoral molecules. These molecules may be used to develop new leishmanicidal and anticancer drugs.

Diversity and bioprospecting of fungal communities associated with endemic and cold-adapted macroalgae in Antarctica

“…The plates were incubated at 10±2 1C for 15 days, and the cultured materials from each Petri dish were then cut and transferred to 50-ml vials containing 35 ml of ethanol. After 48 h at room temperature, the organic phase was decanted, and the solvent was removed under a vacuum centrifuge at 35 1C (Santiago et al, 2012). An aliquot of each dried extract was dissolved in DMSO (Merck) to prepare a 100-mg ml À 1 stock solution, which was stored at À 20 1C.…”

“…However, the potential of extremophile fungi to produce bioactive compounds is poorly understood. According to Santiago et al (2012), the ability of Antarctic fungi to survive in extreme conditions suggests that they may display unusual biochemical pathways that allow them to generate specific or new molecules that could be used to develop new drugs. Our bioprospecting results show that the extracts from Penicillium sp.…”

Diversity and Biological Activities of Endophytic Fungi Associated with Micropropagated Medicinal Plant <i>Echinacea purpurea</i> (L.) Moench

“…Five millimeter diameter plugs of each endophytic fungus were place at the center of Petri dishes (90 mm diameter), each containing 20 mL of PDA, and cultured for 13 days at 25˚C ± 2˚C [17]. The material from the resulting fungal cultures were cut from the each Petri dish Conidia concentrations were determined photometrically [18] from a standard curve based on absorbance at 625 nm, and suspensions were adjusted with sterile distilled water to a concentration of 1.0 × 10 6 conidia/mL.…”

Antimicrobial activity of Phoma sp. URM 7221: An endophyte from Schinus terebinthifolius Raddi (Anacardiaceae)

“…Several studies have demonstrated that endophytic fungi can produce numerous compounds with biological activities of interest, such as antitumor (Jin-long et al, 2011;Chandra, 2012), antimicrobial (Siqueira et al, 2011;Tayung et al, 2012;Bagchi and Banerjee, 2013;Pinheiro et al, 2013;Orlandelli et al, 2015), enzymes (Chandra, 2012), plant growth hormones (Hwang et al, 2011), leishmanicidal (Santiago et al, 2012), cytotoxic compounds and compounds with industrial and pharmaceutical potential (Meng et al, 2011;Wang and Dai, 2011), reinforcing the broad biotechnological potential of these microorganisms.…”