Serial Exhaustive Extraction Revealed Antimicrobial and Antioxidant Properties of Platycerium stemaria (Beauv) Desv.

Microbial infections are increasing worldwide, and the widespread emergence of antibiotic-resistant pathogens poses a severe threat to public health. Medicinal plants are well-known sources of bioactive ingredients. This study was designed to determine the antimicrobial and antioxidant activities of extracts from Platycerium stemaria. The serial exhaustive extraction method using a solvent of increasing polarity from nonpolar (hexane) to polar (water) was designed to prepare crude extracts; liquid-liquid partition was used to fractionate of active extracts. The extracts and fractions were screened for antimicrobial activity on bacteria and yeasts using the microdilution method. The antioxidant activity was done using DPPH and FRAP assays. Out of the sixteen extracts screened, four (PsHex, PsH2O(H), PsMeOH(EA), and PsMeOH) exhibited potency with minimal inhibitory concentration (MIC) values ranging from 31.25 to 500 µg/mL. Out of the four extracts, two, including PsMeOH and PsMeOH(EA), exhibited DPPH radical scavenging activity with the antiradical power of 8.94 × 10-5 and 47.96 × 10-5, respectively, and ferric reducing antioxidant power values ranging from 0.34 to 61.53 µg equivalent Vit C/g of extract. The phytochemical screening of the promising crude extracts revealed flavonoids, glycosides, phenols, tannins, terpenoids, saponins, and anthraquinones. This study reports the antimicrobial and antioxidant activities of P. stemaria for the first time. The results showed that the serial exhaustive extraction approach used in this study allowed capturing the antimicrobial and antioxidant metabolites beyond the single extraction, indicating the need for a rigorous choice of an appropriate solvent and method for extracting P. stemaria. Further investigation is needed to characterize the active ingredients present in the promising extracts.

Bioprospecting endophytic fungi from Fusarium genus as sources of bioactive metabolites.

Endophytic fungi became an attractive source for the discovery of new leads, because of the complexity and the structural diversity of their secondary metabolites. The genus Fusarium comprising about 70 species is extremely variable in terms of genetics, biology, ecology, and consequently, secondary metabolism and have been isolated from countless plants genera from diverse habitats. These endophytic microbes may provide protection and survival strategies in their host plants with production of a repertoire of chemically diverse and structurally unprecedented secondary metabolites reported to exhibit an incredible array of biological activities including antimicrobial, anticancer, antiviral, antioxidants, antiparasitics, immunosuppressants, immunomodulatory, antithrombotic, and biocontrol ability against plants pathogens and nematodes. This review comprehensively highlights over the period 1981-2019, the bioactive potential of metabolites produced by endophytes from Fusarium genus. Abbreviations: AIDS: Acquired immune deficiency syndrome; BAPT: C-13 phenylpropanoid side chain-CoA acyltransferase; CaBr2: Calcium bromide; DBAT: 10-deacetylbaccatin III-10-O-acetyl transferase; DNA: Deoxyribonucleic acid; EI-MS: Electron ionization mass spectrometer; EN: Enniatin; ERK: Extracellular regulated protein kinase; EtOAc: Ethyl acetate; FDA: Food and Drug Administration; GAE/g: Gallic acid equivalent per gram; GC-MS: Gas chromatography-mass spectrometry; HA: Hyperactivation; HCV: Hepatitis C Virus; HCVPR: Hepatitis C Virus protease; HeLa: Human cervical cancer cell line; HIV: Human immunodeficiency viruses; HPLC: High Performance Liquid Chromatography; IAA: Indole-3-acetic acid; IARC: International Agency for Research on Cancer; IC50: Half maximal inhibitory concentration; LC50: Concentration of the compound that is lethal for 50% of exposed population; LC-MS: Liquid chromatography-mass spectrometry; MCF-7: Human breast cancer cell line; MDR: Multidrug-resistant; MDRSA: Multidrug-resistant S. aureus; MFC: Minimum fungicidal concentration; MIC: Minimum inhibitory concentration; MRSA: Multidrug-resistant S. aureus; MTCC: Microbial type culture collection; PBMCs: Peripheral blood mononuclear cells; PCR: Polymerase chain reaction; TB: Tuberculosis; TLC: Thin layer chromatography; TNF: Tumor necrosis factor; WHO: World Health Organization http://www.zoobank.org/urn:lsid:zoobank.org:pub:D0A7B2D8-5952-436D-85C8-C79EAAD1013C.

Endophytic Penicillium species and their agricultural, biotechnological, and pharmaceutical applications.

Penicillium genus constituted by over 200 species is one of the largest and fascinating groups of fungi, particularly well established as a source of antibiotics. Endophytic Penicillium has been reported to colonize their ecological niches and protect their host plant against multiples stresses by exhibiting diverse biological functions that can be exploited for countless applications including agricultural, biotechnological, and pharmaceutical. Over the past 2 decades, endophytic Penicillium species have been investigated beyond their antibiotic potential and numerous applications have been reported. We comprehensively summarized in this review available data (2000-2019) regarding bioactive compounds isolated from endophytic Penicillium species as well as the application of these fungi in multiple agricultural and biotechnological processes. This review has shown that a very large number (131) of endophytes from this genus have been investigated so far and more than 280 compounds exhibiting antimicrobial, anticancer, antiviral, antioxidants, anti-inflammatory, antiparasitics, immunosuppressants, antidiabetic, anti-obesity, antifibrotic, neuroprotective effects, and insecticidal and biocontrol activities have been reported. Moreover, several endophytic Penicillium spp. have been characterized as biocatalysts, plant growth promoters, phytoremediators, and enzyme producers. We hope that this review summarizes the status of research on this genus and will stimulate further investigations.