New ring-A modified cycloartane triterpenoids from Dysoxylum malabaricum bark: Isolation, structure elucidation and their cytotoxicity.

The Genus Dysoxylum (Meliaceae) consists of approximately 80 species that are abundant in structurally diverse triterpenoids. The present study focused on isolating new triterpenoids from the bark of Dysoxylum malabaricum, one of the predominant species of Dysoxylum present in India. The methanol-dichloromethane bark extract was subjected to LCMS profiling followed by silica gel column chromatography and HPLC analysis to target new compounds. Two new ring A-modified cycloartane-type triterpenoids (1 and 2) were isolated from the bark extract. Spectroscopic methods like NMR, HRESIMS data, and electronic circular dichroism calculations elucidated the structuresandabsolute configurations of the isolated compounds. These compounds were evaluated for their cytotoxic potential against breast cancer cells and displayed notable cytotoxicity. Compound 1 exhibited the highest cytotoxicity against the MDA-MB-231 cells and induced apoptotic cell death. Also, it was able to inhibit glucose uptake and increase nitric oxide production in breast cancer cells.

Unveiling the cytotoxic and anti-proliferative potential of green-synthesized silver nanoparticles mediated by Colletotrichum gloeosporioides.

Fungal endophytes are a putative source of bioactive metabolites that have found significant applications in nanomedicine due to their metabolic versatility. In the present study, an aqueous extract of the fungal endophyte, Colletotrichum gloeosporioides associated with a medicinal plant Oroxylum indicum, has been used for the fabrication of green silver nanoparticles (CgAgNPs) and further evaluated their cytotoxic and anti-proliferative activity. Bioanalytical techniques including UV-Vis spectral analysis revealed a sharp band at 435 nm and functional molecules from the aqueous extract involved in the synthesis of CgAgNPs were evidenced through FTIR. Further, the crystalline nature of CgAgNPs was determined through XRD analysis and microscopy techniques including AFM, TEM and FESEM demonstrated the spherical shape of CgAgNPs exhibiting a crystalline hexagonal lattice and the size was found to be in the range of 9-29 nm. The significant cytotoxic potential of CgAgNPs was observed against breast cancer cells, MDA-MB-231 and MCF-7 with IC50 values of 18.398 ± 0.376 and 38.587 ± 1.828 µg mL-1, respectively. The biochemical study revealed that the treatment of MDA-MB-231 and MCF-7 cells with CgAgNPs reduces glucose uptake, suppresses cell proliferation, and enhances LDH release, indicating reduced cell viability and progression. Moreover, our research revealed differential expression of genes associated with apoptosis, cell cycle inhibition and metastasis suppression, evidencing anti-proliferative activity of CgAgNPs. The main objective of the present study is to harness anti-breast cancer activity of novel biogenic nanoparticles synthesized using the aqueous extract of O. indicum associated C. gloeosporioides and study the underlying mechanistic pathway exerted by these mycogenic nanoparticles.

Isolation and characterization of N-(2-Hydroxyethyl)hexadecanamide from Colletotrichum gloeosporioides with apoptosis-inducing potential in breast cancer cells.

Endophytic fungi are a well-established reservoir of bioactive compounds that are pharmaceutically valuable and therefore, contribute significantly to the biomedical field. The present study aims to identify the bioactive anticancer compound from ethyl acetate extract of fungal endophyte, Colletotrichum gloeosporioides associated with the leaf of the medicinal plant Oroxylum indicum. The fatty acid amide compound N-(2-Hydroxyethyl)hexadecanamide (Palmitoylethanolamide; PEA) was identified using antioxidant activity-guided fractionation assisted with tandem liquid chromatography coupled with quadrupole time of flight mass spectrometry, Fourier transform-infrared spectroscopy, time-of-flight mass spectrometry, and nuclear magnetic resonance. In-Silico molecular docking analysis showed that PEA potentially docked to the active sites of apoptosis-inducing proteins including BAX, BCL-2, P21, and P53. Further validation was done using in vitro study that showed PEA inhibitsthe proliferation, alters nuclear morphology and attenuates the wound closure ability of MDA-MB-231 and MCF-7 cells. PEA induces apoptosis via upregulating cell-cycle arrest (P21), tumor suppression (P53), pro-apoptotic (BAX, CASPASE-8, and FADD) genes, and downregulating anti-apoptotic gene BCL-2. The upregulation of the active form of Caspase-3 was also reported. This is the first-ever report for the isolation of PEA from C. gloeosporioides with anticancer activity against human breast cancer cells and therefore holds great potential for future therapeutics.

Bioprospecting of fungal endophytes from Oroxylum indicum (L.) Kurz with antioxidant and cytotoxic activity.

Oroxylum indicum (L.) Kurz, a medicinal plant, shows numerous pharmacological properties which may be attributed to the bioactive compounds produced by O. indicum or due to associated endophytes. In the present study, leaf of O. indicum was evaluated for the presence of associated fungal endophytes, and antioxidant and cytotoxic activities of bioactive compounds produced from them. Using culture-dependent approach, eight fungal endophytes belonging to five different genera were identified. Two endophytes Daldinia eschscholtzii and Ectophoma multirostrata have been reported for the first time from the leaf of O. indicum plant. High-performance thin-layer chromatography (HPTLC) of ethyl acetate (EA) extract of isolated fungal endophytes showed a distinct fingerprinting profile in EA extract of Colletotrichum gloeosporioides. Among identified endophytes, EA extract of C. gloeosporioides showed significant antioxidant activity against DPPH free radical, superoxide anion radical, nitric oxide radical and hydroxyl radical with EC50 values of 22.24±1.302 µg/mL, 67.46±0.576 µg/mL, 80.10±0.706 µg/mL and 61.55±1.360 µg/mL, respectively. EA extract of C. gloeosporioides exhibited potential cytotoxicity against HCT116, HeLa and HepG2 cancer cell lines with IC50 values of 76.59 µg/mL, 176.20 µg/mL and 1750.70 µg/mL, respectively. A comparative HPTLC fingerprinting and the antioxidant activity of C. gloeosporioides associated with two different hosts (leaf of O. indicum and dead twigs of other plant) showed that C. gloeosporioides produces bioactive compounds in a host-dependent manner.

Characterization and evaluation of mycosterol secreted from endophytic strain of Gymnema sylvestre for inhibition of α-glucosidase activity.

Endophytic fungi produce various types of chemicals for establishment of niche within the host plant. Due to symbiotic association, they secrete pharmaceutically important bioactive compounds and enzyme inhibitors. In this research article, we have explored the potent α-glucosidse inhibitor (AGI) produced from Fusarium equiseti recovered from the leaf of Gymnema sylvestre through bioassay-guided fraction. This study investigated the biodiversity, phylogeny, antioxidant activity and α-glucosidse inhibition of endophytic fungi isolated from Gymnema sylvestre. A total of 32 isolates obtained were grouped into 16 genera, according to their morphology of colony and spores. A high biodiversity of endophytic fungi were observed in G. sylvestre with diversity indices. Endophytic fungal strain Fusarium equiseti was identified through DNA sequencing and the sequence was deposited in GenBank database (https://ncbi.nim.nih.gov) with acession number: MF403109. The characterization of potent compound was done by FTIR, LC-ESI-MS and NMR spectroscopic analysis with IUPAC name 17-(5-ethyl-6-methylheptan-2-yl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a] phenanthren-3-ol. The isolated bioactive compound showed significant α-amylase and α-glucosidase inhibition activity with IC50 values, 4.22 ± 0.0005 µg/mL and 69.72 ± 0.001 µg/mL while IC50 values of acarbose was 5.75 ± 0.007 and 55.29 ± 0.0005 µg/mL respectively. This result is higher in comparison to other previous study. The enzyme kinetics study revealed that bioactive compound was competitive inhibitor for α-amylase and α-glucosidase. In-silico study showed that bioactive compound binds to the binding site of α-amylase, similar to that of acarbose but with higher affinity. The study highlights the importance of endophytic fungi as an alternative source of AGI (α-glucosidase inhibition) to control the diabetic condition in vitro.