Cytotoxicity Potential of Endophytic Fungi Extracts from Terminalia catappa against Human Cervical Cancer Cells.

Endophytic fungi are potential sources of novel bioactive metabolites from a natural product drug discovery perspective. This study reports the bioactivity-directed fractionation of the secondary metabolites of the ethyl acetate extract of a fermentation culture of endophytic fungi from Terminalia catappa which were then evaluated for their cytotoxicity against human cervical cancer (HeLa) cells and human foreskin fibroblast (HFF) cells. Furthermore, apoptosis was determined using the Annexin V/propidium iodide (PI) flow cytometry assay. Endophyte extracts N2, N7, N8, N97, N169, and N233 were obtained from Trichoderma sp, Phoma sp, Phomopsis phyllanticola, Fusarium oxyporum, Collectotrichum sp, and Cryptococcus flavescens, respectively. The N97 extract was most active with a 50% inhibitory concentration (IC50) of 33.35 µg/ml. A 50% cytotoxic concentration (CC50) of 268.4 µg/ml was obtained with HFF cells and the selectivity index (SI) was 8.01. The percentages of cell populations were increased at late apoptosis (Annexin+/PI+), with the percentages of 27.4 ± 0.3 and 19.2 ± 0.01 obtained, respectively, for 50 µg/ml and 80 µg/ml of the N97 extract and 2.1 ± 0.1 obtained for the control in late apoptosis (Annexin V+/PI+) . Moreover, a higher reduction in the percentage of viable cells was observed in the HeLa control cells (93.6 ± 0.3), but the percentages of viable HeLa cells were 37 ± 0.05 and 45 ± 0.1, respectively, for the 50 µg/ml and 80 µg/ml treatments with the N97 extract. Also, the percentages of 34.7 ± 0.1 and 33.9 ± 0.4 were, respectively, obtained for 50 µg/ml and 80 µg/ml compared to the control with 4.6 ± 0.2, in early apoptosis (Annexin V+/PI-). These findings highlight the anticancer potential of the N97 extract of endophytic fungi from Terminalia catappa, which is mediated through apoptosis and presumably also attenuation of chemoresistance.

Enhanced Anti-Bacterial Activity Of Biogenic Silver Nanoparticles Synthesized From Terminalia mantaly Extracts.

BACKGROUND: The global increase in outbreaks and mortality rates associated with multi-drug-resistant (MDR) bacteria is a major health concern and calls for alternative treatments. Natural-derived products have shown potential in combating the most dreadful diseases, and therefore serve as an effective source of bioactive compounds that can be used as anti-bacterial agents. These compounds are able to reduce metal ions and cap nanoparticles to form biogenic nanoparticles (NPs) with remarkable anti-bacterial activities. This study explores the use of Terminalia mantaly (TM) extracts for the synthesis of biogenic silver NPs (TM-AgNPs) and the evaluation of their antibacterial activity. METHODS: TM-AgNPs were synthetized by the reduction of AgNO3 with aqueous and methanolic TM extracts. UV-visible (UV-vis) spectrophotometry, Dynamic Light Scattering (DLS), Transmission Electron Microscopy, and Fourier Transform Infrared (FTIR) analyses were used to characterise the TM-AgNPs. Anti-bacterial activity of the TM extracts and TM-AgNPs was evaluated against eight bacterial strains using the broth microdilution assay. The growth inhibitory kinetics of the bio-active TM-AgNPs was assessed on susceptible strains for a period of 8 hrs. RESULTS: Polycrystalline biogenic AgNPs with anisotropic shapes and diameter range of 11 to 83 nm were synthesized from the TM extracts. The biogenic TM-AgNPs showed significant antibacterial activity compared to their respective extracts. The MIC values for TM-AgNPs and extracts were 3 and 125 µg/mL, respectively. Biogenic AgNPs synthesised from the aqueous TM leaf extract at 25°C (aTML-AgNPs-25°C) showed significant antibacterial activity against all the bacterial strains tested in this study. Their bactericidal effect was particularly higher against the Streptococcus pneumoniae and Haemophilus influenzae. CONCLUSION: This study demonstrated the ability of TM extracts to synthesize biogenic AgNPs. The NPs synthesized from the aqueous TM extracts demonstrated higher antibacterial activity against the tested microorganisms compared to the methanolic extracts. Studies are underway to identify the phytochemicals involved in NP synthesis and their mechanism of action.

Glyphaea brevis - In vitro antioxidant and in silico biological activity of major constituents and molecular docking analyses.

Previous studies have revealed that leaf extracts of Glyphaea brevis possess antioxidant activity but the bioactivity and mechanisms of action of its major constituents remain unknown. This study evaluated in vitro antioxidant and free radical scavenging activities of Glyphaea brevis twigs and leaves, and probable toxicity profile, pharmacological activities and mechanisms of action of major phytoconstituents in silico. Phytochemical screening detected saponins, tannins, steroids, anthraquinones, flavonoids, terpenoids and phenolics in the extracts. HPLC fingerprinting revealed major compounds as ferulic, catechuic and coumaric acids. Twig extract contained more flavanols compared to the leaf extract while the leaf extract had more flavonol content. Extract of the twigs demonstrated higher ORAC, TEAC and FRAP compared to the leaf extract. In silico analyses predicted low acute toxicity risk and pharmacological activities which are in agreement with traditional use of the plant in the management of diseases such as dyspepsia, ulcers, chest pains, diarrhea, dysentery and sleeping sickness. The molecular docking studies revealed that coumaric acid and ferulic acid have the best binding for all proteins tested. In summary, Glyphaea brevis twigs possess higher antioxidant activity than the leaves and major constituents showed low toxicological potential and promising biological activities which support its ethnomedical use.