Development of sodium alginate-pectin biodegradable active food packaging film containing cinnamic acid.

Plastics are still the most popular food packaging material and many of them end up in the environment for a long period. Due to packaging material's inability to inhibit microbial growth, beef often contains microorganisms that affect its aroma, colour and texture. Cinnamic acid is categorized as generally recognised as safe and is permitted for use in food. The development of biodegradable food packaging film with cinnamic acid has never been conducted before. This present study was aimed to develop a biodegradable active packaging material for fresh beef using sodium alginate and pectin. The film was successfully developed with solution casting method. The films' thickness, colour, moisture level, dissolution, water vapour permeability, bending strength and elongation at break were comparable to those of polyethylene plastic film in terms of these attributes. The developed film also showed the degradability in soil of 43.26% in a duration of 15 days. Fourier Transform Infrared (FTIR) spectra showed that cinnamic acid was successfully incorporated with the film. The developed film showed significant inhibitory activity on all test foodborne bacteria. On Hohenstein challenge test, a 51.28-70.45% reduction on bacterial growth was also observed. The antibacterial efficacy of the established film by using fresh beef as food model. The meats wrapped with the film showed significant reduction in bacterial load throughout the experimental period by 84.09%. The colour of the beef also showed significant different between control film and edible film during 5 days test. Beef with control film turned into dark brownish and beef with cinnamic acid turn into light brownish. Sodium alginate and pectin film with cinnamic acid showed good biodegradability and antibacterial activity. Further studies can be conducted to investigate the scalability and commercial viability of this environmental-friendly food packaging materials.

Metabolites characterisation of endophytic Phyllosticta fallopiae L67 isolated from Aloe vera with antimicrobial activity on diabetic wound microorganisms.

This study aimed to assess the antimicrobial activity of endophytic Phyllosticta fallopiae L67 isolated from Aloe vera against diabetic wound microorganisms and characterise their active fraction for biologically important metabolites. The dichloromethane (DCM) extract exhibited the most significant activity with inhibition zones ranging from 11.33 to 38.33 mm. The minimal inhibitory and lethality concentrations of DCM extract ranged from 78.13 to 2500.00 µg/ml and 625.00 to 5000.00 µg/ml, respectively. The extract showed teratogenicity and lethality in the zebrafish model, where peritoneal and hepatic oedema occurred at 62.50 µg/ml, and no abnormality appeared at 31.25 µg/ml. The extract also inhibited more than 82% biofilm formation. Bioassay-guided fractionation on DCM extract yielded 18 fractions and the most active fraction was subjected to UPLC-QTOF-MS/MS analysis. Flavones, stilbenes, flavanonols, isoflavonoids, phenolic glycosides and phenol derivatives were detected. In conclusion, endophytic P. fallopiae possessed bioactive metabolites with significant antimicrobial activity against diabetic wound microorganisms.

Plant Terpenoids as the Promising Source of Cholinesterase Inhibitors for Anti-AD Therapy.

Plant-derived terpenes are the prolific source of modern drugs such as taxol, chloroquine and artemisinin, which are widely used to treat cancer and malaria infections. There are research interests in recent years on terpene-derived metabolites (diterpenes, triterpenes and sesquiterpenes), which are believed to serve as excellent cholinesterase inhibitors. As cholinesterase inhibitors are the current treatment for Alzheimer's disease, terpene-derived metabolites will have the potential to be involved in the future drug development for Alzheimer's disease. Hence, a bibliographic search was conducted by using the keywords "terpene", "cholinesterase" and "Alzheimer's disease", along with cross-referencing from 2011 to 2020, to provide an overview of natural terpenes with potential anticholinesterase properties. This review focuses on the extraction, chemical structures and anti-cholinesterase mechanisms of terpenes, which support and encourage future research on drug discovery and development in treating Alzheimer's disease.

The potentiation of beta-lactam and anti-bacterial activities of lipophilic constituents from Mesua ferrae leaves against methicillin-resistant Staphylococcus aureus.

OBJECTIVES: Mesua ferrae, from the family of Calophyllaceae, is traditionally used for the treatment of piles, fever and renal disorders. The present study was aimed to examine the antibacterial compounds from the leaves of M. ferrae and their ß-lactam antibiotic potentiate activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). METHODS: Stigmasterol (1) and ß-caryophyllene oxide (2) were isolated from the n-hexane fraction of the leaves of M. ferrae using a bioassay-guided fractionation approach. RESULTS: The isolated compounds displayed anti-Staphylococcus and anti-MRSA activities. It is worth to note that both compounds demonstrated synergism with ß-lactam antibiotics against S. aureus and MRSA. Gas chromatography-mass spectrometry (GC-MS) analysis indicated the n-hexane fraction was dominated by triterpenes and sesquiterpenes, suggesting the total antibacterial activity exhibited by the fraction. CONCLUSION: Based on the findings, it could conclude that M. ferrae is a promising natural source for the discovery of new anti-MRSA lead compounds.

A Bottom-Up Synthesis Approach to Silver Nanoparticles Induces Anti-Proliferative and Apoptotic Activities Against MCF-7, MCF-7/TAMR-1 and MCF-10A Human Breast Cell Lines.

A bottom-up approach for synthesizing silver nanoparticles (AgNPs-GA) phytomediated by Garcinia atroviridis leaf extract is described. Under optimized conditions, the AgNPs-GA were synthesized at a concentration of 0.1 M silver salt and 10% (w/v) leaf extract, 1:4 mixing ratio of reactants, pH 3, temperature 32 °C and 72 h reaction time. The AgNPs-GA were characterized by various analytical techniques and their size was determined to be 5-30 nm. FTIR spectroscopy indicates the role of phenolic functional groups in the reduction of silver ions into AgNPs-GA and in supporting their subsequent stability. The UV-Visible spectrum showed an absorption peak at 450 nm which reflects the surface plasmon resonance (SPR) of AgNPs-GA and further supports the stability of these biosynthesized nanoparticles. SEM, TEM and XRD diffractogram analyses indicate that AgNPs-GA were spherical and face-centered-cubic in shape. This study also describes the efficacy of biosynthesized AgNPs-GA as anti-proliferative agent against human breast cancer cell lines, MCF-7 and MCF-7/TAMR-1. Our findings indicate that AgNPs-GA possess significant anti-proliferative effects against both the MCF-7 and MCF-7/TAMR-1 cell lines, with inhibitory concentration at 50% (IC50 values) of 2.0 and 34.0 µg/mL, respectively, after 72 h of treatment. An induction of apoptosis was evidenced by flow cytometry using Annexin V-FITC and propidium iodide staining. Therefore, AgNPs-GA exhibited its anti-proliferative activity via apoptosis on MCF-7 and MCF-7/TAMR-1 breast cancer cells in vitro. Taken together, the leaf extract from Garcinia atroviridis was found to be highly capable of producing AgNPs-GA with favourable physicochemical and biological properties.

Homalomena pineodora essential oil nanoparticle inhibits diabetic wound pathogens.

Essential oil of Homalomena pineodora inhibits diabetic pathogens; however, the activity was not sustainable when applied as wound dressing. This study aims to synthesise the essential oil nanoparticle using chitosan. The nanoparticles were synthesised with ion gelation method, confirmed by spectroscopic analysis. The spherical nanoparticles display a size of 70 nm, with strong surface charge of +24.10 mV. The nanoparticles showed an initial burst release followed by a slow release pattern for 72 h, following the first order of kinetic. The release behaviour was ideal for wound dressing. The antimicrobial activity was broad spectrum. The formation of nanoparticle enhanced the antimicrobial efficacy of the essential oil. The nanoparticle also showed a concentration-dependent killing behaviour on time-kill assay. In the 3D collagen wound models, the nanoparticles reduced the microbial growth by 60-80%. In conclusion, H. pineodora nanoparticles showed pharmaceutical potential in inhibiting microbial growth on diabetic ulcers.

Sesquiterpenes rich essential oil from Garcinia celebica L. and its cytotoxic and antimicrobial activities.

Garcinia celebica L., locally known as "manggis hutan" in Malaysia is widely used in folkloric medicine to treat various diseases. The present study was aimed to examine the chemical composition of the essential oil from the leaves of G. celebica L. (EO-GC) and its cytotoxic and antimicrobial potential. EO-GC obtained by hydrodistillation was analysed using capillary GC and GC-MS. Twenty-two compounds were identified, dominated by α-copaene (61.25%), germacrene D (6.72%) and ß-caryophyllene (5.85%). In the in vitro MTT assay, EO-GC exhibited significant anti-proliferative effects towards MCF-7 human breast cancer cells with IC50 value of 45.2 µg/mL. Regarding the antimicrobial activity, it showed better inhibitory effects on Gram-positive bacteria than Gram-negative bacteria and none on the fungi and yeasts tested.

Chemical composition and cytotoxic activity of Garcinia atroviridis Griff. ex T. Anders. essential oils in combination with tamoxifen.

Garcinia atroviridis Griff. ex T. Anders. is used as a medication agent in folkloric medicine. The present study was to examine the chemical composition of the stem bark and leaf of G. atroviridis as well as their cytotoxic effects against MCF-7 cells. The constituents obtained by hydrodistillation were identified using GC-MS. The stem bark oil (EO-SB) composed mainly the palmitoleic acid (51.9%) and palmitic acid (21.9%), while the leaf oil (EO-L) was dominated by (E)-ß-farnesene (58.5%) and ß-caryophyllene (16.9%). Treatment of MCF-7 cells using EO-L (100 µg/mL) caused more than 50% cell death while EO-SB did not induce cytotoxic effect. EO-L has stimulated the growth of BEAS-2B normal cells, but not in MCF-7 cancerous cells. The IC50 of EO-L in MCF-7 and BEAS-2B cells were 71 and 95 µg/mL, respectively. A combination treatment of EO-L and tamoxifen induced more cell death than the treatment with drug alone at lower doses.

Endophytic Diaporthe sp. ED2 Produces a Novel Anti-Candidal Ketone Derivative.

This study aimed to examine the anti-candidal efficacy of a novel ketone derivative isolated from Diaporthe sp. ED2, an endophytic fungus residing in medicinal herb Orthosiphon stamieus Benth. The ethyl acetate extract of the fungal culture was separated by open column and reverse phase high-performance liquid chromatography (HPLC). The eluent at retention time 5.64 min in the HPLC system was the only compound that exhibited anti-candidal activity on Kirby-Bauer assay. The structure of the compound was also elucidated by nuclear magnetic resonance and spectroscopy techniques. The purified anti-candidal compound was obtainedas a colorless solid and characterized as 3-hydroxy-5-methoxyhex-5-ene-2,4-dione. On broth microdilution assay, the compound also exhibited fungicidal activity on a clinical strain of Candida albicans at a minimal inhibitory concentration of 3.1 µg/ml. The killing kinetic analysis also revealed that the compound was fungicidal against C. albicans in a concentration- and time-dependent manner. The compound was heat-stable up to 70°C, but its anti-candidal activity was affected at pH 2.

New cholinesterase inhibitors from Garcinia atroviridis.

A triflavanone, Garcineflavanone A (1) and a biflavonol, Garcineflavonol A (2) have been isolated from the stem bark of Garcinia atroviridis (Clusiaceae), collected in Peninsular Malaysia. Their structures were established using one and two-dimensional NMR, UV, IR and mass spectrometry and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activity. Molecular docking studies of the isolated compounds were performed using docking procedure of AutoDock to disclose the binding interaction and orientation of these molecules into the active site gorge.