METHODS: A total of 20 methanolic crude extracts (bark and leaf) from ten different plants were screened using a colorimetric hyaluronidase enzymatic assay. The active plant extract (Payena dasyphylla) was then studied for its hyaluronidase inhibitory activity in the interleukin-1β (IL-1β) stimulated human chondrocytes cell line (NHAC-kn) using zymography method. The Payena dasyphylla methanolic bark extract was then fractionated into several fractions in where the ethyl acetate (EA) fraction was evaluated for its inhibitory effects on the HYAL1 and HYAL2 gene expressions using reverse transcription-polymerase chain reaction (RT-PCR) technique. While the MMP-3 and MMP-13 protein expressions were evaluated using western blot method. The phenolic and flavonoid contents of the three fractions as well as the antioxidant property of the EA fraction were also evaluated.
RESULTS: Bark extract of Payena dasyphylla (100 μg/ml) showed the highest inhibitory activity against bovine testicular hyaluronidase with 91.63%. The plant extract also inhibited hyaluronidase expression in the cultured human chondrocyte cells in response to IL-1β (100 ng/ml). Similarly, treatment with Payena dasyphylla ethyl acetate (EA) fraction (100 μg/ml) inhibited the HYAL1 and HYAL2 mRNA gene expressions as well as MMP-3 and MMP-13 protein expression in a dose dependent manner. Payena dasyphylla EA fraction has demonstrated the highest amount of phenolic and flavonoid content with 168.62 ± 10.93 mg GAE/g and 95.96 ± 2.96 mg RE/g respectively as compared to water and hexane fractions. In addition, the Payena dasyphylla EA fraction showed strong antioxidant activity with IC₅₀ value of 11.64 ± 1.69 μg/mL.
CONCLUSION: These findings have shown that Payena dasyphylla might contained potential phenolic compounds that inhibiting the key enzyme in osteoarthritis development, which is the hyaluronidase enzyme through interruption of HYAL1 and HYAL1 gene expressions. The degradation of cartilage could also be inhibited by the plant through suppression of MMP-3 and MMP-13 protein expressions. We also reported that the inhibitory effect of Payena dasyphylla on hyaluronidase activity and expression might be due to its anti-oxidant property.
METHODS: Palm kernel oil esters (PKOEs)-based nanoemulsions were loaded with P. urinaria extract using a spontaneous method and characterized with respect to particle size, zeta potential, and rheological properties. The release profile of the extract was evaluated using in vitro Franz diffusion cells from an artificial membrane and the antioxidant activity of the extract released was evaluated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method.
RESULTS: Formulation F12 consisted of wt/wt, 0.05% P. urinaria extract, 1% cetyl alcohol, 0.5% glyceryl monostearate, 12% PKOEs, and 27% Tween 80/Span 80 (9/1) with a hydrophilic lipophilic balance of 13.9, and a 59.5% phosphate buffer system at pH 7.4. Formulation F36 was comprised of 0.05% P. urinaria extract, 1% cetyl alcohol, 1% glyceryl monostearate, 14% PKOEs, 28% Tween 80/Span 80 (9/1) with a hydrophilic lipophilic balance of 13.9, and 56% phosphate buffer system at pH 7.4 with shear thinning and thixotropy. The droplet size of F12 and F36 was 30.74 nm and 35.71 nm, respectively, and their nanosizes were confirmed by transmission electron microscopy images. Thereafter, 51.30% and 51.02% of the loaded extract was released from F12 and F36 through an artificial cellulose membrane, scavenging 29.89% and 30.05% of DPPH radical activity, respectively.
CONCLUSION: The P. urinaria extract was successfully incorporated into a PKOEs-based nanoemulsion delivery system. In vitro release of the extract from the formulations showed DPPH radical scavenging activity. These formulations can neutralize reactive oxygen species and counteract oxidative injury induced by ultraviolet radiation and thereby ameliorate skin aging.
METHODS: Well diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were used to test antibacterial activity against four pathogenic bacteria namely Staphylococcus aureus, Escherichia coli, Bacillus cereus, and Pseudomonas aeruginosa. DPPH (2, 2-diphenyl-1- picrylhydrazyl) and superoxide dismutase (SOD) assays were used to evaluate antioxidant activity. HPLC and gel filtration were used for purification of the peptides. Scanning electron microscope was applied to investigate the mode of attachment of the peptides on target microbial membranes.
RESULTS: Aqueous extraction of the mixture showed no inhibition zones against all the test bacteria. Mean diameter of inhibition zones for ethanol extraction of this mixture attained 8.33 mm, 7.33 mm, and 6.33 mm against S. aureus at corresponding concentrations of 500, 250 and 125 mg/ml while E .coli showed inhibition zones of 9.33 mm, 8.00 mm and 6.66 mm at the same concentrations. B. cereus exhibited inhibition zones of 11.33 mm, 10.33 mm and 10.00 mm at concentrations of 500, 250 and 125 mg/ml respectively. The peptide extract demonstrated antibacterial activity against S. aureus, E. coli and B. cereus. The MIC and MBC values for ethanol extracts were determined at 125 mg/ml concentration against S. aureus and E. coli and B. cereus value was 31.5 mg/ml. MIC and MBC values showed that the peptide extract was significantly effective at low concentration of the Australian plant mixture (APM). Phenolic compounds were detected in hot aqueous and ethanolic extracts of the plant mixture. Hot aqueous, ethanol and peptides extracts also exhibited antioxidant activities.
CONCLUSIONS: It was concluded that APM possessed good antibacterial and antioxidant activities following extraction with different solvents. The results suggest that APM provide a new source with antibacterial agents and antioxidant activity for nutraceutical or medical applications.
METHODS: The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3) cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control) at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH) or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls).
RESULTS: Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL). The extract reduced significantly (p < 0.05) apoptotic cell death due to DPPH and ABTS by 4 to 5-fold although the activity was less than vitamin C. Based on the DPPH assay, the radical scavenging activity of the extract was higher than phycocyanin and was at least 50% of vitamin C and vitamin E. Based on the ABTS assay, the antioxidant activity of the extract at 50 μmug/mL was as good as vitamin C and vitamin E.
CONCLUSIONS: The results showed that aqueous extract of Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring.
AIM OF THE STUDY: To investigate the wound healing ability of a concentrated extract of B. orientale in a hydrogel formulation in healing diabetic ulcer wounds.
MATERIALS AND METHODS: The water extract from the leaves of B. orientale was separated from the crude methanolic extract and subjected to flash column chromatography techniques to produce concentrated fractions. These fractions were tested for phytochemical composition, tannin content, antioxidative and antibacterial activity. The bioactive fraction was formulated into a sodium carboxymethylcellulose hydrogel. The extract-loaded hydrogels were then characterized and tested on excision ulcer wounds of streptozotocin-induced diabetic rats. Wound size was measured for 14 days. Histopathological studies were conducted on the healed wound tissues to observe for epithelisation, fibroblast proliferation and angiogenesis. All possible mean values were subjected to statistical analysis using One-way ANOVA and post-hoc with Tukey's T-test (P<0.05).
RESULTS: One fraction exhibited strong antioxidative and antibacterial activity. The fraction was also highly saturated with tannins, particularly condensed tannins. Fraction W5-1 exhibited stronger antioxidant activity compared to three standards (α-Tocopherol, BHT and Trolox-C). Antibacterial activity was also present, and notably bactericidal towards Methicillin-resistant Staphylococcus aureus (MRSA) at 0.25mg/ml. The extract-loaded hydrogels exhibited shear-thinning properties, with high moisture retention ability. The bioactive fraction at 4% w/w was shown to be able to close diabetic wounds by Day 12 on average. Other groups, including controls, only exhibited wound closure by Day 14 (or not at all). Histopathological studies had also shown that extract-treated wounds exhibited re-epithelisation, higher fibroblast proliferation, collagen synthesis, and angiogenesis.
CONCLUSION: The ethnopharmacological effects of using B. orientale as a topical treatment for external wounds was validated and was also significantly effective in treating diabetic ulcer wounds. Thus, B. orientale extract hydrogel may be presented as a potential treatment for diabetic ulcer wounds.
Methods: Antioxidant properties were assessed through various radical (DPPH, ABTS, and nitric oxide) scavenging assays and determination of total phenolic content and ferric reducing antioxidant power level. ARPE-19 cells were preincubated with samples before the addition of GO (to generate H2O2). Cell viability, change in intracellular reactive oxygen species (ROS), H2O2 levels in cell culture supernatant, and gene expression were assessed.
Results: F2 showed higher antioxidant levels than the extract when assessed for radical scavenging activities and ferric reducing antioxidant power. F2 protected the ARPE-19 cells against GO-H2O2-induced oxidative stress by reducing the production of H2O2 and intracellular reactive oxygen species. This was achieved by the activation of nuclear factor erythroid 2-related factor 2 (Nrf2/NFE2L2) and superoxide dismutase (SOD2), as well as downregulation of nitric oxide producer (NOS2) at the transcriptional level.
Conclusions: The results showed that myricetin derivatives from S. malaccense have the capacity to exert considerable exogenous antioxidant activities and stimulate endogenous antioxidant activities. Therefore, these derivatives have excellent potential to be developed as therapeutic agents for managing DR.
MATERIALS AND METHODS: The antioxidant effect of these compounds was initially performed in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay methods before subjecting them to in vivo experiments. Compounds showing potent antioxidant activity (CS-1 and CS-2) were investigated further for their antidepressant activity using the forced swim test (FST) and tail suspension test (TST). Ascorbic acid (AA) and fluoxetine (20 mg/kg, p.o) were used as reference drugs for comparison in the antioxidant and antidepressant experiments, respectively.
RESULTS: It was observed that CS-2 and CS-3 exhibited highest DPPH (half maximal inhibitory concentration [IC50]: 16.22 and 25.18 μg/mL) and ABTS (IC50: 17.2 and 28.86 μg/mL) radical scavenging activity, respectively, compared to AA (IC50: 15.73 and 16.79 μg/mL) and therefore, both CS-2 and CS-3 were tested for their antidepressant effect using FST and TST as experimental models. Pretreatment of CS-2 and CS-3 (20 mg/kg) for 10 days considerably decreased the immobility time in both the FST and TST models.
CONCLUSION: The antioxidant and antidepressant effect of CS-2 and CS-3 may be attributed to the presence of azomethine linkage in the molecule.