The aim of this study was to develop and validate a rapid and simple high performance thin layer chromatographic (HPTLC) method to screen for antioxidant activity in algal samples. 16 algal species were collected from local Victorian beaches. Fucoxanthin, one of the most abundant marine carotenoids was quantified directly from the HPTLC plates before derivatization, while derivatization either with 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric chloride (FeCl3) was used to analyze antioxidants in marine algae, based on their ability to scavenge non biological stable free radical (DPPH) or to chelate iron ions. Principal component analysis of obtained HPTLC fingerprints has classified algae species into 5 groups according to their chemical/antioxidant profiles. The investigated brown algae samples were found to be rich in non-and moderate-polar compounds and phenolic compounds with antioxidant activity. Most of the phenolic iron chelators also have shown free radical scavenging activity. Strong positive and significant correlations between total phenolic content and DPPH radical scavenging activity showed that, phenolic compounds, including flavonoids are the main contributors of antioxidant activity in these species. The results suggest that certain brown algae possess significantly higher antioxidant potential when compared to red or green algae and could be considered for future applications in medicine, dietary supplements, cosmetics or food industries. Cystophora monilifera extract was found to have the highest antioxidant concentration, followed by Zonaria angustata, Cystophora pectinate, Codium fragile, and Cystophora pectinata. Fucoxanthin was found mainly in the brown algae species. The proposed methods provide an edge in terms of screening for antioxidants and quantification of antioxidant constituents in complex mixtures. The current application also demonstrates flexibility and versatility of a standard HPTLC system in the drug discovery. Proposed methods could be used for the bioassay-guided isolation of unknown natural antioxidants and subsequent identification if combined with spectroscopic identification.
Recent increased interest in seaweed is motivated by attention generated in their bioactive components that have potential applications in the functional food and nutraceutical industries. In the present study, nutritional composition, metabolite profiles, phytochemical screening and physicochemical properties of freeze-dried brown seaweed, Sargassum polycystum were evaluated. Results showed that the S. polycystum had protein content of 8.65 ± 1.06%, lipid of 3.42 ± 0.01%, carbohydrate of 36.55 ± 1.09% and total dietary fibre content of 2.75 ± 0.58% on dry weight basis. The mineral content of S. polycystum including Na, K, Ca, Mg Fe, Se and Mn were 8876.45 ± 0.47, 1711.05 ± 0.07, 1079.75 ± 0.30, 213.85 ± 0.02, 277.6 ± 0.12, 4.70 ± 0.00 and 4.45 ± 0.00 mg 100/g DW, respectively. Total carotenoid, chlorophyll a and b content in S. polycystum were detected at 45.28 ± 1.77, 141.98 ± 1.18 and 111.29 µg/g respectively. The total amino acid content was 74.90 ± 1.45%. The study revealed various secondary metabolites and major constituents of S. polycystum fibre to include fucose, mannose, galactose, xylose and rhamnose. The metabolites extracted from the seaweeds comprised n-hexadecanoic acid, 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester, benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy- methyl ester, 1-dodecanol, 3,7,11-trimethyl-, which were the most abundant. The physicochemical properties of S. polycystum such as water-holding and swelling capacity were comparable to several commercial fibre-rich products. In conclusion, results of this study indicate that S. polycystum is a potential candidate as functional food sources for human consumption and its cultivation needs to be encouraged.
Kaempferia parviflora or commonly known as "Kunyit hitam" by locals, is an edible plant, native to tropical regions, has been extensively utilized for culinary and medicinal applications. The present study aimed to investigate the phytochemical composition and biological activities of the rhizomes of K. parviflora. The ethanol crude and fractionated extracts (hexane and chloroform) of the rhizomes were evaluated for their total phenolic content, total steroidal content, as well as antioxidant, anti-obesogenic, and anti-diabetic activities. The chloroform extract demonstrated the highest concentration of plant sterols (432±0.23 mg BSE/g extract) and a substantial amount of phenolic compounds (1.19×103±0.41 mg GAE/g extract). Gas chromatography-mass spectrometry (GC/MS) analysis revealed that the chloroform extract of the rhizomes is predominantly composed of bioactive flavonoids including tectochrysin (1), 5,7-dimethoxyflavone (2), 3,5,7-trimethoxyflavone (3), 3,4',5,7-tetramethoxyflavone (4), and 4',5,7-trimethoxyflavone (5). Furthermore, the chloroform extract exhibited the highest overall radical scavenging and α-glucosidase inhibitory activities, which can be attributed to the presence of compounds 1-5 in the extract. Collectively, these findings suggest that the chloroform extract of the rhizomes of K. parviflora is a potentially valuable source of bioactive compounds with antioxidant, anti-obesogenic, and anti-diabetic properties, with potential application in therapeutics and functional foods.
The present study aims to formulate a stimuli-responsive in situ hydrogel system to codeliver acacia honey and glycyrrhizic acid for topical application that will aid in absorbing wound exudates, control microbial infestation, and produce angiogenic and antioxidant effects to accelerate wound healing. Therefore, both the natural active constituents were incorporated within an in situ hydrogel composed of poloxamer and hydroxypropyl methylcellulose (HPMC), where the concentrations of the polymers were optimized using Design-Expert software considering optimum values of the dependent variables, gelation temperature (34-37 °C), gelation time (<10 min), and the viscosity (2000-3500 cPs). The optimized formulation showed improved physicochemical properties such as mucoadhesiveness, porosity, swelling, and spreadability, which makes it suitable for wound application. Additionally, the in situ hydrogel exhibited potent in vitro and ex vivo antioxidant effects, in vitro antimicrobial activities, and ex ovo angiogenic effects. Furthermore, the optimized formulation was found to be nontoxic while tested in the HaCaT cell line and acute dermal irritation and corrosion study. The findings of the in vivo wound-healing studies in experimental animal models showed complete wound closure within 15 days of treatment and accelerated development of the extracellular matrix. In addition, the antioxidant, antimicrobial, angiogenic, and wound-healing properties of acacia honey and glycyrrhizic acid coloaded in situ hydrogel were also found to be promising when compared to the standard treatments. Overall, it can be concluded that the optimized stimuli-responsive in situ hydrogel containing two natural compounds could be an alternative to existing topical formulations for acute wounds.
In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8%) after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH) (56.00%) and ferrous ion-chelating (FIC) (59.00%) methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions.
The aim of this study was to examine the effects of extraction methods on antioxidant capacities of red dragon fruit peel and flesh. Antioxidant capacities were measured using ethylenebenzothiozoline-6-sulfonic acid (ABTS) radical cation assay and ferric reducing antioxidant power assay (FRAP). Total phenolic content (TPC) was determined using Folin-Ciocalteu reagent while quantitative determination of total flavonoid content (TFC) was conducted using aluminium trichloride colorimetric method. Betacyanin content (BC) was measured by spectrophotometer. Red dragon fruit was extracted using conventional (CV) and ultrasonic-assisted extraction (UE) technique to determine the most efficient way of extracting its antioxidant components. Results indicated that UE increased TFC, reduced the extraction yield, BC, and TPC, but exhibited the strongest scavenging activity for the peel of red dragon fruit. In contrast, UE reduced BC, TFC, and scavenging activity but increased the yield for the flesh. Nonetheless, UE slightly increases TPC in flesh. Scavenging activity and reducing power were highly correlated with phenolic and flavonoid compounds. Conversely, the scavenging activity and reducing power were weakly correlated with betacyanin content. This work gives scientific evidences for the consideration of the type of extraction techniques for the peel and flesh of red dragon fruit in applied research and food industry.
Artocarpus altilis (breadfruit) pulp, peel and whole fruit were extracted with various solvents such as hexane, dichloromethane (DCM) and methanol. The antioxidant activity of these extracts were examined using the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test. IC50 was 55 ± 5.89 μg/ml for the pulp part of methanol extract. In the β-carotene bleaching assay, the antioxidant activity was 90.02 ± 1.51 % for the positive control (Trolox) and 88.34 ± 1.31 % for the pulp part of the fruit methanol extract. The total phenolic content of the crude extracts was determined using the Folin-Ciocalteu procedure; methanol pulp part demonstrated the highest phenol content value of 781 ± 52.97 mg GAE/g of dry sample. While the total flavonoid content was determined using the aluminium chloride colorimetric assay, the highest value of 6213.33 ± 142.22 mg QE/g was indicated by pulp part of the fruit methanol extract. The antimicrobial activity of the crude extracts was tested using disc diffusion method against pathogenic microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Salmonella typhimurium, Escherichia coli, Klebsiella pneumonia and Candida albicans. Methanol extract of pulp part was recorded to have the highest zone of inhibition against Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) and MBC/minimal fungicidal concentration (MFC) for the extracts were also determined using the microdilution method ranging from 4000 to 63 μg/ml against pathogenic microbes. The MBC/MFC values varied from 250 to 4000 μg/ml. A correlation between antioxidant activity assays, antimicrobial activity and phenolic content was established. The results shows that the various parts of A. altilis fruit extracts promising antioxidant activities have potential bioactivities due to high content of phenolic compounds.
The leaf of Gardenia jasminoides Ellis was used as explants and was cultured on MS and WPM media supplemented with various concentrations of NAA, IAA, 2,4-D, IBA, TDZ, and Kn (0 to 5 mg L(-1) with 0.5 increment). After six months, the higher percentage of callus (100%) and the best dry and fresh weight of callus were formed on WPM medium supplemented with 2,4-D and NAA (2.0-3.0 mg L(-1)) and this amount was decreased from (84%) to (69%) when this media supplemented with Kinetin and TDZ (1 mg L(-1)) respectively were used. Leaf segments cultured on WPM media added with Kn (1 mg L(-1)) and TDZ (2 mg L(-1)) yielded the least amount of callus. It was found that WPM media added with IAA (4.5-5.0 mg L(-1)) were optimum for root induction from G. jasminoides plantlets. Antibacterial screening of leaf extracts (in vivo) showed no inhibitory effect against E. coli, P. aeruginosa, S. aureus, and B. cereus, in contrast to callus extracts from leaf cultures supplemented with NAA, which showed inhibition activity against E. coli and B. cereus. The callus extracts from leaf cultures grown on both MS and WPM media showed higher antioxidant and superoxide dismutase activities than leaf extracts.
Species of the genus Ganoderma are a cosmopolitan wood decaying white rot fungi, which has been used by the Asians for therapeutic purposes for centuries. In the present study, solid-substrate fermentation (SSF) of wheat grains (Triticum aestivum L.) was carried out with indigenous Ganoderma australe (KUM60813) and G. neo-japonicum (KUM61076) selected based on ethnomycological knowledge. G. lucidum (VITA GL) (a commercial strain) was also included in the study. Antioxidant activities of the crude ethanol and aqueous extracts of the fermented and unfermented wheat grains were investigated by ferric reducing antioxidant power (FRAP), Trolox equivalent antioxidant capacity (TEAC), diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging ability, and lipid peroxidation assay. Among the six mycelia extracts tested, the ethanol extract from wheat fermented with KUM61076 mycelia showed the most potent antioxidant activities, whereas the ethanol extract of wheat grains fermented with KUM60813 mycelia has a good potential in protecting frying oils against oxidation. Total phenolic content (TPC) in the ethanol extracts were higher than that in the aqueous extract. The wheat grains fermented with G. australe (KUM60813) and G. neo-japonicum KUM61076 have greater antioxidant potential compared to the commercially available G. lucidum (VITA GL). The antioxidant activities of the mycelia extracts had a positive correlation with their phenolic contents. Thus phenolic compounds may play a vital role in the antioxidant activities of the selected Ganoderma spp.
The present study was conducted in order to assess the effect of various doses of acute gamma irradiation (0, 10, 15, and 20 Gy) on the improvement of bioactive compounds and their antioxidant properties of Curcuma alismatifolia var. Sweet pink. The high performance liquid chromatography (HPLC) and gas chromatography (GC) analysis uncovered that various types of phenolic, flavonoid compounds, and fatty acids gradually altered in response to radiation doses. On the other hand, antioxidant activities determined by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), ferric reduction, antioxidant power (FRAP), and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay showed a higher irradiation level significantly increased the antioxidant properties. This study revealed an efficient effect of varying levels of gamma radiation, based on the pharmaceutical demand to enhance the accumulation and distribution of bioactive compounds such as phenolic and flavonoid compounds, fatty acids, as well as their antioxidant activities in the leaves of C. alismatifolia var. Sweet pink.
4-Methylbenzimidazole 1-28 novel derivatives were synthesized and evaluated for their antiglycation and antioxidant activities. Compounds 1-7 and 11 showed excellent activities ranged 140-280 μM, better than standard drug rutin (294.46 ± 1.50 μM). Compound 1-28 were also evaluated for DPPH activities. Compounds 1-8 showed excellent activities, ranging 12-29 μM, better than standard drug n-propylgallate (IC50 = 30.30 ± 0.40 μM). For superoxide anion scavenging activity, compounds 1-7 showed better activity than standard n-propylgallate (IC50 = 106.34 ± 1.6 μM), ranged 82-104 μM. These compounds were found to be nontoxic to THP-1 cells.
Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1-F7). Antioxidant activity was measured via total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16 ± 6.2 mg GAE/g extract, DPPH; EC50: 30.5 ± 3.2 μg/mL, FRAP; 1169 ± 20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50: 25.75 ± 1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.
Freshly prepared, hand-pressed strawberry fruit juice was exposed to ultraviolet radiation (254 nm) at room temperature (25 ℃ ± 1 ℃) for 15, 30 and 60 min with 0 min serving as control. Results revealed decrease in pH, total soluble solids and titratable acidity, while colour parameters (L*, a* and b* values) and clarity of juice (% transmittance) increased significantly. All the results corresponded to exposure time to ultraviolet radiation. Bioactive compounds (total phenolics, ascorbic acid and anthocyanins) decreased along with a recorded reduction in polyphenol oxidase enzyme and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activities, which were again dependent on exposure time. Results on the microbial studies showed significant reduction by 2-log cycles in aerobic plate count as well as in total yeast and mould counts. Though negative results were observed for certain parameters, this is the first time it was endeavoured to demonstrate the impact of ultraviolet radiation radiation on freshly prepared, hand-pressed strawberries juice.
Hypertension is one of the major causes of cardiovascular-related diseases, which is highly associated with angiotensin-I-converting enzyme (ACE) activity and oxidative stress. In this study, winged bean seed (WBS), a potential source of protein, was utilised for the production of bifunctional proteolysate and biopeptides with ACE inhibitory and antioxidative properties. An enzymatic approach was applied, coupled with pretreatment of shaking and centrifuging techniques to remove endogenous ACE inhibitors prior to proteolysis. ACE inhibition reached its highest activity, 78.5%, after 12 h proteolysis while antioxidative activities, determined using assays involving DPPH˙ radical scavenging activity and metal ion-chelating activity, reached peaks of 65.0% and 65.7% at 8 h and 14 h, respectively. The said bioactivities were proposed to share some common structural requirements among peptides. A two-dimensional approach was employed for characterisation of effective peptides based on hydrophobicity, using RP-HPLC, and isoelectric property, using isoelectric focusing technique. Results revealed that acidic and basic peptides with partially higher hydrophobicity provided higher ACE inhibition activity than did neutral peptides. Finally, by using Q-TOF mass spectrometry, two peptide sequences (YPNQKV and FDIRA) with ACE inhibitory and antioxidative activities were successfully matched with a database. This study indicates that the WBS proteolysate can be a potential bifunctional food ingredient as the identified biopeptides demonstrated both ACE inhibitory and antioxidative activities in vitro.
The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.
C-5-bromo-2-hydroxyphenylcalix[4]-2-methylresorcinarene (I) was synthesized by cyclocondensation of 5-bromo-2-hydroxybenzaldehyde and 2-methylresorcinol in the presence of concentrated HCl. Compound I was characterized by infrared and nuclear magnetic resonance spectroscopic data. X-ray analysis showed that this compound crystallized in a triclinic system with space group of Pī, a = 15.9592(16)Å, b = 16.9417(17)Å, c = 17.0974(17)Å, α = 68.656(3)°, β = 85.689(3)°, γ = 81.631(3)°, Z = 2 and V = 4258.6(7)Å3. The molecule adopts a chair (C2h) conformation. The thermal properties and antioxidant activity were also investigated. It was strongly antiviral against HSV-1 and weakly antibacterial against Gram-positive bacteria. Cytotoxicity testing on Vero cells showed that it is non-toxic, with a CC50 of more than 0.4 mg/mL.
Antioxidative and antihypertensive bioactive peptides were successfully derived from Parkia speciosa seed using alcalase. The effects of temperature (25 and 50 °C), substrate-to-enzyme ratio (S/E ratio, 20 and 50), and incubation time (0.5, 1, 2 and 5h) were evaluated based on 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and angiotensin-converting enzyme (ACE) assays. Bioactive peptide extracted at a hydrolysis condition of: temperature=50 °C, S/E ratio=50 and incubation time=2h, exhibited the highest DPPH radical scavenging activity (2.9 mg GAE/g), reducing power (11.7 mM) and %ACE-inhibitory activity (80.2%). The sample was subsequently subjected to fractionation and the peptide fraction of <10 kDa showed the strongest bioactivities. A total of 29 peptide sequences from peptide fraction of <10 kDa were identified as the most potent contributors to the bioactivities. These novel bioactive peptides were suggested to be beneficial to nutraceutical and food industries.
Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase.