Strategies for improvement of gamma-aminobutyric acid (GABA) biosynthesis via lactic acid bacteria (LAB) fermentation

Gamma-aminobutyric acid (GABA) is a non-protein amino acid widely distributed in nature and extensively explored for its numerous physiological functions and effects on metabolic disorders. Lactic acid bacteria (LAB) are one of the most important GABA producers, vigorously pursued due to their high GABA content and generally regarded as safe (GRAS) status that allows for direct formulation in various GABA-enriched food products. To meet the strict requirements of the food and nutraceutical industries, the biosynthesis of GABA is typically preferred over the chemical synthesis route. The production of GABA varies among various strains of LAB and is affected by different fermentation conditions. Hence, optimizing the fermentation conditions to enhance the activity of the key enzyme glutamic acid decarboxylase is essential to maximize GABA production. This paper reviews the beneficial effects of GABA on human health and its applications in fermented food products. A particular emphasis is given to the biosynthetic approach for producing GABA by various LAB species via the microbial fermentation route. Efficient strategies for enhancing GABA production through optimization of the fermentation conditions, mode of fermentation, two-step fermentation, co-culturing approach, immobilization technique and genetic engineering are discussed in detail.

Short-chain fatty acids: possible regulators of insulin secretion

The benefits of gut microbiota-derived short-chain fatty acids (SCFAs) towards health and metabolism have been emerging since the past decade. Extensive studies have been carried out to understand the mechanisms responsible in initiating the functionalities of these SCFAs towards body tissues, which greatly involves the SCFA-specific receptors free fatty acid receptor 2 (FFAR2) and free fatty acid receptor 3 (FFAR3). This review intends to discuss the potential of SCFAs particularly in regulating insulin secretion in pancreatic β-cells, by explaining the production of SCFAs in the gut, the fate of each SCFAs after their production, involvement of FFAR2 and FFAR3 signalling mechanisms and their impacts on insulin secretion. Increased secretion of insulin after SCFAs treatments were reported in many studies, but contradicting evidence also exist in several other studies. Hence, no clear consensus was achieved in determining the true potential of SCFA in regulating insulin secretion. In this review, we explore how such differences were possible and hopefully be able to shed some perspectives in understanding SCFAs-signalling behaviour and preferences.

Influence of Dietary Biosynthesized Zinc Oxide Nanoparticles on Broiler Zinc Uptake, Bone Quality, and Antioxidative Status

A total of 180 broiler chickens (Cobb500) were randomly allotted to five experimental groups consisting of six replicates and six birds in each pen. Each group was fed a basal diet supplemented with 100 mg/kg ZnO (control) and 10, 40, 70, and 100 mg/kg ZnO NPs for 35 days. Resultantly, Zn uptake and accumulation in serum, breast muscle, tibia bone, and liver were linearly and significantly (p < 0.05) increased with increasing dietary ZnO NPs supplementation at 100 mg/kg compared to the control group (dietary 100 mg/kg ZnO), implying effective absorption capacity of ZnO NPs. This was followed by lower Zn excretion in feces in broilers fed ZnO NPs compared to controls (p < 0.05). Furthermore, dietary ZnO NPs at 40, 70, and 100 mg/kg levels improved broiler tibia bone morphological traits, such as weight, length, and thickness. Similarly, tibia bone mineralization increased in broilers fed ZnO NPs at 100 mg/kg compared to the control (p < 0.05), as demonstrated by tibia ash, Zn, Ca, and P retention. Antioxidative status in serum and liver tissue was also increased in broilers fed dietary ZnO NPs at 70 and 100 mg/kg compared to the control (p < 0.05). In conclusion, dietary ZnO NPs increased Zn absorption in broiler chickens and had a positive influence on tibia bone development and antioxidative status in serum and liver tissue, with dietary ZnO NPs supplementation at 70 and 100 mg/kg showing the optimum effects.

Formulation and Hardness Evaluation of Tablets Containing Citrus limon and Hylocereus polyrhizus Powder using D-Optimal Mixture Design

The powder of mixed fruits that are Lemon (Citrus limon) and Red Pitaya (Hylocereus polyrhizus) was used as a nutritional supplement in tablet form for nutraceutical application. D-optimal mixture experimental design (D-Optimal MED) was employed to investigate the influence of different components on the response hardness of the tablet. For tablet formulation, magnesium stearate, A (0.2-1.0% w/w), menthol, B (0.2-1.0% w/w), lemon powder, C (1.0-10.0 w/w), maltodextrin, D (5.0 -10.0) and glucose, E (37.5-53.1%) are the variables while red pitaya powder and preservative are fixed components. The experimental data were used to analyze analysis of variance (ANOVA) and to develop a polynomial regression model for tablet hardness in terms of the five design factors considered in this study. D-Optimal MED predicted the hardness of the tablet at 8.5 kg/cm2. The results showed that the best mixture was the formulation that included 0.66% A, 0.74% B, 6.15% C, 7.61% D and 44.34% E, with the actual hardness of the optimized tablet recorded at 8.581 kg/cm2 (R2 = 0.9925). The study demonstrated the potentiality of mixed fruit tablets as a nutritional supplement with therapeutic properties for general consumers well-being.

Gel Textural Characteristics of Hair Gel with Cocoa Shell Extract by Using Mixture D-optimal Method

This study was used a mixture design to optimize the spreadability and viscosity of topical hair gel incorporates cocoa shell extract. The factor of the hair gel ingredient was thickener (0.2 – 0.8%), styling polymer A (2-5%), styling polymer B (2-6%), and solvent (84.63-91.63%) were studied on two responses selected spreadability and viscosity. The data collected were fitted to the model with high coefficient determination (R2= 0.994 for the spreadability and 0.9937 for the viscosity). The model can be predicted by showing the good lack of fit test result not significant with the p-value bigger than 0.05. From the ramp function simulation, the optimized formulation was selected and established at thickener (0.55%), styling polymer A (3.61%), styling polymer B (3.72%), and solvent (88.55%) with the spreadability and viscosity at 353.77 g.s and 39.91 pa.s respectively. The benefit of using mixture design in this experiment, it can help a formulator to understand the complex interaction between factors and can easily modify the formulation through ramp function simulation to obtain the desired result. The predicted validation test shows that both values were comparable. Under this condition showed that the model development could be used to predict future observations within the design range thickener (0.2 – 0.8%), styling polymer A (2-5%), styling polymer B (2-6%), and solvent (84.63-91.63%).

Comparison of Joint Effect of Acute and Chronic Toxicity for Combined Assessment of Heavy Metals on Photobacterium sp.NAA-MIE

Predicting the crucial effect of single metal pollutants against the aquatic ecosystem has been highly debatable for decades. However, dealing with complex metal mixtures management in toxicological studies creates a challenge, as heavy metals may evoke greater toxicity on interactions with other constituents rather than individually low acting concentrations. Moreover, the toxicity mechanisms are different between short term and long term exposure of the metal toxicant. In this study, acute and chronic toxicity based on luminescence inhibition assay using newly isolated Photobacterium sp.NAA-MIE as the indicator are presented. Photobacterium sp.NAA-MIE was exposed to the mixture at a predetermined ratio of 1:1. TU (Toxicity Unit) and MTI (Mixture Toxic Index) approach presented the mixture toxicity of Hg²⁺ + Ag⁺, Hg²⁺ + Cu²⁺, Ag⁺ + Cu²⁺, Hg²⁺ + Ag⁺ + Cu²⁺, and Cd²⁺ + Cu²⁺ showed antagonistic effect over acute and chronic test. Binary mixture of Cu²⁺ + Zn²⁺ was observed to show additive effect at acute test and antagonistic effect at chronic test while mixture of Ni²⁺ + Zn²⁺ showing antagonistic effect during acute test and synergistic effect during chronic test. Thus, the strain is suitable and their use as bioassay to predict the risk assessment of heavy metal under acute toxicity without abandoning the advantage of chronic toxicity extrapolation.

Biofunctional characteristics of banana peel dietary fibre (BPDF) and its associated in vitro antidiabetic properties

The potential applications of banana peel waste can resolve environmental issues; however, the potentials of banana peels as antidiabetic remain unexplored. Therefore, the present work was carried out to investigate the biofunctional and surface properties of banana peel dietary fibre (BPDF) and its enzyme inhibitory activities. The water holding capacity (WHC), oil holding capacity (OHC), swelling capacity (SC), and glucose absorption capacity (GAC) were measured, and the glucose retardation index (GDRI) was analysed. The inhibitory effect of BPDF against α-amylase activity was also observed. The findings showed that the WHC (0.7 g/g), OHC (0.3 g/g), SC (0.73 mL/g), GDRI (6.58 - 31.72%), and GAC (0.162 - 19.211 mmol/g) of BPDF could have the potential in regulating diabetes, and explain the physiological effects of dietary fibre. The surface morphology of BPDF was analysed using scanning electron microscope. Interestingly, BPDF hampering effects on the diffusion of glucose through α-amylase inhibitory activity with IC50 8.9 µg/mL was found to be comparable to acarbose (IC50 8.6 µg/mL), thus showing potential in lowering postprandial blood glucose (type 2 diabetes mellitus).

Optimizing Conditions for Microwave-Assisted Extraction of Polyphenolic Content and Antioxidant Activity of Barleria lupulina Lindl

Barleria lupulina Lindl. (Acanthaceae) as an ornamental plant has been widely used in folklore medicine due to its abundancy in polyphenolic compounds. The present study examined conditions for optimal extraction of antioxidants from B. lupulina leaf extracts by using the microwave-assisted extraction (MAE) method. The effects of ethanol concentrations, microwave power, and extraction time on total phenolic content (TPC), total flavonoid content (TFC), 1-diphenyl-2-picrylhydrazyl (DPPH), and 2,20-azino-bis (3-ethylbenzothizoline-6-sulfonic acid) (ABTS) were investigated by single-factor experiments. Response surface methodology (RSM) was applied to observe interactions of three independent variables (ethanol concentrations, microwave power, and extraction time) on the dependent variables (TPC, TFC, DPPH, and ABTS) to establish optimal extraction conditions. Quadratic polynomial equations in all experimental models yielded favorably with fitted models with R2 and R2adj of more than 0.90 and a non-significant lack of fit at p > 0.05. The optimal conditions for the extraction of antioxidant activity were established at 80% (v/v) ethanol, 400 W, and 30 s with TPC (238.71 mg gallic acid equivalent (GAE)/g sample), TFC (58.09 mg QE/g sample), DPPH (87.95%), and ABTS (89.56%). Analysis by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) successfully identified four new phenylethanoid glycoside compounds in the species.

Antioxidants and Characterization of Stability and Organoleptic Properties of Cocoa Facial Mask

Beauty products plant based are getting increasing interest from users and the cosmetic industry. Cocoa liquor is a natural source of antioxidants from (Theobrama cacao L.) cocoa beans, with potential health benefits. The present study was conducted to determine the stability of cocoa facial mask in different temperature, the durability of CFM in extreme high and low temperature and the prospect of integrating CFM offers additional skin defence capability by eliminating free radicals from the environment. CFM shown stabled with different storage conditions. The amount of ferric ion reducing power (FRAP) in CFM was evaluated by the reduction of ferric-TPTZ to blue ferrous-TPTZ color, while β-carotene linoleate bleaching (β-CB) assay were determined by using β-carotene emulsion. FRAP and β- carotene recorded values of 252.31 ± 0.001 mmol Fe2+/g and 83.42 ± 0.03%, respectively. The EC50 of β-carotene linoleate bleaching (β-CB) reported at 2.92 ± 0.03 mg/mL. The results suggest that CFM is a potential source of phytochemicals. The study presents scientific validation on its phytochemical contents showing presence of bioactive compounds with nutritional and therapeutic values which may have positive impact on skin health and suggesting its prospective use in value-added products such as skin care cosmetics.

Biostimulation of Microbial Communities from Malaysian Agricultural Soil for Detoxification of Metanil Yellow Dye; a Response Surface Methodological Approach

In the present study, a mixed culture from a local agricultural soil sample was isolated for Metanil Yellow (MY) dye decolorization. The metagenomic analysis confirmed that 42.6% has been dominated by genus Bacillus, while Acinetobacter (14.0%) is present in the microbial communities of the mixed culture. For fungi diversity analysis, around 97.0% was “unclassified” fungi and 3% was Candida. The preliminary investigation in minimal salt media (MSM) showed that 100% decolorization was achieved after 24 h of incubation. Response surface methodology (RSM) was successfully applied using Box-Behnken design (BBD) to study the effect of four independent parameters—MY dye concentration, glucose concentration, ammonium sulfate concentration, and pH—on MY dye decolorization by the mixed bacterial culture. The optimal conditions predicted by the desirability function were 73 mg/L of MY, 1.934% glucose, 0.433 g/L of ammonium sulfate, and a pH of 7.097, with 97.551% decolorization The correlation coefficients (R2 and R2 adj) of 0.913 and 0.825 indicate that the established model is suitable to predict the effectiveness of dye decolorization under the investigated condition. The MY decolorization of the mixed bacterial culture was not affected by the addition of heavy metals in the growth media. Among the 10 heavy metals tested, only copper gave 56.19% MY decolorization, whereas the others gave almost 100% decolorization. The decolorization potential of the mixed bacterial culture indicates that it could be effective for future bioremediation of soil-contaminated sites and treatment solutions of water bodies polluted with the MY dye.

Biosynthesis of zinc oxide nanoparticles by cell-biomass and supernatant of Lactobacillus plantarum TA4 and its antibacterial and biocompatibility properties

This study aims to utilize the cell-biomass (CB) and supernatant (CFS) of zinc-tolerant Lactobacillus plantarum TA4 as a prospective nanofactory to synthesize ZnO NPs. The surface plasmon resonance for the biosynthesized ZnO NPs-CFS and ZnO NPs-CB was 349 nm and 351 nm, respectively, thereby confirming the formation of ZnO NPs. The FTIR analysis revealed the presence of proteins, carboxyl, and hydroxyl groups on the surfaces of both the biosynthesized ZnO NPs that act as reducing and stabilizing agents. The DLS analysis revealed that the poly-dispersity indexes was less than 0.4 for both ZnO NPs. In addition, the HR-TEM micrographs of the biosynthesized ZnO NPs revealed a flower-like pattern for ZnO NPs-CFS and an irregular shape for ZnO NPs-CB with particles size of 291.1 and 191.8 nm, respectively. In this study, the biosynthesized ZnO NPs exhibited antibacterial activity against pathogenic bacteria in a concentration-dependent manner and showed biocompatibility with the Vero cell line at specific concentrations. Overall, CFS and CB of L. plantarum TA4 can potentially be used as a nanofactory for the biological synthesis of ZnO NPs.

Bioluminescent method for the rapid screening of toxic heayy metals in environmental samples using Photobacterium leiognathi strain AK-MIE

Assessment of eco-toxicant using bioluminescent bacterial assay is a widely used and globally accepted method. In this work, a new luminescent bacterium was isolated from squid (Loligo duvauceli) and identified as Photobacterium leiognathi strain AK-MIE using 16S rRNA, phylogeny analysis. The predicted optimum conditions by RSM were 2.76% (w/v) NaCl, 2.28% (w/v) peptone, 0.34% (w/v) yeast extract, and pH 6.83 with 541,211.80 RLU of luminescent production whereas the predicted optimum conditions by ANN were 2.21% (w/v) NaCl, 2.27% (w/v) peptone, 0.39% (w/v) yeast extract, and pH 6.94 which produced 541,986.20 RLU. The validation analysis of both RSM and ANN show 0.60% and 0.69% deviation from the predicted results indicating that both models provided good quality predictions with ANN showing a superior data fitting capability for non-linear regression analysis. Toxicity tests show strain AK-MIE was sensitive to mercury (concentration causing 50% inhibition or IC₅₀ of 0.00978 mgL^-1), followed by cadmium (IC₅₀ of 0.5288 mgL^-1), copper IC₅₀ of (0.8117 mgL^-1), silver (IC₅₀ of 1.109 mgL^-1), and lead (IC₅₀ of 10.71 mgL^-1) which are more sensitive than previously isolated luminescent bacteria, suggesting that strain AK-MIE has the potential to be used in toxicity assessment of heavy metals in the environment. Based on the field trial results, several sediment samples from industrial areas in Bangi, Selangor managed to inhibit the bioluminescence of strain AK-MIE. Validation method carried out using ICP-MS proved the presence of several toxic heavy metal elements.

Exploring the Potential Use of Hylocereus polyrhizus Peels as a Source of Cosmeceutical Sunscreen Agent for Its Antioxidant and Photoprotective Properties

Currently, consumers' demand for sunscreens derived from natural sources that provide photoprotection from ultraviolet (UV) radiation is pushing the cosmetic industry to develop breakthrough formulations of sun protection products by incorporating plant antioxidants as their active ingredients. In this context, the present study was initiated to evaluate the antioxidant and photoprotective properties of the underutilized Hylocereus polyrhizus peel extract (HPPE) using in vitro spectrophotometric techniques. The phytochemical screenings of HPPE conducted via high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) revealed the presence of phenolic acids and flavonoids as the major secondary metabolites in HPPE. The antioxidant potentials evaluated based on 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and total antioxidant capacity assays were in the range of 22.16 ± 0.24%-84.67 ± 0.03% with 50% inhibitory concentration (IC50) of 36.39 ± 0.04 μg/mL and 23.76 ± 0.14%-31.87 ± 0.26% (IC50 = 21.93 ± 0.07 μg/mL), respectively. For the photoprotective evaluation, the results showed that HPPE had significantly high absorbance values (3.1-3.6) at 290-320 nm with an exceptional sun protection factor (SPF) value of 35.02 ± 0.39 at 1.00 mg/mL. HPPE also possessed a broad-spectrum shielding power against both UVA and UVB radiations. Hence, in terms of practical implications, our findings would offer an exciting avenue to develop a photoprotective formulation incorporating the ethanolic extract of Hylocereus polyrhizus peels as a synergistic active ingredient for its excellent UV absorption properties and the strong antioxidant activities.

Sustainable microbial cell nanofactory for zinc oxide nanoparticles production by zinc-tolerant probiotic Lactobacillus plantarum strain TA4

BACKGROUND

The use of microorganisms in the biosynthesis of zinc oxide nanoparticles (ZnO NPs) has recently emerged as an alternative to chemical and physical methods due to its low-cost and eco-friendly method. Several lactic acid bacteria (LAB) have developed mechanisms in tolerating Zn²⁺ through prevention against their toxicity and the production of ZnO NPs. The LAB's main resistance mechanism to Zn²⁺ is highly depended on the microorganisms' ability to interact with Zn²⁺ either through biosorption or bioaccumulation processes. Besides the inadequate studies conducted on biosynthesis with the use of zinc-tolerant probiotics, the understanding regarding the mechanism involved in this process is not clear. Therefore, this study determines the features of probiotic LAB strain TA4 related to its resistance to Zn²⁺. It also attempts to illustrate its potential in creating a sustainable microbial cell nanofactory of ZnO NPs.

RESULTS

A zinc-tolerant probiotic strain TA4, which was isolated from local fermented food, was selected based on the principal component analysis (PCA) with the highest score of probiotic attributes. Based on the 16S rRNA gene analysis, this strain was identified as Lactobacillus plantarum strain TA4, indicating its high resistance to Zn²⁺ at a maximum tolerable concentration (MTC) value of 500 mM and its capability of producing ZnO NPs. The UV-visible spectroscopy analysis proved the formations of ZnO NPs through the notable absorption peak at 380 nm. It was also found from the dynamic light scattering (DLS) analysis that the Z-average particle size amounted to 124.2 nm with monodisperse ZnO NPs. Studies on scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy, and Fourier-transform infrared spectroscopy (FT-IR) revealed that the main mechanisms in ZnO NPs biosynthesis were facilitated by the Zn²⁺ biosorption ability through the functional groups present on the cell surface of strain TA4.

CONCLUSIONS

The strong ability of zinc-tolerant probiotic of L. plantarum strain TA4 to tolerate high Zn²⁺ concentration and to produce ZnO NPs highlights the unique properties of these bacteria as a natural microbial cell nanofactory for a more sustainable and eco-friendly practice of ZnO NPs biosynthesis.

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal's body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.

Optimization of an Ultrasound-Assisted Extraction Condition for Flavonoid Compounds from Cocoa Shells (Theobroma cacao) Using Response Surface Methodology

This study investigates the ultrasound-assisted extraction of flavonoids from Malaysian cocoa shell extracts, and optimization using response surface methodology. There are three variables involved in this study, namely: ethanol concentration (70⁻90 v/v %), temperature (45⁻65 °C), and ultrasound irradiation time (30⁻60 min). All of the data were collected and analyzed for variance (ANOVA). The coefficient of determination (R²) and the model was significant in interaction between all variables (98% and p < 0.0001, respectively). In addition, the lack of fit test for the model was not of significance, with p > 0.0684. The ethanol concentration, temperature, and ultrasound irradiation time that yielded the maximum value of the total flavonoid content (TFC; 7.47 mg RE/g dried weight (DW)) was 80%, 55 °C, and 45 min, respectively. The optimum value from the validation of the experimental TFC was 7.23 ± 0.15 mg of rutin, equivalent per gram of extract with ethanol concentration, temperature, and ultrasound irradiation time values of 74.20%, 49.99 °C, and 42.82 min, respectively. While the modelled equation fits the data, the T-test is not significant, suggesting that the experimental values agree with those predicted by the response surface methodology models.

Lipase-catalyzed synthesis of red pitaya (Hylocereus polyrhizus) seed oil esters for cosmeceutical applications: process optimization using response surface methodology

Esters were synthesized via the alcoholysis of red pitaya seed oil with oleyl alcohol catalyzed by immobilized lipase, Lipozyme RM IM. The effects of synthesis parameters, including temperature, time, substrate molar ratio and enzyme loading, on the yield and productivity of esters were assessed using a central composite response surface design. The optimum yield and productivity were predicted to be about 80.00% and 0.58 mmol h^-1, respectively, at a synthesis temperature of 50.5 °C, time of 4 h, substrate molar ratio of 3.4 : 1 and with 0.17 g of enzyme. Esters were synthesized under the optimum synthesis conditions; it was found that the average yield and productivity were 82.48 ± 4.57% and 0.62 ± 0.04 mmol h^-1, respectively, revealing good correspondence with the predicted values. The main esters were oleyl linoleate, oleyl oleate, oleyl palmitate and oleyl stearate. The synthesized esters exhibited no irritancy effects and their physicochemical properties showed their suitability for use as cosmeceutical ingredients.

Development of Phaleria macrocarpa (Scheff.) Boerl Fruits Using Response Surface Methodology Focused on Phenolics, Flavonoids and Antioxidant Properties

In this study, the optimal conditions for the extraction of antioxidants from the Buah Mahkota Dewa fruit (Phaleria macrocarpa) was determined by using Response Surface Methodology (RSM). The optimisation was applied using a Central Composite Design (CCD) to investigate the effect of three independent variables, namely extraction temperature (°C), extraction time (minutes) and extraction solvent to-feed ratio (% v/v) on four responses: free radical scavenging activity (DPPH), ferric ion reducing power assay (FRAP), total phenolic content (TPC) and total flavonoid content (TFC). The optimal conditions for the antioxidants extraction were found to be 64 °C extraction temperature, 66 min extraction time and 75% v/v solvent to-feed ratio giving the highest percentage yields of DPPH, FRAP, TPC and TFC of 86.85%, 7.47%, 292.86 mg/g and 3.22 mg/g, respectively. Moreover, the data were subjected to Response Surface Methodology (RSM) and the results showed that the polynomial equations for all models were significant, did not show lack of fit, and presented adjusted determination coefficients (R²) above 99%, proving that the yield of phenolic, flavonoid and antioxidants activities obtained experimentally were close to the predicted values and the suitability of the model employed in RSM to optimise the extraction conditions. Hence, in this study, the fruit from P. macrocarpa could be considered to have strong antioxidant ability and can be used in various cosmeceutical or medicinal applications.