Evaluation of antioxidants activity of Momordica charantia using LC-MS metabolomics approach

Objectives: The present study was design to identify the significant biomarkers from M.charantia that possessing antioxidant activity using liquid chromatography-mass spectrometry (LC-MS) based metabolomics approaches. Design and method: Initially, the fruit was extracted by soaking in different solvents with different concentrations of ethanol in water (0, 20, 40, 60, 80, 100%, v/v). Then, the extracts were tested for antioxidant activity using 1, 1-diphenyl-2 picrylhydrazyl (DPPH) and ferric reducing antioxidant power assay. LC-MS based metabolomics approach correlated with multivariate data analysis was applied to profile the bioactive compounds present in the extract. Results The 80% ethanol extract showed a high inhibitory activity on 1, 1-diphenyl-2 picrylhydrazyl (DPPH) radical and high ferric reducing antioxidant power, LC-MS based metabolomics approaches helped to identify several antioxidants in this extract such as ascorbic acid, margarolic acid, brevifolincarboxylic acid, quercetin 3-O-glycoside, kuguacin H, cucurbitacin E, 3-malonylmomordicin I, goyaglycoside G. Conclusion: The results of the present study shows possible antioxidants from M. charantia fruit can be identified Keywords: Momordica charantia, LCMS, Metabolomics, antioxidant, multivariate data analysis

Muscle and serum metabolomics for different chicken breeds under commercial conditions by GC–MS

Globally, village chicken is popular and is known as a premium meat with a higher price. Food fraud can occur by selling other chicken breeds at a premium price in local markets. This study aimed to distinguish local village chicken from other chicken breeds available in the market, namely, colored broiler (Hubbard), broiler (Cobb), and spent laying hen (Dekalb) in pectoralis major and serum under commercial conditions using an untargeted metabolomics approach. Both pectoralis major and serum were analyzed using gas chromatography–mass spectrometry (GC–MS). The principal component analysis (PCA) results distinguished four different chicken breeds into three main groups for pectoralis major and serum. A total of 30 and 40 characteristic metabolites were identified for pectoralis major and serum, respectively. The four chicken breeds were characterized by the abundance of metabolites such as amino acids (L−glutamic acid, L−threonine, L−serine, L−leucine), organic acids (L−lactic acid, succinic acid, 3−hydroxybutyric acid), sugars (D−allose, D−glucose), sugar alcohols (myo−inositol), and fatty acids (linoleic acid). Our results suggest that an untargeted metabolomics approach using GC–MS and PCA could discriminate chicken breeds for pectoralis major and serum under commercial conditions. In this study, village chicken could only be distinguished from colored broiler (Hubbard) by serum samples

Antioxidant effects of some selected flavonoids: a structure-activity relationship based study

Objective: To investigate the antioxidant and radical scavenging activities of some selected flavonoids with respect to identify key positions responsible for antioxidant effects as well as the effect of derivatisation on the antioxidative effects. Design and method: Antioxidant potential was evaluated using different sets of assays viz., rapid test by dot blot, 1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, ABTS+ radical cation scavenging, ferric reducing antioxidant powder (FRAP) and xanthine oxidase inhibitory (XOI) assays. Results: It was determined that the total number and the configuration of hydroxyl group play an important role in regulating bioactivity of flavonoids in scavenging DPPH radical, ABTS+ radical cation and FRAP assays. Presence of catechol and the absence of C-2-C-3 double bond as well as ketonic group at C-4 reduced the xanthine oxidase inhibitory activity. Methylation and acetylation of hydroxyl groups at particular positions were also found to decrease the in vitro bioactivity of flavonoids. Conclusions: The results of this study will further help to understand the role of flavonoids as natural antioxidants which might facilitate in the development of nutritional products and semi synthetic analogs that retain substantial antioxidant capacity with minimal adverse effects. Keywords: Flavonoids; antioxidant activity; derivatisation, structure activity relationshi

Characterization of antioxidant activity of Momordica charantia fruit by infrared-based fingerprinting

Momordica charantia is widely consumed edible fruit. The food and pharmaceutical industries use it as a natural antioxidant. However, the quality control of M. charantia-based medicinal products is questionable due to the complexity of metabolites in this fruit. Hence, this study has developed a statistical model in predicting the antioxidant value through the 2, 2-diphenyl-1 picrylhydrazyl radical scavenging activity and ferric reducing antioxidant power based on infrared spectroscopy with attenuated total reflectance. This technique was reliably used for quality control. Six ethanol extracts (0, 20, 40, 60, 80, and 100% in water) of this plant’s fruit were prepared. The radical scavenging and ferric reducing antioxidant power activities were measured and the chemical profiling of the extracts was fingerprinted by infrared spectroscopy between 4,000 and 600 cm−1 at a resolution of 4 cm−1. Statistical analysis was developed by correlating the bioactivity and infrared spectra of each extract using orthogonal partial least square discriminant analysis. The C–N, C˭O, C–O, C–H, and OH infrared signals were positively correlated with biological activity. The antioxidant activity of the fruit of M. charantia may be due to the presence of several antioxidants that work synergistically

Effect of cooking time and temperature on extraction yield and antioxidant properties of Beef Rendang

Rendang is a popular traditional cuisine in Southeast Asia, particularly Malaysia and Indonesia. Rendang ingredients vary according to different countries and mainly consist of spices, coconut milk, and meat, either chicken or beef. Spices such as coriander, fennel, cumin, ginger, galangal, lemongrass, garlic, and onion used in rendang mostly contributed to its antioxidant properties. However, the beef rendang's antioxidant properties may be lost due to the long cooking period. This study aims to determine the effect of cooking time and temperature on the extraction yield and antioxidant properties of beef. Rendang samples prepared using lean beef and mixed with coconut milk and other spices were collected every hour up to five hours of cooking. The samples were subjected to methanol extraction for total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay using Folin-Ciocalteu and DPPH solution, respectively. The data were analysed by one-way analysis of variance (ANOVA) followed by Tukey's test. Data for extraction yield showed that rendang samples cooked for one and two hours had significantly lesser yield (p<0.05) than those cooked for three to five hours. For TPC analysis, rendang that was cooked for three hours had the highest total phenolic content (8.018 ± 0.911 mg GAE/g) (p<0.05) compared to those that were cooked for one, two, four, and five hours (4.205±0.364, 2.368±0.127, 2.746±0.080, and 1.839±0.110 mg GAE/g). For the DPPH assay, one-hour beef rendang sample had the lowest EC50 (20.278±0.733 µg/ml) (p<0.05) followed by those cooked for two, three, four, and five hours (39.041±1.368, 40.143±4.502, 48.338±2.115, and 58.159±3.060 µg/ml), indicating a low EC50 value which exhibited high antioxidant power. It can be concluded that antioxidant properties were significantly lost due to prolonged heating with increasing cooking time

Identification of α-glucosidase inhibitorsfrom Clinacanthus nutans leaf extract using liquid chromatography-mass spectrometry-based metabolomics and protein-ligand interaction with molecular docking

The present study used in vitro and in silico techniques, as well as the metabolomics approach to characterise α-glucosidase inhibitors from different fractions of Clinacanthus nutans. C. nutans is a medicinal plant belonging to the Acanthaceae family, and is traditionally used to treat diabetes in Malaysia. n-Hexane, n-hexane: ethyl acetate (1:1, v/v), ethyl acetate, ethyl acetate: methanol (1:1, v/v), and methanol fractions were obtained via partitioning of the 80% methanolic crude extract. The in vitro α-glucosidase inhibitory activity was analyzed using all the fractions collected, followed by profiling of the metabolites using liquid chromatography combined with mass spectrometry. The partial least square (PLS) statistical model was developed using the SIMCA P+14.0 software and the following four inhibitors were obtained: (1) 4,6,8-Megastigmatrien-3-one; (2) N-Isobutyl-2-nonen-6,8-diynamide; (3) 1′,2′-bis(acetyloxy)-3′,4′-didehydro-2′-hydro-β, ψ-carotene; and (4) 22-acetate-3-hydroxy-21-(6-methyl-2,4-octadienoate)-olean-12-en-28-oic acid. The in silico study performed via molecular docking with the crystal structure of yeast isomaltase (PDB code: 3A4A) involved a hydrogen bond and some hydrophobic interactions between the inhibitors and protein. The residues that interacted include ASN259, HID295, LYS156, ARG335, and GLY209 with a hydrogen bond, while TRP15, TYR158, VAL232, HIE280, ALA292, PRO312, LEU313, VAL313, PHE314, ARG315, TYR316, VAL319, and TRP343 with other forms of bonding

Antidiabetic and antioxidants activities of Clinacanthus nutans (Burm F.) Lindau leaves extracts

Clinacanthus nutans (C. nutans) is a local plant belongs to the family Acanthaceae. It is consumed as ‘jamu’ (healthy drink) in Indonesia and as ‘ulam’ in Malaysia. This plant has been claimed for its ability to prevent many diseases including diabetes. However, its scientific proof on this claim is still lacking. Thus, this study was designed to evaluate the antidiabetic potential and antioxidant capacity of C. nutans leaves extracts using in vitro bioassay tests. The 80% methanolic crude extract of this plant was further partitioned using different polarity solvents viz., hexane, hexane: ethyl acetate (1:1, v/v), ethyl acetate, ethyl acetate: methanol (1:1, v/v) and methanol. All the sub-fractions were analysed for antioxidant effect via 2, 2-diphenyl-2-picrylhydrazil (DPPH) scavenging activity, ferric reducing power (FRAP) and xanthine oxidase (XO) assays followed by antidiabetic evaluation via α-glucosidase and dipeptidyl peptidase-IV (DPP-IV) inhibitory assays and glucose uptake experiment. The ethyl acetate fraction showed a good antioxidant potential while hexane exhibit high α-glucosidase and DPP-IV enzyme inhibition. The hexane fraction also improved glucose uptake in a dose-dependent manner. The study provides an informative data on the potential of C. nutans to be developed as a functional food in preventing diabetes

Antioxidant and antidiabetic effects of flavonoids: a structure-activity relationship based study

The best described pharmacological property of flavonoids is their capacity to act as potent antioxidant that has been reported to play an important role in the alleviation of diabetes mellitus. Flavonoids biochemical properties are structure dependent; however, they are yet to be thoroughly understood. Hence, the main aim of this work was to investigate the antioxidant and antidiabetic properties of some structurally related flavonoids to identify key positions responsible, their correlation, and the effect of methylation and acetylation on the same properties. Antioxidant potential was evaluated through dot blot, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ABTS+ radical scavenging, ferric reducing antioxidant power (FRAP), and xanthine oxidase inhibitory (XOI) assays. Antidiabetic effect was investigated through α-glucosidase and dipeptidyl peptidase-4 (DPP-4) assays. Results showed that the total number and the configuration of hydroxyl groups played an important role in regulating antioxidant and antidiabetic properties in scavenging DPPH radical, ABTS+ radical, and FRAP assays and improved both α-glucosidase and DPP-4 activities. Presence of C-2-C-3 double bond and C-4 ketonic group are two essential structural features in the bioactivity of flavonoids especially for antidiabetic property. Methylation and acetylation of hydroxyl groups were found to diminish the in vitro antioxidant and antidiabetic properties of the flavonoids

Evaluation of antidiabetic properties of Momordica charantia in streptozotocin induced diabetic rats using metabolomics approach

Momordica charantia, also known as bitter melon or 'peria katak' in Malaysia, is a member of the family Cucurbitaceae. Bitter melon is an excellent source of vitamins and minerals that made it extensively nutritious. Moreover, the seed, fruit and leave of the plant contain bioactive compounds with a wide range of biological activities that have been used in traditional medicines in the treatment of several diseases, including inflammation, infections, obesity and diabetes. The aim of this study was to evaluate changes in urinary metabolite profile of the normal, streptozotocin-induced type 1 diabetes and M. charantia treated diabetic rats using proton nuclear magnetic resonance (1H-NMR) -based metabolomics profiling. Study had been carried out by inducing diabetes in the rats through injection of streptozotocin, which exhibited type 1 diabetes. M. charantia extract (100 and 200 mg/kg body weight) was administrated to the streptozotocin-induced diabetic rats for one week. Blood glucose level after administration was measured to examine hypoglycemic effect of the extract. The results obtained indicated that M. charantia was effective in lowering blood glucose level of the diabetic rats. The loading plot of Partial Least Square (PLS) component 1 showed that diabetic rats had increased levels of lactate and glucose in urine whereas normal and the extract treated diabetic rats had higher levels of succinate, creatine, creatinine, urea and phenylacetylglycine in urine. While the loading plot of PLS component 2 showed a higher levels of succinate, citrate, creatine, creatinine, sugars, and hippurate in urine of normal rat compared to the extract treated diabetic rat. Administration of M. charantia extract was found to be able to regulate the altered metabolic processes. Thus, it could be potentially used to treat the diabetic patients

Antioxidant and α‐glucosidase inhibitory activities and gas chromatography–mass spectrometry pro le of salak (salacca zalacca) fruit peel extracts

Background: This study was aimed to investigate antioxidant and α‑glucosidase inhibitory activity, with a proximate analysis of total phenolic and total flavonoid content with gas chromatography–mass spectrometry (GC‑MS) profiling of salak (Salacca zalacca) fruit peel extracts. Materials and Methods: The peels extracts were prepared by maceration process at room temperature with different ratio of ethanol/water. Results: Phytochemical screening showed the presence of phenolic and flavonoid contents in all the extracts. About 100% ethanol extract shows the highest phenolic content (116.70 ± 0.764 μg/mL) while 60% ethanol extract has the lowest content 18.65 ± 1.155 μg/ml using gallic acid as a reference. 100% ethanol extract was observed to exhibit highest radical scavenging, ferric reducing antioxidant power (FRAP), and α‑glucosidaseinhibitory activities (IC50: 49.45 ± 3.87 μg/mL, 144.81 ± 3.72 μg AAE/g,IC50: 11.62 ± 0.67b μg/mL), respectively. Water extracts had the lowestFRAP, radical scavenging activity as well as α‑glucosidase activity. The phytochemical investigation on GC‑MS showed the presence of active compounds in salak fruit peel extracts. Conclusion: Salak fruit peels showed the highest antioxidant as well as α‑glucosidase inhibitory activities. Phytochemical analysis on GC‑MS confirms the presence of gallic acid, linoelaidic acid, palmitic acid, α‑tocopherol, and steric acid whichmay contribute to α‑glucosidase inhibitory activity