Displaying publications 61 - 80 of 940 in total

Abstract:
Sort:
  1. Dian-Nashiela, F., Noriham, A., Nooraain, H., Azizah, A.H.
    MyJurnal
    Herbal tea is widely consumed around the world because people believed that it contained high amount of antioxidant. However, usage of different maturity of the plants as raw materials could affect the antioxidant capacities in herbal tea. Hence, this paper reports the antioxidant activity of herbal tea prepared from Cosmos caudatus at different maturity namely young, mature and old leaves. The analyses carried out were total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP) and DPPH (2-2-diphenyl- 1-picrylhydrazyl) radical scavenging assays. Based on the results obtained, herbal tea prepared from young leaves had significantly strong (p
  2. Farah Diyana, A., Abdullah, A., Shahrul Hisham, Z.A., Chan, K. M.
    MyJurnal
    Antioxidants in seaweeds have attracted increasing interest for its role in protecting human health. Therefore, the aim of this study was to assess the Total phenolic content (TPC) values and antioxidant activities in red seaweeds Kappaphycus alvarezii and Kappaphycus striatum of different solvent extracts. Total phenolic content (TPC) and antioxidant activities (DPPH scavenging assay and Trolox equivalent antioxidant capacity assay, TEAC) for both K. alvarezii and K. striatum extracts were determined using different solvents at different concentrations (ethanol: 50%, 70%, 100%; acetone: 50%, 70%, 100%; methanol: 50%, 70%, 100%). The TPC value was measured using the Folin-Ciocalteu’s method. The antioxidant activities were measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and Trolox Equivalent Antioxidant Capacity (TEAC) assay. The highest TPC value of K. alvarezii antioxidant extract was obtained by 50% ethanol extracts while for K. striatum obtained by 50% methanol extract. The highest percentage of DPPH free radical inhibition for K. alvarezii was shown by 50% acetone extract while K. striatum was shown using 50% methanol extract. The highest TEAC value for K. alvarezii was shown by 50% acetone while K. striatum extract was shown by 50% ethanol extract. The TPC values and antioxidant activities of all solvent extracts of K. striatum were significantly higher (p< 0.05) than K. alvarezii antioxidant extracts. The TPC values showed strong correlation (r = 0.797) with TEAC values for K. alvarezii antioxidant extract (p< 0.01). The TEAC values also showed strong correlation (r = 0.735) with percentage of DPPH free radical inhibition for K. alvarezii (p< 0.01). The TPC value, DPPH free radical scavenging assay and TEAC assay for K. striatum extracts showed strong correlation (r> 0.8) with each other (p< 0.01). In summary, K. striatum showed better antioxidant activity and higher TPC value than K. alvarezii.
  3. Mandana, B., Russly, A.R., Farah, S.T., Noranizan, M.A., Zaidul, I.S., Ali. G.
    MyJurnal
    In this study, the effect of different solvent including ethanol, n-hexane and ethyl acetate on antioxidant
    activity and total phenolic content (TPC) of winter melon (Benincasa hispida) seeds extract was investigated using conventional Soxhlet extraction (CSE). DPPH and ABTS scavenging activity and TPC results indicated that the seed extracts obtained using ethanol possessed the highest antioxidant activity and followed by ethyl acetate and n-hexane. By considering obtained results, it was clear that there was a high positive correlation between TPC and antioxidant activity. Linoleic acid forms a significant percentage of unsaturated fatty acids of the seed extract (60.6%). It is well known that essential fatty acids including linoleic acid and linolenic acid which are detected in extracts play important roles in preventing many disease and abnormal differentiation problems. B. hispida seeds are potential source of natural antioxidant compounds to replace synthetic antioxidants.
  4. Maisarah, A.M., Nurul Amira, B., Asmah, R., Fauziah, O.
    MyJurnal
    This study was conducted to compare the total antioxidant activity (TAA), total phenolic content (TPC) and total flavonoid content (TFC) from the different parts of papaya tree including their ripe and unripe fruit, seeds and the young leaves. Two methods namely DPPH radical scavenging activity and ß-carotene bleaching assay were used to determine the TAA, whereas TPC was determined by Folin-Ciocalteu’s method while TFC by aluminium trichloride (AlCl3). For these purposes, methanolic extracts (80%) were prepared. The results showed that the highest antioxidant activity through ß-carotene bleaching assay was observed in unripe fruit (90.67 ± 0.29%) followed by young leave, ripe fruit and the seed. In other hand, young leaves exhibited a significant higher scavenging effect compared to others and the dose required in reducing the absorbance of DPPH control solution by 50% (EC50) was calculated at 1.0 ± 0.08mg/ml. The EC50 values were 4.3 ± 0.01mg/ml, 6.5 ± 0.01mg/ml and 7.8 ± 0.06mg/ml for unripe fruit, ripe fruit and seeds respectively. Interestingly, both TPC and TFC also showed that young leaves had the highest antioxidant content (424.89 ± 0.22mg GAE/ 100 g dry weight and 333.14 ± 1.03mg rutin equivalent/ 100 g dry weight, respectively). Statistically, Pearson correlation showed there were positive correlations between TPC and TFC with antioxidant activity assayed by DPPH radical scavenging assay (r=0.846 and r=0.873, respectively). However there was no correlation between TPC and TFC with ß-carotene bleaching activity. In brief, taken into account all the parameters measured, antioxidants were highly remarkable in the sequence of young leaves > unripe fruit > ripe fruit > seed. Nevertheless, further investigation for isolation and identification of the phytoconstituents responsible for antioxidant activity is desirable.
  5. Gan, C.H., Nurul Amira, B., Asmah, R.
    MyJurnal
    Consumption of mushroom has increased remarkably because of their desirable aroma, taste and high nutritional content. This study was undertaken to measure and compare the antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC) of Agaricus bisporous (white button mushroom) and Agaricus brasiliensis (Brazilian mushroom) in aqueous and 60% ethanol extract. Results showed that button mushroom (21.47 ± 0.48 mg GAE/g of dry weight) had significant higher TPC in aqueous whereas Brazilian mushroom (12.50 ± 0.22 mg GAE/g of dry weight) had significant higher TPC in 60% ethanol (p< 0.05). In terms of TFC, Brazilian mushroom had higher content than button mushroom in both types of solvents. For FRAP assay, Brazilian mushroom had significantly higher total antioxidant activity than the button mushroom in 60% ethanol (p < 0.05) but opposite trend with aqueous. For DPPH radical scavenging activity, Brazilian mushroom (60% ethanol) had the lowest EC50 value, followed by button mushroom (60% ethanol), Brazilian mushroom (aqueous) and button mushroom (aqueous). Pearson correlation test (p < 0.05) showed strong positive correlation between TPC and FRAP assay in both extracts (r = 0.969 for 60% ethanol extract; r = 0.973 for aqueous extract). For TFC, there was a strong positive, correlation with FRAP assay (r = 0.985) in aqueous extract. In conclusion, high antioxidant activity in ethanol extract of mushrooms due to presence of phenolic content can potentially be used as a source of natural antioxidants.
  6. Irna, C., Jaswir, I., Othman, R., Jimat, D.N.
    MyJurnal
    The use of High Pressure Processing as an extraction method was studied by evaluating the yield of astaxanthin from shrimp carapace as a model. Previous studies have demonstrated the antioxidant and antimicrobial properties of astaxanthin. The aim of this research was to compare these properties of astaxanthin as a surrogate for its yield from High Pressure Processing (HPP) extraction with the effect of hydrostatic pressure, holding time and amount of solvents versus chemical extraction method. A solvent mixture of acetone and methanol 7:3 (v/v) was used in both methods. The pressure treated was at 238 MPa with 16.29 min of holding time and 6.59 ml of solvents for HPP method. Antioxidant activity was evaluated using scavenging activity of DPPH radical, the reducing activity of Ferrum redox reaction and oxygen radical absorption capacity. Antimicrobial activity was evaluated using a zone of inhibition test against four strain of bacteria: E. coli, E. aerogenes, S. aureus and B. subtilis. The sample of astaxanthin demonstrated a significant increase in DPPH radical scavenging activity (25.47% to 87.90%), reducing activity of Ferrum redox reaction (2.86 µmol TE/g to 8.13 µmol TE/g) and oxygen radical absorption capacity (2,000 µmol TE/100 g to 4,000 µmol TE/100 g) compared to the chemical extraction sample. The antimicrobial activity of the astaxanthin from the HPP sample produced a greater zone of inhibition against all four strains of bacteria when compared to the chemically extracted sample. A higher quality of astaxanthin was achieved with the HPP extraction method compared to chemical extraction.
  7. Tan, H. M., Leong, K. H., Song, J., Mohd Sufian, N. S. F., Mohd Hazli, U. H. A., Chew, L. Y., et al.
    MyJurnal
    Strobilanthes crispus and Clinacanthus nutans are popular herbal plants in the Southeast
    Asian region. The present work was aimed at determining the antioxidant activities and the
    associated components in the leaf extracts of both species using polar and non-polar solvents
    namely water, methanol, ethyl acetate, and hexane. The total phenolic content (TPC) and total
    flavonoid content (TFC) were higher in the leaf extracts of S. crispus as compared to C.
    nutans. Among the solvents, methanol was the best solvent in extracting the antioxidant
    components for S. crispus (TPC: 159.85 ± 0.89 mg GAE/g extract and TFC: 955.47 ± 2.66 mg
    RE/g extract). However, for C. nutans, its methanolic extract yielded the highest TPC (36.39
    ± 0.17 mg GAE/g extract), whereas ethyl acetate yielded the highest TFC (229.61 ± 7.81 mg
    RE/g extract). The high levels of both TPC and TFC contributed to the antioxidant activities
    of S. crispus extract as reflected in the methanolic extract attaining the highest level of
    antioxidant activities, measured by ferric reducing antioxidant power (FRAP) (6.84 ± 1.12
    mmol Fe2+/g extract), DPPH radical scavenging (IC50: 203.60 ± 7.28 μg/mL), and Trolox
    equivalent antioxidant capacity (TEAC) (1.01 ± 0.01 mmol TE/g extract) assays. This
    contrasted with C. nutans which showed lower antioxidant activities owing to its lower TPC
    and TFC. Correlation analysis revealed significant correlations (p < 0.05, r = 0.915 - 0.985)
    between both TPC and TFC in S. crispus and antioxidant activities. However, only TPC of C.
    nutans showed a significant correlation with FRAP values (r = 0.934). Further tentative
    identification of the constituents in the extracts using HPLC-ESI-QToF-MS/MS revealed the
    existence of 20 polyphenolic compounds in both S. crispus and C. nutans, which were likely
    responsible for their antioxidant activities. In addition, 15 polyphenolic compounds classified
    as chalcones, isoflavanoids, flavones, and flavonols have not been previously reported in both
    species. The methanolic extracts of both species yielded a higher content of antioxidants, with
    S. crispus offering a richer source of dietary antioxidants as compared to C. nutans. However,
    further study is needed to identify their bioactivities in relation to their bioactive components.
  8. Noridayu, A.R., Hii, Y.F., Faridah, A., Khozirah, S., Lajis, N.
    MyJurnal
    This study was undertaken to evaluate the antioxidant and acetylcholinesterase inhibition properties of stems and leaves of hexane and methanolic extracts of Pluchea indica. Methanolic extract of leaves showed the highest antioxidant activity (IC50 = 24.45 ± 0.34 µg/ml) and total phenolic contents (573.52 ± 6.2 mg GAE/100 g crude extract), in DPPH radical scavenging and Folin-Ciocalteu assays respectively, however, it failed to inhibit acetylcholinesterase in TLC bioautographic detection. The rest of plant extracts, including methanolic extract of stems, hexane extract of both leaves and stems, were detected to have acetylcholinesterase inhibitory properties. Hexane extract of both leaves and stems exhibited lower or negligible level of antioxidant activity and phenolic contents. Pluchea indica may provide a potential natural source of bioactive compounds, and maybe beneficial to the human health.
  9. Lee, S.Y., Mediani, A., Nur Ashikin, A.H., Abas, F., Azliana, A.B.S.
    MyJurnal
    The study was aimed to determine the antioxidant and α-glucosidase inhibition activities of
    the stem and leaf of five different traditional medicinal plants. The studied plants exhibited
    varied antioxidant and α-glucosidase inhibition activities. The antioxidant activities of the
    plants were determined through their free radical scavenging capabilities using DPPH assay.
    The most potent antioxidant activity was demonstrated by Neptunia oleracea with an IC50 of
    35.45 and 29.72 μg/mL for leaf and stem, respectively. For α-glucosidase inhibition activity,
    Neptunia oleracea exhibited potential α-glucosidase inhibition activity with IC50 value of
    19.09 and 19.74 μg/mL for leaf and stem, respectively. The highest total phenolic content
    (TPC) was also marked in Neptunia oleracea leaf and stem with value of 40.88 and 21.21 mg
    GAE/g dry weight, respectively. The results also showed that Strobilanthes crispus collected
    from two different locations possessed different levels of phenolic content, antioxidant and
    α-glucosidase inhibition activities. The study revealed that phenolic compounds could be the
    main contributors to the antioxidant and α-glucosidase inhibition activities with R values of 78.9
    and 67.4%, respectively. In addition, antioxidant and α-glucosidase were positively correlated
    (R = 81.9%). Neptunia oleracea could be suggested as a potential natural source of antioxidant
    and antidiabetic compounds that can be used for the prevention or treatment of diabetes.
  10. Konsue, N., Amron, N.A.
    MyJurnal
    Cruciferous vegetables belong to the mustard family of plants such as Brussels sprouts, kale, broccoli, cabbage and cauliflower. They are well known for their cancer prevention properties which are due to high content of bioactive compounds, isothiocyanates (ITCs). This study was aimed to investigate nitrosation inhibition ability of the cruciferous vegetables commonly consumed with meat products namely, broccoli, cauliflower and cabbage. Aqueous extracts of fresh and steamed (2 and 4 min) vegetables were subjected to determination of antioxidant capacity (DPPH and FRAP assay) and chemical composition i.e. total phenolic and isothiocyanate (ITC) content. It was found that TPC, DPPH and FRAP values of raw vegetables were different in each vegetable and ranged from 17.12-38.91 mg GAE/100 ml, 44.09-63.31% and 1.36-6.81 mg TE/100 ml, respectively. Among three types of cruciferous vegetable, broccoli had the highest PEITC content being 0.21 mmol/100 g compared to cauliflower (0.15 mmol/100 g) and cabbage (0.06 mmol/100 g). Moreover, it was found that steaming process significantly enhanced antioxidant activity, TPC as well as PEITC content in a timedependent manner up to 4 min (p
  11. Hagr, T.E., Mirghani, M.E.S., Elnour, A.A.H.M., Bkharsa, B.E.
    MyJurnal
    This study aimed to evaluate antioxidant capacity of honey samples that were collected from Blue Nile State, Sudan by determining total phenolic content (TPC) and total flavonoids content (TFC). Antioxidant activities were evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity and ferric reducing power assay (FRAP). High-Performance Liquid Chromatography (HPLC) was used for the determination of sugars content. The results showed that the highest TPC was (85.7±1 mg GAE /100g Fw), the highest TFC was found to be (55.14
    ± 1.09 mg QE /100g Fw) using quercetin equivalent (QE) as standard and the inhibition value of (DPPH) was (52.93 ± 0.44%). The FRAP showed the highest value of (281 μM TE/100g Fw), also the results indicated that the honey contained fructose (38.6 ± 1.8 g/100g - 42.9 ± 1.3 gL100g Fw), and glucose (30.4 ± 0.75 - 31.7 ± 0.68 g/100g Dw). Protein content was found to be ranging between and 0.60% and 1.04%. In conclusion, the results showed that honey is a good source of antioxidants due to the presence of phenolic compounds, flavonoids and carotene. Also, an excellent source of the simple reducing sugars.
  12. Esua, O.J., Makinde, O.O., Arueya, G.L., Chin, N.L.
    MyJurnal
    The Nigerian hog plum (Spondias mombin) seed kernel was studied for its possible antioxidative
    potential and its proximate and nutrient compositions measured. The fruits were
    submitted to washing, pulp removal and drying to facilitate fibre separation from the seed
    kernel. Seeds were Milled to obtain samples, while analysis was carried out using standard
    Association of Analytical Communities (AOAC) methods and phytochemical assays. The seed
    kernel contains carbohydrate (40.56%), ash (8.09%), crude fibre (31.86%), moisture content
    (8.48%), crude protein (7.73%), crude fat (3.28%), calcium (1317 mg/kg), iron (839.08 mg/
    kg), magnesium (494.71 mg/kg), manganese (17.93 mg/kg), zinc (15.27 mg/kg), and copper
    (7.68 mg/kg). Phytochemical analyses indicated the presence of tannins (0.06%) and phytate
    (0.0022%), but did not indicate the presence of flavonoids, oxalate and saponins. The free
    radical scavenging activity against the 2, 2–diphenyl–1–picrylhydrazyl (DPPH) radical
    was at the level of 15.09%, while total antioxidant capacity and total phenolic content were
    856.7±5.84 mgAAE/100g and 573.32±11.5 mgGAE/100g respectively. The seed kernel of
    Spondias mombin is a potential source of nutritious food, good anti-anaemic and anti-diabetic
    agent as a result of iron and zinc content, and potential chemo-protective agent with the ability
    to offer possible protection against the activities of the toxic Reactive Oxygen Species (ROS)
    from the results of total phenolic content, antioxidant and free radical scavenging activities.
  13. Tan, B.L., Suhaniza, H.J., Lai, C. C., Norazalina, S., Roselina, K., Norhaizan, M.E.
    MyJurnal
    Temukut, or brewers’ rice, is a mixture of broken rice, rice bran, and rice germ. Extensive studies have been conducted on rice bran, which possesses various health benefits. Temukut, however has been less well studied. The present study aimed to investigate the antioxidant and growth inhibition properties of temukut extract using colon cancer (HT-29), ovary cancer (Caov-3), and liver cancer (HepG2) cell lines. The antioxidant activity was determined by the β-carotene bleaching assay, analysis of the DPPH radical scavenging capacity, and a FRAP assay. The total phenolic compounds, oryzanol, vitamin E, and phytic acid levels in temukut were also investigated. The antiproliferative activity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was a significant difference in the cytotoxicity of two types of temukut extract (water and methanol) for HT-29 and Caov-3 cells (p < 0.05) but not for HepG2 cells. The HepG2 cell line is the least sensitive to temukut, (IC50 = 55.30 μg/mL), whereas the highest sensitivity was observed in Caov-3 cells (IC50 =36.67 μg/mL). No cytotoxic effect of temukut was observed on normal cells (BalBlc3T3). Although the content of the phytochemicals studied (total phenolic compounds, vitamin E, oryzanol, and phytic acid) in temukut was lower than that in rice bran, as has been previously reported, the present study demonstrated temukut’s potential to inhibit the proliferation of HT-29, Caov-3, and HepG2 cells.
  14. Azrina, A., Nurul Nadiah, M.N., Amin, I.
    MyJurnal
    The antioxidant properties of skin, flesh and kernel of Canarium odontophyllum fruit were determined. The methanolic extracts of the fruit were screened for their total phenolic content and antioxidant properties. The averaged antioxidant properties (mM TE/g FM) in skin, flesh, and kernel of Canarium odontophyllum were 16.46 ± 0.24, 20.54 ± 0.35, and 8.89 ± 0.29, respectively by DPPH assay; 151.24 ± 9.75, 70.58 ± 2.98, and 5.65 ± 0.02, respectively by FRAP assay; and 47.9 ± 0.00, 11.61 ± 1.14, and 3.00 ± 0.00, respectively by β-Carotene bleaching method. The averaged OH scavenging activity (mg DMSOE/mg FM) in skin, flesh, and kernel of Canarium odontophyllum were 43.33 ± 13.85, 7.81 ± 1.42, and 3.31 ± 0.80, respectively. While averaged total phenolic content (mg GAE/100g FM) were 387.5 ± 33.23, 267.0 ± 4.24, and 51.0 ± 0.00 for skin, flesh, and kernel respectively. Antioxidant activities were positively correlated with the total phenolic content (0.71 ≤ r ≤ 0.84).
  15. Rahman, M.M., Fazlic, V, Saad, N.W.
    MyJurnal
    Garlic has been a favorite additive in food for many years in various cultures. It is known that garlic
    (Allium sativum) possesses antimicrobial, antiprotozoal, antimutagenic, antiplatelet and antihyperlipidemic
    properties. Allicin, a thiosulfinate extract of garlic, has been presumed to be a very strong antioxidant. High performance liquid chromatography (HPLC) analysis of raw garlic extract was not conclusive to determine allicin’s presence. However, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging methods to determine the antioxidant activity of raw garlic extract shows a color change from deep violet to yellow, indicating antioxidant activity. Thus, raw garlic can be a source of antioxidant based on the results of the DPPH scavenging analysis.
  16. Gan, Y.Z., Azrina, A.
    MyJurnal
    This study aimed to determine total antioxidant and antioxidant activity of selected local varieties
    of lettuce (Lactuca sativa L.). Five varieties (iceberg, butterhead, romaine, green coral and
    red coral) were subjected to DPPH radical scavenging activity and ferric reducing antioxidant
    power assay (FRAP) assays for determination of antioxidant activity. Total phenolic content
    and total flavonoid content were determined as total antioxidant. The EC50 values obtained from
    the DPPH radical scavenging assay ranged from 303.56 to 4485.41 μg/ml. The red coral lettuce
    had the lowest EC50 value indicating it possesses the highest antioxidant activity among the
    varieties. This variety also showed the highest FRAP value compared with the other varieties,
    where the values ranged from 48.05 to 2135.82 mM Fe2+/100 g fresh weight. Total phenolic
    content of samples ranged from 4.85 to 76.05 mg gallic acid equivalent/100 g fresh weight,
    with the red coral lettuce had the highest value. Total flavonoid content of the lettuce samples
    ranged from 2.28 to 21.96 mg quercetin equivalent/100 g fresh weight, and were significantly
    different (p
  17. Nurliyana, R., Syed Zahir, I., Mustapha Suleiman, K., Aisyah, M.R., Kamarul Rahim, K
    MyJurnal
    The aim of this study is to compare antioxidant level and activities (i.e. primary and secondary) in pulps and peels of two species of dragon fruits, Hylocereus undatus (white dragon fruit) and Hylocereus polyrhizus (red dragon fruit). Total phenolic content (TPC) assay demonstrated that peels of both Hylocereus species contained higher phenolic content than the pulps. The phenolic content in peels of H. undatus was higher than H. polyrhizus, but the phenolic content in pulps of H. undatus was much lower than H. polyrhizus. 2, 2, diphenyl-1-picrylhydrazyl (DPPH) assay showed that radical scavenging activities of peels for both species were higher than the pulps. For ferrous ion chelating (FIC) assay, peels and pulps of both Hylocereus species showed moderate metal ion chelating effect as compared to EDTA. Overall, the results suggested that the TPC showed good relationship with the primary antioxidant activities for general comparison between the peels and the pulps.
  18. Zarinah, Z., Maaruf, A.G., Nazaruddin, R., Wong, W.W.W., Xuebing, X.
    MyJurnal
    Some vegetable oils contain natural antioxidants such as beta carotene and vitamin E namely alpha tocopherol. The objective of this study was to screening the value of α-tocopherol, β-carotene, antioxidant capacity, antimicrobial activity and toxicological properties of roasted pili nut oil (RPNO) and unroasted pili nut oil (UPNO). The result showed that RPNO contained higher amount of vitamin E and less amount of beta carotene compared to UPNO. RPNO and UPNO scavenged DPPH radicals by 24.66% and 9.52% at concentration of 140 μg/ml. The total phenolic compound (TPC) in UPNO and RPNO were about 19.96 ± 0.52 mg/kg and 12.43 ± 0.69 mg/kg respectively. It was observed that bacteria species exhibited different sensitivities towards RPNO, UPNO, Gentamycin, Ampicillin and Chloramphenicol. Bacillus cereus 14570 was the most sensitive bacterium and all strains of Staphylococcus aureus tested were resistant against both samples RPNO and UPNO. An in vitro toxicological study based on the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) cytotoxicity assay was also performed. In vitro cytotoxicity indicated that both RPNO and UPNO had no effect against HeLa (cervical cancer cell), MCF-7 (breast cancer cell) and HT-29 (human colon adenocarcinoma cell) cell lines tested.
  19. Lee, S.Y., Ismail, I.S., Ang, E.L., Abas, F.
    MyJurnal
    Neptunia oleracea Lour. is a tropical plant cultivated in Southeast Asia. It is consumed as vegetable and traditional herb for the treatment of several disorders. The objective of the present work was to isolate the phenolic compounds from N. oleracea, followed by their bioactivity evaluation and quantitative analysis. The ethyl acetate (EtOAc) and methanol (MeOH) fractions of N. oleracea were subjected to various chromatographic techniques to isolate the phenolic compounds. The isolated phenolic compounds were characterised by several spectroscopic methods, including mass spectrometry (MS) and nuclear magnetic resonance (NMR). Then, these compounds were subjected to DPPH free radical scavenging as α-glucosidase inhibitory assays for the evaluation of their activities. Their contents in the fractions were analysed via high performance liquid chromatography (HPLC) quantitative analysis. Five phenolic compounds including quercetin-3-O-β-D-xylopyranoside (1), quercetin-3-O-α-Larabinopyranoside (2), quercetin-3-O-α-L-rhamnoside (3), methylgallate (4) and rutin (5) were isolated from N. oleracea for the first time. Evaluation on the DPPH free radical scavenging and α-glucosidase inhibitory activities of these compounds showed that methylgallate (4) was the most potent antioxidant and α-glucosidase inhibitors among them, with IC50 values of 17.25 and 50.76 μM, respectively. The HPLC quantitative analysis revealed the high content of the quercetin derivatives (compounds 1, 2 and 3) in the EtOAc fraction (ranging from 125.68 to 157.55 μg/mg) and methylgallate (4) in the MeOH fraction (75.25 μg/mg). Comparison of the bioactivities of the isolated phenolic compounds with the fractions indicated their significant contribution for the DPPH free radical scavenging of N. oleracea; while they might be working synergistically for the α-glucosidase inhibitory activity. The results of the present work could help to validate the contribution of phenolic compounds for the studied bioactivities of N. oleracea.
  20. Huda-Faujan, N., Noriham, A., Norrakiah, A.S., Babji, A.S.
    MyJurnal
    This study was conducted on selected local herbs such as ulam raja (Cosmos caudatus), kesum (Polygonum minus), selom (Oenanthe javanica), pegaga (Centella asiatica) and curry leaves (Murraya koenigii) to investigate their antioxidative activities. The water extracts of the herbs were analysed for total phenolic content, reducing antioxidant power, ferric thiocyanate (FTC) and the thiobarbituric acid (TBA) test was also accried out. Polygonum minus showed the highest total phenolic content and reducing power among the herbs. Increasing the concentration of the extracts resulted in increased Fe3+ reducing antioxidant power for all the herbs. FTC and TBA tests on the extracts during seven days of storage showed that all the herbs extracts had the ability to reduce oxidation compared to the control (P < 0.05). From the FTC analysis, Murraya koenigii leaves was best in reducing the oxidation rate (67.67%) compared to the other herbs studied. Analysis of TBA showed that Centella asiatica extract had the highest antioxidant effect. However, both TBA and FTC analysis for these two herbs showed no significant difference (P >0.05) from Polygonum minus and butylated hydroxyanisole (BHT) a synthetic antioxidant. Correlation analysis showed positive correlations between amount of total phenolic content and reducing power (r = 0.75) and antioxidative activities (r = 0.58) in linoleic acid emulsion system. This shows that antioxidative activities of these Malaysian herbal plants especially Polygonum minus may be a potential source of natural antioxidants with similar characteristics to the synthetic antioxidant, BHT.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links