Dosage response of atherosclerotic lesions to dietary cholesterol in rabbits

Litsea garciae, known locally in Sabah, Malaysia as Pengolaban, is an underutilized edible fruit endemic to Borneo. This study was conducted to determine the antioxidant activity and total phenolic, total flavonoid, and total anthocyanin contents of different parts (i.e., flesh, stem cap, and seed) of the fruits. All samples were freezedried and extracted using 80% methanol and distilled water. For 80% methanol extract, stem cap of pengolaban displayed the highest free radical scavenging activity and ferric reducing activities as compared to other parts of the fruit. Total phenolic and total flavonoid content were highest in stem cap with the values of 8.29±0.70 mg gallic acid equivalents/g and 6.90±0.61 mg rutin equivalents/g, respectively. Total anthocyanin content was highest in flesh of the fruit with the value of 4.12±0.10 mg cyanidin-3-glucoside equivalents/100 g. The same trend of antioxidant and phytochemical content were also observed in the distilled water extract. These findings suggested that pengolaban has an acceptable high amount of phytochemicals which has a potential as natural antioxidant that can contribute to human health.     

Quorum Quenching and Microbial Control through Phenolic Extract of Eugenia Uniflora Fruits

We describe the characterization of the centesimal composition, mineral and phenolic content of Eugenia uniflora fruit and the determination of the antioxidant, antimicrobial and quorum quenching activities of the pulp phenolic extract. Centesimal composition was determined according to standard methods; trace elements were measured by total reflection X‐ray fluorescence spectroscopy. The phenolic compounds were extracted by solid‐phase chromatography and quantified by spectrophotometry. Antioxidant activity was determined by using 3 different methods. Antimicrobial activity was evaluated against a panel of foodborne microorganisms and antiquorum sensing activity in Chromobacterium violaceum was performed by measuring inhibition of quorum sensing dependent violacein production. The centesimal composition (per 100 g of pulp) was as follows: protein 3.68 ± 0.21 g, lipids 0.02 ± 0.03 g, carbohydrates 10.31 g and fiber 2.06 g. Trace elements (mg/g of pulp) were determined as: K 0.90, Ca 3.36, Fe 0.60, Zn 0.17, Cl 0.56, Cr 0.06, Ni 0.04, and Cu 0.07. The pulp is a source of phenolic compounds and presents antioxidant activity similar to other berries. The fruit phenolic extract inhibited all tested bacteria. We also found that the fruit phenolic extract at low subinhibitory concentrations inhibited up to 96% of violacein production in C. violaceum, likely due to the fruit's phenolic content. This study shows the contribution of E. uniflora phenolic compounds to the antioxidant, antimicrobial and the newly discovered quorum quenching activity, all of which could be used by the food and pharmaceutical industries to develop new functional products.     

木贼醇提物不同萃取部位总酚酸、黄酮含量测定及抗氧化活性研究

目的:对木贼的乙醇提取物不同萃取部位进行总酚酸、黄酮含量测定及抗氧化活性比较,以探知木贼抗氧化活性物质基础。方法:木贼经70%乙醇超声提取浓缩后,采用有机溶剂萃取法依次得到石油醚、乙酸乙酯、正丁醇、水相4个部位萃取物;利用紫外-分光光度法比较各萃取部位总黄酮、酚酸含量差异;以抗坏血酸为阳性对照,比较不同萃取部位还原能力、羟自由基(·OH)、1,1-二苯基-2-三硝基苯肼(DPPH·)、2,2'-联氮-双(3-乙基苯并噻唑-6-磺酸)二铵盐(ABTS+·)清除率的差异,评价各部位抗氧化能力强弱。结果:木贼各萃取物总黄酮含量在5.70~61.55 mg/g 范围内,总酚酸含量在4.07~19.10 mg/g 范围内,乙酸乙酯萃取物总黄酮与酚酸含量明显高于其他萃取物,其还原能力、羟自由基、DPPH·、ABTS+·清除率也明显高于正丁醇、石油醚和水相萃取物,乙酸乙酯萃取物对羟自由基、ABTS+·、DPPH·清除能力IC₅₀值分别为:(0.321±0.0026)、(0.213±0.0010)和(0.169±0.0014) mg/mL。结论:经各相溶剂萃取后木贼有效成分得到初步分离,乙酸乙酯相萃取部位总黄酮和酚酸相对含量及抗氧化活性明显强于总提物和其他萃取部位,且其抗氧化能力呈量效关系。实验发现木贼中黄酮和酚酸类成分与其抗氧化能力密切相关。     

Betalain and Phenolic Compositions,Antioxidant Activity of Tunisian Red Beet (Beta vulgaris L. conditiva) Roots and Stems Extracts

In the present study, betalains content, phenolic composition, and antioxidant activity of different parts of red beet (Beta vulgaris L. conditiva) (i.e., roots and stems) were compared. Crude extract of root showed the highest betalain content with a maximum of 53 ± 4 mg betanin eq and 46 ± 3 mg vulgaxantin I eq g^?1 of extract stems showed higher total phenolic concentration than roots, ranging between 2.0 ± 0.4 and 14.6 ± 0.5 mg gallic acid eq^?1 of extract. Chemical composition was analyzed using LC-MS. Betalains (vulgaxanthin I, betanin, and isobetanin) and phenolics (gallic acid, ferulic acid, chlorogenic acid, caffeic acid, vanillic acid, syringic acid, ellagic acid myricetin, quercetin, rutin, kampferol) were identified in roots and stems. Betalain extract obtained from roots showed higher antioxidant activity than extract obtained from stems.     

Fatty acids,tocopherols, phenolic and antioxidant properties of six citrus fruit species: a comparative study

Citrus fruit is a rich source of bioactive phytochemicals. Information on the fatty acid and tocopherol composition of locally grown citrus fruits in Korea is elusive. This work was aimed to study fatty acid, tocopherols, ascorbic acid, antioxidant potential, and selected phenolics from peel and pulp of six citrus species. The most dominant fatty acid was linoleic acid (15–45%), followed by linolenic, palmitic, and oleic acid. Stearic acid was highly abundant in yuzu peel (14.45%) and pulp (15.88%) compared to the other fruits. Unsaturated fatty acids (54–74%) contributed higher composition than saturated fatty acids (25–46%). Peel exhibited better antioxidant potential and contained higher phytochemicals than pulp. The concentrations of α-tocopherol and γ-tocopherol were ranged from 22.96 (yuzu) to 86.93 (cheonhyeyang) and 38.59 (yuzu) ~83.03 (tangerine) μg/g DW, respectively. J-Redhyeyang peel exhibited highest total flavonoids (4.17?±?0.10 mgQE/g DW) and DPPH radical scavenging activity (6.17?±?0.03 mgTE/g DW). FRAP values were highest (20.05?±?0.64 mgTE/g DW) in yuzu peel, while peel of cheonhyeyang was superior in total phenolic contents. Tangerine (3.02?±?0.05 mg/g DW) and yuzu (7.49?±?0.38 mg/g DW) had higher hesperidin concentrations in pulp and peel, respectively. Naringin was found in an appreciable amount in yuzu pulp (2.04?±?0.09 mg/g DW) and peel (6.30?±?0.19 mg/g DW) but not detected in all other fruit species. Our results indicate that citrus fruit peel is the rich source of antioxidant compounds, which can be used to prepare antioxidant rich food product.     

Phenolic composition,antioxidant, antibacterial,larvacidal against Culex pipiens,and cytotoxic activities of Hyacinthella lineata steudel extracts

This study reports the phenolic composition, antioxidant, antibacterial, larvacidal, and cytotoxic activity of methanol and acetone extracts of Hyacinthella lineata leaves and bulbs. The phenolic composition of H. lineata was determined by HPLC. The most abundant component was gallic acid (421.9µg/g). The β-carotene/DPPH/ABTS/FRAP decoloration method was used to estimate the total antioxidant activity. The total antioxidant activity was the highest for bulb-methanol fraction (65.41 ± 0.05%). The total phenolic content for leaves-methanol extract of the plant was determined as 6.56 ± 4.027mg/mL gallic acid equivalents. Analysis of the antibacterial activity showed that the methanolic-bulb extract are efficient against gram positive and gram negative bacteria. The cytotoxic effect on Artemia salina was assessed by Brine shrimp assay. Brine shrimp lethality assay showed that LC₅₀ values of HBM were obtained as 4.105 ± 2.42μg/ml. The bulb extract of H. lineata showed the highest larvicidal activity against Cx pipiens with value LC₅₀ (64.3275μg/ml). This study suggested that H. lineata may be used as a potential source of antioxidant, and for their biological activity, cytotoxic and antimicrobial properties.     

Evaluation of the Phenolic Content,Antiradical, Antioxidant,and Antimicrobial Activity of Different Floral Sources of Honey

Thirty-five honeys were evaluated for total phenolic content by Folin-Ciocalteu method, for potential antioxidant activity using phosphomolibdenum assay and by the 1,1-diphenyl-2-picrylhydrazyl method for antiradical activity. The antimicrobial activity was studied by the agar diffusion method, using 12 bacteria and 2 yeasts. The means of the total phenolic contents of chestnut, honeydew, multifloral, thyme, and astragalus were 47 ± 18, 24.2 ± 0.6, 14 ± 11, 11 ± 6, and 9 ± 7 mg/100 g honey as gallic acid equivalent, respectively. The lowest antioxidant activity was observed in honeydew 70 ± 5 mg ascorbic acid equivalent/g honey while the highest content was observed in astragalus honey 86 ± 16 mg ascorbic acid equivalent/g honey. Correlation between the phenolic content and antioxidant activity were found to be statistically significant. Chestnut honeys (n = 5) exhibited maximum free radical scavenging activity with an average 68 ± 9%. The honey samples showed the highest antimicrobial activity against some microorganisms, especially Escherichia coli O157:H7, Salmonella typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Proteus mirabilis. On the other side, Aeromonas hydrophila, Bacillus subtilis, and E. coli were the most resistant microorganisms. The results revealed that the Turkish honeys studied proved to be a good source of antioxidant and antimicrobial agents that might serve to protect human health.     

Optimization of the Process Parameters to Establish the Quality Attributes of DPPH Radical Scavenging Activity,Total Phenolic Content,and Total Flavonoid Content of Apple (Malus domestica) Honey Using Response Surface Methodology

The response surface methodology was used to study the combined effect of temperature (60 to 80°C), time (10 to 15 min), and pH (3 to 6) on the antioxidant activity (1,1-diphenyl-2-picrylhydrazyl-radical scavenging activity, total phenolic content, and total flavonoid content) of apple honey. Statistical analysis revealed that all the responses were significantly (p < 0.05) affected by independent process variables. 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, total phenolic content, and total flavonoid content increased with the increase in time and temperature due to the formation of browning pigments. The antioxidant properties of apple honey significantly (p < 0.05) decreased with increase in pH from 3 to 6. The thermal treatment of apple honey at 80°C was found to be more effective than at 70 and 60°C. The average increase in 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, total phenolic content, and total flavonoid content of raw apple honey due to combined effect of three process variables was 9.6% ± 1.9, 13.7 ± 2.5 mg gallic acid equivalent/100 g and 49.3 ± 3.3 mg quercetin/100 g, respectively. The results showed that the most desirable optimum conditions for temperature, time and pH for 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (92.39%), total phenolic content (133.55 mg gallic acid equivalent/100 g of honey), and total flavonoid content (25.82 mg quercetin/100 g of honey) were 80°C, 15 min and 3.01, respectively. The results demonstrated that thermal treatment significantly increased the antioxidant activity of apple honey.     

The antioxidant activities and the xanthine oxidase inhibition effects of walnut (Juglans regia L.) fruit,stem and leaf

The antioxidant activities and xanthine oxidase inhibition effects of walnut fruit, stem and leaf were studied in this work. The total phenolic contents were in a descending sequence: shell extract > leaf extract > stem extract > defatted walnut kernel (DWK) extract > green husk extract (GHE). The sequence of total phenolic contents was in agreement with the sequence of antioxidant capacities evaluated by ferric reducing antioxidant power and oxygen radical absorbance capacity (ORAC) assays except for DWK extract. The walnut shell extract showed the highest phenolic content (14.81 gallic acid equivalent g/100 g dry extract) and the best antioxidant activity (the ORAC value was 3423.44 ± 142.52 μmol Trolox equivalents g^?1). All tested samples possessed xanthine oxidase inhibitory (XOI) effects, the inhibition percentages of which were >50% at 2 mg mL^?1 except for stem and DWK extracts. The contents of the major compound (hydrojuglone) in all extracts were in a descending order: GHE > walnut stem extract > walnut shell extract > walnut leaf extract > DWK extract.     

Effects of Heat Treatment on Total Phenolic Contents,Antioxidant and Anti-Inflammatory Activities of Pleurotus Sajor-Caju Extract

Untreated and heat treated Pleurotus sajor-caju methanolic extracts were examined for total phenolic content, antioxidant and anti-inflammatory activities. Total phenolic content was determined by using the Folin-Ciocalteu method, and results were expressed as mg gallic acid equivalent per g of sample extract. Antioxidant activity was measured by using the DPPH free radical scavenging method while anti-inflammatory activity was measured by using the Griess assay. Methanolic extracts of fresh fruiting bodies were heated at 100 and 121°C for 15 and 30 min. The results showed that total phenolic contents of heat-treated samples did not increase significantly when compared to the control sample. Total phenolic contents were within the range of 0.06 ± 0.05 to 0.08 ± 0.05 mg gallic acid/equivalents g of dry weight. The samples heated at 100°C for 15 and 30 min showed the highest radical scavenging activity at 500 μg/ml with the lowest IC₅₀ values of 10.4 ± 3.11 and 11.67 ± 2.75 μg/ml, respectively. The results suggested that the increased antioxidant activity of P. sajor-caju after the heat treatment might have increased the health beneficial effects to humans.     

A novel antioxidant source: evaluation of in vitro bioaccessibility,antioxidant activity and polyphenol profile of phenolic extract from black radish peel wastes (Raphanus sativus L. var. niger) during simulated gastrointestinal digestion

The aim of this study was to evaluate the potency of polyphenolic extract from black radish (Raphanus sativus L. var. niger) root peel waste (PEBRRP) as an antioxidant food additive. PEBRRP was found a powerful antioxidant extract, in which had 172.9 ± 11.5, 462.72 ± 3.05, and 796.51 ± 10.4 mg TE per g dw of total antioxidant capacity (TAC) by CUPRAC, DPPH, and FRAP assays, respectively. The total phenolic content (TPC) and total flavonoid content (TFC) of PEBRRP were found as 305.51 ± 5.2 mg GAE per g dw and 171.58 ± 6.2 mg CAE per g dw, respectively. The ferulic acid (28.02 ± 4.5 mg per g dw) and epicatechin (19.82 ± 3.6 mg per g dw) were identified as the main polyphenols in undigested PEBRRP. The bioaccessibility of total phenolic and total flavonoid compounds of PEBRRP was found approximately 5%, and the antioxidant capacity of bioaccessible PEBRPP fraction was determined 6% in CUPRAC, 36% in DPPH and 47% in FRAP methods.     

Aqueous extraction kinetics of phenolic compounds from jamun (Syzygium cumini L.) seeds

In this study, aqueous extraction of phenolic compounds from jamun (Syzygium cumini L.) seed was undertaken. The effects of various parameters such as extraction temperature (34.8–85.2°C), extraction time (49.8–100.2 min), and liquid-to-solid ratio (9.8–60.2 mL/g) on the extraction yield, extract purity (i.e., total polyphenol content), and its antioxidant activities (1,1-diphenyl-2-picrlthydrazyl free radical scavenging assay and ferric reducing antioxidant power) were investigated. Response surface methodology was used to optimize the extraction conditions. The optimum extraction conditions (49.2°C, 89.4 min, and 51.6:1 mL/g) produced an extract with 17.3% extraction yield, high total polyphenol content (415 mg gallic acid equivalent/g dried extract) and significant antioxidant activity (IC₅₀: 35.4 ± 0.7 µg/mL). The high-performance liquid chromatography analysis of seed extract revealed the presence of gallic acid (90.8 mg/g dried extract), ellagic acid (36 mg/g dried extract), caffeic acid (26.07 mg/g dried extract), p-coumaric acid (0.26 mg/g dried extract), catechin (9.05 mg/g dried extract), epicatechin (0.42 mg/g dried extract), and quercetin (1.54 mg/g dried extract). Tannic acid (188.5 mg/g dried extract) was also identified as a major phenolic compound. The extraction kinetics was also studied and experimental data were fitted to four kinetic models such as first-order model, second-order model, Peleg’s model, and Minchev and Minkov model, to evaluate their applicability.     

Phenolic contents and antioxidant activities of bitter gourd (Momordica charantia L.) leaf, stem and fruit fraction extracts in vitro

Bitter gourd (Momordica charantia L.) has long been regarded as a food and medicinal plant. We investigated the antioxidant activity of the water extract of leaf, stem and fruit fractions by several in vitro systems of assay, namely DPPH radical-scavenging activity, hydroxyl radical-scavenging activity, β-carotene–linoleate bleaching assay, ferric reducing/antioxidant power (FRAP) assay and total antioxidant capacity. Total phenolic content was measured by Folin–Ciocalteu reagent. Identification of phenolic compounds was achieved using HPLC with the UV-diode array detection. The extracts of different fractions were found to have different levels of antioxidant activity in the systems tested. The leaf extract showed the highest value of antioxidant activity, based on DPPH radical-scavenging activity and ferric reducing power, while the green fruit extract showed the highest value of antioxidant activity, based on hydroxyl radical-scavenging activity, β-carotene–linoleate bleaching assay and total antioxidant capacity. The predominant phenolic compounds were gallic acid, followed by caffeic acid and catechin. The present study demonstrated that the water extract fractions of bitter gourd have different responses with different antioxidant methods. Total phenol content was shown to provide the highest association with FRAP assay in this present study (R² = 0.948).     

Antioxidant effects of solvent extracts from the dried jujube (Zizyphus jujube) sarcocarp,seed, and leaf via sonication

Antioxidant effects of extracts from sarcocarp, seed, and leaf of dried jujube (Zizyphus jujube) were investigated. The highest amount of flavonoids and polyphenol was found in 80% methanol leaf extract at value of 43.04±0.34 and 324.75±6.01 mg/g, respectively. For 2,2′-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) radical scavenging activity analysis at a concentration of 1,000 μg/mL, 70% ethanol seed extract (94.76±0.23%), and 80% methanol leaf extract (95.46±0.14%) were observed to have higher activity than those of controls, such as butylated hydroxyl anisole (BHA) (89.60±0.00%), butylated hydroxyl toluene (BHT) (84.07±0.50%), vitamin C (89.27±0.12%), and vitamin E (88.53±0.12%). All solvent extracts from leaf showed higher ABTS radical scavenging activity (over 98%) than those of controls with their activity values around 94% (500 g/mL). All extracts from sarcocarp and seed showed superoxide dismutase (SOD)-like activity of 24.46–34.84% on the concentrations (100–1,000 g/mL), and 80% methanol leaf extract showed the highest activity (43.66±0.37%) among samples. These results indicate that sarcocarp, seed of dried jujube are all excellent antioxidants, and especially leaf showed higher antioxidant effect than those of vitamin C and E.     

Analysis of Phenolic Composition of Noble Muscadine (Vitis rotundifolia) by HPLC‐MS and the Relationship to Its Antioxidant Capacity

Abstract: Phenolic compounds and anthocyanins in muscadines have attracted much attention due to their diverse biological activities. With bioassays of antioxidant activities in terms of total phenolic content (TPC), total anthocyanin content (TAC), total procyanidin content (TPA), oxygen radical absorbance capacity (ORAC), and ferric reducing antioxidant power (FRAP) of different parts of the Noble muscadine, the butanol (BuOH) extract of the muscadine skin showed the highest TPC (317.91 ± 1.83 mg GAE/100 g FW), which might be ascribed to its high TAC of 227.06 ± 1.29 mg/100 g fresh weight (FW). The ethyl acetate (EtOAc) extract of the muscadine seed contained the highest TPA (55.30 ± 0.63 mg CE/100 g FW). Correlation analyses demonstrated a significant linear relationship of TPC and TAC compared to their ORAC and FRAP values within the range of R² from 0.9283 to 0.9936, which suggested that phenolics and anthocyanins in the extracts contributed significantly to their antioxidant potential. Nineteen individual phenolics and 5 anthocyanins were identified by HPLC‐MS, which indicated different chemical profiles of anthocyanins and other phenolics in the muscadine extracts. Practical Application: The paper has provided rich information of bioactive phytochemical profiles in different solvent extracts and their correlation with the antioxidant activity in the muscadine that is a very special regional fruit in U.S. Its high content of phenolic compounds demonstrates that muscadine could be beneficial to human health.     

Antioxidant and antigenotoxic effect of dairy products supplemented with red ginseng extract

The purpose of this study was to evaluate the antioxidant and antigenotoxic effect of dairy products milk (M) and yogurt (Y) after the addition of 2% red ginseng extract to milk (RM) and to yogurt (RY). Total phenolic content, total flavonoid content, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, oxygen radical absorbance capacity, and total radical trapping antioxidant potential were determined in the samples. Furthermore, antigenotoxic effect of samples was measured, using comet assay in human leukocytes. Total phenolic content and total flavonoid content of RM [38.3 ± 0.8 mg of gallic acid equivalents (GAE)/100 g, 23.6 ± 0.1 mg of quercetin equivalents (QE)/100 g] and RY (41.1 ± 0.9 mg of GAE/100 g, 18.7 ± 0.1 mg of QE/100 g), respectively, were higher than those of M (6.31 ± 0.2 mg of GAE/100 g, 10.4 ± 0.1 mg of QE/100 g) and Y (8.1 ± 0.9 mg of GAE/100 g, 8.4 ± 0.2 mg of QE/100 g), respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and oxygen radical absorbance capacity values increased significantly after the addition of 2% red ginseng in both. Additionally, the total radical trapping antioxidant potential in RM (787.7 ± 7.0 μg/mL) was lower than in M (2074.0 ± 28.4 μg/mL). The H₂O₂-induced DNA damage in RY (0.1 ± 0.0 mg/mL) was less than the damage in Y (0.4 ± 0.0 mg/mL), but we found no significant difference between M and RM. This study indicates that supplementation with red ginseng can fortify the antioxidant and antigenotoxic effects of dairy products effectively.     

Influence of altitudinal variation on the antioxidant potential of tartar buckwheat of Western Himalaya

In the present work, the effect of altitudinal variations on the total phenol, flavonoid, and antioxidant potential of seeds and hull of Tartar buckwheat collected from 15 different locations of Western Himalaya has been investigated. Methanolic and acetonic extracts of seed and hull powder showed significantly increasing amounts of total polyphenol content, and antioxidant potential with rising altitude. Methanolic extract of seed and hull powder were found to have significantly greater polyphenol, and antioxidant potential as compared to acetonic extract. The methanolic seed extract of Inderdhara (3,133 m) showed the maximum total phenolic content 1,651 μg gallic acid equivalent/50 mg of dry weight. The methanolic seed extract of Inderdhara showed the maximum antioxidant activity (77.29±1.2%) and antiradical activity (55.5±0.5%) also. The results of this study exhibited good correlation with total polyphenol and antioxidant potential in all the samples followed by the increasing tendency towards rising altitude.     

Phenolic compounds’ characterization of Artemisia rutifolia spreng from Pakistani flora and their relationships with antioxidant and antimicrobial attributes

Artemisia rutifolia (Asteraceae) had been used in traditional medicines for the treatment of different ailments. In the current study, an effort was made to explore the phenolic composition, antioxidant, and antimicrobial activities of different solvent extracts obtained from A. rutifolia leaves. The reverse-phase high-performance liquid chromatographic (RP-HPLC) analysis revealed the higher extent of polyphenolic compounds (i.e., gallic acid, caffeic acid, chlorogenic acid, syringic acid, sinapic acid, p-coumaric acid, m-coumaric acid, ferulic acid, vanillic acid, myricetin, and quercetin) in methanol extract. Methanol extract consistently showed the highest total phenolic contents (98 ± 2 µg GAE/mg of plant extract), total flavonoid contents (28 ± 0.0 µg QE/mg of plant extract), antimicrobial activity, free radical (DPPH) scavenging (IC₅₀ = 39 µg/mL) activity, and reducing power (18.3 ± 0.2 mg GAE/g of plant extract) followed by those of chloroform and hexane extracts, respectively. The current study concluded that extracts of A. rutifolia are novel natural source of antioxidative and antimicrobial agents for the treatment of oxidative stress-related disorders and microbial infections.     

Organic acids,antioxidant capacity,phenolic content and lipid characterisation of Georgia-grown underutilized fruit crops

Four underutilized Georgia-grown fruit crops, namely loquat (Eriobotrya japonica), mayhaw (Crataegus sp.), fig (Ficus carica), and pawpaw (Asimina triloba), and their leaves were analysed for total polyphenols by Folin–Ciocalteau method, and antioxidant capacity by ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) assays. Organic acids and phenolic compounds were identified by RP-HPLC. For lipid profile, fruits were separated into two fractions – seed and fruit (i.e., without seed); lipid was extracted using the Folch method and analysed for fatty acids, phytosterols, tocopherols, and phospholipids. The major organic acid identified in all samples was malic acid (177–1918 mg/100 g FW). The predominant phenolic acids in all the fruits were gallic (1.5–6.4 mg/100 g FW) and ellagic (0.2–33.8 mg/100 g FW), and the most abundant flavonoid was catechin (12.2–37.8 mg/100 g FW). Total lipid content varied from 0.1% in mayhaw fruit to 21.5% in pawpaw seed. Linoleic acid was the predominant fatty acid in all of the samples (28.2–55.7%).     

Antioxidant and tyrosinase inhibitory activities of different parts of guava (<Emphasis Type="Italic">Psidium guajava</Emphasis> L.)

The antioxidant and the tyrosinase inhibitory activities of 4 different solvents (acetone, ethanol, methanol, and water) for preparation of extracts from guava (branch, fruit, leaf, and seed) were evaluated by measuring total phenolic contents (TPC), DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power (RP), and tyrosinase inhibitory activity. The extracts of branch and leaf showed relatively higher antioxidant properties than those of fruit and seed. The highest TPC (141.28 mg/g gallic acid equivalents), DPPH radical scavenging activity (IC₅₀=34.01 μg/mL), ABTS radical scavenging activity (IC₅₀=3.23 μg/mL), and RP (IC₅₀= 75.63 μg/mL) were found in acetone extract of leaf, while water extract of seed had the lowest antioxidant activity. The tyrosinase inhibitory activity of ethanol extract from guava leaf was 69.56%, which was the highest activity among the extracts. These results indicate that useful bioactive substances exist in the guava branch as well as leaf extracts.