Antioxidant potential of non-oil seed legumes of Indonesian’s ethnobotanical extracts

This study investigated the in vitro antioxidant properties (DPPH, ABTS, CUPRAC and FRAP), total phenolic content and flavonoid content of extracts from three non-oil seed legumes (Phaseolus lunatus red and white, and Canavalia ensiformis), local edible seeds from Indonesia, obtained using different solvent system (distilled water, 70% ethanol, and 100% ethanol). The variety of legume was a major source of variation in the phenolic contents, flavonoid content and antioxidant activity. HPLC analysis of the non-oil seed legume extracts identified gallic acid, epicatechin and coumaric acid. Among the varieties of non-oil seed legume extracts, the phenolic content varied from 15.21–38.60 mg gallic acid equivalents/g dry weight and the flavonoid content was 11.73–24.61 mg catechin equivalents/g dry weight. The antioxidant activity of the extracts suppressed the reactive oxygen species (ROS) generation and cellular damage induced by UV-B in HaCaT cells. These results showed that antioxidant activity (1.83–19.42% of inhibition DPPH; 2.99–37.29% of inhibition ABTS; 0.20–2.47 µM CUPRAC value; and 0.96–1.10 µM of FRAP value) of extracts possessed strong radical scavenging activity as well as inhibited ROS generation in a dose-dependent manner without showing any cytotoxicity. Collectively, the data presented that antioxidant of the extracts have potent antioxidant activity and decreasing ROS generation in HaCaT cells. It can be intimately used as alternative criterion for antioxidant and antiradical activities that can be utilized as a functional food and nutraceutical ingredients.     

Tunisian Native Mentha pulegium L. Extracts: Phytochemical Composition and Biological Activities

Mint species (Lamiaceae family) have been used as traditional remedies for the treatment of several diseases. In this work, we aimed to characterize the biological activities of the total phenolic and flavonoid contents of Mentha pulegium L. extracts collected from two different regions of Tunisia. The highest amounts of total phenols (74.45 ± 0.01 mg GAE/g DW), flavonoids (28.87 ± 0.02 mg RE/g DW), and condensed tannins (4.35 ± 0.02 mg CE/g DW) were found in the Bizerte locality. Methanolic leaf extracts were subjected to HPLC-UV analysis in order to identify and quantify the phenolic composition. This technique allowed us to identify seven phenolic compounds: two phenolic acids and five flavonoid compounds, such as eriocitrin, hesperidin, narirutin, luteolin, and isorhoifolin, which were found in both extracts with significant differences between samples collected from the different regions (p < 0.05). Furthermore, our results showed that the methanolic extract from leaves collected from Bizerte had the highest antioxidant activities (DPPH IC₅₀ value of 16.31 μg/mL and 570.08 μmol Fe²⁺/g, respectively). Both extracts showed high radical-scavenging activity as well as significant antimicrobial activity against eight tested bacteria. The highest antimicrobial activities were observed against Gram-positive bacteria with inhibition zone diameters and MIC values ranging between 19 and 32 mm and 40 and 160 µg/mL, respectively. Interestingly, at 10 μg/mL, the extract had a significant effect on cell proliferation of U87 human glioblastoma cells. These findings open perspectives for the use of Mentha pulegium L. extract in green pharmacy, alternative/complementary medicine, and natural preventive therapies for the development of effective antioxidant, antibacterial, and/or antitumoral drugs.     

Antioxidant Potential and Cytotoxic Effect of Isoflavones Extract from Thai Fermented Soybean (Thua-Nao)

Thua-nao, or Thai fermented soybeans, is a traditional Lanna fermented food in Northern Thailand. It is produced by using a specific bacterial species called Bacillus subtilis var. Thua-nao. We investigated the antioxidant activity and cytotoxic effect of isoflavones from Thua-nao. The phenolic compound contents and total flavonoid contents were determined by spectrophotometry. The antioxidant activity was examined using the ABTS, FRAP, and DPPH assays. The isoflavone contents and phenolic compositions were examined by the high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) techniques. The ability of isoflavones to inhibit human cancer cell growth was assessed by the MTT assay. The total phenolic content, total flavonoid content, and antioxidant activities of the isoflavones were 49.00 ± 0.51 mg GAE/g of dry extract (DE), 10.76 ± 0.82 mg QE/g of DE, 61.03 ± 0.97 µmol Trolox/g of DE, 66.54 ± 3.97 µM FeSO₄/g of DE, and 22.47 ± 1.92% of DPPH inhibition, respectively. Additionally, the isoflavone extracts from Thua-nao had high isoflavone contents and polyphenolic compound compositions, especially daidzein and genistein. The isoflavone demonstrated a weak inhibition of MCF-7 and HEK293 cancer cell growth. It has a high antioxidant component, which is beneficial and can be developed for new therapeutic uses. However, further studies on the benefits of Thua-nao should be performed for realizing better and more effective uses soon.     

The Optimization of Extraction Process,Antioxidant, Whitening and Antibacterial Effects of Fengdan Peony Flavonoids

Flavonoids have important biological activities, such as anti-inflammatory, antibacterial, antioxidant and whitening, which is a potential functional food raw material. However, the biological activity of Fengdan peony flavonoid is not particularly clear. Therefore, in this study, the peony flavonoid was extracted from Fengdan peony seed meal, and the antioxidant, antibacterial and whitening activities of the peony flavonoid were explored. The optimal extraction conditions were methanol concentration of 90%, solid-to-liquid ratio of 1:35 g:mL, temperature of 55 °C and time of 80 min; under these conditions, the yield of Fengdan peony flavonoid could reach 1.205 ± 0.019% (the ratio of the dry mass of rutin to the dry mass of peony seed meal). The clearance of Fengdan peony total flavonoids to 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, hydroxyl radical and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical could reach 75%, 70% and 97%, respectively. Fengdan peony flavonoid could inhibit the growth of the Gram-positive bacteria. The minimal inhibitory concentrations (MICs) of Fengdan peony flavonoid on S. aureus, B. anthracis, B. subtilis and C. perfringens were 0.0293 mg/mL, 0.1172 mg/mL, 0.2344 mg/mL and 7.500 mg/mL, respectively. The inhibition rate of Fengdan peony flavonoid on tyrosinase was 8.53–81.08%. This study intensely illustrated that the antioxidant, whitening and antibacterial activity of Fengdan peony total flavonoids were significant. Fengdan peony total flavonoids have a great possibility of being used as functional food materials.     

Rhamnus pallasii subsp. sintenisii fruit,leaf, bark and root: Phytochemical profiles and biological activities

The genus Rhamnus has received a lot of interest as a source of phenolic chemicals. There have been no reports on the phytochemicals and biological activities of R. pallasii subsp. sintenisii various morphological components (fruit, leaf, bark, and root) in Iran to yet. Two crude ether petroleum (EP) and hydro-methanolic (HM) extracts were obtained from the separate parts. The antioxidant and antibacterial capabilities of the extracts, as well as their phytochemical screening (total phenolic, flavonoid, phenolic acid, and anthocyanin concentrations), were measured. Furthermore, the phytochemical profiles of EP and HM extracts were determined using GC–MS and LC-ESI–MS, respectively. LC-ESI-MS detected 59 chemicals in HM extracts, including flavonoids (62.71 %), phenolic acids (10.16 %), and anthraquinones (16.94 %). Furthermore, the predominant group components in EP extracts examined by GC–MS were fatty acids (58.82%), phenolic compounds (49.28%), and hydrocarbons (35.15 to 59.45 %). In terms of biological testing (DPPH radical scavenging and anti-bacterial activity), all examined extracts, particularly the fruit, had the highest activities in both assays (IC₅₀: 7.52 to 22.39 µg/ml and MIC: 0.39 to 3.12 mg/ml), owing to their high phenolic content. As a result, individual morphological elements of the species might be thought of as natural antioxidant and antibacterial agents.     

Effect of Extraction Method on Total Flavonoid,Total Phenolic Content,Antioxidant and Anti-bacterial Activity of Zingiberis Officinale Rhizome

This research aims to compare between decocta and maceration method using water and ethanol as a solvent on total flavonoid, total phenolic content, antioxidant and antibacterial activity of Zingiber officinale rhyzome extract. The Rhyzome was dryed by oven method on 50 °C for 24 hours and 48 hours. Total flavonoid, total phenolic content and antioxidant activity were assay by spectrophotometric method. The antibacterial activity was determined by difussion agar method against Bacillus subtilis (Bs) and Escherichia colli InaCC B5 (Ec). Ethanol extract from dried rhyzome processed for 24 hours (R-24) indicated the best result for total flavonoid, total phenolic content and antioxidant activity. The yield of total flavonoid for R-24 was 286 μg/mL. The yield of total phenolic content for R-24 was 504 μg/mL and the yield of IC₅₀ antioxidant activity for R-24 was 5.753 μg/mL. The extract should antibacterial activity againts Bs with inhibition diameter of 10% and 20% of samples concentration are 10 and 11.5 mm respectively. Meanwhile, The inhibition diameter result against Ec for 10% and 20% of samples concentration are 7.5 and 8.5 mm respectively.     

Phenolic Compounds and Antioxidant Activity of Bulb Extracts of Six <em>Lilium</em> Species Native to China

Lily (Lilium) is used as an important edible and medical plant species with a vague taxonomic classification and a long history in China. Bulbs of six Lilium species (L. regale, L. concolor, L. pumilum, L. leucanthum, L. davidii var. unicolor and L. lancifolium) native to China were investigated with a view to their exploitation as a potential source of natural antioxidants due to their phenolic composition and dietary antioxidant potential. The results showed that all bulb extracts exhibited strong antioxidant activities, which generally correlated positively with the total phenolic contents (r = 0.68 to 0.94), total flavonoid contents (r = 0.51 to 0.89) and total flavanol contents (r = 0.54 to 0.95). High-performance liquid chromatography (HPLC) analysis revealed that rutin and kaempferol were the major phenolic components in the extracts. Hierarchical cluster analysis showed that L. regale belonged to the group with high phenolic content and strong antioxidant power. L. concolor and L. pumilum were arranged in one group characterized by moderate phenolic content and antioxidant capacity, while L. leucanthum, L. davidii var. unicolor and L. lancifolium were clustered in the third group with low phenolic content and weak antioxidant activity. These strongly suggest that lily bulbs may serve as a potential source of natural antioxidant for food and pharmaceutical applications.     

Changes in Organic Acids,Phenolic Compounds,and Antioxidant Activities of Lemon Juice Fermented by Issatchenkia terricola

High content of citric acid in lemon juice leads to poor sensory experience. The study aimed to investigate the dynamics changes in organic acids, phenolic compounds, and antioxidant activities of lemon juice fermented with Issatchenkia terricola WJL-G4. The sensory evaluation of fermented lemon juice was conducted as well. Issatchenkia terricola WJL-G4 exhibited a potent capability of reducing the contents of citric acid (from 51.46 ± 0.11 g/L to 8.09 ± 0.05 g/L within 60 h fermentation) and increasing total phenolic level, flavonoid contents, and antioxidant activities compared to those of unfermented lemon juice. A total of 20 bioactive substances, including 10 phenolic acids and 10 flavonoid compounds, were detected both in fermented and unfermented lemon juice. The lemon juice fermented for 48 h had better sensory characteristics. Our findings demonstrated that lemon juice fermented with Issatchenkia terricola exhibited reduced citric acid contents, increased levels of health-promoting phenolic compounds, and enhanced antioxidant activities.     

Antioxidant,Antimicrobial and Metmyoglobin Reducing Activity of Artichoke (Cynara scolymus) Powder Extract-Added Minced Meat during Frozen Storage

The present study aimed to investigate the bioactive compounds in artichoke (Cynara scolymus) powder, having antioxidant and antimicrobial activity, and to determine the effectiveness of artichoke (C. scolymus) powder extract within the minced meat. C. scolymus was extracted using two different methods. The method incorporating high phenolic and flavonoid content levels was used in other analyses and the phenolic and flavonoid contents in C. scolymus extract was determined using LC-QTOF-MS. Antioxidant, antimicrobial, and metmyoglobin (metMb) reducing activities and pH values of the extract-added minced meat samples were measured for 10 days during storage. DPPH, FRAP, and ABTS were used in the antioxidant analyses. The antimicrobial activity of C. scolymus extract was evaluated on five different food pathogens by using the disc diffusion method. The most resistant bacterium was found to be Listeria monocytogenes (18.05 mm ± 0.24). The amount of metMb was measured in the minced meat sample that was added to the extract during storage (p < 0.05). MetMb formation and pH value on the sixth day of storage were found to be at lower levels than in the control group. In conclusion, C. scolymus exhibited a good antimicrobial and antioxidant effect and can be used in storing and packaging the food products, especially the meat and meat products.     

The Isorhamnetin-Containing Fraction of Philippine Honey Produced by the Stingless Bee Tetragonula biroi Is an Antibiotic against Multidrug-Resistant Staphylococcus aureus

Honey exhibits antibacterial and antioxidant activities that are ascribed to its diverse secondary metabolites. In the Philippines, the antibacterial and antioxidant activities, as well as the bioactive metabolite contents of the honey, have not been thoroughly described. In this report, we investigated the in vitro antibacterial and antioxidant activities of honey from Apis mellifera and Tetragonula biroi, identified the compound responsible for the antibacterial activity, and compared the observed bioactivities and metabolite profiles to that of Manuka honey, which is recognized for its antibacterial and antioxidant properties. The secondary metabolite contents of honey were extracted using a nonionic polymeric resin followed by antibacterial and antioxidant assays, and then spectroscopic analyses of the phenolic and flavonoid contents. Results showed that honey extracts produced by T. biroi exhibits antibiotic activity against Staphylococcal pathogens as well as high antioxidant activity, which are correlated to its high flavonoid and phenolic content as compared to honey produced by A. mellifera. The bioassay-guided fractionation paired with Liquid Chromatography Mass Spectrometry (LCMS) and tandem MS analyses found the presence of the flavonoid isorhamnetin (3-methylquercetin) in T. biroi honey extract, which was demonstrated as one of the compounds with inhibitory activity against multidrug-resistant Staphylococcus aureus ATCC BAA-44. Our findings suggest that Philippine honey produced by T. biroi is a potential nutraceutical that possesses antibiotic and antioxidant activities.     

Phytochemical profiling,in vitro biological activities,and in-silico molecular docking studies of Typha domingensis

A comparative study between methanolic extract and n-hexane fraction of Typha domingensis (Typhaceae) was conducted for the evaluation of phytochemical potential, in vitro biological activities, and in-silico molecular docking studies. The phytochemical composition was estimated by total phenolic and total flavonoid contents, and by GC–MS analysis. Several biological activities were performed such as antioxidant assays (ABTS, FRAP, DPPH, & CUPRAC), enzyme inhibition activity (Tyrosinase, Acetylcholinesterase & Butyrylcholinesterase), thrombolytic activity, and antimicrobial activity (antibacterial & antiviral) to evaluate the medicinal importance of Typha domingensis. The results of the comparative study showed that methanolic extract has more total phenolic and total flavonoid contents (95.72 ± 5.76 mg GAE/g, 131.66 ± 7.92 mg QE/g, respectively) as compared to n-hexane fraction which confirms its maximum antioxidant potential (ABTS 114.31 ± 8.17, FRAP 116.84 ± 3.01, DPPH 283.54 ± 7.3 & CUPRAC 284.16 ± 6.5 mg TE/g). In the case of in vitro enzyme inhibition study and thrombolytic activity, better results were observed for methanolic extract. Almost similar antimicrobial patterns were observed for both methanolic extract and n-hexane fraction of Typha domingensis. The major bioactive phytochemicals identified by GC–MS were further analyzed for in-silico molecular docking studies to determine the binding affinity between ligands and the enzymes. The docking study indicated that most of the bioactive compounds showed a better binding affinity with enzymes as compared to the standard compounds (kojic acid & galantamine). The results of this study recommended that Typha domingensis has promising pharmaceutical importance and it should be further analyzed for the isolation of bioactive phytochemicals which may be useful for the treatment of several diseases.     

Antioxidant and antimicrobial study of Schefflera vinosa leaves crude extracts against rice pathogens

Plant extracts are one of the best possible sources of bioactive molecules, and are being used globally as an antioxidants and natural antimicrobial compounds. In current study, Schefflera vinosa leaves extract was prepared through Soxhlet extraction procedure using methanol and chloroform as solvents. The extract was investigated for total antioxidant, phenolic and flavonoid contents, free radical scavenging and antimicrobial activities. The free radical scavenging activities were evaluated through 2,2- diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzotiazolin-6-sulfonic acid (ABTS) and Ferric-reducing/ antioxidant power (FRAP) assay. The antimicrobial activity of extract was determined through poisoned food method. The methanolic extract has exhibited high antioxidant, phenolic, and flavonoid activities compared to chloroform extract. Similarly, free radical scavenging activities (ABTS, DPPH and FRAP) were higher in methanolic extract. Further, Fourier-Transform Infrared Spectroscopy (FTIR) used to determine the functional group and Gas chromatography-mass spectrometry (GC–MS) to elucidate volatile composition of the crude extract. Different functional group like N-H, O-H, C-O, C-N, C-H, C=O, C≡C and C-O-H presence indicate the existence of many metabolites in the extracts. GC–MS study identified 61 compounds and subsequently, these molecules were screened virtually using DockThor. Furthermore, antimicrobial study was confirmed against rice pathogens like Magnaporthe oryzae (M. oryzae) and Xanthomonas oryzae pv. oryzae (Xoo). Molecular docking study further suggested that phytomolecules (3-Isopropoxy-1,1,1,7,7,7-hexamethyl-3,5,5-tris (trimethylsiloxy) tetrasiloxane, and 2-Methoxy-5-methylthiophene) targets Histone Deacetylase (HDAC) of M. oryzae and Peptide Deformylase (PDF) of Xoo, which could inhibit their growth. Hence, this study indicated that Schefflera vinosa extracts could be an important ingredient as an antioxidant as well as antimicrobial agent against rice pathogens.     

Comparative analysis of phytochemical profile,antioxidant and anti-inflammatory activity from Hibiscus manihot L. flower

Hibiscus manihot L. is a kind of healthy plant with edible value and health benefits, which possesses multiple pharmacological activities that are closely related to antioxidant and anti-inflammatory activities. The dynamic changes of main active components and biological activities in Hibiscus manihot L. flower (HMLF) during its flowering period were systematically studied to determine the appropriate harvest time. Chemopreventive efficacies of the investigated HMLF extracts, by means of their anti-inflammatory and antioxidant activities, were assessed. The sample harvested on early August had the supreme total flavonoid content, total phenolic content and the strongest antioxidant activity (DPPH radical scavenging activity (IC₅₀ 0.160 mg/mL), ABTS radical scavenging activity (1.570 mmol/g Trolox), reducing power (IC₅₀ 0.101 mg/mL) and FRAP (3.644 mmol FeSO₄/g)). The results of principal component analysis indicated that the primary active components included hyperin, isoquercetin, hibifolin and quercetin-3′-O-glucoside, which were strongly associated with the antioxidant activity in the early August sample, while neochlorogenic acid, chlorogenic acid and caffeic acid were associated with the anti-inflammatory activity. The extracts significantly inhibited lipopolysaccharide-induced nitric oxide production in RAW264.7 cells, especially the samples harvested around August, which was only 3.569 μΜ with the inhibition ratio of>50%. This study indicated that HMLF harvested on the early August possessed the highest antioxidant and anti-inflammatory potential and could be used as high bioactive resources for healthy production.     

Total phenolic and flavonoid contents,antioxidant, antidiabetic and antiplasmodial activities of Garcinia forbesii King: A correlation study

Garcinia forbesii King belongs to Clusiaceae is a source of secondary metabolites especially xanthones with various biological activities. G. forbesii King is also known for its empirical use for malaria and diabetes. This study investigated the total phenolic and flavonoid contents, in vitro antioxidant, antidiabetic and antiplasmodial activities of four extracts attained from the stem bark of G. forbesii King. The total phenolic and flavonoid contents were determined by spectrophotometric methods and antioxidant activity was evaluated by DPPH, ABTS, FRAP assays. In vitro antidiabetic activity was assessed by α-glucosidase and α-amylase assays and antiplasmodial activity was studied against chloroquine sensitive Plasmodium falciparum strain 3D7. The highest value of total phenolic (187.37 ± 0.06 mg GAE/g) and flavonoid (35.97 ± 0.02 mg QE/g) contents were recorded in n-hexane and methanolic extracts. n-Hexane extract showed the highest DPPH activity with IC₅₀ of 8.12 ± 0.02 μg/mL. Ethyl acetate extract exhibited better scavenging ability for ABTS with IC₅₀ of 3.88 ± 0.04 μg/mL. The FRAP assay showed better activity in methanol extract with an inhibition value of 73.68 ± 3.66 µM Fe²⁺/g. The strong inhibition against α-glucosidase and α-amylase were displayed by dichloromethane extract with IC₅₀ of 35.13 ± 2.01 μg/mL and 4.83 ± 0.20 μg/mL. n-Hexane and methanol extracts showed significant antiplasmodial activity with IC₅₀ of 0.23 ± 0.01 μg/mL and 0.73 ± 0.01 μg/mL, respectively. The correlation analysis indicated a positive relationship of total phenolic and flavonoid contents with antiplasmodial activity. The results revealed that n-hexane and methanol extracts could be used as a potential natural antiplasmodial, while dichloromethane extract is a promising natural antidiabetic.     

Influence of In Vitro Human Digestion Simulation on the Phenolics Contents and Biological Activities of the Aqueous Extracts from Turkish Cistus Species

Oxidative stress is one of the significant precursors of various metabolic diseases such as diabetes, Parkinson’s disease, cardiovascular diseases, cancer, etc. Various scientific reports have indicated that secondary plant metabolites play an important role in preventing oxidative stress and its harmful effects. In this respect, this study was planned to investigate the phenolic profile and antioxidant and antidiabetic potentials of the aqueous extracts from Turkish Cistus species by employing in vitro methods. In vitro digestion simulation procedure was applied to all extracts to estimate the bioavailability of their phenolic contents. Total phenolic, flavonoid, phenolic acid and proanthocyanidin contents were determined for all phases of digestion. In addition, changes in the quantity of the assigned marker flavonoids (tiliroside, hyperoside and quercitrin) were monitored by High-Performance Thin Layer Chromatography (HPTLC) analysis. The antioxidant activity potentials of the extracts were studied by various methods to reveal their detailed activity profiles. On the other hand, in vitro α-amylase and α-glucosidase enzymes and advanced-glycation end product (AGE) inhibitory activities of the extracts were determined to evaluate the antidiabetic potentials of extracts. The results showed that aqueous extracts obtained from the aerial parts of Turkish Cistus species have rich phenolic contents and potential antioxidant and antidiabetic activities; however, their bioactivity profiles and marker flavonoid concentrations might significantly be affected by human digestion. The results exhibited that total phenolic contents, antioxidant activities and diabetes-related enzyme inhibitions of the bioavailable samples were lower than non-digested samples in all extracts.     

HPLC-ESI-MS/MS analysis of phenolics and in vitro antioxidant activity of Epilobium angustifolium L.

The aerial parts of Epilobium plants are widely used as folk medicine and food around the world. The present study was aimed to investigate the antioxidant activities and active chemical constituents from Epilobium angustifolium L. The results revealed that the EtOAc extract, rich in phenolic compounds and flavonoids (16.81 ± 0.67 g GAE/100 g extract and 4.95 ± 0.21 g QE/100 g extract, respectively), possessed significantly antioxidant activities in reducing power, DPPH radical scavenging activity, ABTS radical scavenging activity and highly in inhibiting lipid peroxidation activity. Simultaneously, active fractions F to H from EtOAc extracts showing potent in vitro antioxidant activities also contained high content of total phenolic and flavonoid. Twenty-eight compounds were identified as phenolic compounds and flavonoids by LC-MS/MS. The results illustrate that the E. angustifolium L., which is rich in phenolics, could be used as a natural resource of antioxidant ingredient.     

Antimicrobial and antioxidant phytochemicals in leaf extracts of Bergenia ligulata: a Himalayan herb of medicinal value

Phenolic and flavonoid contents in leaf extracts of Bergenialigulata have been analysed for their contribution in antimicrobial and antioxidant activities. The extracts were prepared in three solvents (separately) following maceration and soxhelt methods. The antimicrobial activity was tested using disc diffusion assay against a range of microorganisms along with the determination of minimum inhibitory concentration (MIC), while the antioxidant activity was tested following DPPH assay. Leaf extracts exhibited antimicrobial activity against all the three groups of microorganisms; results coincided with respective MIC. In general, the methanol extracts prepared through maceration favoured the determination of antimicrobial and antioxidant activities. Maximum values for phenolic and flavonoid contents were obtained in macerated methanol and ethyl acetate extracts, respectively. The statistical correlations exhibited the extent of the contribution of phenolic and flavonoid contents in antimicrobial and antioxidant activities and also indicated the involvement of other plant metabolites.     

Wild olive fruits: Phenolics profiling,antioxidants, antimicrobial,thrombolytic and haemolytic activities

In this study, wild olive fruits were evaluated for the occurrence of phenolic antioxidant components and valuable nutrients which are distributed wildly in Soon valley of Pakistan. The shade-dried fruits of wild olive were extracted using different solvents to recover phenolic antioxidants. The highest concentration of extractable antioxidant components was recovered from tested fruits using aqueous ethanol compared to other solvents used. Crude concentrated extracts (CCEs) and phenolic rich fractions (PRFs) of tested fruits using hydroxyethanol were found to contain higher amount of total phenolic compounds and total flavonoid compounds along with superior biological attributes. According to ICP-OES analysis, potassium (17.96 g/kg) was the dominant macro element among other identified twenty-five minerals. The tested wild olive fruits juice was found to contain individual natural sugars including galactose (4.92 g/100 g dry weight), sucrose (2.75 g/100 g dry weight), glucose (0.73 g/100 g dry weight); and succinic acid (8.80 mg/100 g of dry matter) as major organic acid when analyzed on HPLC. Oleic acid (47.41 %) was the major monounsaturated fatty acid in the oil extracted from tested fruits. The concentration of phenolic antioxidants and biological activities vary significantly (p < 0.05) among extracting systems used. A strong correlation was also recorded among total phenolic (TP), total flavonoids (TF) and biological attributes of tested wild olive fruits. The results of this study explored wild olive fruits as a propitious source of natural phenolic components and valuable nutrients which reveal its potential use in the development of functional food and nutra-pharmaceuticals.     

Leptospermum petersonii as a Potential Natural Food Preservative

Leptospermum petersonii (family Myrtaceae) is often cultivated for ornamental purposes but also serves as a rich source of bioactive essential oils. While several studies focused on the activities of the essential oils, this study analysed the potential of spent L. petersonii leaves as a natural food preservative. Method: We investigated the in vitro antioxidant and antimicrobial activities of crude L. petersonii extracts against activities of the purified isolated flavonoid, 6-methyltectochrysin, which was characterized using spectroscopic methods. The antioxidant assays followed ORAC, FRAP and TEAC tests. The antimicrobial activities of the extract and purified flavonoid were analysed against six multi-drug resistant microbial strains in broth dilution assays. Result: The results revealed that both the crude extracts and isolated 6-methyltectochrysin exhibited positive radical ion scavenging antioxidant potential, however the crude extract was about 6-fold more potent antioxidant than the purified 6-methyltectochrysin. The crude extract also showed strong antimicrobial activities against Bacillus cereus, and even more potent antimicrobial agent than the reference ampicillin antibiotic against Klebsiella pneumoniae subsp. pneumoniae. A higher resistance was observed for the tested Gram-negative strains than for the Gram-positive ones. 6-methyltectochrysin was generally inactive in the antimicrobial assays. Conclusion: The crude methanolic extract showed significant bioactivity which validates the medicinal relevance of the plant. The observed biological activities, especially against a notorious strain of B. cereus, suggest that L. petersonii could be a promising natural source of food preservatives.     

Bioactive compounds content and their biological properties of acetone extract of Cuscuta reflexa Roxb. grown on various host plants

The present study is aimed to evaluate the total phenolic and flavonoid contents, and free phenolic compounds of acetone extract of Cuscuta reflexa grown on five different hosts: Coccinia grandis, Ficus racemosa, Samanea saman, Streblus asper and Zollingeria dongnaiensis, and to explore the antioxidant activities, α-glucosidase and tyrosinase inhibitory properties of the extracts. The highest level of total phenolic and flavonoid contents were observed in the extract of C. reflexa that was grown on S. asper (65.45 mg GAE/g extract) and C. grandis (97.83 mg QE/g extract), respectively. According to HPLC results, vanillic acid, rutin and quercetin were found in all extracts of C. reflexa grown on diversified hosts. The extract of C. reflexa grown on C. grandis possessed the greatest antioxidant activities (DPPH; 251.64 μg/mL, FRAP; 26.44 mg GAE/g extract), α-glucosidase inhibition accounted for 84.36 per cent and antityrosinase activity was at 18.29 mg KAE/g sample.