Actinomycete Endophytes from the Ethno Medicinal Plants of Southern India: Antioxidant Activity and Characterization Studies

The hawthorn Crataegus mexicana is a traditional Mexican fruit with properties that make this fruit useful for the treatment of many ailments, including diseases of the respiratory and urinary tract. This paper reports the antioxidant capacity of the n-hexane, dichloromethane, ethyl acetate, acetone, ethanol and methanol extracts of C. mexicana. Samples were evaluated for total phenolic and carotenoid contents, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, the inhibition of the formation of thiobarbituric acid reactive species (TBARS) and the neutralization of the cation-radical 2,2´-azino-bis(3ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS). The total phenolic content was 2.65 ± 0.23 mg of gallic acid equivalents per gram, and the carotenoid content was 26.4 ± 0.02 µg/g in dry hawthorn skin. The most active extract in scavenging DPPH radicals and inhibiting TBARS formation was the acetone extract, with activities of 21.9 ± 0.15 and 13.27 ± 0.70%, respectively, at 10 mg/L. The extracts were compared for activity against ascorbic acid, caffeic acid, α- tocopherol and quercetin. The acetone extract was the most active, with an IC50 value of 15.2 mg/L in DPPH and 17.7 mg/L in TBARS. A high correlation was observed between the results for TBARS and DPPH. These results demonstrate the potential nutritional and antioxidant value of this Mexican fruit.

The main aim of this study was to determine Total Phenolic Content, Total Flavonoid Content, terpenoid content, steroid content and analyze the antioxidant activity of different leaf extracts of Entada rheedii. Correlation between antioxidant activities and total phenolic content, total flavonoids content, terpenoid content and steroid content were also analyzed. The total phenolic content in E. rheedii hexane, ethyl acetate, methanol, and aqueous leaf extracts were found to be 10.16 mg GAE/g, 24.73 mg GAE/g, 26.11 mg GAE/g, and 24.85 mg GAE/g sample dry weight respectively. The Total flavonoid content of E. rheedii hexane, ethyl acetate, methanol, and aqueous leaf extracts was found to be 8.433 mg QE/g, 8.730 mg QE/g, 8.607 mg QE/g, and 8.545 mg QE/g respectively. Hexane extract showed the highest steroid content at 32.75 g/mL, followed by ethyl acetate extract at 31.37 g/mL. The methanol extract and aqueous extract had the lowest steroid content at 22.2 g/mL and 21.21 g/mL, respectively. Terpenoid content was the highest in hexane extract with 62 mg/100 mg of dry extract, followed by the ethyl acetate extract with 45 mg/100 mg dry extract. The total content of terpenoids in the methanol extract was 25 mg/100 mg dry extract and the total content of terpenoids was lowest in the aqueous extract with 18 mg/100 mg dry extract. In 1-1-diphenyl- 2-picryl hydrazine Free Radical Scavenging (DPPH) Assay, the methanol extract displayed the highest antioxidant activity with an IC50 value of 173.581 μg/mL while the hexane extract showed the lowest activity; with IC50 value of 389.13 μg/mL. Reducing power assay was evaluated and aqueous extract was shown to possess the highest reducing power. Evaluation of total antioxidant capacity by phosphomolybdenum assay indicated that methanol extract had the highest antioxidant capacity. Significant correlations were also found between Total Phenol Content, Total flavonoid Content, and antioxidant activities of different leaf extracts of Entada rheedii.

Myrmecodia, or ant nest plant, is an indigenous medicinal plant traditionally used by local people in West Papua to treat a variety of hereditary diseases. It has been empirically proven to have a positive effect in treating various types of cancer, diabetes, heart problems, hypertension, lung, stroke, etc. High performance thin layer chromatographic (HPTLC) methods were developed and validated in order to compare antioxidant activity and to evaluate the contribution of selected phenolic compounds and stigmasterol to total antioxidant capacity in different extracts from Myrmecodia platytyrea. As expected, total phenolic content is highly correlated with antioxidant activity (R=0.86). The ethyl acetate extract had the highest reducing antioxidant activity, followed by ethanol, methanol and dichloromethane. The phenolic content of extracts was observed to increase in the following order: methanol>ethyl acetate>ethanol>dichloromethane. Although, the highest solubility of sterols observed in the ethyl acetate extract, might contribute to the highest antioxidant activity observed in this extract, there was no significant antioxidant activity of stigmasterol observed. While polyphenolic content is highly correlated to gallic acid concentration, free radical scavenging activity is related to caffeic acid. Strong positive and significant correlations between total phenolic content and radical scavenging activity, suggests that phenolic compounds are the main contributors to antioxidant activity in the sample extracts. Although the ethyl acetate extract has significant antioxidant activity, its' antioxidant activity was found not to be related to the plant sterols present in the extract.

Objective: The aim of the present study is to determine the phytochemical screening, antioxidant activity and α-amylase inhibitory activity of the crude hexane, ethyl acetate and ethanolic stem bark extract of Pisonia grandis.Methods: The evaluation of antioxidant and antimicrobial activity, total phenolic, and flavonoid content were assessed using 2,2-diphenyl-1- picrylhydrazyl, Folin–Ciocalteu’s reagent, and aluminum chloride assay, respectively. The antidiabetic activity was assessed for porcine pancreatic α-amylase for the stem bark of P. grandis. Results: Phytochemical screening confirmed the presence of phenolic, flavonoids, tannins, saponins, terpenoids, and steroids in all the three extracts. The antioxidant activity showed 148.2 μg/ml, total phenolic content (gallic acid equivalent), 0.0665±0.0002 mg/g, flavonoid content (quercetin equivalent), 0.6061±0.1817 mg/g, and inhibitory concentration 50% values were found to be 40.42 μg/ml and showed better in ethyl acetate extract. The antidiabetic activity exhibited mimic action with insulin due to the presence of pinnatol in the stem bark and leaves of P. grandis. Conclusion: P. grandis stem bark crude ethyl acetate extract showed strong antioxidant activity, high phenolic, and flavonoid content. The antimicrobial activity was studied in both Gram-positive and Gram-negative strains against ampicillin and rifampicin as reference drugs. Antidiabetic activity shows effective result by α-amylase inhibitory activity.

Biological activities and phytochemical content of the rhizome hairs of Cibotium barometz (Cibotiaceae)

BackgroundSynthetic antioxidants and antimicrobials are losing ground to their natural counterparts and therefore, the food industry has motivated to seek other natural alternatives. Apple pomace, a by-product in the processing of apples, is rich in polyphenols, and plant polyphenols have been used as food additives owing to their strong antioxidant and antimicrobial properties. The goal of this study was to screen the individual polyphenols with antioxidant and antimicrobial activities from the extracts (methanol, ethanol, acetone, ethyl acetate, and chloroform) of Golden Delicious pomace.ResultsFirst, the polyphenolic compounds (total phenol content, TPC; total flavonoids, TFD; total flavanols, TFL) and antioxidant activities (AAs) with four assays (ferric reducing antioxidant power, FRAP; 1,1-diphenyl-2-picryhydrazyl radical scavenging capacity assay, DRSC; hydroxyl radical averting capacity assay, HORAC; oxygen radical absorbance capacity assay, ORAC) were analyzed. The results showed a significant positive correlation (P < 0.05) between AAs and TFD. Ethyl acetate extract (EAE) exhibited the highest TFD with a concentration of 1.85 mg RE/g powder (expressed as rutin equivalents), and the highest AAs (expressed as butylated hydroxytoluene (BHT) equivalents) with 2.07 mg BHT/g powder for FRAP, 3.05 mg BHT/g powder for DRSC, 5.42 mg BHT/g powder for HORAC, and 8.89 mg BHT/g powder for ORAC. Composition and AA assays of individual polyphenols from the EAE were then performed. Phloridzin and phloretin accounted for 46.70 and 41.94 % of TFD, respectively. Phloretin displayed the highest AA, followed by phloridzin. Finally, the antimicrobial activities of the EAE, phloridzin, and phloretin were evaluated. EAE displayed good inhibitory activities against Staphylococcus aureus with a minimum inhibition concentration (MIC) of 1.25 mg/ml and against Escherichia coli with a MIC of 2.50 mg/ml. Phloridzin and phloretin showed better inhibitory activities than the EAE, which were MICs of 0.50 and 0.10 mg/ml, respectively, against S. aureus and MICs of 1.50 and 0.75 mg/ml, respectively, against E. coli.ConclusionsEthyl acetate was the best solvent of choice to extract natural products to obtain the maximum antioxidant and antibacterial benefits. Phloridzin and phloretin have the potential to be used as natural alternatives to synthetic antioxidants and antimicrobials.

Unlike phenotypic methods of bacterial identification, 16S rRNA gene sequencing is an innovative DNA-based technique for the rapid identification of foodborne pathogens. In this study, the ability of both partial 16S rRNA gene sequencing and the API Rapid20E, for identification of 48 different bacterial strains isolated from meat products, plus 2 control bacterial strains, was compared. Genotypically, the partial (770 bp) 16S rRNA gene sequencing was able to identify 38 (76%) isolates to the species level and 11 (22%) isolates to the genus level, whereas only one (2%) isolate could not be correctly identified. Phenotypically, the API Rapid20E could identify 24 (48%) isolates to the specie level, and 14 (28%) isolates to the genus level, while 12 (24%) isolates could not be discriminated at any taxonomic level. The results revealed that partial 16S rRNA gene sequencing was useful in ascertaining the relevance of tested strains; hence, it can be used in food microbiology laboratory for correct and rapid identification of foodborne pathogens.

Moringa stenopetala is a socioeconomic valued tree that is widely available and cultivated in Southern part of Ethiopia. The leaves have been traditionally used as a food source with high nutritional and medicinal values. The present work was carried out to evaluate the effect of thermal treatment on the total phenolic content, total flavonoid content, antioxidant activities and α-amylase inhibition of aqueous leaf extracts obtained from M. stenopetala during maceration and different decoction time interval (5, 10 and 15 min). The total phenolic and flavonoid contents were determined by the Folin-ciocalteu and aluminum chloride methods, respectively whereas antioxidant activities were determined by 2,2-diphenyl-1-picryl-hydrazyl(DPPH) radical scavenging, reducing power, phosphomolybdenum and ferrous ion chelating assays and α-amylase inhibition potential was determined using 3,5-dinitrosalicylic acid method. Total phenolic and total flavonoid contents ranged from 34.35 ± 1.06 to 39.47 ± 1.33 mgGAE/g and 10.44 ± 0.61 to 20.36 ± 0.93 mgQRE/g, respectively. Decoction for 10 min extract showed ferrous ion chelating (92.52 ± 0.17 %), DPPH radical scavenging (91.52± 0.59 %), α-amylase inhibition (69.06 ± 0.14%), ferric reducing power (0.765 ± 0.14) and total antioxidant activity (0.329 ± 0.32), respectively. DPPH, reducing power, total antioxidant and α-amylase inhibition activities showed positive linear correlation (R2=0.853, R2= 0.857 , R2= 0.864 and R2=0.930), respectively with total phenolic content but ferrous ion chelating activity were found to be weakly correlated (R2=0.481). Based on present investigation, it could be concluded that major lose of total phenolic content, antioxidant and α-amylase inhibition activities of the crude leaf extracts of M. stenopetala leaves were observed at decoction time for 15 min. Therefore, to maintain the total phenolic content, antioxidant and α-amylase inhibition activities of leaves, cooking practice should be at the optimum decoction time (5-10 min). Key words: Moringa stenopetala, antioxidant, total phenolic content, α-amylase inhibition.

This research was based on the examination of the total phenolic content, antioxidant and antimicrobial activities of hexane, diethyl ether, ethyl acetate, and methanol extracts of Origanum heracleoticum L. grown in Serbia. The antimicrobial activity was determined against five bacteria and two fungi using the disk diffusion method. The total phenolic content of O. heracleoticum solvent extracts was determined and five different tests were used for screening of the antioxidant capacity. The highest total phenolic content was found in ethyl acetate extract (848.48 μg GAE/mg dry extract) and methanol extract (733.43 μg GAE/mg dry extract). The examination of antioxidant activity showed that methanol and ethyl acetate extracts had the strongest activity. The highest correlation was found between DPPH and FRAP (R2 = 0.99), as well as DPPH and CUPRAC (R2= 0.96) assays. The ABTS test was highly correlated with the FRAP test (R2 = 0.95). The antimicrobial assay proved that each extract had an effect against all bacteria and fungi, except against the bacterium Pseudomonas aeruginosa. The highest antibacterial activities were found for methanol extract and ethyl acetate extract against Staphylococcus aureus. The highest antifungal activity was observed for the ethyl acetate extract against both Candida albicans and Aspergillus brasiliensis.

Introduction: This work was done to determine phytochemical content, antioxidant activity, and hepatoprotective effects of Zizyphus xylopyrus leaves extracts against carbon tetrachloride-induced hepatotoxicity in in vitro and in vivo models. Materials and Methods: The total flavonoids content (TFC), total phenolic content (TPC), and total tannin content (TTC) were determined using quercetin and tannic acid equivalents, as standard while antioxidant activities of extracts were determined using the standard in vitro methods. All the extracts subjected to in-vitro HepG2 cell line study as well as to evaluate in vivo hepatoprotective effects against carbon tetrachloride (CCl4) intoxicated rats. Results: Among all extracts, ethyl acetate extract (EAE) possess potent antioxidant activity, viz., ferric reducing ability of plasma (abs = 0.379 ± 0.07), 2,2-diphenyl-1-picrylhydrazyl (inhibitory concentration 50% [IC50]: 103.50 ± 2.05 μg/mL), OH• (89.33 ± 1.79 μg/mL), NO• (IC50 129.34 ± 1.29 μg/mL), O2ˉ (IC50 62.03 ± 2.78 μg/mL), and inhibition of lipid peroxidation (110.05 ± 2.96 μg/mL). Treatment with EAE significantly increased the cell viability (IC50 80.93 ± 1.02 μg/mL) by preventing CCl4 induced cell damage in in-vitro HepG2 cell line. In case of both prophylactic and curative study, EAE extract significantly (P < 0.001) decreased CCl4-induced increased serum liver enzymes activities in CCl4-intoxicated rats, comparable to silymarin. Hepatoprotective potential further supported by pentobarbitone induced sleeping time and improved hepatic tissue histopathology. Study results suggest that antioxidant activity and hepatoprotective effect of EAE might be due to presence of polyphehols, viz., TFC (43.76 ± 0.78 Quercetin equivalent [QE] mg/g extract), TPC (194.16 ± 0.74 gallic acid equivalent [GAE] mg/g extract), and TTC (20.45 ± 2.31 GAE mg/g extract). Reversed-phase high-performance liquid chromatography analysis results showed highest quercetin content (32.8 ± 0.24 mg/g) in EAE. Conclusion: This study advocated that due to the presence of flavonoids, Z. xylopyrus leaves exhibited marked antioxidant and hepatoprotective activities.

Plant species contain many secondary metabolites, and these compounds differ from species to species. These differences in the concentrations of these compounds have many health implications. Today, studies on plants' antioxidant and antibacterial effects are gaining importance. In particular, the adverse effects of some existing antibiotics and the constant development of bacterial resistance are leading to the search for new natural antimicrobial agents. In this study, methanol, ethanol, ethyl acetate, acetone, and chloroform extracts were obtained from the aerial parts of Marrubium bourgaei Boiss and Glaucium alakirensis Aykurt, K.Yıldız &amp;amp; A.Özçandır, and Peucedanum alpinum B.L.Burtt &amp;amp; Davis, species which are naturally distributed in Türkiye. The antioxidant activity of the extracts was determined by the DPPH (2,2 Difenil-1-pikrihidrazil) and ABTS (2,2' azino-bis(3-ethylbenz-thiazoline-6-sulfonic-acid)) methods, the total phenolic content by Folin-Ciocalteu method, the total flavonoid content by aluminium chloride colorimetric method, and the antibacterial activity against ten bacteria by the disc diffusion method. According to the results, methanol, ethanol, and acetone extracts had higher antioxidant activity, total phenolic, and total flavonoid contents than other extracts. However, the total flavonoid content of M. bourgaei was higher in the ethyl acetate extract. When evaluated for their antibacterial activity, ethanol, chloroform, and ethyl acetate in P. alpinum, chloroform in M. bourgaei, and methanol, chloroform, and ethyl acetate in G. alakirensis extracts showed antibacterial activity against more bacteria than others. This is the first study to evaluate and compare the total phenolic and flavonoid content, and antioxidant and antibacterial activities of 5 different extracts of these plants.

The efficacy of partial 16S rRNA gene sequencing for precise determination of phylogenetic relatedness among Salmonellae

Unlike phenotypic methods of bacterial identification, 16S rRNA gene sequencing is an innovative DNA-based technique for the rapid identification of foodborne pathogens. In this study, the ability of both partial 16S rRNA gene sequencing and the API Rapid20E, for identification of 48 different bacterial strains isolated from meat products, plus 2 control bacterial strains, was compared. Genotypically, the partial (770 bp) 16S rRNA gene sequencing was able to identify 38 (76%) isolates to the species level and 11 (22%) isolates to the genus level, whereas only one (2%) isolate could not be correctly identified. Phenotypically, the API Rapid20E could identify 24 (48%) isolates to the specie level, and 14 (28%) isolates to the genus level, while 12 (24%) isolates could not be discriminated at any taxonomic level. The results revealed that partial 16S rRNA gene sequencing was useful in ascertaining the relevance of tested strains; hence, it can be used in food microbiology laboratory for correct and rapid identification of foodborne pathogens.

This study aimed to investigate the phytochemical screening, total phenolic content, antioxidant and antimicrobial activities of Coleus forskohlii L. stem extract in Al-Baha area, Saudi Arabia. Stem samples were collected from Al-Baha area and air-dried followed by extraction with ethanol, petroleum ether, chloroform, ethyl acetate, and n-butanol. The extracts were then subjected to phytochemical screening, determination of total phenolic content, antioxidant and antimicrobial activities. Results showed the presence of flavonoids, alkaloids, tannins, terpenoids, steroids, saponins, and reducing sugars. Total phenolic content was significantly (P&lt;0.001) higher in n-butanol extract (274.33±3.29 mg GAE/gm), followed by ethyl acetate extract (182.94±1.82 mg GAE/gm), ethanol extract (79.63±2.02 mg GAE/gm) and petroleum ether extract (73.38±3.07 mg GAE/gm), while the lowest content was in chloroform extract (60.06±2.12 mg GAE/gm). The antioxidant activity was significantly (P&lt;0.001) higher in n-butanol extract (67.68±1.55%), followed by ethyl acetate extract (43.38±1.27%), ethanol extract (36.02±1.29%), petroleum ether extract (20.71±0.59%) and chloroform extract (19.73±0.74%). The antimicrobial activity showed that all microorganisms tested were resistant at the concentration of 25 and 50 mg/ml of plant extracts, whereas the concentrations of 100, 150 and 200 mg/ml showed varying activities against gram-negative (Escherichia coli, Pseudomonas aeruginosa), gram-positive (Staphylococcus aureus, Bacillus cereus) and Candida albicans. The study concluded that the stem extracts of C. forskohlli have promising pharmacological and biological activities that could be beneficial in pharmaceutical as well as food and medicinal industries.

In the present study different extracts of Acacia nilotica leaves were tested for total phenolic and flavonoid content, antioxidant activities. Extracts were also subjected to phytochemical analysis using GC-MS analytical techniques. Antioxidant potential was determined using DPPH free radical scavenging assay, hydrogen peroxide scavenging assay, metal chelating assay and β-carotene-linoleic acid assay. Methanol extract exhibited maximum antioxidant activity (94.3 %) followed by the ethyl acetate extract (90.7 %). Total phenolic content was highest in the methanol extract and total flavonoid content in ethyl acetate extract. Positive correlation was observed between the total phenolic content, total flavonoid content and antioxidant activities. Principle component analysis revealed correlation between different parameters. D-pinitol, catechol, N-2,4-dnp-L-arginine, squalene, R-limonene, 9-octadecen-12-ynoic acid, methyl ester, androst-5-en, 2(1-H)-quinolinone, heptacosane, 2-pentadecanone, 6,10,14-trimethyl, linoleic acid, γ-linoleic acid, palmitic acid, stearic acid were the main compounds present in different extracts of Acacia nilotica leaves and could serve as a possible source of natural antioxidants in food and pharmaceutical industry.