Differently substituted flavanones were isolated from Leguminosae and their antibacterial activity was comparatively studied against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MICs) of phytochemical flavanones to clinical isolates of MRSA were determined by a serial agar dilution method. The structure-activity relationship has indicated that 2',4'- or 2',6'-dihydroxylation of the B ring and 5,7-dihydroxylation of the A ring in the flavanone structure are important for significant anti-MRSA activity and that substitution with a certain aliphatic group at the 6- or 8-position also enhances the activity. Among the thirteen flavanones tested, tetrahydroxyflavanones with these structural characteristics isolated from Sophora exigua and Echinosophora koreensis showed intensive activity to inhibit the growth of all MRSA strains at 3.13-6.25 micrograms/ml. The present hydroxyflavanones would be useful in the phytotherapeutic strategy against MRSA infections.

Comparative Study on the Antibacterial Activity of Phytochemical Flavanones against Methicillin-resistant Staphylococcus aureus.

Scrophularia striata, commonly known as figwort, is one of the most important medicinal plants that mainly grows in cold regions of the Zagros Mountains (West of Iran). Although the chemical composition of this plant species has not yet been explored, people living in Ilam province (W Iran) have used it for many years to treat different illnesses. The present study aims to analyze the effect of some ecological factors on the antioxidant potential and the amount of phenol present in this plant species, using a random factorial design with two factors (elevation and region) and three replicates. The fruits of the plant were gathered from three different elevations. They were collected from three regions of the Ilam province (Badreh, Dareshahr, and Dehloran) in June 2016, when the fruits appear. Moreover, to analyze different soil chemical and physical features, soil samples were gathered from a depth of 0.5 m under the shrubs. The antioxidant action of the methanol extract from the plant samples and the total amount of phenol compounds were measured using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and the Folin-Ciocalteu method, respectively. The results showed that the effects of site and elevation, and the interaction between these factors, on the antioxidant potential and total phenol amount were significant with a probability of error of 1%. The maximum extract efficiency (19.37 ± 3.07%), antioxidant potential (126.5656 ± 0.96 µg/mL), and total amount of phenol (55.7689 ± 3.17 µg/mL) were obtained from Dareshahr at an elevation of 600 m above mean sea level. The minimum amount of total phenol (24.6544 ± 3.21 µg/ml) was recorded at the lowest elevation of Badreh, at which phosphorus, potassium, organic carbon, organic material, nitrogen, acidity, lime, and silt were present at the lowest amount. However, the antioxidant activity and total amount of phenol had a strong direct correlation in the two districts of Dareshahr and Badreh, but were reversely and strongly correlated in Dehloran. Therefore, it can be stated that Scrophularia striata has the potential for antioxidant activity, however, the complexity of the effect of ecological factors on one hand, and the emergence of different chemical processes in the plant under such effects on the other hand, has led to the synthesis of different compounds with antioxidant potential in the plant in different regions.

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Effects of ecological factors on the antioxidant potential and total phenol content of Scrophularia striata Boiss.

Ethnopharmacological analysis of medicinal plants and animals used in the treatment and management of pain in Mauritius

Background Phytochemicals are found in abundance at different levels in many medicinal plants. It is important to measure the total phenolic compounds correctly in such medicinal plants, the better to assess their antioxidant capacity. Methods Our study sought to evaluate the total phenolic, flavonoid, and tannin contents of three Algerian medicinal plants: Echium pycnanthum Pomel, Haloxylon articulatum Boiss, and Solenostemma oleifolium Bull. & Bruce. We employed six different testing methods to help ascertain whether these compounds have an antioxidant capacity, including total antioxidant capacity, 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid + , β-carotene, reducing, and chelating assays. Results Our study showed that these medicinal plants exhibited significantly different total polyphenol contents varying from 27.3 ± 2.1 mg to 120.3 ± 5.6 mg gallic acid equivalents/g dry weight. The phenolic content in H. articulatum was superior to those in E. pycnanthum and S. oleifolium . The same tendency was observed for the relative amounts of flavonoids and condensed tannins in the three medicinal plants. The antioxidant activities varied greatly among the different plants used in this study. Indeed, H. articulatum shoots exhibited the strongest antioxidant activity, with the lowest IC 50 (6.3 ± 0.25 μg/mL) and EC 50 (0.21 ± 0.01 mg/mL) values for 1,1-diphenyl-2-picrylhydrazyl and iron reducing tests, respectively. In addition, the superiority of this plant was more marked as compared to positive controls. Strong and positive correlations were found between phenolic classes and antioxidant activities with a correlation coefficient reaching R  ≥ 0.99. Conclusion This investigation confirmed that several medicinal herbs from South Algeria possess high in vitro antioxidant potency. Overall, our results can be considered very promising in the continuing effort to utilize plant species successfully for medicinal purposes in humans, providing further justification for the hypothesis that phenolic compounds in these plants can provide substantial antioxidant activity.

Evaluation of antioxidant activity of hydromethanolic extracts of some medicinal species from South Algeria.

Leaves essential oils of Syzygium cumini L. Cupressus sempervirens L. and Lantana camara L., from Alexandria, Egypt were analysed by Gas chromatography-mass spectrometry (GC-MS). The antibacterial and antioxidant activities were assessed for each oil using minimum inhibitory concentrations (MICs) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods; respectively. The main oil constitutes were alpha-pinene (17.53%), alpha-terpineol (16.67%) and alloocimene (13.55%) in S. cumini, trans-caryophyllene (15.57%) and alpha-humulene (9.16%) in L. camara and cedrol (21.29%), delta3-carene (17.85%) and alpha-pinene (6.9%) in C. Sempervirens. The antibacterial activity was studied against some bacterial strains. The oil of S. cumini demonstrated strong inhibition activity against the tested bacterial strains. The total antioxidant activity (TAA %) was 11.13, 9.13, 3.13% for S. cumini, L. camara and C. sempervirens, respectively. Our work revealed that the studied leaf oils are new promising potential sources of antioxidants and antibacterial compounds and good future practical applications for human and plant health.

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Chemical Composition, Antibacterial and Antioxidant Activities of Leaves Essential Oils from Syzygium cumini L., Cupressus sempervirens L. and Lantana camara L. from Egypt

Five Libyan medicinal plants Thapsia garganica, Hammada scoparia, Euphorbia serrata, Hyoscyamus albus and Retama rateam were selected to evaluate their biological activities. Their total phenolic and flavanoid contents were assessed. The antioxidant activity was estimated using 2, 2-di- phenyl-1-picrylhydrazyl (DPPH) as free radical scavenger. Their crude extracts showed reducing potential proportional to their concentration. The correlation coefficient (R2) between antioxidant activity and their total phenolics and flavanoids content is 0.77 and 0.98 respectively. Crude aqueous, methanolic as well as alkaloids extracts of the five plants were tested against a number of G+ve and G-ve sensitive resistant (e.g MRSA) bacteria beside some fungal species. The aqueous extracts displayed weak antibacterial activity whereas methanolic extracts were profoundly effective against both G+ve and G-ve bacteria. The extracts of E. serrata and H. scoparia were highly effective against E. coli in particular. The alkaloid-rich extracts of H. albus and H. scoparia induced remarkable bacteriostatic and fungistatic effects. The bioactive ingredients of H. scoparia, E. serrata and R. rateam extracts are shown to be potential sources of natural antioxidant and antimicrobial ingredients favoring their possible use in industrial pharmacology on large scale.

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Antioxidant and antimicrobial properties of five medicinal Libyan plants extracts

The natural forests and meadows of the Green Mountain of Libya are classified as the richest floristic region of the country. Among various species Cynara scolymus L. (Asteraceae), is the most used medicinal plant. C. scolymus L., has long been regarded as noncrop food and also as an effective medicinal plant. In the current study, total phenols as well as flavanoids were determined in methanolic and aqueous extracts the of C. scolymus L. rhizomes in order to assess their contribution to the antioxidant activity. Free radical scavenging activity of the extracts was investigated and compared with ascorbic acid. Methanolic extract exhibited a higher total phenols (45.11 mg GAE/g DW) and flavonoids (37.00 mg Rutin/g), that results in a high antioxidant activity with IC50 (17.77 µg/ml). In contrast, aqueous extract showed a lower total phenolic and flavonoid contents (37.79 mg GAE/g DW and 15.51 mg Rutin/g DW, respectively) and IC50 (66.3 µg/ml). Isolated flavonoids showed the highest free radical scavenging activities (IC50 = 13.33 µg/ml). The in vitro antibacterial activity of C. scolymus L. rhizomes was investigated against various strains of bacteria by hole-plate diffusion method. The minimum inhibitory concentrations (MICs) of the crude methanol, flavonoids and alkaloids extracts found to be between 0.03 and 200 mg/ml for the susceptible organisms, with that of MRSA being the least.

https://ccsenet.org/journal/index.php/mas/article/download/17256/12075

Antioxidant and Antimicrobial Activities of Cynara scolymus L. Rhizomes

Increasing attention has been paid to the use of natural antioxidants, particularly of plant origin in order to substitute synthetic antioxidant due to their negative health effects. Â The aim of this study was to screen the Â flavonoid extracted from leaves and flowers of A. pavarii and their mixture of to show any antioxidant activity in vitro. the antioxidant and free radical scavenging activity were determined by several standard methods using spectrophotomer. Â Flavonoid extracts showed higher reducing ability in comparison with ascorbic and BHA. Â It was found that flavonoids extracted from leaves have the most activity to reduce the DPPH with an IC50 of 0.625mg/mL; more effective than others. Â This extract also exhibited fairly good antioxidant activity by inhibiting the generation of OH (IC50= 0.625mg/mL) and Â NO radicals (IC50= 1.25mg/ml). The inhibition of lipid peroxidation was recorded in flavonoids extracted from leaves (60%). Synergism was the main effect among the combined extract, C3 (L:F; 2: 1). Â Three types of interactions (synergistic, additive and negative synergistic effect) were observed.

Hussein El-Saltani

Papers

Antioxidant and antimicrobial properties of five medicinal Libyan plants extracts

Antioxidant and Antimicrobial Activities of Cynara scolymus L. Rhizomes

In Vitro Elucidation Free Radical Scavenging Activity of Flavonoids Extracted From Leaves and Flowers of Arbutus Pavarii (Ericaceae)