Antifungal activity of methanolic extracts of four Algerian marine algae species

Since ancient times antimicrobial properties of seaweeds have been recognized. In this study, antifungal activity of four species of marine algae of Bejaia coast (Algeria) was explored. This activity was evaluated by agar diffusion method. The minimum inhibitory concentrations were also determined for all the strains. All the extracts used in this study exhibited antifungal activity. The highest inhibiting effect was noted for Rhodomela confervoides (red algae) and Padina pavonica (brown algae), respectively against Candida albicans (diameter of inhibition zone: 24 mm) and Mucor ramaniannus (diameter of inhibition zone: 26 mm) for the first one and Candida albicans (diameter of inhibition zone: 26 mm) for the second one. Aspergillus niger showed resistance against majority of methanolic extracts. The evaluation of minimum inhibitory concentrations showed that extracts of Padina pavonica, Rhodomela confervoides and Ulva lactuca were very efficient against Mucor ramaniannus and Candida albicans. These results suggest that seaweeds collected from Algerian coast present a significant capacity which makes them interesting for screening for natural products.Key words: Marine algae, antifungal activity, methanolic extracts, natural substances

Assessment of Antioxidant and Antibacterial Activities of Cystoseira mediterranea and Padina pavonica from Algerian North-East for a Potential Use as a Food Preservative

The aim of this work was to evaluate the antioxidant and antibacterial activities of two marine algae, Cystoseira mediterranea and Padina pavonica, extracts. Total phenols (TPC), carotenoids, and phlorotannins contents of the extracts obtained by four extraction solvents were determined and compared. The highest TPC content was observed for aqueous extract of C. mediterranea with 37.09±0.46 mg GAE/g DE followed by ethanol extract of P. pavonica (24.28±0.99 mg GAE/g DE), which showed the highest phlorotannins content (1.18±0.18 mg PE/g DE), while its methanol extract held carotenoids content of 66.96±4.78 μg g–1 DE. Ethanol extract of C. mediterranea exhibited the best antioxidant activity with an EC50 of 58.3±1.16 μg ml–1. The antibacterial activity screening against MRSA and E. coli showed that ethanol extract of C. mediterranea towards a Methicillin resistant Staphyloccocus aureus (20.33±0.28 mm) and E. coli (15.66±0.57 mm) was more efficient with MICs about 80 mg ml–1 and 20 mg ml–1, respectively. Ethanol extract of C. mediterranea seems to have the highest potential for use in food industries

Formulation and characterization of zein/gum arabic nanoparticles for the encapsulation of a rutin-rich extract from Ruta chalepensis L

Rutin, a plant flavonol characterized by a wide range of biological effects, has limited application in foods because of its low water solubility and scarce bioavailability. This work aimed to investigate the encapsulation of a rutin-rich extract (200.6 ± 1.5 mg/g of rutin) from Ruta chalepensis L. in zein nanoparticles (hydrodynamic diameter of 80–170 nm) prepared by antisolvent precipitation and stabilized by gum arabic (GA). The addition of GA (1:1 mass ratio with zein) significantly reduced the instability phenomena of zein nanoparticles through the deposition of a negatively charged layer as evidenced by the zeta potential and the UV–visible measurement, suggesting an electrostatic interaction between zein and GA. It also contributed to enhancing the encapsulation efficiency of rutin and inducing a rapid release during simulated digestion. These findings show that zein/GA nanoparticles represent a promising delivery system for natural extracts, fabricated through a facile and versatile process

High-pressure homogenization-assisted extraction of bioactive compounds from Ruta chalepensis

High-pressure homogenization (HPH) was investigated to promote the extraction in water of bioactive molecules from Ruta chalepensis, a medicinal plant widely used in folk medicine. Aqueous suspensions (5% wt) of the pre-milled plant were treated by high-shear mixing (HSM), followed by HPH at 100 MPa for up to 10 passes. A considerable decrease in the size of the suspended particles was observed when applying HPH, which was related to cell deagglomeration and fragmentation. In contrast, no significant changes at the cellular level were observed when only maceration or HSM treatments were applied. Remarkably, HPH treatment did not significantly change the antioxidant activity of the aqueous extracts, but affected their composition: HPLC analysis revealed that HPH treatment significantly increased the content in the aqueous phase of quercetin (+ 452.7%), recovered by fractionation of the aqueous phase with ethyl acetate, and rutin (+ 29.8%), recovered with butanol. In addition, GC/MS analysis of the chloroform fractions obtained from the aqueous extracts revealed that the HPH treatment caused also a significant (p < 0.05) increase in γ-fagarine and chalepin of + 177% and + 1420%, respectively, whereas pteleine, skimmianine, kokusaginine, and arborinine levels were higher in the extracts obtained by maceration than the HPH-treated samples. These findings suggest that the recovery of low water-solubility compounds from R. chalepensis, such as rutin and quercetin, as well as of some alkaloids, such as γ-fagarine and chalepin, significantly improved by HPH-assisted extraction and associated cell disruption effect

High-pressure homogenization-assisted extraction of bioactive compounds from Ruta chalepensis

High-pressure homogenization (HPH) was investigated to promote the extraction in water of bioactive molecules from Ruta chalepensis, a medicinal plant widely used in folk medicine. Aqueous suspensions (5% wt) of the pre-milled plant were treated by high-shear mixing (HSM), followed by HPH at 100&nbsp;MPa for up to 10 passes. A considerable decrease in the size of the suspended particles was observed when applying HPH, which was related to cell deagglomeration and fragmentation. In contrast, no significant changes at the cellular level were observed when only maceration or HSM treatments were applied. Remarkably, HPH treatment did not significantly change the antioxidant activity of the aqueous extracts, but affected their composition: HPLC analysis revealed that HPH treatment significantly increased the content in the aqueous phase of quercetin (+ 452.7%), recovered by fractionation of the aqueous phase with ethyl acetate, and rutin (+ 29.8%), recovered with butanol. In addition, GC/MS analysis of the chloroform fractions obtained from the aqueous extracts revealed that the HPH treatment caused also a significant (p &lt; 0.05) increase in γ-fagarine and chalepin of + 177% and + 1420%, respectively, whereas pteleine, skimmianine, kokusaginine, and arborinine levels were higher in the extracts obtained by maceration than the HPH-treated samples. These findings suggest that the recovery of low water-solubility compounds from R. chalepensis, such as rutin and quercetin, as well as of some alkaloids, such as γ-fagarine and chalepin, significantly improved by HPH-assisted extraction and associated cell disruption effect

Chemical composition, antioxidant, and anticancer effect of Ruta chalepensis&apos;s extracts against human leukemic cells

Ruta chalepensis is a native herb of the Mediterranean region used in the traditional medicine of many countries. Phytochemical screening has shown the presence of bioactive molecules that are responsible for its pharmacological properties. The present study aimed at investigating the in vitro antioxidant and cytotoxic effect of volatile, ethanol and aqueous extracts of R. chalepensis collected from Bejaia, a region in Algeria. The phenolic compounds composition of the extracts was analyzed by HPLC-UV (High Performance Liquid Chromatography with UV detector) and the essential oil composition was analyzed by GC-MS (Hewlett Packard 5973-6890 GC-MS system) analysis. The antioxidant activity was assessed by the scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazyl) and the cytotoxic effect of MTT assay against cancerous cells (T-leukemic cells and B lymphoblasts) and normal blood cells (PBLs: stimuled peripheral blood cells by PHA/IL2). Ethanol extract of R. chalepensis presented the highest amount of total phenolics (72. 08 ± 1.94 mg GAE/g DW (Milligrammes of Galic Acid per Grammes of Dry Weight), flavonoids (31.90 ± 2.12 mg QE/g DW (Milligrammes of Quercetin Equivalent per Grammes of DryWeight), and flavonols (13.22 ± 0.86 mg QE/g DW) compared to the aqueous extract, which presented a total phenolics of 39.71 ± 0.22 mg GAE/g DW, flavonoids of 1.96 ± 0.12 mg QE/g DW, and flavonols of 3.00 ± 0.2586 mg QE/g DW. Ethanol extract also showed a potent antioxidant activity (IC50= 51.18 ± 1, 14 μg/ml) and a high reducing power (IC50 = 660 ± 8, 3 μg/ml). Moreover, we establish herein that ethanol extract exerts a strong cytotoxicity against T-leukemic cells (CEM, H9, Jurkat, and CEM-IRCs) and B lymphoblast cells (SKW 6.4) without affecting normal blood cells (PBL and PBLs).This study showed that Ruta chalepensis can be used as promising source of natural antioxidant and anticancer agents. The encouraging results obtained on anticancer activity suggest further investigations can be undertaken to isolate the bioactive phenolic compounds and to understand their mechanism of cytotoxicity. © Lavoisier SAS 2017