Chemical Composition, Antibacterial and Antifungal Activities of Crude Dittrichia viscosa (L.) Greuter Leaf Extracts.

The small amount of data regarding the antifungal activity of Dittrichia viscosa (L.) Greuter against dermatophytes, Malassezia spp. and Aspergillus spp., associated with the few comparative studies on the antimicrobial activity of methanolic, ethanolic, and butanolic extracts underpins the study herein presented. The total condensed tannin (TCT), phenol (TPC), flavonoid (TFC), and caffeoylquinic acid (CQC) content of methanol, butanol, and ethanol (80% and 100%) extracts of D. viscosa were assessed and their bactericidal and fungicidal activities were evaluated. The antibacterial, anti-Candida and anti-Malassezia activities were evaluated by using the disk diffusion method, whereas the anti-Microsporum canis and anti-Aspergillus fumigatus activities were assessed by studying the toxicity effect of the extracts on vegetative growth, sporulation and germination. The methanolic extract contained the highest TPC and CQC content. It contains several phytochemicals mainly caffeoylquinic acid derivatives as determined by liquid chromatography with photodiode array and electrospray ionisation mass spectrometric detection (LC/PDA/ESI-MS) analysis. All extracts showed an excellent inhibitory effect against bacteria and Candida spp., whereas methanolic extract exhibited the highest antifungal activities against Malassezia spp., M. canis and A. fumigatus strains. The results clearly showed that all extracts, in particular the methanolic extract, might be excellent antimicrobial drugs for treating infections that are life threatening (i.e., Malassezia) or infections that require mandatory treatments (i.e., M. canis or A. fumigatus).

Bioactive compounds from Hypericum humifusum and Hypericum perfoliatum: inhibition potential of polyphenols with acetylcholinesterase and key enzymes linked to type-2 diabetes.

CONTEXT: Natural products are reported to have a wide spectrum of pharmacological properties such as antimicrobial, anti-inflammatory and anti-cholinesterase. The genus Hypericum (Hypericaceae) is a source of a variety of molecules with different biological activities, notably hypericin and various phenolics. OBJECTIVES: The goals of the present work were the determination of total phenolic and flavonoid content, hypericin and hyperforin concentration as well as the evaluation of biological of Hypericum humifusum L. (Hhu) and Hypericum perfoliatum L. (Hper). MATERIALS AND METHODS: The various extracts of aerial parts were powdered, and then extracted with methanol. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) methods against four Gram-positive bacteria, four Gram-negative bacteria and yeast. RESULTS: The results revealed that H. humifusum, bear the highest total phenolic and flavonoid content (48-113 mg GAE/g and 8-41 mg RE/g, respectively) as well as hypericin (60-90 mg/g) and hyperforin (8-30 mg/g) concentration. Both species showed significant antioxidant activity as revealed by DPPH, FRAP, ABTS, and metal chelating assays. H. humifusum exhibited a strong acetylcholinesterase (3.86-4.57 mg GALAEs/g), α-glucosidase (0.73-2.55 mmol ACEs/g) and α-amylase (3-8 mmol ACEs/g) inhibitory activity. The extract of H. humifusum exhibited strong antibacterial activity mainly against Staphylococcus epidermidis, Staphylococus aureus, and Enterococcus faecium (MIC values ranging from 200 to 250 µg/mL). The highest antifungal activity was showed for H. perfoliatum extract (MIC value = 250 µg/mL). CONCLUSION: The data suggest that H. humifusum could be used as valuable new natural agents with functional properties for pharmacology industries.

Removal of Penicillin G and Erythromycin with Ionizing Radiation Followed by Biological Treatment.

The decomposition of penicillin G and erythromycin antibiotics at concentration of 0.2 mg ml(-1) by gamma irradiation at 50 kGy followed by biological treatment with Cupriavidus metallidurans CH34 was evaluated. Degradation of penicillin G and erythromycin was analyzed using nuclear magnetic resonance analysis (NMR), fourier transform infrared spectroscopy (FTIR), and chemical oxygen demand (COD). The exposure to the absorbed dose of 50 kGy caused degradation of penicillin G and erythromycin in the aqueous solution. The complete disappearance of NMR and FTIR peaks following irradiation confirmed the breakage of the ß-lactam ring in penicillin G, and the decarboxylation and cleavage of the thiazolidine ring and for erythromycin, the complete destruction of the three aromatic rings. Irradiation alone removed 52.8 and 65.5 % of penicillin G and erythromycin, respectively. Further reduction to 12.6 and 14 % of the original penicillin G and erythromycin COD, respectively, was achieved using treatment of the irradiation products with C. metallidurans.

Antimicrobial Activities and Mode of Flavonoid Actions.

The emergence of antibiotics-resistant bacteria has been a serious concern for medical professionals over the last decade. Therefore, developing new and effective antimicrobials with modified or different modes of action is a continuing imperative. In this context, our study focuses on evaluating the antimicrobial activity of different chemically synthesized flavonoids (FLAV) to guide the chemical synthesis of effective antimicrobial molecules. A set of 12 synthesized molecules (4 chalcones, 4 flavones and 4 flavanones), bearing substitutions with chlorine and bromine groups at the C6' position and methoxy group at the C4' position of the B-ring were evaluated for antimicrobial activity toward 9 strains of Gram-positive and Gram-negative bacteria and 3 fungal strains. Our findings showed that most tested FLAV exhibited moderate to high antibacterial activity, particularly against Staphylococcus aureus with minimum inhibitory concentrations (MIC) between the range of 31.25 and 125 µg/mL and that chalcones were more efficient than flavones and flavanones. The examined compounds were also active against the tested fungi with a strong structure-activity relationship (SAR). Interestingly, leakage measurements of the absorbent material at 260 nm and scanning electron microscopy (SEM) demonstrated that the brominated chalcone induced a significant membrane permeabilization of S. aureus.

Dittrichia viscosa L. Ethanolic Extract Based Ointment with Antiradical, Antioxidant, and Healing Wound Activities.

Dittrichia viscosa which belongs to the Asteraceae family is frequently used to treat hematomas and skin disorders in Mediterranean herbal medicine. This study aims to validate its antioxidant effects and its potential on healing wounds. The ethanolic extract of D. viscosa leaves was formulated as 2.5% and 5% (w/w) in ointment bases on the beeswax and sesame oil. During this study, the ethanolic D. viscosa extract, ointments containing 2.5% and 5% of D. viscosa extract, and the vehiculum were assessed for their total phenol content (TPC), caffeoylquinic acid content (CQC), and antioxidant activities using complementary methods (TAC, the DPPH, ABTS, FRAP, and the BCB). The effects on wound healing of obtained ointments were evaluated by excision of the wound in a mice model for 12 days. Subsequently, the excised wound areas were measured at the 3rd, 9th, and 12th days. The skin tissues were isolated for histological studies. The ointments containing D. viscosa extract (2.5%, 5%) possessed a considerable TPC, CQC, radical scavenging potential, and antioxidant activities compared to the vehiculum. Treated animals with ointments containing D. viscosa extract at 2.5% and 5% showed almost and totally healed wounds compared to the vehiculum and control groups, evidenced by good skin regeneration and reepithelialization. The present work showed the role of D. viscosa antioxidants exerted by its polyphenolic compounds, in particular, caffeoylquinic acids, in enhancing wound healing.

Chemical characterization and acaricidal activity of Drimia maritima (L) bulbs and Dittrichia viscosa leaves against Dermanyssus gallinae.

The emergence of resistance to chemical acaricides in Dermanyssus gallinae, together with their toxicity and high costs, has prompted investigations into the use of plant extracts as alternatives to chemical acaricidal treatments. Drimia maritima bulbs and Dittrichia viscosa (D. viscosa) leaf extracts were here characterized by HPLC-PDA-ESI-MS/MS, and their toxicity against D. gallinae was evaluated using contact methods. Twenty-nine compounds were identified in D. maritima extracts, with glucoscilliphaeoside derivatives (i.e., quercetin, kaempferol and bufadienolides) as the major components. Twenty-four phenolic compounds, mainly caffeic acid derivatives, were detected in D. viscosa extracts. D. maritima extracts displayed a significantly higher (p < 0.05) acaricidal activity than D. viscosa extracts, with 100% of D. gallinae mortality at a concentration of 100 mg/mL following 24 h exposure. The mortality rate of D. gallinae induced by D. viscosa extracts ranged from 25 to 45% following 48 h exposure at a concentration of 200 mg/mL. The acetonic extract of D. viscosa and D. maritima displayed the highest efficacy against D. gallinae. This study provides evidence of the diversity of bioactive compounds present in D. maritima bulbs and D. viscosa leaf extracts, which are both efficacious against D. gallinae. The higher efficacy of D. maritima bulb extracts might be linked to the presence of bufadienolides in its extracts.

Effect of Ionizing Radiation on the Microbiological Safety and Phytochemical Properties of Cooked Malva sylvestris L.

Nowadays, recent studies have demonstrated that plant-derived foods were characterized by their richness in bioactive phytochemicals and their consumption has a protective effect for human health. The effects of ionizing radiation on phytochemical properties of cooked Malva sylvestris L. (Mallow) were investigated. Irradiation increased significantly (P<0.05) the total polyphenols and flavonoids content of cooked Mallow. Irradiation at 2 and 4 kGy doses resulted in a significant increase in the DPPH and ABTS radical-scavenging ability of cooked Mallow extracts. There was no significant change on carbohydrate, lipid, ash, and protein content. While the mineral composition of K and Na was affected slightly after irradiation, the amounts of Mg, P, Ca, Fe, Z, and Cu remain unaffected at 2 kGy and reduced slightly at 4 kGy. The antimicrobial activity was unaffected after irradiation. Postirradiation storage studies showed that the cooked irradiated Mallow was microbiologically safe even after 20 days of storage period. Sensory properties of cooked irradiated Mallow were unaffected by the treatment. This study supports that cooking process followed by gamma irradiation did not compromise the chemical composition and sensory characteristics of Mallow.

Effect of ionising radiation on polyphenolic content and antioxidant potential of parathion-treated sage (Salvia officinalis) leaves.

The γ-irradiation effects on polyphenolic content and antioxidant capacity of parathion-pretreated leaves of Salvia officinalis plant were investigated. The analysis of phenolic extracts of sage without parathion showed that irradiation decreased polyphenolic content significantly (p<0.05) by 30% and 45% at 2 and 4kGy, respectively, compared to non-irradiated samples. The same trend was observed for the Trolox equivalent antioxidant capacity (TEAC), as assessed by the anionic DPPH and cationic ABTS radical-scavenging assays. The antioxidant potential decreased significantly (p<0.01) at 2 and 4kGy, by 11-20% and 40-44%, respectively. The results obtained with a pure chlorogenic acid solution confirmed the degradation of phenols; however, its TEAC was significantly (p<0.01) increased following irradiation. Degradation products of parathion formed by irradiation seem to protect against a decline of antioxidant capacity and reduce polyphenolic loss. Ionising radiation was found to be useful in breaking down pesticide residues without inducing significant losses in polyphenols.