Insecticidal activity of Thymus pallescens de Noë and Cymbogon citratus essential oils against Sitophilus zeamais and Tribolium castaneum.

The thrust of the study was to determine the chemical composition of the essential oils extracted from Thymus pallescens de Noé and Cymbogon citratus Stapf. as well as to evaluate their efficacy in controlling Sitophilus zeamais Motschulsky and Tribolium castaneum (Herbst) in either single or combined populations. Carvacrol (56.04%) and geraniol (20.86%) were identified as the major constituents of T. pallescens and C. citratus respectively. The tested essential oils showed pronounced insecticidal activity against the pest species in relation with the applied doses. T. pallescens EO had the highest efficacy and S. zeamais was found to be more susceptible to both individual and combined treatments. With reference to the contact and fumigation assessments, T. pallescens EO effectuated corrected mortality rates ranging from 42.5-100% to 25-100% in S. zeamais with corresponding lethal concentration (LC50) values of 17.7 µl/ml and 15µL/L air respectively. Whereas, the T. pallescens EO exhibited corrected mortality rates of 42.5-100% and 20-100% with corresponding LC50 values of 18.1 µl/ml and 15.5 µL/L air against T. castaneum in contact and fumigation assessments, respectively. The corrected mortality rates increased for both insect species when using combination treatments, with significant increases in the LC50 values, ranging from 8.59 to 49.9% for both pest species. Analysis of energy biomarkers in the treated insects indicate significantly increased protein and carbohydrate contents and decreased lipids levels. The study therefore demonstrated the bio-insecticidal toxicity of the EOs from T. pallescens and C. citratus against two important maize post-harvest pests, concurrently revealing significant positive and negative insecticidal activity gradients in relation to single or combined populations.

Exploring the potential of Inula viscosa extracts for antioxidant, antiproliferative and apoptotic effects on human liver cancer cells and a molecular docking study.

In folk medicine, Inula viscosa (Asteraceae) has been traditionally utilized for treating various ailments, including diabetes, bronchitis, diarrhea, rheumatism, and injuries. In this study, we aimed to investigate the chemical composition, antioxidant, antiproliferative, and apoptotic properties of I. viscosa leaf extracts. Extraction was performed using solvents of varying polarities. Antioxidant activity was determined using Ferric reducing antioxidant power (FRAP) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The results revealed that aqueous ethanol (70%) and aqueous ethyl acetate (70%) extracts contained high levels of phenols (645.58 ± 8.77 mg CE/g) and flavonoids (180.69 ± 1.54 mg QE/g), respectively. Aqueous ethanol (70%) extract exhibited the highest antioxidant activity with IC50 of 572.74 µmol TE/g DW (µmol Trolox equivalent in 1g of dry extract) in the ABTS assay and 76862.06 µM TE/g DW in the FRAP test. All extracts showed a considerable dose-dependent cytotoxic effect on cancerous HepG2 cells (P < 0.05). The aqueous ethanol extract demonstrated the highest inhibitory effect (IC50 = 1.67 mg/ml). Treatment with aqueous ethanol (70%) and pure ethyl acetate extracts significantly increased the number of apoptotic cells to 8 and 6%, respectively, in HepG2 cells (P < 0.05). Additionally, the aqueous ethanol extract significantly elevatedreactive oxygen species (ROS) levels (53%) in HepG2 cells. The molecular docking study identified paxanthone and banaxanthone E as the compounds that exhibited the highest binding affinities with BCL-2. This study demonstrated the potent antioxidant, antiproliferation, and intracellular ROS production of I. viscosa leaf extracts. Further studies should be conducted to identify the active compounds involved.

Antibacterial and antioxidant potency of floral honeys from different botanical and geographical origins.

In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin-Ciocalteu method and the free radical scavenging activity by the Fe(3+)reducing power (FRAP) assay. Manuka honey was the most effective against Staphylococcus aureus Oxa R and S. aureus Oxa S with a Minimum Inhibitory Concentration (MIC) of 6% and 7%, respectively, whereas wild carrot honey was the most effective against Pseudomonas aeruginosa, with a MIC of 12%. Lavender honey was the least effective against all tested strains, even though was found to have the lowest pH and water content. Manuka honey had the highest content of polyphenols, with 899.09 ± 11.75 mg gallic acid/kg, whereas lavender honey had the lowest, with 111.42 ± 3.54 mg gallic acid/kg. A very significant correlation (r value was 0.9079 at P < 0.05) was observed between the total polyphenolic content and the Fe(2+) content formed in the presence of the honey antioxidants. The differences between honey samples in terms of antibacterial and antioxidant activity could be attributed to the natural variations in floral sources of nectar and the different locations.

Molecular mechanism underlying anti-inflammatory and anti-allergic activities of phytochemicals: an update.

The resort worldwide to edible medicinal plants for medical care has increased significantly during the last few years. Currently, there is a renewed interest in the search for new phytochemicals that could be developed as useful anti-inflammatory and anti-allergic agents to reduce the risk of many diseases. The activation of nuclear transcription factor-kappa B (NF-κB) has now been linked to a variety of inflammatory diseases, while data from numerous studies underline the importance of phytochemicals in inhibiting the pathway that activates this transcription factor. Moreover, the incidence of type I allergic disorders has been increasing worldwide, particularly, the hypersensitivity to food. Thus, a good number of plant products with anti-inflammatory and anti-allergic activity have been documented, but very few of these compounds have reached clinical use and there is scant scientific evidence that could explain their mode of action. Therefore, this paper intends to review the most salient recent reports on the anti-inflammatory and anti-allergic properties of phytochemicals and the molecular mechanisms underlying these properties.

Inula viscosa phenolic extract suppresses colon cancer cell proliferation and ulcerative colitis by modulating oxidative stress biomarkers.

Inula viscosa is a perennial herbaceous plant native to the Mediterranean Basin, which is used topically for the treatment of various diseases in folk medicine. This study aimed to evaluate the in vivo intestinal anti-inflammatory activity of the ethanolic extract of I. viscosa (EEIV) and to test its effect on a colorectal cancer cell line. EEIV was administered to rats orally and daily at 100 and 200 mg/kg body weight for 7 days, and then colitis was induced by intrarectal instillation of 2 ml of 4% (v/v) acetic acid (AA) solution. At the end of the experiment, clinical examinations of the rats were conducted by evaluating macroscopic and histological signs of colonic tissues and measuring erythrocyte sedimentation rate (ESR) and the levels of C-reactive protein, fibrinogen, myeloperoxidase (MPO), malondialdehyde (MDA) and nitric oxide (NO). Using MTS assay, the antiproliferative effect of EEIV against human colon carcinoma HT29 cells and cytotoxicity on nondifferentiated Caco-2 cell line was evaluated. EEIV significantly decreased the ESR and fibrinogen levels as compared to control colitic rats (P < 0.001). It also significantly decreased the NO, MDA, and MPO levels in the colon tissue compared with the untreated colitic group (P < 0.001). These results were confirmed by macroscopic and histological examination, which showed significant protection against AA-induced ulcerative colitis. Furthermore, EEIV at a concentration of 369.88 µg/ml did not show cytotoxicity on confluent Caco-2 cells, with significant inhibition of colorectal cancer cell (HT29) growth (EC50 = 62.39 µg/ml). These results demonstrate that EEIV plays a potential role as a pharmacological tool in the management of inflammatory bowel disease and prevention of colorectal cancer.

Semipapposides A-M, triterpenoid bidesmosides saponins from the roots of Scabiosa semipapposa.

Phytochemical investigations of the roots of Scabiosa semipapposa Salzem ex D.C. have led to the isolation of 12 undescribed triterpenoid saponins named semipapposides A-L, one undescribed saponin semipapposide M obtained as an inseparable mixture, together with three known oleanolic acid glycosides. Their structures were elucidated by analysis of 1D and 2D-NMR (1H-1H COSY, TOCSY, HSQC-TOCSY, HSQC, ROESY or NOESY, and HMBC) spectroscopic data and mass spectrometry (HR-ESI-MS), and by comparison with those of related metabolites. All saponins possess a partial sequence rhamnopyranosyl-(1 â†’ 2)-xylopyranosyl or rhamnopyranosyl-(1 â†’ 2)-arabinopyranosyl- at C-3 of the aglycon and a gentiobiose unit at C-28. These results represent a contribution to the knowledge of the saponins of Scabiosa species and their chemotaxonomy.

Concurrent measurement of cellular turbidity and hemoglobin to evaluate the antioxidant activity of plants.

In past decades, a multitude of analytical methods for measuring antioxidant activity of plant extracts has been developed. However, when using methods to determine hemoglobin released from human erythrocytes treated with ginger extracts, we found hemoglobin concentrations were significantly higher than in untreated control samples. This suggests in the presence of antioxidants that measuring hemoglobin alone is not sufficient to determine hemolysis. We show concurrent measurement of erythrocyte concentration and hemoglobin is essential in such assays, and describe a new protocol based on simultaneous measurement of cellular turbidity and hemoglobin.

Phytochemicals to prevent inflammation and allergy.

Recently, much interest has been generated for a wide range of phyto-constituents with reports demonstrating their role in the modulation of inflammatory responses, including phenolics, alkaloids, and terpenoids. Natural products have long been, over the years, contributed to the development of modern therapeutic drugs. At present, steroids, antihistaminic drugs, suppressants or inhibitors of the release of mediators and the like have been used as anti-allergic agents. However, some of them lack immediate effectiveness or have central side effects. Drug discovery from plants involves a multidisciplinary approach combining botanical, ethno-botanical, phytochemical and biological techniques. Several natural product drugs of plant origin are in clinical use and some are undergoing Phase II and Phase III clinical trials. A major effort was directed toward discovery of novel anti-inflammatory and anti-allergic agents, which resulted in the invention of several patented formulations. These formulations concern a variety of pharmaceutical preparations which can be used as solid or liquid dosage forms or encapsulated as a soft or hard gelatin capsule. The present article is a short review of recent patents on the role of phytochemicals in preventing inflammation and allergy.

Evaluation of the antioxidant activity of three varieties of honey from different botanical and geographical origins.

It is well established that honey contains substantial antioxidant compounds that could protect cell components from the harmful action of free radicals. One can speculate that these compounds may strengthen the organism defenses and consequently prevent oxidative stress in humans. Therefore, over time, impaired cells can accumulate and lead to age-related diseases. A comparative study was carried out to assess the antioxidant activity of three varieties of honey from different botanical and geographical (Manuka honey from New Zealand, Acacia Honey from Germany and Wild carrot honey from Algeria). Manuka honey had the highest phenolic content with 899.09 ± 11.75 mg gallic acid/kg. A strong correlation between the antioxidant activities of honeys and their total phenol contents has been noticed.