Preliminary Phytochemical Screening and Antispasmodic Activity of Artemisia macrocephala Jacquem

The current work describes the antispasmodic action of Artemisia macrocephala, which is achieved via blocking of the calcium channels. This explains its traditional use as an antispasmodic.The crude methanolic extract of A. macrocephala was studied for possible relaxant effect(s) on spontaneous rabbits’ jejunum preparations. Analytical-grade chemicals were used in the experimental protocols. A. macrocephala gave positive tests for flavonoids, saponins, glycosides, alkaloids, and terpenes. A. macrocephala caused relaxation of spontaneous rabbits’ jejunum preparations (n=6) at a dose of 10.0 mg/mL (EC50 = 6.95 ± 0.20 mg/mL; 95% CI: 6.2 to 7.5). Contractions induced by 80 mM potassium chloride (KCl) were also relaxed by the A. macrocephala at dose of 10.0 mg/mL. Attempting to find an explanation for the possible mode of action, we found that, A. macrocephala at concentration of 1.0 mg/mL produced rightward shift in the calcium chloride curves, with EC50 value of –1.65 ± 0.02 log [Ca++] M vs control with EC50 value of –2.44 ± 0.043 for calcium chloride curves. At a concentration of 1.0 mg/mL it could produce 52.4% of the control response at log [Ca++] M = –1.6. Similarly, verapamil at a concentration of 0.1 μM produced a rightward shift, with EC50 value of –1.74 ± 0.026 log [Ca++] M (95% CI: –1.66 to –1.82; n=6) vs control with EC50 value of –2.45 ± 0.05 log [Ca++] M (95% CI: – 2.23 to –2.91; n=6). The right shift of the EC50 values is justification for the folkloric use of A. macrocephala as an antispasmodic, suggesting that the possible mode of action is through calcium channel blockade

Preliminary Phytochemical Screening and Antispasmodic Activity of Artemisia macrocephala Jacquem

The current work describes the antispasmodic action of Artemisia macrocephala, which is achieved via blocking of the calcium channels. This explains its traditional use as an antispasmodic.The crude methanolic extract of A. macrocephala was studied for possible relaxant effect(s) on spontaneous rabbits’ jejunum preparations. Analytical-grade chemicals were used in the experimental protocols. A. macrocephala gave positive tests for flavonoids, saponins, glycosides, alkaloids, and terpenes. A. macrocephala caused relaxation of spontaneous rabbits’ jejunum preparations (n=6) at a dose of 10.0 mg/mL (EC50 = 6.95 ± 0.20 mg/mL; 95% CI: 6.2 to 7.5). Contractions induced by 80 mM potassium chloride (KCl) were also relaxed by the A. macrocephala at dose of 10.0 mg/mL. Attempting to find an explanation for the possible mode of action, we found that, A. macrocephala at concentration of 1.0 mg/mL produced rightward shift in the calcium chloride curves, with EC50 value of –1.65 ± 0.02 log [Ca++] M vs control with EC50 value of –2.44 ± 0.043 for calcium chloride curves. At a concentration of 1.0 mg/mL it could produce 52.4% of the control response at log [Ca++] M = –1.6. Similarly, verapamil at a concentration of 0.1 μM produced a rightward shift, with EC50 value of –1.74 ± 0.026 log [Ca++] M (95% CI: –1.66 to –1.82; n=6) vs control with EC50 value of –2.45 ± 0.05 log [Ca++] M (95% CI: – 2.23 to –2.91; n=6). The right shift of the EC50 values is justification for the folkloric use of A. macrocephala as an antispasmodic, suggesting that the possible mode of action is through calcium channel blockade

Antibacterial and antibiotic potentiating capabilities of extracts isolated from Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus against human pathogenic bacteria

Antibiotics which once a boon in medicine and saved millions of lives are now facing an ever-growing menace of antibacterial resistance, which desperately needs new antibacterial drugs which are innovative in chemistry and mode of action. For many years, the world has turned to natural plants with antibacterial properties to combat antibiotic resistance. On that basis, we aimed to identify plants with antibacterial and antibiotic potentiating properties. Seventeen different extracts of 3 plants namely Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus were tested against multi-drug resistant Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Methicillinresistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Antibacterial activity of hexane, methanol and chloroform extracts of bark, seed, fruit, flesh and leaves from these plants were tested using, disk diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiotic potentiating capabilities were tested using time-kill assay. B. malaccensis fruit chloroform extract showed the biggest zone of inhibition against MRSA (13.00±0.0 mm) but C. bracteosus bark methanol extract showed the biggest inhibition zone against MSSA (15.33±0.6 mm). Interestingly, bark methanol extract of C. bracteosus was active against MRSA (8.7±0.6 mm), MSSA (7.7±0.6 mm) (Gram-positive) and A. baumannii (7.7±0.6 mm) (Gram-negative). Overall, the leaf methanol and bark methanol extract of C. bracteosus warrants further investigation such as compound isolation and mechanism of action for validating its therapeutic use as antibiotic potentiator importantly against MRSA and A. baumannii

First recorded eruption of Nabro volcano, Eritrea, 2011

We present a synthesis of diverse observations of the first recorded eruption of Nabro volcano, Eritrea, which began on 12 June 2011. While no monitoring of the volcano was in effect at the time, it has been possible to reconstruct the nature and evolution of the eruption through analysis of re- gional seismological and infrasound data and satellite remote sensing data, supplemented by petrological analysis of erupted products and brief field surveys. The event is notable for the comparative rarity of recorded historical eruptions in the region and of caldera systems in general, for the prodi- gious quantity of SO2 emitted into the atmosphere and the significant human impacts that ensued notwithstanding the low population density of the Afar region. It is also relevant in understanding the broader magmatic and tectonic signifi- cance of the volcanic massif of which Nabro forms a part and which strikes obliquely to the principal rifting directions in the Red Sea and northern Afar. The whole-rock compositions of Editorial responsibility: G. Giordano the erupted lavas and tephra range from trachybasaltic to trachybasaltic andesite, and crystal-hosted melt inclusions contain up to 3,000 ppm of sulphur by weight. The eruption was preceded by significant seismicity, detected by regional networks of sensors and accompanied by sustained tremor. Substantial infrasound was recorded at distances of hundreds to thousands of kilometres from the vent, beginning at the onset of the eruption and continuing for weeks. Analysis of ground deformation suggests the eruption was fed by a shal- low, NW–SE-trending dike, which is consistent with field and satellite observations of vent distributions. Despite lack of prior planning and preparedness for volcanic events in the country, rapid coordination of the emergency response miti- gated the human costs of the eruption

In vivo evaluation of a hybrid nanoparticle for molecular imaging of amyloid aggregation

International audienceAmyloid-β (Aβ) fibrillization is described as a central event in the pathogenesis of Alzheimer’s disease (AD). Amyloid imaging is expected to play a pivotal role in early and differential diagnosis of dementias, and in the evaluation of anti-Aβ treatments. Luminescent conjugated oligothiophenes (LCO) have been proposed as optical biomarkers of protein fibrillation [1]. In this paper, we evaluated a fluorescent magnetic hybrid nanoprobe (HNP5011), based on gadolinium fluoride nanoparticles functionalized with luminescent conjugated polythiophenes moieties (Fig. 1). The aim of this study was to investigate its potential for molecular imaging in a rat model bearing intracerebral pre-aggregated Aβ peptides

Cyclic Tetrapyrrolic Photosensitisers from the leaves of Phaeanthus ophthalmicus

<p>Abstract</p> <p>Background</p> <p>Twenty-seven extracts from 26 plants were identified as photo-cytotoxic in the course of our bioassay guided screening program for photosensitisers from 128 extracts prepared from 64 terrestrial plants in two different collection sites in Malaysia - Royal Belum Forest Reserve in the State of Perak and Gunung Nuang in the State of Selangor. One of the photo-cytotoxic extracts from the leaves of <it>Phaeanthus ophtalmicus </it>was further investigated.</p> <p>Results</p> <p>The ethanolic extract of the leaves from <it>Phaeanthus ophtalmicus </it>was able to reduce the <it>in vitro </it>viability of leukaemic HL60 cells to < 50% when exposed to 9.6 J/cm²of a broad spectrum light at a concentration of 20 μg/mL. Dereplication of the photo-cytotoxic fractions from <it>P. ophthalmicus </it>extracts based on TLC R_fvalues and HPLC co-injection of reference tetrapyrrolic compounds enabled quick identification of known photosensitisers, pheophorbide-<it>a</it>, pheophorbide-<it>a </it>methyl ester, 13²-hydroxypheophorbide-<it>a </it>methyl ester, pheophytin-<it>a </it>and 15¹-hydroxypurpurin 7-lactone dimethyl ester. In addition, compound <b>1 </b>which was not previously isolated as a natural product was also identified as 7-formyl-15¹-hydroxypurpurin-7-lactone methyl ester using standard spectroscopic techniques.</p> <p>Conclusions</p> <p>Our results suggest that the main photosensitisers in plants are based on the cyclic tetrapyrrole structure and photosensitisers with other structures, if present, are present in very minor amounts or are not as active as those with the cyclic tetrapyrrole structure.</p