Coumarins from the Roots of Angelica archangelica and Antibacterial Activity Against Methicillin Resistant Staphylococcus aureus

Angelica archangelica (Fam. Apiaceae) roots were extracted sequentially with n-hexane, dichloromethane (DCM) and methanol (MeOH) using a Soxhlet apparatus. The n-hexane and DCM extracts were fractionated by Vacuum Liquid Chromatography (VLC) over silica gel followed by Preparative Thin Layer Chromatography (PTLC) to yield two coumarins, osthol (1) and osthenol (2). However, the methanol extract was fractionated by solid-phase extraction using C18 cartridge followed by analysis of components by analytical High Performance Liquid Chromatography (HPLC) and purification by preparative High Performance Liquid Chromatography (HPLC) to give two coumarins, bergapten (3) and heraclenol (4) along with sucrose (5). Compounds were identified by a series of 1D (1H and 13C) and 2D (COSY, HSQC and HMBC) NMR spectroscopy and mass spectrometric analysis. The crude extracts (n-hexane, DCM, and methanol) and compound 1, were screened for antimicrobial activity against Gram-positive bacteria (Methicillin resistant Staphylococcus aureus, MRSA and Micrococcus luteus), Gram-negative bacteria, Pseudomonas aeruginosa, and a fungus, Candida albicans. The antimicrobial assays showed that the crude DCM and n-hexane extracts, alongside compound 1, largely inhibited the growth of the microorganisms at high concentrations. Compound 1, which was further tested for antibacterial activity against a series of clinical isolates of methicillin resistance Staphylococcus aureus, showed moderate level of activity against only one strain

Apocynin prevented inflammation and oxidative stress in carbon tetrachloride induced hepatic dysfunction in rats

Background: Liver fibrosis is a leading pathway to cirrhosis and a global clinical issue. Oxidative stress mediated tissue damage is one of the prime causes of hepatic dysfunction and fibrosis. Apocynin is one of many strong antioxidants. Objective: To evaluate the effect of apocynin in the CCl4 administered hepatic dysfunction in rats. Methods: Female Long Evans rats were administered with CCl4 orally (1 mL/kg) twice a week for 2 weeks and were treated with apocynin (100 mg/kg). Both plasma and liver tissues were analyzed for alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase activities. Oxidative stress parameters were also measured by determining malondialdehyde (MDA), nitric oxide (NO), myeloperoxidase (MPO), advanced protein oxidation product (APOP). In addition, antioxidant enzyme activities such as superoxide dismutase (SOD) and catalase activities in plasma and liver tissues were analyzed. Moreover, inflammation and tissue fibrosis were confirmed by histological staining of liver tissue sections. Results: Apocynin significantly reduced serum AST, ALT, and ALP activities in carbon tetrachloride treated rats. It also exhibited a considerable reduction of the oxidative stress markers (MDA, MPO, NO, and APOP level) which was elevated due to CCl4 administration in rats. Apocynin treatment also restored the catalase and superoxide dismutase activity in CCl4 treated rats. Histological analysis of liver sections revealed that apocynin prevented inflammatory cells infiltration and fibrosis in CCl4 administered rats. Conclusion: These results suggest that apocynin protects liver damage induced by CCl4 by inhibiting lipid peroxidation and stimulating the cellular antioxidant system

Authentication and Discrimination of Green Tea Samples Using UV-Visible, FTIR and HPLC Techniques Coupled with Chemometrics Analysis

Green tea is a popular beverage consumed worldwide. Its quality should be controlled adequately as the quality is influenced by several factors in addition to adulterations. This study aimed to develop a simple method for assessing the quality of green tea samples obtained from the South and the East Asian regions. The UV-Visible, FTIR and HPLC data from 38 samples were subjected to multivariate analyses using the unsupervised recognition techniques comprising Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA). The model for their authentication was constructed and validated by applying the supervised recognition techniques as Soft Independent Modeling of Class Analogy (SIMCA) and Partial Least Square Discriminant Analysis (PLS-DA). The percentages of caffeine in the identified samples were determined using a validated HPLC assay in addition to in vitro determination of their antioxidant activity using DPPH radical-scavenging capacity assay. HCA and PCA based on UV data successfully distributed the tested samples into informative clusters. However, that obtained from visible data could only differentiate samples with respect to their powdered condition. On the contrary, PCA from FTIR and HPLC data could hardly discriminate any of the samples. The models constructed using SIMCA and PLS-DA showed a good class separation between the South and the East Asian samples. The percentages of caffeine in the identified samples and the IC50 in DPPH assay are greatly diverse among all the tested samples. Thus, UV spectroscopy and chemometrics have provided a simple and quick tool for the quality control of commercial green tea samples

A Phase I/II Trial of Oral SRA737 (a Chk1 Inhibitor) Given in Combination with Low-Dose Gemcitabine in Patients with Advanced Cancer.

PURPOSE: This was a Phase I/II trial of the novel checkpoint kinase 1 (Chk1) inhibitor SRA737 given in combination with gemcitabine. Its objectives were to establish the safety profile, recommended Phase 2 dose (RP2D), pharmacokinetics profile, and clinical activity of SRA737. PATIENTS AND METHODS: Patients with advanced solid tumors were enrolled into dose-escalation cohorts and treated in 28-day cycles with oral SRA737 on days 2, 3, 9, 10, 16, and 17, and intravenous gemcitabine on days 1, 8, and 15. Treatment was continued until progression. Each expansion cohort included up to 20 patients with specific genetically defined tumors. RESULTS: The RP2D was determined to be 500 mg SRA737 combined with low-dose (250 mg/m2) gemcitabine. Of 143 enrolled patients, 77 were treated at doses of at least 500 mg SRA737 combined with 250 mg/m2 gemcitabine. Common toxicities of nausea, vomiting, fatigue, and diarrhea were primarily mild to moderate, and rarely led to treatment discontinuation. Anemia, neutropenia, and thrombocytopenia were grade ≥3 in 11.7%, 16.7%, and 10% of patients treated at the RP2D, respectively. The objective response rate (ORR) was 10.8% overall and notably the ORR in anogenital cancer was 25%. Partial tumor responses were observed in anogenital cancer, cervical cancer, high-grade serous ovarian cancer, rectal cancer, and small cell lung cancer. CONCLUSIONS: SRA737 in combination with low-dose gemcitabine was well tolerated with lower myelotoxicity than has been seen at standard doses of gemcitabine or with other combinations of Chk1 inhibitors with gemcitabine. Tumor responses were observed in anogenital and other solid tumors

A mini-review on oxysporone

Oxysporone, possessing a 4H-furo(2,3-b)pyran-2(3H)-one structure, is a fungal metabolite, first isolated from Fusarium oxysporum. Later, this compound was also reported from the fungal genera, Diplodia, Pestalotia and Pestalotiopsis. Oxysporone was patented as an antibiotic for the treatment of dysentery, and its phytotoxic property has been well-established. Interesting biological and chemical properties of oxysporone make this compound attractive for its potential biotechnological applications in agriculture, especially as a new agrochemical with a lower environmental impact. However, it requires further extensive bioactivity screening looking at beyond its established phytotoxicity and preliminary antifungal property. It has a simple chemical structure (C7H8O4), and the hydroxyl group at C-4 provides options for synthesising numerous analogues by simply incorporating various functionalities at C-4, whilst keeping the main skeleton intact. This mini-review provides a critical overview on the occurrence, production, synthesis, structure elucidation and bioactivities of oxysporone

A Cross-Sectional Survey on Knowledge and Perceptions of Health Risks Associated with Arsenic and Mercury Contamination from Artisanal Gold mining in Tanzania.

An estimated 0.5 to 1.5 million informal miners, of whom 30-50% are women, rely on artisanal mining for their livelihood in Tanzania. Mercury, used in the processing gold ore, and arsenic, which is a constituent of some ores, are common occupational exposures that frequently result in widespread environmental contamination. Frequently, the mining activities are conducted haphazardly without regard for environmental, occupational, or community exposure. The primary objective of this study was to assess community risk knowledge and perception of potential mercury and arsenic toxicity and/or exposure from artisanal gold mining in Rwamagasa in northwestern Tanzania. A cross-sectional survey of respondents in five sub-villages in the Rwamagasa Village located in Geita District in northwestern Tanzania near Lake Victoria was conducted. This area has a history of artisanal gold mining and many of the population continue to work as miners. Using a clustered random selection approach for recruitment, a total of 160 individuals over 18 years of age completed a structured interview. The interviews revealed wide variations in knowledge and risk perceptions concerning mercury and arsenic exposure, with 40.6% (n=65) and 89.4% (n=143) not aware of the health effects of mercury and arsenic exposure respectively. Males were significantly more knowledgeable (n=59, 36.9%) than females (n=36, 22.5%) with regard to mercury (x²=3.99, p<0.05). An individual's occupation category was associated with level of knowledge (x²=22.82, p=<0.001). Individuals involved in mining (n=63, 73.2%) were more knowledgeable about the negative health effects of mercury than individuals in other occupations. Of the few individuals (n=17, 10.6%) who knew about arsenic toxicity, the majority (n=10, 58.8%) were miners. The knowledge of individuals living in Rwamagasa, Tanzania, an area with a history of artisanal gold mining, varied widely with regard to the health hazards of mercury and arsenic. In these communities there was limited awareness of the threats to health associated with exposure to mercury and arsenic. This lack of knowledge, combined with minimal environmental monitoring and controlled waste management practices, highlights the need for health education, surveillance, and policy changes

Sonneratinone: A New Antimicrobial Benzofuranone Derivative from the Endophytic Fungus Aspergillus niger Isolated from the Mangrove Plant Sonneratia apetala Buch.-Ham

A new antimicrobial benzofuranone derivative, named, sonneratinone (1), was isolated from the endophytic fungus Aspergillus niger, obtained from the leaves of Sonneratia apetala, a mangrove plant from the Sundarbans. Whilst the fungal strain was identified by macroscopic, microscopic and molecular techniques, the structure of the new compound was elucidated by spectroscopic means, e.g., 1D and 2D NMR, and HRESIMS. Sonneratinone (1) showed considerable antimicrobial activity against Micrococcus luteus, Staphylococcus aureus and Candida albicans in the resazurin 96-well microtitre plate antimicrobial assay

Generation and characterization of antibodies specific for caspase-cleaved neo-epitopes: a novel approach

Apoptosis research has been significantly aided by the generation of antibodies against caspase-cleaved peptide neo-epitopes. However, most of these antibodies recognize the N-terminal fragment and are specific for the protein in question. The aim of this project was to create antibodies, which could identify caspase-cleaved proteins without a priori knowledge of the cleavage sites or even the proteins themselves. We hypothesized that many caspase-cleavage products might have a common antigenic shape, given that they must all fit into the same active site of caspases. Rabbits were immunized with the eight most prevalent exposed C-terminal tetrapeptide sequences following caspase cleavage. After purification of the antibodies we demonstrated (1) their specificity for exposed C-terminal (but not internal) peptides, (2) their ability to detect known caspase-cleaved proteins from apoptotic cell lysates or supernatants from apoptotic cell culture and (3) their ability to detect a caspase-cleaved protein whose tetrapeptide sequence differs from the eight tetrapeptides used to generate the antibodies. These antibodies have the potential to identify novel neo-epitopes produced by caspase cleavage and so can be used to identify pathway-specific caspase cleavage events in a specific cell type. Additionally this methodology may be applied to generate antibodies against products of other proteases, which have a well-defined and non-promiscuous cleavage activity

The Cysteine Protease α-Clostripain is Not Essential for the Pathogenesis of Clostridium perfringens-Mediated Myonecrosis

Clostridium perfringens is the causative agent of clostridial myonecrosis or gas gangrene and produces many different extracellular toxins and enzymes, including the cysteine protease α-clostripain. Mutation of the α-clostripain structural gene, ccp, alters the turnover of secreted extracellular proteins in C. perfringens, but the role of α-clostripain in disease pathogenesis is not known. We insertionally inactivated the ccp gene C. perfringens strain 13 using TargeTron technology, constructing a strain that was no longer proteolytic on skim milk agar. Quantitative protease assays confirmed the absence of extracellular protease activity, which was restored by complementation with the wild-type ccp gene. The role of α-clostripain in virulence was assessed by analysing the isogenic wild-type, mutant and complemented strains in a mouse myonecrosis model. The results showed that although α-clostripain was the major extracellular protease, mutation of the ccp gene did not alter either the progression or the development of disease. These results do not rule out the possibility that this extracellular enzyme may still have a role in the early stages of the disease process

Antimicrobial and antioxidant activity of kaempferol rhamnoside derivatives from Bryophyllum pinnatum

Abstract Background Bryophyllum pinnatum (Lank.) Oken (Crassulaceae) is a perennial succulent herb widely used in traditional medicine to treat many ailments. Its wide range of uses in folk medicine justifies its being called "life plant" or "resurrection plant", prompting researchers' interest. We describe here the isolation and structure elucidation of antimicrobial and/or antioxidant components from the EtOAc extract of B. pinnatum. Results The methanol extract displayed both antimicrobial activities with minimum inhibitory concentration (MIC) values ranging from 32 to 512 μg/ml and antioxidant property with an IC50 value of 52.48 μg/ml. Its partition enhanced the antimicrobial activity in EtOAc extract (MIC = 16-128 μg/ml) and reduced it in hexane extract (MIC = 256-1024 μg/ml). In addition, this process reduced the antioxidant activity in EtOAc and hexane extracts with IC50 values of 78.11 and 90.04 μg/ml respectively. Fractionation of EtOAc extract gave seven kaempferol rhamnosides, including; kaempferitrin (1), kaempferol 3-O-α-L-(2-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (2), kaempferol 3-O-α-L-(3-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (3), kaempferol 3-O-α-L-(4-acetyl)rhamnopyranoside-7-O-α-L-rhamnopyranoside (4), kaempferol 3-O-α-D- glucopyranoside-7-O-α-L-rhamnopyranoside (5), afzelin (6) and α-rhamnoisorobin (7). All these compounds, except 6 were isolated from this plant for the first time. Compound 7 was the most active, with MIC values ranging from 1 to 2 μg/ml and its antioxidant activity (IC50 = 0.71 μg/ml) was higher than that of the reference drug (IC50 = 0.96 μg/ml). Conclusion These findings demonstrate that Bryophyllum pinnatum and some of its isolated compounds have interesting antimicrobial and antioxidant properties, and therefore confirming the traditional use of B. pinnatum in the treatment of infectious and free radical damages.</p