Batch adsorption study and kinetic profile of Cr(VI) using lumbang (Aleurites moluccana)-derived activated carbon-chitosan composite crosslinked with epichlorohydrin

Batch adsorption of toxic Cr(VI) ion from an aqueous solution using lumbang (Aleurites moluccana) activated carbon-chitosan composite crosslinked with epichlorohydrin as an adsorbent was investigated. The adsorption experiments were performed at varying pH, agitation time, initial Cr(VI) ion concentration, temperature, and adsorbent dose. At an initial concentration of 60 ppm Cr(VI), the maximum adsorption was observed at pH 3, adsorbent dose of 3 g/L, contact time of 75 min, and temperature of 30°C. Analysis of the experimental data using different kinetic models revealed that the biosorption phenomenon behaved under a pseudo second-order rate mechanism. © 2017, Oriental Scientific Publishing Company. All rights reserved

Hepatoprotective activity of aqueous and ethanolic bixa orellana L. leaf extracts against carbon tetrachloride-induced hepatotoxicity

Background: There is an increasing incidence of liver failure and lack of effective drugs for liver diseases. Aim and Objective: This study identified the phytochemicals present in aqueous and ethanolic Bixa orellana L. leaf extracts and investigated the hepatoprotective activity against carbon tetrachloride (CCl4)-induced hepatotoxicity in mice. Specifically, the study compared serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and examined liver tissues histopathology. Materials and Methods: Aqueous and ethanolic B. orellana L. leaf extracts were prepared and screened for phytochemical contents. An oral dose of 500 mg/kg body weight was identified from toxicity test and administered to albino mice. Microscopic examination of the liver tissues assessed the extent of hepatic injury. Serum AST and ALT levels were compared using one-way analysis of variance with Bonferroni post hoc analysis at 5% level of significance using Stata/SE V12.0 software. Results: B. orellana L. leaves contained alkaloids, anthraquinones, sugars, and tannins. Aqueous and ethanolic leaf extracts of B. orellana L. did not show any toxicity up to 2000 mg/kg body weight oral dose in mice. Pre-treatment for 7 days before CCl4 administration significantly prevented elevation of serum AST and ALT levels with histopathologic findings showing a protective effect on the hepatocytes. Conclusion: B. orellana L. leaves have potent hepatoprotective activity against oxidative damage. © 2017 Derick Erl P Sumalapao, et al

Therapeutic and prophylactic effect of Andrographis paniculata on aspirin-induced gastric ulcer

Background: Andrographis paniculata is extensively used in the Southeast Asia in treating different kinds of diseases. Aims and Objectives: The study aimed to determine the chemical constituents of A. paniculata extract and its therapeutic and prophylactic effects on aspirin-induced gastric ulcer in male albino mice using histopathological analysis. Materials and Methods: Lyophilized filtered leaf extract of A. paniculata was administered to the experimental subjects at varying doses of 25%, 50%, and 75% concentrations once a day for 3 consecutive days in the prophylactic group followed by aspirin administration for another 3 days. For the therapeutic group, aspirin was administered first and after 3 days, plant extract was administered for 3 consecutive days. On the 7th day, longitudinal sections of the gastric tissue from the fundus of the mice were excised for histopathologic analysis using light microscopy to assess gastric mucosal lesions, presence of necrosis, and degree of inflammation. Results: Phytochemical tests on A. paniculata extract revealed the presence of tannins, glycosides, reducing substances, terpenoidal compounds, and flavones. Administration of 25%,50%, and 75% A. paniculata extract remarkably decreased the severity of ulceration, hastened regeneration and repair, and produced normal gastric mucosa, respectively. The prophylactic group showed similar results regardless of A. paniculata extract concentration in delaying gastric ulcer progression. Conclusion: Crude extract of A. paniculata plant has an ulcer-healing and prophylactic potential. © 2017, Mr Bhawani Singh. All rights reserved

Synthesis and characterization of epichlorohydrin-crosslinked lumbang (Aleurites moluccana)-derived activated carbon chitosan composite as cr(VI) bioadsorbent

Lumbang (Aleurites moluccana) activated carbon chitosan composite crosslinked with epichlorohydrin was synthesized for batch adsorption of toxic Cr(VI) ion from an aqueous solution. The synthesized biosorbent was characterized by instrumental techniques such as FTIR and SEM. The surface morphology of the adsorbent had a porous texture with round-and elliptical-shaped voids as adsorption sites for the adsorbate. Some functionalities including -OH and -NH2 groups were identified on the surfaces. The synthesized activated lumbang-biocharcoal chitosan composite crosslinked with epichlorohydrin adsorbent at the optimized conditions adsorbed 93% of Cr(VI) ion. The investigated adsorption phenomenon described a chemisorption process due to the functional groups identified and the high porosity of the adsorbent surfaces. © 2017 Bautista et al

Removal of lead (α) by lumbang, aleurites moluccana activated carbon carboxymethylcellulose composite crosslinked with epichlorohydrin

Removal of Pb(II) using lumbang activated carbon carboxymethylcellulose composite crosslinked with epichlorohydrin was investigated. Batch adsorption studies were performed to evaluate the effects of pH, contact time, temperature, adsorbent dose, and metal concentration. To characterize the adsorbent, proximate analysis, bulk density, DSC, FT-IR, and SEM analysis were performed. Results of FT-IR revealed that crosslinking did not alter the structure of carboxymethylcellulose due to the presence of the-COO functional groups, while the presence of the C-O signal indicates that the adsorbent was successfully crosslinked by epichlorohydrin. Furthermore, SEM results showed highly porous nature of the prepared adsorbent. The optimized parameters of the adsorbent were pH 3, contact time of 15 min. 30 oC temperature, adsorbent dose of 4 g/L at 5 ppm Pb (II) solution. With these optimized parameters, 73% removal of Pb (II) was attained in aqueous solutions, while 37% removal was observed in the wastewater sample. Moreover, the adsorption process was best described by Dubinin-Radushkevich isotherm and obeyed the pseudo-second order kinetic model. © 2018 Oriental Scientific Publishing Company. All rights reserved

Biosorption of methylene blue from aqueous solution by coconut (Cocos nucifera) shell-derived activated carbon-chitosan composite

Charcoal produced from coconut shells through the retort method was consequently activated using CaCl2. The activated carbon-chitosan composite was prepared by coating the activated carbon with chitosan. Batch experiments with methylene blue as adsorbate were conducted under varying pH, contact time, initial dye concentration, adsorbent dosage, and temperature. The effects of these factors were investigated using batch adsorption studies with optimal conditions identified at pH 5, 30 min. contact time, 10 mg L-1 initial dye concentration, 9 g L-1 adsorbent dosage, and 25 °C adsorption temperature. Results of adsorption experiments showed that the composite had better removal efficiency compared to activated carbon. © 2018 Oriental Scientific Publishing Company. All Rights Reserved

Topological Polar Surface Area, Molecular Weight, and Rotatable Bond Count Account for the Variations in the Inhibitory Potency of Antimycotics against Microsporum canis

Multivariate statistical models were utilized to identify the interaction between the inhibitory activity and the molecular properties of the different antimycotics against Microsporum canis. Information on the inhibitory potency against M. canis and molecular properties of antifungal agents were obtained from literature. The relationship between the inhibitory potency and the molecular properties of the different antimycotics against M. canis was established using multiple linear regression analysis (MLRA) and principal component analysis (PCA). Three major descriptors: topological polar surface area, molecular weight, and rotatable bond count of the antimycotics were identified to confer inhibitory action against M. canis using MLRA (r2 =0.8968, p<0.0001) and PCA (95.86% total contribution rate). Both MLRA and PCA as statistical approaches demonstrate their potential as tools in computational structure design and for possible synthesis of next generation antimycotics as more effective treatments of fungal infections

Biosorption kinetic models on the removal of Congo red onto unripe calamansi (Citrus microcarpa) peels

Unripe calamansi peels were prepared and used as a bioadsorbent in the removal of congo red from an aqueous solution using batch adsorption studies. The efficiency of adsorption was evaluated by varying adsorbent dose and contact time. The removal of congo red increased at higher adsorbent dose and longer contact time. The overall rate of adsorption processes appeared to be in accordance with the pseudo-second order reaction mechanism. Higher initial adsorption rate, extent of surface coverage, and activation energy were favored at a lower adsorbent dose, while the intraparticle diffusion was relatively faster at a higher adsorbent dose. The intraparticle diffusion, Elovich, and MacArthur-Wilson models were adequate in describing the chaotic behavior of the kinetic processes involved in the removal of congo red dye onto unripe calamansi peels. © 2016, Oriental Scientific Publishing Company. All rights reserved

In vitro resistance pattern of selected antifungal azoles against Candida albicans biofilms on silicone nasogastric tube

Prolonged use of implanted medical devices has been linked with device-associated infections. Since enteral tube feeding is increasing worldwide, the present study described the morphology of Candida albicans biofilms on the surface of silicone nasogastric tube (NGT) using fluorescence microscopy. With the emergence of multidrug-resistant fungal infections, the present study assessed the susceptibility profile of the biofilms to antifungal azoles namely fluconazole, miconazole, voriconazole, and posaconazole using the standard disc diffusion method. Microscopic studies of C. albicans biofilms revealed a complex heterogeneous structure with yeast cells and hyphal elements entrenched within a polysaccharide matrix. Planktonic C. albicans cells remained susceptible with posaconazole, fluconazole, miconazole, and voriconazole. However, the fungal biofilms exhibited resistance with miconazole. There was a significant reduction in the zone of inhibition on the 24-h, 48-h, and 72-h biofilm formation with posaconazole, voriconazole, and fluconazole, respectively. Kinetic investigation on C. albicans biofilm with posaconazole revealed a zero-order kinetic profile (R2=0.9774) whereas with voriconazole exhibited a first-order kinetic profile (R2=0.9974). These findings can possibly provide information regarding the resistance of fungal biofilms with antifungal azoles. Demonstration of common biofilm features will extend the findings of this study beyond fungi to polymicrobial infections, as new information and insights will influence several disciplines ranging from environmental microbiology to pharmaceutical drug design intended for biofilm-associated infections. © The Author(s) 2019

Susceptibility profile of Candida albicans biofilms on polyvinyl chloride endotracheal tube to antifungal azoles

One of the most prevalent causative organisms in human fungal infections is Candida albicans. The extensive utility of medical devices such as endotracheal tube has resulted in the increased cases of fungal infections. The present study visualized Candida albicans biofilm on polyvinyl chloride endotracheal tube and described the susceptibility profile of the biofilm to antifungal azoles. Biofilm was examined using light and fluorescence microscopy. The susceptibility profile of planktonic and sessile cells with posaconazole, miconazole, voriconazole, and fluconazole was assessed employing the standard disc diffusion method. Planktonic C. albicans was susceptible to the identified antifungal azoles, whereas the sessile cells had varying susceptibility profiles. The biofilms remained susceptible to voriconazole and fluconazole, susceptible-dose dependent to posaconazole, and resistant to miconazole. Findings of the present study can provide relevant information on the resistance mechanism of fungal biofilms with azoles and in the design of new pharmacologic interventions intended as treatment of mycoses. © The Author(s) 2020