AIM OF THE STUDY: Chemico-biological standardization with respect to its vasorelaxation potential is the main objective of the present study. To investigate the vasorelaxation potential of key phytochemical of KGR, i.e., ethyl-p-methoxycinnamate (EPMC) and to study it's the mechanism of action.
MATERIALS AND METHODS: A HPLC method was developed and validated for the quality assessment of KGR using its two major phytochemicals i.e. ethyl-p-methoxycinnamate (EPMC) and ethyl cinnamate (EC) in KGR. The vasorelaxation effect of major phytochemicals of KGR was evaluated on the main mesenteric arteries isolated from male Wistar rats. Specific BKca channel blocker tetraethylammonium (TEA), receptor antagonist, nitric oxide scavenging capacity, and antioxidant potential were also evaluated for its plausible mechanism.
RESULTS: Present validated HPLC method facilitates simultaneous quantitation of EPMC and EC faster than classical GC techniques. EPMC has shown a dose-dependent relaxation in rat main mesenteric arteries (MMA) contracted by U46619 with an Emax of 58.68 ± 3.31%. Similarly, in endothelium-denuded MMA rings, relaxation was also observed (Emax of 61.83 ± 3.38%). Moreover, relaxation response to EPMC has strongly inhibited (Emax 14.76 ± 2.29%) when the tissue exposed to depolarizing high K+ containing buffer for the contraction. The point correlation dimension (pD2) values were also significantly decreased in high K+ treated arterial rings compared to control. Interestingly, when MMA rings incubated with a specific BKca channel blocker (TEA, 1 mM), the relaxation response to EPMC was also significantly blocked.
CONCLUSIONS: The first time this study demonstrated the chemical standardization of K. galanga rhizome and EPMC is responsible for its vasorelaxation potential as demonstrated by the endothelium-independent response mediated by Ca2+ dependent potassium channels.
OBJECTIVE: Identify the predictive factors for development of CI-AKI in patients prescribed NAC.
DESIGN: Prospective, cross-sectional.
SETTING: A tertiary hospital in Malaysia.
PATIENTS AND METHODS: All adult patients who were prescribed NAC for prevention of CI-AKI were identified through an NAC drug us.age monitoring card maintained by the inpatient pharmacy. The study was conducted from March to July 2017.
MAIN OUTCOME MEASURES: Statistically significant predictive fac.tors for development of CI-AKI despite NAC administration.
SAMPLE SIZE: 152 RESULTS: The most commonly recognized risk factors for CI-AKI present in the study population were renal impairment (n=131, 86.2%), anemia (n=107, 70.4%), and diabetes mellitus (n=90, 59.2%). Hydration therapy was initiated in 128 patients (84.2%) prior to the contrast-enhanced procedure. Sixty-one (40.1%) were treated with nephrotoxic medications concomitantly with NAC. Fifteen (9.9%) patients developed AKI. Hypotension (OR: 6.02; 95% CI 1.25-28.97) and use of high contrast volume (OR: 6.56; 95% CI: 1.41-30.64) significantly increased the odds for AKI. Prior hydration therapy (OR: 0.13; 95% CI 0.03-0.59) showed protective effects.
CONCLUSION: The risk predictors identified for CI-AKI were hypotension, high contrast volume and prior hydration therapy.
LIMITATION: May not have identified other confounding factors for development of CI-AKI.
CONFLICT OF INTEREST: None.
METHODS: The phenolic compounds of PKC were obtained by solvent extraction and the product rich in phenolic compounds was labeled as phenolic-enriched fraction (PEF). This fraction was evaluated for its phenolic compounds composition. The antioxidant activity of PEF was determined by using 1,1-diphenyl-2-picryl-hydrazil scavenging activity, ferric reducing antioxidant power, inhibition of ß-carotene bleaching, and thiobarbituric acid reactive substances assays. The cytotoxicity assay and molecular biomarkers analyses were performed to evaluate the cytoprotective effects of PEF towards aflatoxin B1 (AFB1)-induced cell damage.
RESULTS: The results showed that PEF contained gallic acid, pyrogallol, vanillic acid, caffeic acid, syringic acid, epicatechin, catechin and ferulic acid. The PEF exhibited free radical scavenging activity, ferric reducing antioxidant power, ß-carotene bleaching inhibition and thiobarbituric acid reactive substances inhibition. The PEF demonstrated cytoprotective effects in AFB1-treated chicken hepatocytes by reducing the cellular lipid peroxidation and enhancing antioxidant enzymes production. The viability of AFB1-treated hepatocytes was improved by PEF through up-regulation of oxidative stress tolerance genes and down-regulation of pro-inflammatory and apoptosis associated genes.
CONCLUSIONS: The present findings supported the proposition that the phenolic compounds present in PKC could be a potential cytoprotective agent towards AFB1 cytotoxicity.