- A Big Thank You to our Reviewers in the Past Year! [Journal Article]
- PMPlanta Med 2017; 83(1-02):2-6
- Editorial. [Journal Article]
- PMPlanta Med 2017; 83(1-02):1
- Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography. [Journal Article]
- PMPlanta Med 2017 Jan 17
- A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessnes...
A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydrokavain, demethoxyyangonin, kavain, yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC(2) BEH 1.7 µm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 °C could kavain and yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.
- Antichlamydial Dimeric Indole Derivatives from Marine Actinomycete Rubrobacter radiotolerans. [Journal Article]
- PMPlanta Med 2017 Jan 17
- Chlamydiae are widely distributed pathogens of human populations, which can lead to serious reproductive and other health problems. In our search for novel antichlamydial metabolites from marine deri...
Chlamydiae are widely distributed pathogens of human populations, which can lead to serious reproductive and other health problems. In our search for novel antichlamydial metabolites from marine derived-microorganisms, one new (1) and two known (2, 3) dimeric indole derivatives were isolated from the sponge-derived actinomycete Rubrobacter radiotolerans. The chemical structures of these metabolites were elucidated by NMR spectroscopic data as well as CD calculations. All three metabolites suppressed chlamydial growth in a concentration-dependent manner. Among them, compound 1 exhibited the most effective antichlamydial activity with IC50 values of 46.6 ~ 96.4 µM in the production of infectious progeny. Compounds appeared to target the mid-stage of the chlamydial developmental cycle by interfering with reticular body replication, but not directly inactivating the infectious elementary body.
- Biosynthetic Studies on Acetosellin and Structure Elucidation of a New Acetosellin Derivative. [Journal Article]
- PMPlanta Med 2017 Jan 12
- Natural products from fungi, especially Ascomycota, play a major role in therapy and drug discovery. Fungal strains originating from marine habitats offer a new avenue for finding unusual molecular s...
Natural products from fungi, especially Ascomycota, play a major role in therapy and drug discovery. Fungal strains originating from marine habitats offer a new avenue for finding unusual molecular skeletons. Here, the marine-derived fungus Epicoccum nigrum (strain 749) was found to produce the azaphilonoid compounds acetosellin and 5',6'-dihydroxyacetosellin. The latter is a new natural product. The biosynthesis of these polyketide-type compounds is intriguing, since two polyketide chains are assembled to the final product. Here we performed (13)C labeling studies on solid cultures to prove this hypothesis for acetosellin biosynthesis.
- Nano-Pelargonidin Protects Hyperglycemic-Induced L6 Cells against Mitochondrial Dysfunction. [Journal Article]
- PMPlanta Med 2017 Jan 10
- Nano-encapsulation of several natural products has become an important tool in enhancing the bioavailability of some modern drugs against many diseases. Pelargonidin is an anthocyanidin found in many...
Nano-encapsulation of several natural products has become an important tool in enhancing the bioavailability of some modern drugs against many diseases. Pelargonidin is an anthocyanidin found in many fruits and vegetables. Pelargonidin is loaded with poly-lactide-co-glycolic-acid, a non-toxic biodegradable polymer, to produce nano-pelargonidin. Size, morphology, zeta potential, and planar uniformity of formulated nano-pelargonidin were determined by atomic force microscopy and dynamic light scattering. The time required for cellular entry, folds of nano-pelargonidin, and drug encapsulation efficiency of poly-lactide-co-glycolic-acid were also ascertained. Relative functional efficacy of nano-pelargonidin and pelargonidin was evaluated by examining markers such as pyruvate kinase, glucokinase, calcium ion level, ATP/ADP ratio, mitochondrial membrane potential, cytosolic release of mitochondrial cytochrome-c, and structural analysis of mitochondrial DNA in controlled and experimental sets of alloxan-induced hyperglycemic L6 cells. Expressions of mitochondrial apoptotic proteins, such as bcl2 and caspase3, and glucose signalling cascades, such as GLUT4, IRS1, IRS2, and PI3, were analyzed. Nano-pelargonidin at a nearly 10-fold reduced dose significantly enhanced protection, presumably due to its smaller size, ability of faster entry, and drug delivery at target-specific sites. Thus, nano-pelargonidin can be used in formulating protective drugs for therapeutic management of mitochondrial dysfunction often encountered in diabetic conditions.
- In Vitro Inhibition of Human CYP450s 1A2, 2C9, 3A4/5, 2D6 and 2E1 by Grandisin. [Journal Article]
- PMPlanta Med 2017 Jan 10
- Grandisin, a lignan isolated from many species of plants, such as Virola surinamensis, is a potential drug candidate due to its biological properties, highlighted by its antitumor and trypanocidal ac...
Grandisin, a lignan isolated from many species of plants, such as Virola surinamensis, is a potential drug candidate due to its biological properties, highlighted by its antitumor and trypanocidal activities. In this study, the inhibitory effects of grandisin on the activities of human cytochrome P450 enzymes were investigated by using human liver microsomes. Results showed that grandisin is a competitive inhibitor of CYP2C9 and a competitive and mechanism-based inhibitor of CYP3A4/5. The apparent Ki value for CYP2C9 was 50.60 µM and those for CYP3A4/5 were 48.71 µM and 31.25 µM using two different probe substrates, nifedipine and midazolam, respectively. The apparent KI, kinact, and kinact/KI ratio for the mechanism-based inhibition of CYP3A4/5 were 6.40 µM, 0.037 min(-1), and 5.78 mL · min(-1) µmol(-1), respectively, by examining nifedipine oxidation, and 31.53 µM, 0.049 min(-1), and 1.55 mL · min(-1) µmol(-1), respectively, by examining midazolam 1'-hydroxylation. These apparent kinact/KI values were comparable to or even higher than those for several therapeutic drugs that act as mechanism-based inhibitors of CYP3A4/5. CYP1A2 and CYP2D6 activities, in turn, were not substantially inhibited by grandisin (IC50 > 200 µM and 100 µM, respectively). In contrast, from a concentration of 4 µM, grandisin significantly stimulated CYP2E1 activity. These results improve the prediction of grandisin-drug interactions, suggesting that the risk of interactions with drugs metabolized by CYP3A4/5 and CYP2E1 cannot be overlooked.
- In Vitro Metabolism of Artepillin C by Rat and Human Liver Microsomes. [Journal Article]
- PMPlanta Med 2017 Jan 10
- Artepillin C, a natural product present in the Brazilian green propolis, has several biological properties. Among these properties, the antitumor action of this product is noteworthy and makes it a p...
Artepillin C, a natural product present in the Brazilian green propolis, has several biological properties. Among these properties, the antitumor action of this product is noteworthy and makes it a promising drug candidate for the treatment of several types of cancer. This paper describes the in vitro metabolism of Artepillin C in rat and human liver microsomes. The rat model suggested a sigmoidal profile for the metabolism, adapted to the Hill's kinetic model. The enzymatic kinetic parameters were as follows: maximal velocity = 0.757 ± 0.021 µmol/mg protein/min, Hill coefficient = 10.90 ± 2.80, and substrate concentration at which half-maximal velocity of a Hill enzyme is achieved = 33.35 ± 0.55 µM. Based on these results, the calculated in vitro intrinsic clearance for Artepillin C was 16.63 ± 1.52 µL/min/mg protein. The in vitro metabolism assay conducted on the human model did not fit any enzymatic kinetic model. Two novel metabolites were formed in both mammal microsomal models and their chemical structures were elucidated for the first time. The main human cytochrome P450 isoforms involved in Artepillin C metabolism had been identified, and the results suggest a majority contribution of CYP2E1 and CYP2C9 in the formation of the two metabolites.
- Erratum: Naphthoquinones from Onosma paniculatum with Potential Anti-inflammatory Activity. [Journal Article]
- PMPlanta Med 2017 Jan 09
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- Evodiamine Prevents Isoproterenol-Induced Cardiac Fibrosis by Regulating Endothelial-to-Mesenchymal Transition. [Journal Article]
- PMPlanta Med 2016 Dec 23
- Evodiamine, a major component of Evodia rutaecarpa, can protect the myocardium against injury induced by atherosclerosis and ischemia-reperfusion. However, the effect of evodiamine against cardiac fi...
Evodiamine, a major component of Evodia rutaecarpa, can protect the myocardium against injury induced by atherosclerosis and ischemia-reperfusion. However, the effect of evodiamine against cardiac fibrosis remains unclear. This study aims to investigate the possible effect and mechanism involved in the function of evodiamine on isoproterenol-induced cardiac fibrosis and endothelial-to-mesenchymal transition. Isoproterenol was used to induce cardiac fibrosis in mice, and evodiamine was gavaged simultaneously. After 14 days, cardiac function was accessed by echocardiography. The extent of cardiac fibrosis and hypertrophy was evaluated by pathological and molecular analyses. The extent of endothelial-to-mesenchymal transition was evaluated by the expression levels of CD31, CD34, α-smooth muscle actin, and vimentin by immunofluorescence staining and Western blot analysis. After 14 days, the heart weight/body weight ratio and heart weight/tibia length ratio revealed no significant difference between the isoproterenol group and the isoproterenol/evodiamine-treated groups, whereas the increased heart weight was reduced in the isoproterenol/evodiamine-treated groups. Echocardiography revealed that interventricular septal thickness and left ventricular posterior wall thickness at the end diastole decreased in the evodiamine-treated groups. Evodiamine reduced isoproterenol-induced cardiac fibrosis as accessed by normalization in collagen deposition and gene expression of hypertrophic and fibrotic markers. Evodiamine also prevented endothelial-to-mesenchymal transition as evidenced by the increased expression levels of CD31 and CD34, decreased expression levels of α-smooth muscle actin and vimentin, and increased microvascular density in the isoproterenol/evodiamine-treated mice hearts. Furthermore, isoproterenol-induced activation of transforming growth factor-β1/Smad signal was also blunted by evodiamine. Therefore, evodiamine may prevent isoproterenol-induced cardiac fibrosis by regulating endothelial-to-mesenchymal transition, which is probably mediated by the blockage of the transforming growth factor-β1/Smad pathway.