Antioxidants from the Brown Alga Dictyopteris undulata.

An investigation of anti-oxidative compounds from the brown alga Dictyopteris undulata has led to the isolation and identification of isozonarol, isozonarone, chromazonarol, zonaroic acid and isozonaroic acid. Their structures were identified by comparison of MS and NMR spectra. Full NMR assignment and absolute configuration of isozonaroic acid are described. Isozonarol showed the most potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity among the compounds isolated.

Evidence that naturopathic therapy including Cordyceps sinensis prolongs survival of patients with hepatocellular carcinoma.

HYPOTHESIS: Naturopathic treatment will benefit patients with hepatocellular carcinoma (HCC). STUDY DESIGN: Retrospective analysis of case series of HCC patients treated with naturopathic agents. METHODS: HCC was diagnosed by dynamic computed tomography (CT) imaging and α-fetoprotein (AFP) or PIVKA II, or by histology. Tumor staging was determined by CT. A modified Childs-Pugh scoring was used to assess liver disease. Patients were treated with orally administered combinations of 12 naturopathic agents. Patients were monitored clinically and by CT tumor imaging, serial tumor markers, and liver function tests. PATIENT CHARACTERISTICS: 101 patients with HCC (67 men and 34 women, age 67.2 ± 8.8 years) were treated for a median of 13.4 months (range 0.8-100.8). Of these 84% had cirrhosis, 63% had hepatitis C virus, 18% had hepatitis B virus, 1% had both, and 9% had metastatic disease. Median modified Childs-Pugh score was 6 (range 3-13). Barcelona Clinic Liver Cancer tumor stages of 0, A, B, C, and D were found in 36%, 25%, 20%, 14%, and 6%, respectively. Median AFP was 40 (range 0-311,000). Median PIVKA II was 59 (0-378,000). Previous treatment was included none (27%), resection with relapse (20%), transarterial chemoembolization (50%), radiofrequency ablation (28%), percutaneous ethanol injection therapy (15%), chemotherapy (14%). OUTCOMES: Initial treatment was with 2.6 ± 0.8 agents (range 2-4). Overall, patients were treated with 3.7 ± 1.2 agents (range 2-7). There was a significant correlation between number of agents administered and survival (P < .0001). Patients treated with ≥4 agents survived significantly longer than patients treated with ≤3 agents (40.2 vs 6.4 months, P < .0001). This difference could not be attributed to statistically significant differences in severity of liver disease or tumor stage, delay in treatment, previous treatment, concurrent nondrug treatment, or censoring effects. The greatest effect was seen in patients treated with at least 4 agents that included Cordyceps sinensis. This prolonged survival was without toxic side effects and appeared to potentiate the survival benefit of conventional therapy. CONCLUSION: Treatment of HCC with a regimen of ≥4 agents prepared from natural products was associated with prolonged survival in a substantial portion of patients. The data provide level II evidence for the efficacy of naturopathic therapy in HCC.

Reciprocal control of hERG stability by Hsp70 and Hsc70 with implication for restoration of LQT2 mutant stability.

RATIONALE: The human ether-a-go-go-related gene (hERG) encodes the α subunit of the potassium current I(Kr). It is highly expressed in cardiomyocytes and its mutations cause long QT syndrome type 2. Heat shock protein (Hsp)70 is known to promote maturation of hERG. Hsp70 and heat shock cognate (Hsc70) 70 has been suggested to play a similar function. However, Hsc70 has recently been reported to counteract Hsp70. OBJECTIVE: We investigated whether Hsc70 counteracts Hsp70 in the control of wild-type and mutant hERG stability. METHODS AND RESULTS: Coexpression of Hsp70 with hERG in HEK293 cells suppressed hERG ubiquitination and increased the levels of both immature and mature forms of hERG. Immunocytochemistry revealed increased levels of hERG in the endoplasmic reticulum and on the cell surface. Electrophysiological studies showed increased I(Kr). All these effects of Hsp70 were abolished by Hsc70 coexpression. Heat shock treatment of HL-1 mouse cardiomyocytes induced endogenous Hsp70, switched mouse ERG associated with Hsc70 to Hsp70, increased I(Kr), and shortened action potential duration. Channels with disease-causing missense mutations in intracellular domains had a higher binding capacity to Hsc70 than wild-type channels and channels with mutations in the pore region. Knockdown of Hsc70 by small interfering RNA or heat shock prevented degradation of mutant hERG proteins with mutations in intracellular domains. CONCLUSIONS: These results indicate reciprocal control of hERG stability by Hsp70 and Hsc70. Hsc70 is a potential target in the treatment of LQT2 resulting from missense hERG mutations.

Self-beating atypically shaped cardiomyocytes survive a long-term postnatal development while preserving the expression of fetal cardiac genes in mice.

The present study was designed to examine the postnatal developmental changes of atypically shaped cardiomyocytes (ACMs) prepared from the heart of newborn [postnatal day 1 (day-1)] through aged (12-month-old) mice. ACMs were identified as a novel type of self-beating cardiomyocyte with a peculiar morphology in mouse cardiac ventricles. The cell length of ACMs significantly increased during the first three postnatal months and further increased over the following 9 months. In contrast, the population of ACMs was significantly decreased within the first 5 weeks and reached a plateau in the adult stage. ACMs obtained from newborn and adult mice exhibited similar spontaneous action potentials. The expression of the fetal cardiac gene products atrial natriuretic peptide and voltage-gated T-type Ca(2+) channel Ca(V)3.2 was confirmed by immunostaining in ACMs obtained from both newborn and aged mice. These observations provide evidence that ACMs that exhibit spontaneous beating survive the long-term postnatal development of cardiac ventricles while preserving the expression of fetal cardiac genes. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

Adrenergic regulation of the rapid component of delayed rectifier K+ current: implications for arrhythmogenesis in LQT2 patients.

BACKGROUND: KCNH2 gene mutations disrupting rapid component of I(K) (I(Kr)) underlie type 2 congenital long QT syndrome (LQT2). Startled auditory stimuli are specific symptomatic triggers in LQT2, thus suggesting fast arrhythmogenic mechanism. OBJECTIVE: We investigated acute alpha(1A)- and cyclic adenosine monophosphate (cAMP)-related beta-adrenergic modulation of I(Kr) in HL-1 cardiomyocytes, wild type (WT)- and 2 LQT2-associated mutant Kv11.1 channels (Y43D- and K595E-Kv11.1) reconstituted in Chinese hamster ovary (CHO) cells. METHODS: I(Kr) and Kv11.1 currents were recorded using the whole-cell patch-clamp technique and confocal microscopy of HL-1 cardiomyocytes transfected with green fluorescent protein (GFP)-tagged pleckstrin homology domain of phospholipase C-delta(1) visualized fluctuations of membrane phosphatidylinositol 4,5-bisphosphate (PIP(2)) content. RESULTS: In HL-1 cardiomyocytes expressing human alpha(1A)-adrenoceptor, superfusion with phenylephrine significantly reduced I(Kr) amplitude, shifted current activation to more positive potentials, and accelerated kinetics of deactivation. Confocal images showed a decline of membrane PIP(2) content during phenylephrine exposure. Simultaneous application of adenylyl cyclase activator forskolin and phosphodiesterase inhibitor 3-isobutyl-1-methylxantine (IBMX) shifted I(Kr) activation to more negative potentials and decreased tail current amplitudes after depolarizations between +10 and +50 mV. In CHO cells, alpha(1A)-adrenoceptor activation downregulated WT-Kv11.1 channels and forskolin/IBMX produced a dual effect. Expressed alone, the Y43D-Kv11.1 or K595E-Kv11.1 channel had no measurable function. However, co-expression of WT-Kv11.1 and each mutant protein evoked currents with loss-of-function alterations but identical to WT-Kv11.1 alpha(1A)- and forskolin/IBMX-induced regulation. CONCLUSION: Acute adrenergic regulation of at least 2 Kv11.1 mutant channels is preserved as in WT-Kv11.1 and native I(Kr). Suppression of alpha(1A)-adrenoceptor-related transduction might have therapeutic implications in some cases of LQT2.

Open-state unblock characterizes acute inhibition of I potassium current by amiodarone in guinea pig ventricular myocytes.

INTRODUCTION: The aim of the present study was to investigate the acute action of amiodarone on the slow component of delayed rectifier K+ current (IKs) under basal conditions and during beta-adrenoceptor stimulation in guinea pig ventricular myocytes. METHODS AND RESULTS: Using the whole-cell patch-clamp method, IKs was evoked by depolarizing voltage-clamp steps, during superfusion with the Na+-, K+-, and Ca2+-free solution supplemented with 0.4 microM nisoldipine and 5 microM E-4031. The acute effect of amiodarone was evaluated, within approximately 10 minutes after starting the bath application, by the amplitude of deactivating tail currents at -50 mV. Amiodarone concentration dependently blocked I(Ks) and exerted a more potent effect on IKs when activated by shorter pulse durations; the degree of block by 30 microM amiodarone on IKs activated by 200 ms, 500 ms, and 2000 ms depolarizing pulses to +30 mV was 55.9 +/- 5.8%, 38.6 +/- 6.0%, and 27.1 +/- 4.0% (n = 5 each), respectively. An envelope of tails test conducted at +10, +30, and +60 mV demonstrated that the degree of IKs block by amiodarone was gradually attenuated during membrane depolarization, which can be described by a monoexponential function, thus supporting the presence of open channel unblock. Amiodarone also blocked IKs maximally stimulated by 1 microM isoprenaline, to an extent similar to control, when IKs was activated by pulse durations of < or =2000 ms. CONCLUSION: We propose that amiodarone acutely blocks native IKs with characteristics associated with open channel unblock, and that the protein kinase A-mediated phosphorylation of channel proteins only minimally affects the amiodarone block.