Gramicidin inhibits human gastric cancer cell proliferation, cell cycle and induced apoptosis

BACKGROUND: Gastric cancer is a common malignant tumor with high morbidity and mortality worldwide, which seriously affects human health. Gramicidin is a short peptide antibiotic which could be used for treating infection induced by bacteria or fungi. However, the anti-cancer effect of gramicidin on gastric cancer cells and its underlying mechanism remains largely unknown. RESULTS: Gastric cancer cells SGC-7901, BGC-823 and normal gastric mucosal cells GES-1 were treated with different concentrations of gramicidin respectively. The results of CCK-8 experiment revealed cellular toxicity of gramicidin to cancer cells while cell colony formation assay showed that gramicidin significantly inhibited the proliferation of gastric cancer cells, but had little effect on normal gastric mucosal cells. In addition, the wound healing assay showed that gramicidin inhibited the migration of SGC-7901 cell. Meanwhile, apoptosis and cell cycle analysis revealed that gramicidin induced cell apoptosis with G2/M cell cycle inhibition. Furthermore, western blot analysis demonstrated that gramicidin down-regulated the expression of cyclinD1 and Bcl-2 as well as the FoxO1 phosphorylation. CONCLUSIONS: The current study illustrated the anti-tumor activity of gramicidin on gastric cancer cells, providing a possibility for gramicidin to be applied in clinical practice for the treatment of gastric cancer.

Korean red ginseng excitation of paraventricular nucleus neurons via non-N-methyl-D-aspartate glutamate receptor activation in mice

It has been reported that Korean red ginseng (KRG), a valuable and important traditional medicine, has varied effects on the central nervous system, suggesting its activities are complicated. The paraventricular nucleus (PVN) neurons of the hypothalamus has a critical role in stress responses and hormone secretions. Although the action mechanisms of KRG on various cells and systems have been reported, the direct membrane effects of KRG on PVN neurons have not been fully described. In this study, the direct membrane effects of KRG on PVN neuronal activity were investigated by using a perforated patch-clamp in ICR mice. In gramicidin perforated patch-clamp mode, KRG extract (KRGE) induced repeatable depolarization followed by hyperpolarization of PVN neurons. The KRGE-induced responses were concentration-dependent and persisted in the presence of tetrodotoxin, a voltage sensitive Na+ channel blocker. The KRGE-induced responses were suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione (10 µM), a non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist, but not by picrotoxin, a type A gamma-aminobutyric acid receptor antagonist. The results indicate that KRG activates non-NMDA glutamate receptors of PVN neurons in mice, suggesting that KRG may be a candidate for use in regulation of stress responses by controlling autonomic nervous system and hormone secretion.

Participation of central GABAA receptors in the trigeminal processing of mechanical allodynia in rats

Here we investigated the central processing mechanisms of mechanical allodynia and found a direct excitatory link with low-threshold input to nociceptive neurons. Experiments were performed on male Sprague-Dawley rats weighing 230-280 g. Subcutaneous injection of interleukin 1 beta (IL-1β) (1 ng/10 µL) was used to produce mechanical allodynia and thermal hyperalgesia. Intracisternal administration of bicuculline, a gamma aminobutyric acid A (GABAA) receptor antagonist, produced mechanical allodynia in the orofacial area under normal conditions. However, intracisternal administration of bicuculline (50 ng) produced a paradoxical anti-allodynic effect under inflammatory pain conditions. Pretreatment with resiniferatoxin (RTX), which depletes capsaicin receptor protein in primary afferent fibers, did not alter the paradoxical anti-allodynic effects produced by the intracisternal injection of bicuculline. Intracisternal injection of bumetanide, an Na-K-Cl cotransporter (NKCC 1) inhibitor, reversed the IL-1β-induced mechanical allodynia. In the control group, application of GABA (100 µM) or muscimol (3 µM) led to membrane hyperpolarization in gramicidin perforated current clamp mode. However, in some neurons, application of GABA or muscimol led to membrane depolarization in the IL-1β-treated rats. These results suggest that some large myelinated Aβ fibers gain access to the nociceptive system and elicit pain sensation via GABA(A) receptors under inflammatory pain conditions.

Estilos de vida nas capitais brasileiras segundo a Pesquisa Nacional de Saúde e o Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas Não Transmissíveis por Inquérito Telefônico (Vigitel), 2013 / Lifestyles in Brazilian capitals according to the National Health Survey and the Surveillance System for Protective and Risk Factors for Chronic Diseases by Telephone Survey (Vigitel), 2013

RESUMO: Objetivo: Descrever os principais resultados dos fatores de risco e proteção de doenças crônicas não transmissíveis (DCNT), nas capitais brasileiras e no Distrito Federal, coletados pela Pesquisa Nacional de Saúde (PNS) e pelo Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas Não Transmissíveis por Inquérito Telefônico (Vigitel) no ano de 2013. Métodos Análise de dados advindos da PNS e do Vigitel, pesquisas realizadas no ano de 2013. Foram analisados indicadores sobre tabagismo, consumo de álcool, alimentação e atividade física, segundo sexo, com intervalo de confiança de 95% (IC95%). Resultados: As prevalências encontradas foram: fumantes atuais de cigarro - PNS 12,5% e Vigitel 11,3%; consumo abusivo de bebida alcoólica - PNS 14,9% e Vigitel 16,4%; consumo recomendado de frutas e hortaliças - PNS 41,8% e Vigitel 23,6%; prática de atividade física no tempo livre - PNS 26,6% e Vigitel 33,8%. Conclusão: Os resultados dos indicadores foram semelhantes, em especial quando as perguntas e opções de resposta também eram. As pesquisas são úteis para o monitoramento dos fatores de risco e proteção das DCNT, podendo apoiar programas de promoção da saúde.

ABSTRACT: Objective: To describe risk and protective factors for chronic diseases, in Brazilian capitals and the Federal District, collected by the National Health Survey (PNS) and by the Surveillance System for Protective and Risk Factors for Chronic Diseases by Telephone Survey (Vigitel) in 2013. Methods: Data analysis of the studies conducted by the PNS and Vigitel in 2013 was performed. Indicators analyzed were: smoking, alcohol consumption, diet, and physical activity, according to sex, with a 95% confidence interval. Results: The prevalences found were: current cigarette smokers: PNS, 12.5% and Vigitel, 11.3%; abuse of alcoholic beverages: PNS, 14.9% and Vigitel, 16.4%; recommended intake of fruits and vegetables: PNS, 41.8% and Vigitel, 23.6%; and physical activity in leisure time: PNS, 26.6% and Vigitel, 35.8%. Conclusion: In the majority of indicators, the results were similar, especially when the questions and response options were equal. Surveys are useful for the monitoring of risk and protective factors of noncommunicable diseases and can support health promotion programs.

Progress in the study of some important natural bioactive cyclopeptides / 药学学报

Natural cyclopeptides are hot spots in chemical and pharmaceutical fields because of the wide spreading bio-resources, complex molecular structures and various bioactivities. Bio-producers of cyclopeptides distribute over almost every kingdom from bacteria to plants and animals. Many cyclopeptides contain non-coded amino acids and non-pepditic bonds. Most exciting characteristic of cyclopeptides is a range of interesting bioactivities such as antibiotics gramicidin-S (2), vancomycin (3) and daptomycin (4), immunosuppressive cyclosporin-A (1) and astin-C (8), and anti-tumor aplidine (5), RA-V (6) and RA-VII (7). Compounds 1-4 are being used in clinics; compounds 5-8 are in the stages of clinical trial or as a candidate for drug research. In this review, the progress in chemical and bioactive studies on these important natural bioactive cyclopeptides 1-8 are introduced, mainly including discovery, bioactivity, mechanism, QSAR and synthesis.

Development of agar diffusion method for dosage of gramicidin / Desenvolvimento do método de difusão em agar para dosagem de gramicidina

Gramicidin, an antimicrobial peptide active against Gram positive bacteria, is commonly used in pharmaceutical preparations for topical use. Considering that only the turbidimetric method has been described in the literature, the present study sought to develop and validate an agar diffusion method for the dosage of gramicidin. The method was developed and validated using the Kocuria rhizophila ATCC 9341 as a test microorganism. Two designs were used: a 3x3 parallel-line model, and a 5x1 standard curve. The validation demonstrated that the method follows the linear model (r²= 0.994), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 5 to 25.3 µg/mL. The results obtained for both designs were precise, having a relative standard deviation (R.S.D.) for intra-day precision of 0.81 for the 3x3 assay and 1.90 for the 5x1 assay. For the inter-day precision, the R.S.D. was 1.35 for the 3x3 and 2.64 for the 5x1. The accuracy was verified and results confirmed to be accurate, having a tolerance interval of 95 percent, which lay within permitted limits and appropriate trueness. In addition, the method was considered selective, with limit of detection and upper and lower limits of quantification of 2.00, 5.00 and 25.3 µg/mL, respectively. No difference in precision between the designs used in the agar diffusion method was evident (p>0.05). The method proved to be appropriate for the microbiological dosage of the raw material gramicidin.

A gramicidina, um peptídeo antimicrobiano ativo contra bactérias Gram positivo, é utilizada em preparações farmacêuticas de uso tópico. Neste trabalho procurou-se desenvolver e validar outro método para o doseamento de gramicidina tendo em vista que somente o método turbidimétrico é descrito. O método de difusão em ágar foi desenvolvido e validado utilizando como microrganismo teste Kocuria rhizophila ATCC 9341. Foram utilizados dois delineamentos: retas paralelas 3x3 e curva padrão 5x1. A validação demonstrou que o método segue o modelo linear (r²= 0,994) havendo regressão significativa entre o diâmetro dos halos de inibição e o logaritmo da concentração na faixa de 5,00 a 25,3 µg/mL. Os resultados obtidos por ambos os delineamentos foram precisos apresentando desvio padrão relativo (DPR) para precisão intra-dia de 0,81 para ensaio 3x3 e de 1,90 para ensaio 5x1. Para a precisão inter-dias o DPR foi de 1,35 para 3x3 e de 2,64 para 5x1. A exatidão foi verificada e os resultados foram exatos apresentando intervalo de tolerância a 95 por cento dentro dos limites permitidos e veracidade adequada. O método foi seletivo com limites de detecção e quantificação inferior e superior iguais a 2,00, 5,00 e 25,3 µg/mL, respectivamente. Não foi observada diferença entre a precisão dos delineamentos empregados no método de difusão em ágar (p>0.05). O método se mostrou adequado para a dosagem microbiológica de gramicidina matéria-prima.

Somatostatin Inhibits Gonadotropin Releasing Hormone Neuronal Activities in Juvenile Mice

BACKGROUND: The gonadotropin releasing hormone (GnRH) neurons perform a pivotal function in the central regulation of fertility. Somatostatin (SST) is an important neuromodulatory peptide in the central nervous system and alters neuronal activities via G protein- coupled SST receptors. A number of studies have shown that SST modulates the reproductive axis at the hypothalamic level. However, the precise action mechanisms of SST and related receptor subtypes have yet to be fully understood. In this study, we evaluated the direct effects of SST on GnRH neurons in juvenile mice. METHODS: Juvenile (postnatal days, < PND 30) GnRH-GFP transgenic mice expressing green fluorescent protein were used in this study. Acute coronal brain slices containing the preoptic area were prepared and all identified GnRH neurons were recorded using the gramicidin perforated-patch clamp technique; type II SST receptor (SSTR2) mRNA expression was evaluated via single cell reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: SST caused membrane hyperpolarization, depolarization, no response, or membrane hyperpolarization with a reduction of action potential. Most (57.7%, 30/52) of the GnRH neurons tested were hyperpolarized by SST and this SST-induced hyperpolarization was found to be concentration-dependent. The percentage of responses, membrane potential changes (MPC), and resting membrane potential (RMP) by SST were not significantly different in juvenile male and female GnRH neurons. The SST-induced hyperpolarization was maintained in the presence of tetrodotoxin (TTX), a sodium channel blocker, and an amino acid blocking cocktail (AABC) containing AP-5 (NMDA receptor antagonist), CNQX (non-NMDA glutamate receptor antagonist), picrotoxin (GABAA receptor antagonist), and strychnine (glycine receptor antagonist). SSTR2 mRNA was expressed on 10 (38%) among 26 GnRH neurons. Seglitide, an SSTR2 agonist, mimicked this SST-induced hyperpolarization (11/23 47.8%) and this response was maintained in the presence of TTX and AABC. CONCLUSION: Our data show that SST can exert potent inhibitory action against GnRH neuronal excitability via SSTR2 activation in juvenile mice.

Polaron hopping in some biomolecular solids and their charge transfer complexes.

The solid state spectroscopy of charge transfer complexes of biomolecules such as fatty acids, tripalmitin, lysozyme. folic acid, beta-carotene, cytochrome c, valinomycin and gramicidin has been carried out. The absorption coefficient is related with electronic conductivity. A half-power beta density is found common among these macromolecular solids, indicating photon-induced polaron hopping or hopping of a charge carrier between two branches of a polariton. Band gap vs full width at half-maximum of the mid-IR peak also reveals a linear relation.

Stability study of tri-otic ear drop

The aim of this method is to study the stability of a potent Tri-Otic ear drop oily suspension non pharmacopoeia, as pharmaceutical dosage form four active ingredients. This ear drop consists from Triamcinolon acetonide as corticosteroid and Neomycin sulphate, Gramicidin as antibacterial agents as well as Nystatin as antifungal agent. This study based upon the accelerated stability study for many samples store at different temperatures 4, 25, 40°C, in amber colour glass containers for three months. The results were analyzed using HPLC technique for Triamcinolon acetonide degassing solution consists from highly purified water: acetonitril 30:70 [V/V%] as mobile phase with rate of flow 1.5 ml/ min, using ODS column. The spectrums were detected at 330 nm for maximum peak and area under the curve [AUC]. While biological methods used for analyzed both Neomycin sulphate and Nystatin. The media used for culture at 35-37°C for 7 days at pH 5.8-8 consist from potassium di hydrogen phosphate with sodium hydroxide for inhibition zone and applied biological assay. All active ingredients were extracted four times. From correlation between the concentration and time used by applying accelerated stability study data, according to the Arrhenius equation, we found the hydrolysis of oil suspension was pseudo first order K = Ln[2] /1 [0.5]. Our conclusion show that the Tri-Otic ear drop useful for two years approximately at 4°C

Research development of chemistry and bioactive activity of plant peptides / 中国中药杂志

As the technologies of separation, purification and determination develop rapidly, more and more peptide compounds, which have special bioactive and medical value, have been separated from natural plants, such as oligopeptides and cyclopeptides. The chemical structures and function of these plant peptides have been researched profoundly. This paper mainly reviews the composition, structure, bioactive function and medicine value of representative plant peptides in recent years, and can give some references about research and application of plant bioactive peptides.

Comparison of preoperative anti-infective preparations for extracapsular lens extraction

Objective: To investigate the effect of three preoperative anti-infective regimens on the sterility of anterior-chamber aspirates (ACA) in eyes undergoing extracapsular cataract extraction (ECCE). Methods: Ninety eyes scheduled to undergo ECCE were randomly assigned to receive one of the following preoperative anti-infective regimens: Group 1 (Control) - no additional preoperative preparation; Group 2 (Eye drop) - neomycin/ polymixin B/gramicidin eye drops applied 3 times daily for 3 days prior to surgery; and Group 3 (Lid scrub) - neomycin/polymixin B/ bacitracin ointment lid scrub applied 3 times prior to surgery. ACAs were obtained from all eyes at the conclusion of surgery and cultured. The patients were followed up for 3 months after the surgery. Results: Positive cultures developed from ACAs in 5 (16.6 percent) of 30 eyes from Group 1, in 0 of 30 from Group 2, and in 3 (10 percent) of 30 from Group 3. No eye developed endophthalmitis. Compared with the control group, preoperative neomycin/polymixin B/gramicidin eye drops significantly reduced the ACA contamination rate (p= 0.03). Conclusion: Preoperative neomycin/polymixin B/bacitracin eyedrops can improve the sterility of the anterior chamber during ECCE.

The Effect of Alcohol in the Nicotinic Acetylcholine Receptor / 대한정신약물학회지

OBJECTIVE: It has been well known that alcohol can modulate several ligand-gated ion channel and voltage-gated ion channels. But the roles of alcohol in the autonomic neurons still remain unclear. In this study, thus we characterized the neuronal acetylcholine receptor (nnAChRs) and investigated the modulation of nnAChRs by ethanol (EtOH). METHODS: We used whole-cells which were acutely dissociated male rat major pelvic ganglion (MPG) neurons, and used gramicidin perforated patch clamp techniques. RESULTS: MPG neurons can be classified on the basis of the response of the soma membrane to depolarizing current pulses ; either tonic or phasic neurons. Sympathetic neurons expressing T-type Ca(2+) channels showed tonic firing pattern, while parasympathetic neurons lacking T-type Ca(2+) channels phasic firing to depolarizing current pulses. When hyperpolarizing currents were injected, sympathetic neurons produced post-anodal rebound spikes, while parasympathetic neurons were silent. Under current clamp mode, Acetylcholine (ACh) evoked significant membrane depolarization and produced subsequently marked membrane hyperporization. Under whole-cell mode, application of ACh-induced inward currents held at holding potentials below 0 mV and reversal potential was close to 0 mV, an equilibrium potential of nonselective cation channel. The ACh-activated current was blocked by methyllycaconitine (MLA ; 10 micrometer), hexamethonium (100 micrometer) and alpha-bungarotoxin (alpha-BuTx ; 100 nM), nAChRs antagonists. EtOH (40 mM) potentiated ACh-induced depolarization and hyperpolarization. EtOH also increased both alpha-BuTx-sensitive and -insensitive ACh-activated currents. Futhermore, EtOH potentiated 5-HT-activated current but had a little effect on GABA-activated current. CONCLUSION: These results suggest that EtOH modulates nnAChRs and 5-HT receptors in MPG neurons.

Effectiveness of combined antibiotic ophthalmic solution in the treatment of hordeolum after incision and curettage: a randomized, placebo-controlled trial: a pilot study.

The presented pilot study compared the effectiveness of combined antibiotic ophthalmic solution (neomycin sulfate, polymyxin B sulfate and gramicidin) with a placebo (artificial tear) in the treatment of hordeolum after incision and curettage (I&C). A randomized, placebo-controlled trial with patients and investigators blinded from the start started from June 2002 to May 2003. Subjects were patients with untreated hordeolum who subsequently underwent I&C at the Ophthalmology Department. The patients were randomized into 2 groups: group A for combined antibiotic ophthalmic solution, and group B for artificial tear containing the antibiotic solution base. Pain score, mass size and duration of cure were recorded before and on the 3rd and 7th day after treatment. The study included 14 patients in each group. Two subjects in group A and three subjects in group B dropped out. There were no statistically significant differences of all outcomes in both groups, even with the intention-to-treat analysis. The conclusion is combined antibiotic ophthalmic solution is not more effective than placebo in the treatment of hordeolum after I&C.

Real physiological neuronal responses revealed by gramicidin perforated patch recording

In order to understand the phenomenon in a living cell correctly, it has been required to obtain intact responses from the cell membrane without disrupting the cytoplasmic circumstances. Gramicidin perforated patch configuration allows the electrical access to the whole cell with a minimal dialysis of cytoplasm and preventing the loss of native intracellular constituents, such as Cl-. Here, we would like to show the background of this method and the actual application of the gramicidin perforated patch recording mode on the dissociated neurons.

Gramicidin channels--a solvable membrane "protein" folding problem.

The linear gramicidins are peptide antibiotics that form cation-selective channels in lipid bilayers. Gramicidin channels have very well-defined functional characteristics, and the structure of membrane-spanning gramicidin A channels is known at atomic resolution. These features make the gramicidins well suited to study how the amino acid sequence encodes the structure and function of a membrane-spanning channel. We show how one can use electrophysiological measurements to obtain structural information about conducting channels and to quantify the conformational preferences of sequence-substituted gramicidin mutants.

Polyspectran in the treatment of bacterial conjunctivitis

Polyspectran[R] [Thilo, Munich, Germany] topical eye medication contains polymyxin B, neomycin, and gramicidin. The combination exhibits broad - spectrum antimicrobial activity. All three drugs are too toxic for systemic use. Our objective was to assess Polyspectran's[R] effectiveness in the treatment of bacterial conjunctivitis, as well as patients' acceptance of and tolerance to this combination. Thirty-three patients with a clinical diagnosis of mucopurulent conjunctivitis who were also culture-positive for bacterial conjunctivitis were entered in the study. All received topical Polyspectran[R] eyedrops six times per day, and Polyspectran[R] eye ointment at bedtime. In two patients [6%], treatment had to be discontinued because of an allergic reaction, later found to be due to the neomycin component. The remaining 31 patients completed a one - week course of therapy. Clinical signs and symptoms were reduced by 50% or more within one week of cassation of therapy in 30 [97%] of these; 28 [90%] had a microbiological cure. The study suggests that topical Polyspectran[R] is a safe and effective therapeutic modality for the treatment of bacterial conjunctivitis

Avaliaçäo da sensibilidade "in vitro" à associaçäo de sulfato de framicetina, sulfato de polimixina B e gramicidina / Evaluation of the sensibility \"in vitro\" to the association of framycetin sulfate, polymyxin B sulfate and gramicidin

A fim de avaliar a sensibilidade "in vitro" à associaçäo de sulfato de framicetina, sulfato de polimixina B e gramicidina, estudamos amostras de 96 pacientes portadores de patologias oculares externas e de 4 lentes de contato gelatinosas. De 112 antibiogramas realizados, 80 (71,4%) foram por Staphylococcus aureus, cuja sensibilidade incluindo todas as bactérias de 85,7% (96). Esta associaçäo é composta por 3 antibióticos bactericidas näo usados sistematicamente de rotina