Dietary Green Tea Extract and Antioxidants Improve Insulin Secretory Functions of Pancreatic β-Cells in Mild and Severe Experimental Rodent Model of Chronic Pancreatitis

Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas. It is predominantly idiopathic (with an unknown cause) in India and mostly due to alcohol in the West. Diabetes that occur secondary to chronic pancreatitis (T3c Diabetes) is often brittle, and is difficult to attain normoglycemia with conventional treatment requiring multiple doses of insulin. Mild and severe model of CP was induced in mice by repeated intraperitoneal injections of cerulein and L-arginine respectively with an intent to study islet dysfunction and develop therapeutic strategy in animal models of CP. Dietary intervention of epigallocatechin-3-gallate (EGCG) was tested in both the models of CP for its beneficial effects on insulin secretory functions. Pancreata collected upon euthanasia were used to study alterations in the morphology of pancreatic parenchyma and inflammation by staining with H&E and fibrotic changes by Masson’s trichrome and picrosirius staining. Insulin secretory functions of islets were evaluated to test the efficacy of the dietary intervention on β-cell functions. Intraperitoneal glucose tolerance test was performed to monitor the glucose homeostasis before and after the dietary intervention. Both the models resulted in CP with dispersed acini, inflammation and fibrosis. The loss of acini and extent of fibrosis was more in L-arginine model. 2-fold improvement in glucose-stimulated insulin secretory functions of islets was observed with 0.5% EGCG dietary intervention in cerulein model of CP and 1.6-fold in L-arginine model of CP. A further improvement in insulin secretion by 3.2-fold was observed with additional dietary supplements like N-acetyl cysteine, curcumin in combination with EGCG. Our results thus demonstrate and highlight the therapeutic potential of dietary green tea (EGCG) supplementation in reversing islet dysfunction and improving glucose homeostasis in experimental chronic pancreatitis in mice.

Cytoprotective effects of amifostine,ascorbic acid and N-acetylcysteine against methotrexate-induced hepatotoxicity in rats

AIM:To investigate the potential role of oxidative stress and the possible therapeutic effects of N-acetyl cysteine(NAC),amifostine(AMF)and ascorbic acid(ASC)in methotrexate(MTX)-induced hepatotoxicity.METHODS:An MTX-induced hepatotoxicity model was established in 44 male Sprague Dawley rats by administration of a single intraperitoneal injection of20 mg/kg MTX.Eleven of the rats were left untreated(Model group;n=11),and the remaining rats were treated with a 7-d course of 50 mg/kg per day NAC (MTX+NAC group;n=11),50 mg/kg per single dose AMF(MTX+AMF group;n=11),or 10 mg/kg per day ASC(MTX+ASC group;n=11).Eleven rats that received no MTX and no treatments served as the negative control group.Structural and functional changes related to MTX-and the various treatments were assessed by histopathological analysis of liver tissues and biochemical assays of malondialdehyde(MDA),superoxide dismutase(SOD),catalase,glutathione(GSH)and xanthine oxidase activities and of serum levels of aspartate aminotransferase,alanine aminotransferase,alkaline phosphatase and total bilirubin.RESULTS:Exposure to MTX caused structural and functional hepatotoxicity,as evidenced by significantly worse histopathological scores[median(range)injury score:control group:1(0-3)vs 7(6-9),P=0.001]and significantly higher MDA activity[409(352-466)nmol/g vs 455.5(419-516)nmol/g,P<0.05].The extent of MTX-induced perturbation of both parameters was reduced by all three cytoprotective agents,but only the reduction in hepatotoxicity scores reached statistical significance[4(3-6)for NAC,4.5(3-5)for AMF and 6(5-6)for ASC;P=0.001,P=0.001 and P<0.005vs model group respectively].Exposure to MTX also caused a significant reduction in the activities of GSH and SOD antioxidants in liver tissues[control group:3.02(2.85-3.43)μmol/g and 71.78(61.88-97.81)U/g vs model group:2.52(2.07-3.34)μmol/g and 61.46(58.27-67.75)U/g,P<0.05];however,only the NAC treatment provided significant increases in these antioxidant enzyme activities[3.22(2.54-3.62)μmol/g and 69.22(61.13-100.88)U/g,P<0.05 and P<0.01vs model group respectively].CONCLUSION:MTX-induced structural and functional damage to hepatic tissues in rats may involve oxidative stress,and cytoprotective agents(NAC>AMF>ASC)may alleviate MTX hepatotoxicity.

Simultaneous Determination of N-Acetyl Cysteine and Taurine by HPTLC Method in Active Pharmaceutical Ingredient and Pharmaceutical Dosage Form

Specific, precise and sensitive TLC-Densitometric method was developed and validated for the simultaneous estimation of N-Acetyl cysteine and Taurine in active pharmaceutical ingredient and pharmaceutical dosage form. An effective separation was achieved on pre-coated silica gel HPTLC plates by using n-butanol:acetic acid:water (8:0.5:1.5 v/v/v). The spots were scanned densitometrically at 295 nm. The RF values of N-Acetyl cysteine and Taurine were found to be 0.29 and 0.52, respectively. Calibration curves were linear in the range of 30 - 180 and 100 - 600 ng/band for N-Acetyl cysteine and Taurine, correspondingly with correlation coefficients of 0.999. The developed method was validated as per ICH guidelines. The limits of detection were 11.24 and 63.40 ng/spot for NAC and TAU respectively. The method developed was found to be precise and specific for the simultaneous analysis of N-Acetyl cysteine and Taurine in pure and tablet dosage form.

Reversal Effects of N-Acetyl Cysteine on <i>Moringa oleifera</i>Leaves-Induced Sub-Acute Hepatotoxicity in Wistar Albino Rats

Background: M. oleifera is a highly valued medicinal plant used widely from time immemorial to treat various ailments. However, with continued un-standardized use of the plant leaves, studies have reported organ toxicity to the liver, kidney and the heart. As communities continue to use M. oleifera leaves for its medicinal and nutritional values, there is need to find an antidote for its hepatotoxicity. Aim: The study established the reversal effect of N-Acetyl Cysteine (NAC) on M. oleifera aqueous leaf extract-induced hepatotoxicity in Wistar albino rats. Methods: Twenty-four (24) rats received a toxic dose (8.05 g/kg bwt) of M. oleifera leaf extract for 28 days to cause sub-acute hepatotoxicity. They were divided into 4 groups of 6 rats each. Group I received 1 ml normal (control group), Group II received 1000 ng/kg NAC, Group III received 1200 mg/kg NAC and Group IV received 1500 mg/kg NAC. Another group of 6 rats (Group V) received 0.75 mg/kg Paracetamol to cause hepatotoxicity. Group V (a positive control) received the prescribed clinical dose of 1200 mg/kg NAC which reverses the hepatotoxicity. All the NAC doses were given once a day intragastric for 7 days. On days: 1, 3 and 7 of receiving NAC, liver serum enzymes and bilirubin were measured. On day 7 the animals were sacrificed and liver tissue harvested for histopathology analysis. Results: A dose of 8.05 g/kg of M. oleifera leaf extract and 0.75 mg/kg Paracetamol were able to induce hepatotoxicity in Wister albino rats in 28 days. The M. oleifera extract induced hepatotoxic rats treated with NAC at doses of 1000 mg/kg, 1200 mg/kg and 1500 mg/kg, had a reduction in mean serum liver enzymes, plus reduced mean serum bilirubin levels. The liver histopathological analysis showed reduced inflammation after treatment with NAC for 3 and 7 days in the M. oleifera and paracetamol induced hepatotoxic rats. Conclusion: NAC can reverse M. oleifera leaf aqueous extract-induced sub-acute hepatotoxicity in Wistar Albino rats.

Therapeutic potential of N-acetyl cysteine during COVID-19 epoch

N-acetyl cysteine(NAC)is a promising drug for prophylaxis and treatment of coronavirus disease 2019(COVID-19)based on antioxidant and anti-inflammatory mechanisms.Further studies with cautious approach are needed to establish the benefits and risks before considering NAC as an adjuvant treatment for COVID-19.

Repurposing the antioxidant and anti-inflammatory agent N-acetyl cysteine for treating COVID-19

Although several considerations have been raised suggesting a beneficial effect of N-acetyl cysteine(NAC)for the treatment of severe acute respiratory syndrome coronavirus 2 infection,there is currently no clinical evidence that NAC truly prevents coronavirus disease 2019(COVID-19),reduces the severity of the disease,or improves the outcome.Appropriately designed clinical trials are warranted to prove or disprove a therapeutic effect of NAC for COVID-19 patients.

Navigating the dynamic landscape of alpha-synuclein morphology: a review of the physiologically relevant tetrameric conformation

N-acetylatedα-synuclein(αSyn)has long been established as an intrinsically disordered protein associated with a dysfunctional role in Parkinson’s disease.In recent years,a physiologically relevant,higher order conformation has been identified as a helical tetramer that is tailored by buried hydrophobic interactions and is distinctively aggregation resistant.The canonical mechanism by which the tetramer assembles remains elusive.As novel biochemical approaches,computational methods,pioneering purification platforms,and powerful imaging techniques continue to develop,puzzling information that once sparked debate as to the veracity of the tetramer has now shed light upon this new counterpart inαSyn neurobiology.Nuclear magnetic resonance and computational studies on multimericαSyn structure have revealed that the protein folding propensity is controlled by small energy barriers that enable large scale reconfiguration.Alternatively,familial mutations ablate tetramerization and reconfigure polymorphic fibrillization.In this review,we will discuss the dynamic landscape ofαSyn quaternary structure with a focus on the tetrameric conformation.

1H magnetic resonance spectroscopy and diffusion weighted imaging findings of medulloblastoma in 3.0T MRI A retrospective analysis of 17 cases

1H magnetic resonance spectroscopy and diffusion weighted imaging features of the cerebellar vermis in 17 medulloblastoma patients were retrospectively analyzed, and 17 healthy volunteers were selected as controls. 1H magnetic resonance spectroscopy showed that in all 17 medulloblastoma patients, N-acetyl aspartate and creatine peaks were significantly decreased, the choline peak was significantly increased, and there was evidence of a myo-inositol peak. Further, 11 patients showed a low taurine peak at 3.4 ppm, five patients showed a lipid peak at 0.9-1.3 ppm, and three patients showed a negative lactic acid peak at 1.33 ppm. Compared with the control group, the ratios of N-acetyl aspartate/choline and N-acetyl aspartate/creatine were significantly decreased, and the ratio of choline/creatine was increased, in medulloblastoma patients. Diffusion weighted imaging displayed hyperintensity and decreased apparent diffusion coefficient in medulloblastoma patients. These findings indicate that 1H magnetic resonance spectroscopy and diffusion weighted imaging are useful for qualitative diagnosis of medulloblastoma.

HPLC考察燕窝加工前后唾液酸的含量变化

目的:建立燕窝中唾液酸的分离分析方法,考察燕窝原料(去除杂质的干燥燕窝)、炖煮和加工成即食罐头前后唾液酸的含量变化。方法:燕窝经过磷酸水解,使唾液酸(即N-乙酰神经氨酸)从唾液酸糖蛋白的结合状态游离,用高效液相色谱法测定唾液酸的含量,应用《中药色谱指纹图谱相似度评价系统》评价燕窝3种样品的指纹图谱,比较3种样品的唾液酸含量变化。结果:燕窝原料的唾液酸含量为9.898%,经炖煮或加工成即食罐头后,唾液酸的含量分别为9.921%,9.913%,略高于原料。结论:燕窝加工成即食罐头后其唾液酸含量与直接炖煮的接近,略高于燕窝原料,提示应用现代工艺将燕窝加工成即食罐头,唾液酸保存较好。

A Case of Abnormal Bishler-Napieralski Cyclization Reaction,Leading to Form Benzyl Oxazole Derivatives

A benzyl oxazole compound 3 was obtained with an excellent yield of 90% when N-acetyl-(2'-methoxy-4',5'-methylenedioxy)-phenylalanine methyl ester 1 was refluxed in POCl1/benzene. However, the anticipated product 3,4-dihydrosioquinoline-3-carboxylic acid methyl ester 2 could not be found. The mechanism was discussed in this article.

Methods of <i>N</i>-acetylated chitosan scaffolds and its <i>In-vitro</i>biodegradation by lysozyme

Generally, the lysozyme degradation on chitosan (CTS) is slower than that of chitin (CT). The CTS can be fabricated in scaffold form but it is difficult to fabricate CT scaffold under mild conditions. The method for the preparation of scaffold from N-acetylated CTS (N-CTS) was investigated in this research. By using this method, the scaffolds could be fabricated chitosan to chitin with the degree of acetylation (DA) 18% - 70%. Among these scaffolds, the highest degradation of scaffold by lysozyme was observed on the N-CTS scaffold with DA 60%, which determined by examination of the reducing end contents in the degradation media and by measuring the weight loss of scaffolds. Moreover, the best condition for the degradation of N-CTS scaffold with DA70% by lysozyme was also investigated. The maximum degradation rate of the scaffold was observed on the treatment with lysozyme 500 mg/l of acetate buffer at pH 4.5, 37°C, 100 rpm and for 7 days.

Amelioration of hepatotoxicity by biocleavable aminothiol chimeras of isoniazid: Design, synthesis, kinetics and pharmacological evaluation

AIM To overcome the hazardous effects on liver caused by long-term use of antitubercular agent isoniazid(INH) by developing a novel hepatoprotective prodrug strategy by conjugating INH with aminothiols as antioxidant promoities for probable synergistic effect.METHODS INH was conjugated with N-acetyl cysteine(NAC) and N-(2)-mercaptopropionyl glycine using the SchottenBaumann reaction and with L-methionine using Boc-anhydride through a biocleavable amide linkage. Synthesized prodrugs were characterized by spectral analysis, and in vitro and in vivo release studies were carried out using HPLC. Their hepatoprotective potential was evaluated in male Wistar rats by performing liver function tests, measuring markers of oxidative stress and carrying out histopathology studies.RESULTS Prodrugs were found to be stable in acidic(pH 1.2) and basic(pH 7.4) buffers and in rat stomach homogenates, whereas they were hydrolysed significantly(59.43%-94.93%) in intestinal homogenates over a period of 6 h. Upon oral administration of prodrug NI to rats, 52.4%-61.3% INH and 47.4%-56.8% of NAC were recovered in blood in 8-10 h. Urine and faeces samples pooled over a period of 24 h exhibited 1.3%-2.5% and 0.94%-0.9% of NAC, respectively, without any presence of intact NI or INH. Prodrugs were biologically evaluated for hepatoprotective activity. All the prodrugs were effective in abating oxidative stress and re-establishing the normal hepatic physiology. The effect of prodrug of INH with NAC in restoring the levels of the enzymes superoxide dismutase and glutathione peroxidase and abrogating liver damage was noteworthy especially. CONCLUSION The findings of this investigation demonstrated that the reported prodrugs can add safety and efficacy to future clinical protocols of tuberculosis treatment.

丹参多酚酸盐治疗老年糖尿病肾病的临床研究

目的通过研究丹参多酚酸盐对老年糖尿病肾病的疗效及对尿N-乙酰β-D-葡萄糖苷酶(NAG)、转化生长因子-β1(TGF-β1)、单核细胞趋化蛋白-1(MCP-1)的影响,探讨丹参多酚酸盐治疗糖尿病肾病的机制及糖尿病肾病发病过程中的关键因子。方法 90例糖尿病肾病患者随机分为2组,每组45例,对照组给予常规治疗,治疗组在对照组的基础上增加丹参多酚酸盐治疗,将200 mg注射用丹参多酚酸盐加入200 m L生理盐水中,静脉滴注,1次/d,4周为1个疗程。比较两组患者的疗效及NAG、尿微量白蛋白(m ALB)、β2-微球蛋白(β2-MG)、TGF-β1、MCP-1和生化指标的变化。结果治疗后对照组和治疗组的有效率分别为82.22%、91.11%,两组比较差异具有统计学意义(P<0.05)。治疗后,两组的尿白蛋白排泄率(UAER)、肌酐(Cr)、血尿素氮(BUN)均较治疗前明显好转,且差异具有统计学意义(P<0.01);与对照组治疗后比较,治疗组的UAER、纤维蛋白原(FIB)明显改善,且差异具有统计学意义(P<0.01)。治疗后,两组的NAG、m ALB、β2-MG、TGF-β1和MCP-1均明显好转,与治疗前相比差异具有统计学意义(P<0.01);与对照组治疗后比较,治疗组的NAG、β2-MG、TGF-β1和MCP-1显著改善,且差异具有统计学意义(P<0.01),两组的m ALB差异不具有统计学意义。结论丹参多酚酸盐对糖尿病肾病的治疗作用主要通过调节TGF-β1和MCP-1水平、延缓近端肾小管损伤实现。

Nutritional and medical food therapies for diabetic retinopathy

Diabetic retinopathy(DR)is a form of microangiopathy.Reducing oxidative stress in the mitochondria and cell membranes decreases ischemic injury and end-organ damage to the retina.New approaches are needed,which reduce the risk and improve the outcomes of DR while complementing current therapeutic approaches.Homocysteine(Hcy)elevation and oxidative stress are potential therapeutic targets in DR.Common genetic polymorphisms such as those of methylenetetrahydrofolate reductase(MTHFR),increase Hcy and DR risk and severity.Patients with DR have high incidences of deficiencies of crucial vitamins,minerals,and related compounds,which also lead to elevation of Hcy and oxidative stress.Addressing the effects of the MTHFR polymorphism and addressing comorbid deficiencies and insufficiencies reduce the impact and severity of the disease.This approach provides safe and simple strategies that support conventional care and improve outcomes.Suboptimal vitamin co-factor availability also impairs the release of neurotrophic and neuroprotective growth factors.Collectively,this accounts for variability in presentation and response of DR to conventional therapy.Fortunately,there are straightforward recommendations for addressing these issues and supporting traditional treatment plans.We have reviewed the literature for nutritional interventions that support conventional therapies to reduce disease risk and severity.Optimal combinations of vitamins B1,B2,B6,L-methylfolate,methylcobalamin(B12),C,D,natural vitamin E complex,lutein,zeaxanthin,alpha-lipoic acid,and n-acetylcysteine are identified for protecting the retina and choroid.Certain medical foods have been successfully used as therapy for retinopathy.Recommendations based on this review and our clinical experience are developed for clinicians to use to support conventional therapy for DR.DR from both type 1 diabetes mellitus(T1DM)and type 2 diabetes mellitus(T2DM)have similar retinal findings and responses to nutritional therapies.

Nutritional and medical food therapies for diabetic retinopathy

Diabetic retinopathy(DR)is a form of microangiopathy.Reducing oxidative stress in the mitochondria and cell membranes decreases ischemic injury and end-organ damage to the retina.New approaches are needed,which reduce the risk and improve the outcomes of DR while complementing current therapeutic approaches.Homocysteine(Hcy)elevation and oxidative stress are potential therapeutic targets in DR.Common genetic polymorphisms such as those of methylenetetrahydrofolate reductase(MTHFR),increase Hcy and DR risk and severity.Patients with DR have high incidences of deficiencies of crucial vitamins,minerals,and related compounds,which also lead to elevation of Hcy and oxidative stress.Addressing the effects of the MTHFR polymorphism and addressing comorbid deficiencies and insufficiencies reduce the impact and severity of the disease.This approach provides safe and simple strategies that support conventional care and improve outcomes.Suboptimal vitamin cofactor availability also impairs the release of neurotrophic and neuroprotective growth factors.Collectively,this accounts for variability in presentation and response of DR to conventional therapy.Fortunately,there are straightforward recommendations for addressing these issues and supporting traditional treatment plans.We have reviewed the literature for nutritional interventions that support conventional therapies to reduce disease risk and severity.Optimal combinations of vitamins B1,B2,B6,L-methylfolate,methylcobalamin(B12),C,D,natural vitamin E complex,lutein,zeaxanthin,alpha-lipoic acid,and n-acetylcysteine are identified for protecting the retina and choroid.Certain medical foods have been successfully used as therapy for retinopathy.Recommendations based on this review and our clinical experience are developed for clinicians to use to support conventional therapy for DR.DR from both type 1 diabetes mellitus(T1DM)and type 2 diabetes mellitus(T2DM)have similar retinal findings and responses to nutritional therapies.

Can the personalized medicine approach contribute in controlling tuberculosis in general and India in particular?

Poor drug compliance and drug-resistant Mycobacterium tuberculosis are the two principal obstacles in controlling tuberculosis(TB)in endemic regions including India,which has contributed the most to global TB burden.We argue here that a personalized medicine approach,to start with the N-acetyl transferase-2–isoniazid(NAT2–INH)model,could be a step forward in dealing with both these limitations in controlling TB in India.