[Possibilities of «therapeutic retargeting» of 3-hydroxypyridine and succinic acid derivatives due to their dopaminergic action]

The review is devoted to a comparative analysis of the clinical efficacy of the original domestic derivatives of 3-hydroxypyridine and succinic acid (emoxipine, reamberin and mexidol) in comparison with the results of an experimental study of their dopaminergic action. The position that the dopaminomimetic activity of emoxipin, reamberin and mexidol largely determines their anti-ischemic, antihypoxic, insulin-potentiating neuroprotective, nootropic and antidepressant potential has been substantiated. A comparative analysis of the safety profile of emoxipine, reamberin and mexidol was carried out, taking into account potential and real side-effects caused by iatrogenic deviations from the eudopaminergic state. It has been shown that mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate), which is simultaneously a derivative of 3-hydroxypyridine and succinic acid, has the best balance of efficacy and safety. A generalized assessment of the available data on the successful use of off-label derivatives of 3-hydroxypyridine and succinic acid indicates the advisability of a significant expansion of indications for their clinical use. The authors resume that the «therapeutic retargeting» of emoxipin, reamberin and mexidol (i.e. their use for qualitatively new indications) will contribute to progress in the treatment of socially significant and most common diseases.

Puerarin-Tanshinone IIA Suppresses atherosclerosis inflammatory plaque via targeting succinate/HIF-1α/IL-1β axis

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory injury is an important pathological factor for the formation of atherosclerotic plaque. It is well known that Puerarin and Tanshinone IIA (Pue-Tan) can significantly reduce interleukin-1β (IL-1β) levels and delay the atherosclerosis (AS) process clinically in China. Previous evidence has shown that the Succinate/HIF-1α/IL-1β inflammatory signaling axis (Succinate axis) promotes the progression of atherosclerotic inflammatory plaques. It is not clear whether Pue-Tan inhibits inflammatory plaques by reducing the level of IL-1β through the succinate signaling axis.

AIM OF STUDY

Find out the interaction between Pue-Tan targets and the succinate axis by means of network pharmacology and bioinformatics analysis and to further confirm whether Pue-Tan can inhibit vascular inflammation and delay the formation of atherosclerotic inflammatory plaques by targeting the succinate signaling axis.

MATERIALS AND METHODS

Firstly, animal experiments were conducted to verify the changing relationship between Succinate and IL-1β under Pue-Tan intervention. Secondly, network pharmacology approach was employed to uncover the specific targets of Pue-Tan in the intervention of AS from multiple levels of components, proteins, and pathways, and at the same time, the target must be a key factor of the succinate signaling axis. Autodock vina1.5.6 was applied to molecular docking for Pue-Tan and target protein. Subsequently, cells experiment and animal experiment were performed to verify Pue-Tan inhibiting the inflammatory progression of atherosclerosis by targeting succinate signaling axis.

RESULTS

Firstly, we first found that the reduction of IL-1β was positively correlated with succinate in the serum of Pue-Tan-treated mice. Secondly, network pharmacology compared with molecular docking showed that hypoxia-induced factor-1α (HIF-1α) was the key target of Pue-Tan and the key node of succinate singling axis. Finally, in vitro study, Pue-Tan significantly reduced the factors of succinate axis just as HIF-1α siRNA; in vivo study, we confirmed a decreased expression of succinate axis and ICAM-1 in the aorta of ApoE-/- mice under Pue-Tan intervention, which was consistent with the in vitro results.

CONCLUSION

This study confirmed that Pue-Tan blocked the succinate axis by targeting HIF-1α to prevent the formation of atherosclerotic inflammatory plaques and delay the pathological process of AS. Network Pharmacology, Bioinformatics of Molecular Docking, and Molecular Biology Validation can be used as a effective way to discover and verify the pharmacological mechanism of TCM.

Phloretin Ameliorates Succinate-Induced Liver Fibrosis by Regulating Hepatic Stellate Cells

BACKGRUOUND

Hepatic stellate cells (HSCs) are the major cells which play a pivotal role in liver fibrosis. During injury, extracellular stimulators can induce HSCs transdifferentiated into active form. Phloretin showed its ability to protect the liver from injury, so in this research we would like to investigate the effect of phloretin on succinate-induced HSCs activation in vitro and liver fibrosis in vivo study.

METHODS

In in vitro, succinate was used to induce HSCs activation, and then the effect of phloretin on activated HSCs was examined. In in vivo, succinate was used to generated liver fibrosis in mouse and phloretin co-treated to check its protection on the liver.

RESULTS

Phloretin can reduce the increase of fibrogenic markers and inhibits the proliferation, migration, and contraction caused by succinate in in vitro experiments. Moreover, an upregulation of proteins associated with aerobic glycolysis occurred during the activation of HSCs, which was attenuated by phloretin treatment. In in vivo experiments, intraperitoneal injection of phloretin decreased expression of fibrotic and glycolytic markers in the livers of mice with sodium succinate diet-induced liver fibrosis. These results suggest that aerobic glycolysis plays critical role in activation of HSCs and succinate can induce liver fibrosis in mice, whereas phloretin has therapeutic potential for treating hepatic fibrosis.

CONCLUSION

Intraperitoneal injection of phloretin attenuated succinate-induced hepatic fibrosis and alleviates the succinate-induced HSCs activation.

Exogenous succinate impacts mouse brown adipose tissue mitochondrial proteome and potentiates body mass reduction induced by liraglutide

Obesity is one of the leading noncommunicable diseases in the world. Despite intense efforts to develop strategies to prevent and treat obesity, its prevalence continues to rise worldwide. A recent study has shown that the tricarboxylic acid intermediate succinate increases body energy expenditure by promoting brown adipose tissue thermogenesis through the activation of uncoupling protein-1; this has generated interest surrounding its potential usefulness as an approach to treat obesity. It is currently unknown how succinate impacts brown adipose tissue protein expression, and how exogenous succinate impacts body mass reduction promoted by a drug approved to treat human obesity, the glucagon-like-1 receptor agonist, liraglutide. In the first part of this study, we used bottom-up shotgun proteomics to determine the acute impact of exogenous succinate on the brown adipose tissue. We show that succinate rapidly affects the expression of 177 brown adipose tissue proteins, which are mostly associated with mitochondrial structure and function. In the second part of this study, we performed a short-term preclinical pharmacological intervention, treating diet-induced obese mice with a combination of exogenous succinate and liraglutide. We show that the combination was more efficient than liraglutide alone in promoting body mass reduction, food energy efficiency reduction, food intake reduction, and an increase in body temperature. Using serum metabolomics analysis, we showed that succinate, but not liraglutide, promoted a significant increase in the blood levels of several medium and long-chain fatty acids. In conclusion, exogenous succinate promotes rapid changes in brown adipose tissue mitochondrial proteins, and when used in association with liraglutide, increases body mass reduction.NEW & NOTEWORTHY Exogenous succinate induces major changes in brown adipose tissue protein expression affecting particularly mitochondrial respiration and structural proteins. When given exogenously in drinking water, succinate mitigates body mass gain in a rodent model of diet-induced obesity; in addition, when given in association with the glucagon-like peptide-1 receptor agonist, liraglutide, succinate increases body mass reduction promoted by liraglutide alone.

Xianglian pill modulates gut microbial production of succinate and induces regulatory T cells to alleviate ulcerative colitis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Xianglian pill (XLP), a traditional Chinese formula, is widely used as treatment for ulcerative colitis (UC) in China. However, the mechanism of its therapeutic effect is still unclear.

AIM OF THE STUDY

Our previous studies showed a low oral bioavailability and a predominant distribution of major XLP ingredients in the gut. In the present study, we aimed to explore the mechanism of action of XLP on UC with respect to the regulation of gut microecology.

MATERIALS AND METHODS

UC model rats established using 5% dextran sulfate sodium were treated with XLP. After the treatment period, bodyweight, colon length, histopathology, and inflammatory changes were evaluated. Further, changes in gut microbiota structure were detected via 16S rRNA sequencing, and microbial metabolites in feces were analyzed via a metabolomic assay. Antibiotic intervention and fecal microbiota transplantation were also employed to explore the involvement of gut microbiota, while the level of regulatory T cells (Tregs) in mesenteric lymph nodes was determined via flow cytometry. Transcriptome sequencing was also performed to determine colonic gene changes.

RESULTS

XLP alleviated colonic injury, inflammation, and gut microbial dysbiosis in UC model rats and also changed microbial metabolite levels. Particularly, it significantly decreased succinate level in the tyrosine pathway. We also observed that fecal microbiota derived from XLP-treated rats conferred resilience to UC model rats. However, this therapeutic effect of XLP on UC was inhibited by succinate. Moreover, XLP increased the level of anti-inflammatory cellular Tregs via gut microbiota. However, this beneficial effect was counteracted by succinate supplementation. Further, XLP induced the differentiation of Treg possibly by the regulation of the PHD2/HIF-1α pathway via decreasing microbial succinate production.

CONCLUSIONS

Our findings indicated that XLP exerts its therapeutic effects on UC mainly via the gut microbiota-succinate-Treg differentiation axis.

Application of metabolomics in urolithiasis: the discovery and usage of succinate

Urinary stone is conceptualized as a chronic metabolic disorder punctuated by symptomatic stone events. It has been shown that the occurrence of calcium oxalate monohydrate (COM) during stone formation is regulated by crystal growth modifiers. Although crystallization inhibitors have been recognized as a therapeutic modality for decades, limited progress has been made in the discovery of effective modifiers to intervene with stone disease. In this study, we have used metabolomics technologies, a powerful approach to identify biomarkers by screening the urine components of the dynamic progression in a bladder stone model. By in-depth mining and analysis of metabolomics data, we have screened five differential metabolites. Through density functional theory studies and bulk crystallization, we found that three of them (salicyluric, gentisic acid and succinate) could effectively inhibit nucleation in vitro. We thereby assessed the impact of the inhibitors with an EG-induced rat model for kidney stones. Notably, succinate, a key player in the tricarboxylic acid cycle, could decrease kidney calcium deposition and injury in the model. Transcriptomic analysis further showed that the protective effect of succinate was mainly through anti-inflammation, inhibition of cell adhesion and osteogenic differentiation. These findings indicated that succinate may provide a new therapeutic option for urinary stones.

Efficacy and safety of the combined metabolic medication, containing inosine, nicotinamide, riboflavin and succinic acid, for the treatment of diabetic neuropathy: a multicenter randomized, double-blind, placebo-controlled parallel group clinical trial (CYLINDER)

INTRODUCTION

Antioxidants may have positive impact on diabetic polyneuropathy (DPN), presumably due to alleviation of oxidative stress. We aimed to evaluate the efficacy and safety of combination of antioxidants: succinic acid, inosine, nicotinamide, and riboflavin (SINR) in the treatment of DPN.

RESEARCH DESIGN AND METHODS

In a double-blind, placebo-controlled clinical trial, men and women aged 45-74 years with type 2 diabetes and symptomatic DPN, with initial Total Symptom Score (TSS) ˃5, were randomized into experimental (n=109) or placebo (n=107) group. Patients received study medication/placebo intravenously for 10 days, followed by oral administration for 75 days. Statistical significance was defined as a two-tailed p<0.05.

RESULTS

In SINR group, mean TSS change after 12 weeks was -2.65 (±1.46) vs -1.73 (±1.51) in the placebo group (p<0.0001; t-test). Reduction of symptoms in the SINR group was achieved regardless of hemoglobin A1c levels, but better results were observed in patients with initial TSS <7.5. The analysis of TSS subscores revealed statistically significant between-group differences by dynamics of the intensity of paresthesia and of numbness starting from day 11 (p=0.035 and p=0.001, respectively; mixed model); by day 57, statistically significant between-group differences were detected also by dynamics of burning intensity (p=0.005; mixed model). Study limitations are small effect size, moderate proportion of patients with severe DPN symptoms, subjective assessment of outcomes, exclusion of participants who received injectable glucose-lowering medications other than insulins, and patients with uncontrolled and type 1 diabetes.

CONCLUSIONS

The combination of SINR effectively alleviates DPN symptoms in patients with type 2 diabetes.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04649203; Unique Protocol ID: CTF-III-DM-2019).

SUCLA2 Arg407Trp mutation can cause a nonprogressive movement disorder - deafness syndrome

SUCLA2 is a component of mitochondrial succinate‐CoA ligase and nucleotide diphosphokinase activities. Its absence results in Krebs cycle failure, mitochondrial DNA depletion, and a childhood‐fatal encephalomyopathy. We describe a purely neurologic allelic form of the disease consisting of deafness, putamenal hyperintensity on MRI and a myoclonic‐dystonic movement disorder unchanging from childhood into, so far, the late fourth decade. We show that succinate supplementation circumvents the Krebs cycle block, but does not correct the neurologic disease. Our patients’ Arg407Trp mutation has been reported in children with (yet) no MRI abnormalities. It remains possible that early succinate supplementation could impact the disease.

Calcium gluconate and sodium succinate for therapy of sodium fluoroacetate experimental intoxication in cats: clinical and electrocardiographic evaluation

Sodium fluoroacetate (SFAC) or Compound 1080 is a potent rodenticide, largely used after 1946 for rodent and home pest control. The toxic effects of SFAC are caused by fluorocitrate action, a toxic metabolite, which has a competitive action with aconitase enzyme, leading to citrate accumulation and resulting in interference in energy production by Krebs cycle blockade. In the present study, domestic cats were intoxicated with oral doses of fluoroacetate (0.45 mg/kg). The intoxicated animals presented emesis, diarrhea with abdominal pain posture and an abdominal palpation, tachypnea, bilateral midriasis, hypothermia, hyperexcitability and convulsions. Blood gas analysis indicated decreased pH and bicarbonate levels. Serum ionized calcium was also decreased. ECG showed non–specific changes in ventricular repolarization and ventricular arrhythmias. The survival rate was 75% in the treated group with calcium gluconate and sodium succinate and 37.5% in the nontreated group.

[DIFFERENTIATED APPROACH TO CLOSING OF WOUND SURFACES TRUNK AND EXTREMITIES AFTER ITS MECHANICAL DAMAGE]

The results of examination and treatment of 231 patients on defects covering tissues of the trunk and limbs were presented. The severity of the injury determined by classification A. V. Kaplan, O. M. Markova. In 10 patients wound treatment method used, developed in the clinic, using the combined preparation of hyaluronic acid with sodium succinate (Latsert), ensuring efficiency of treatment. Differentiated approach to the selection of closing wound surfaces method caused by mechanical damage, allowed to achieve satisfactory results in 97.84% of cases.

[Correction of neurotrophic disorders in patients, suffering consequences of a spinal cord and peripheral nerves trauma]

On clinical base of cathedra of the disasters medicine, military medicine, anesthesiology and reanimatology in 2010 - 2013 yrs 62 patients were treated for neurotrophic disorders, in 12 of them the method was applied, elaborated in the clinic. For neurotrophic ulcers in 5 patients autodermoplasty was performed, using splitted cutaneous flap, in 1 for the wound defect on a forearm--plasty, using rotational cutaneo-adipose flap, based on axial blood supply. In 44 patients after a spinal cord trauma a neurotrophic defects degree III - IV have formed. The kind of operative intervention was selected depending on size of the defect, the wound depth and functional peculiarities of the injured area. Introduction of a new method of treatment of neurotrophic ulcers of the lower extremities, using preparation of hyaluronic acid with sodium succinate, expands the perspectives of treatment in patients, suffering defects of cover tissues. Differentiated approach to choice of the wound closure method, caused by damage of central and peripheral neural system, have permitted to achieve positive results in 98.1% of patients.

[Experience of treatment of diabetic foot syndrome]

In The Clinic of Cathedra of The Catastrophes Medicine, Military Medicine, Anesthesiology and Reanimatology in 2010 - 2013 yrs 53 patients, ageing 23-65 yrs, were treated for diabetic foot syndrome (DFS) of neuropathic and mixed forms. Diagnostic-treatment algorithm was proposed for determination of level and degree of a circulation and neuropathic disorders, introduction of which have promoted optimization of surgical and local treatment, improvement of the complex treatment results in patients, suffering DFS. A new method of treatment application, using combined preparation of hyaluronic acid with the sodium succinic, have permitted to achieve a complete healing of the ulcer defect.

[Quality of life and cognitive functions in patients with end-stage renal failure on hemodialysis using a succinate-containing dialyzing solution]

AIM

To assess changes in quality of life (QL) and cognitive functions in patients with end-stage renal failure (ESRF) treated with hemodialysis using a succinate-containing dialyzing solution (SCDS).

SUBJECTS AND METHODS

Sixty-seven patients with ESRF on hemodialysis using SCDS were examined. The investigators determined QL indicators using a Russianized variant of the Kidney Disease Quality of Life Short Form (KDQOL-SF) and the indicators of cognitive functions by the Benton visual retention test intended to evaluate visual short-term memory. The 6-minute walk test was used to evaluate exercise tolerance. The patients were examined before and 6 months after initiation of SCDS use.

RESULTS

Following 6 months of SCDS treatment, the patients showed positive changes in a number of QL indicators. Their exercise capacity (p = 0.03) and the quality of sleep (p = 0.03), and social interaction (p = 0.02) were improved. The magnitude of the complaints related to disease and treatment decreased (p = 0.001). The level of patient frustration was reduced (p < 0.001). Different limitations associated with chronic kidney disease and dialysis therapy came to disturb the patients to a lesser degree (p = 0.02). The Bentoin visual retention test exhibited fewer errors (p = 0.04).

CONCLUSION

Hemodialysis treatment with SCDS improved a number of QL indicators and cognitive functions in the patients.

[Serum metabolome by gas chromatography-mass spectrometry (GC-MS) in patients with ulcerative colitis and celiac disease]

Metabolomics is the emerging science of measurement and analysis of metabolome--the complete set of low molecular weight compounds in a cell, tissue, organ or whole organism. One of the aims of metabolomics is to research the response of an organism to a pathophysiological insult by measuring the concentrations of small molecule metabolites in biofluids and tissues and its dynamics. Intestinal microbiota is most probably involved in the development and maintenance of autoimmune inflammation in ulcerative colitis and celiac disease. Gas chromatography-mass spectrometry (GC - MS) of serum generates comprehensive metabolic profiles, reflecting integrated human (systemic) and gut microbial metabolism which may be altered in disease states. The aim of this study was to investigate GC - MS-based serum metabolomic profiles in UC and CD patients. Serum metabolic profiles were collected from 75 individuals: 20 patients with mild-moderate active UC, 35 CD patients, and 20 healthy controls (HC). We characterized 84 serum metabolites by use GC-MS. 18 metabolites at least have a combined (human + microbial) origin. In serum of UC patients, phenylacetic acid (PAA), 4-hydroxyphenylacetic acid (4-HPAA), 3-indolylacetic acid (IAA), succinic acid (SA) and fumaric acid (FA) were the metabolites most prominently increased, whereas 3-phenylpropionic acid (PPA) was significantly decreased. Serum of CD patients showed significant increases in IAA, 3-indolepropionic acid (IPA), SA and FA. Increased serum levels of succinic acid suggest its possible damaging effect on intestinal mucosa especially in ulcerative colitis. Orally administered butyrate + inulin as supplement to mesalazine in UC or gluten free diet in CD was effective in reducing disease activity with a marked improvement of serum metabolomic profiles (including SA reduction) and gut microbiota in both diseases. There were no any adverse events.

[Cerebroprotective effect of 3-oxypyridine and succinic acid derivatives in experimental diabetes mellitus]

We studied an effect of original domestic derivatives of 3-oxypyridine and succinic acid (emoxipine, reamberin and mexidol) on changes in the cellular composition of cortical and diencephalic structures in the rat brain in relation to the hyperglycemia severity in rats with alloxan diabetes. The effect of 3-oxypyridine and succinic acid derivatives was compared with the results of alpha-lipoic acid treatment. We determined that administration of 14 optimal doses of any medication in this study prevented the decrease in neuronal count in the primary somatosensory cortex (Par1 field). This effect was particularly evident after treatment with 3-oxypyridine derivatives (emoxipine and mexidol). Additionally, a two-week administration of emoxipine and mexidol led to a decreased percentage of lipofuscin-positive neurons in the neocortex and field CA1 of the hippocampus. Concurrently, emoxipine and mexidol increased the number of basket neurons as well as oligodendrocytes and microglia in the studied structure of the Ammon's horn. Moreover, these two substances prevented the decrease in the number of astrocytes in the somatosensory cortex and the paraventricular nucleus of the hypothalamus. The cerebroprotective activity of reamberin and alpha-lipoic acid in alloxan diabetes was less effective than that of 3-oxypyridine derivatives. Also, reamberin and alpha-lipoic acid induced undesirable side-effects manifested in the decreased number of pyramid neurons in field CA1 in the hippocampus and the increased number of lipofuscin-positive neurons in the somatosensory cortex and the paraventricular nucleus of the hypothalamus. Changes in the cellular composition of cortical and diencephalic structures resulting from administration of medications used in this study did not depend on the ability of these substances to restrain the hyperglycemia in alloxan diabetes.

[Effect of 3-oxypyridine and succinic acid derivatives on affective status in recrudescence of inflammatory diseases of uterus and its appendages]

Short-term, prospective placebo-controlled simple blind randomized study of the effects of 3-oxypyridine and succinic acid derivatives (emoxipin, reamberin, mexidol) on the affective status of females with recrudescence of the inflammatory diseases of uterus and its appendages (IDUA) in comparison to changes of systemic inflammatory response (SIR) markers level in the blood has been conducted. It is established that the inclusion of emoxipin, reamberin and mexidol in complex treatment of IDUA recrudescence reduce depression, anxiety and SIR laboratory signs. Mexidol being both 3-oxypyridine and succinic acid derivative showed the best influence on the dynamics of affective disorders and SIR changes.

[Metabolic correction of structural changes in adrenal glands during experimental widespread purulent peritonitis]

Experiments on 55 male chinchilla rabbits with model widespread purulent peritonitis have been performed for determinig structural changes in adrenal glands with the aid of optical microscopy. The introduction of aerobic-anaerobic culture of E. Coli and B. Fragilis into the abdominal cavity causes expressed structural changes in parenchyma of adrenal glands within 6 hours. It is established for the first time that the administration of metabolic drugs citoflavin (containing succinic acid) and neoton (containing creatine phosphate) prevents the development of pathological structural changes in adrenal glands under conditions of experimental widespread purulent peritonitis.

[Metabolic correctors based on succinic acid as pathogenic therapy in chronic virus hepatitis]

Chronic viral hepatitides (CVH) run with long-term activation of the system of mononuclear phagocytes associated with hyperproduction of active oxygen forms. This can be considered as risk factors of antioxidant insufficiency which determines the course of the disease. Now, antioxidant, cytoprotective medicines are more and more actively used in hepatology. The results are reviewed of many Russian clinical trials of efficacy of metabolic correctors based on siccine acid (reamberin, remaxol) as pathogenetic treatment in CVH. Metabolic correctors in combined treatment of CVH improve basic clinico-laboratory indices, raise efficacy of basic therapy, correct insufficiency of antioxidant defense. The results of the studies confirm advantage of antihypoxic medication over standard infusion therapy for treatment of CVH patients.

[Antinicrobial, antiexudative and immunotropic properties of chlorhexidine bigluconate in combination with zinc oxide, succinic and ascorbic acids]

Optimal combination of chlorhexidine bigluconate with ascorbic acid, succinic acid, and zinc oxide was found as a result of comparative trials. The composition shows antioxidative effects and is capable of initiating antibody producing and phagocytosis. This combination can be used as an active substance of orodispersible tablets for the treatment respiratory tract infections.

[Use of reamberin for correction of enterocyte functional activity in experimental disseminated purulent peritonitis]

Violation of the structural integrity and functional activity of mitochondria in the muscular coat of small intestine is among the main factors responsible for enteroparesis under conditions of widespread purulent peritonitis. This morphofunctional disorder leads to a sharp decrease in ATP synthesis, which is directly related to a low electric activity of parts of the small intestine. The drug reamberin that contains succinic acid favors elimination of the dysfunction of enterocyte mitochondria and restoration of the intestinal motility under conditions of widespread purulent peritonitis.

[Acute coronary syndrome with ST segment depression on ECG: novel outlook of an old problem]

The lecture is devoted to morphological manifestations, clinical and prognostic features of acute coronary syndrome (ACS) with ST segment depressions on ECG. We have studied peculiarities of clinical course of this variant of ACS and its outcomes in 501 patients and suggested a scheme for stratification of patients in groups of risk of complicated course of ischemic heart disease. We have also studied 85 patients with ACS with ST segment depressions on ECG during anginal attack. In therapy of these patients we included drugs with potential metabolic action: trimetazidine (n=29), infusions of polarizing mixture (n=16), enalapril maleate (n=28), potassium succinate (n=12). It has been established that the application of trimetazidine improves course and prognosis of the disease.

[Dynamics of the functional status of autonomic nervous system in rats under combined radiation/thermal injury in case of an open burn wound and wound covered by the polymer film]

The peculiarities of the functional status of autonomic nervous system and physical efficiency were studied in white inbred rats under dynamics of combined radiation/thermal injury (CR/TI). The CR/TI model was obtained under total X-ray irradiation at dose level of 4.37 Gy and inflicting III degree burn injury making 12% of body surface in 24 rats. The studies were performed under conditions of both spontaneous CR/TI development and protecting the burn wound against infection. In 12 rats the wounds were covered by polymer films treated with iodine and succinic acid. On days 3, 7, 14, 21 and 28 of CR/TI, as well as prior to CR/TI (datum level), heart rate variability (HRV) indices, the level of physical efficiency (the retention time of own weight on the vertical pole), indices of body mass, survival, and average life-soan of animals were recorded. For registration of ECG in awake rats, corrections of motor artifacts and analysis of HRV the original software program was used. R-R intervalograms were analyzed in time and frequency domains. The sliding window technique was used (100 R-R intervals with the step of 10 seconds; epoch of analysis--7 minutes). The obtained data indicated that the survival level and the average life-span in rats with the film-covered burn wound were higher as compared to the "pure" CR/TI. At the same time body mass and physical efficiency in animals of both groups did not differ in practice. Data on the functional status of autonomic nervous system were more informative. In rats with film-covered burn wound the dynamics of HRV indices had a biphasic character with the tending to normalization beginning from day 7 of CR/TI, whereas in case of an open wound HRV indices were characterized by monotonous growth until the end of observations. In the overall picture of the CR/TI in both groups of animals the sympathotropic effects of burn stress prevailed. Methods of mathematical analysis of HRV under conditions of CR/TI were for the first time used in this study. The research outcomes signify to the expediency to apply these methods for obtaining data on functional state of the autonomic nervous system in CR/TI models in small laboratory animals.

Fluctuating liver functions in siblings with MPV17 mutations and possible improvement associated with dietary and pharmaceutical treatments targeting respiratory chain complex II

BACKGROUND/AIMS

To describe the clinical and biological findings of two Japanese siblings with novel MPV17 gene mutations (c.451insC/c.509C > T) manifesting hepatic mitochondrial DNA depletion syndrome.

METHODS

We observed these brothers and sought to determine the efficacy of treatment targeting respiratory chain complex II for the younger brother.

RESULTS

A 3-month-old boy had presented with profound liver dysfunction, failure to thrive, and watery diarrhea. Although he was then placed on a carbohydrate-rich diet, his liver function thereafter fluctuated greatly in association with viral infections, and rapidly deteriorated to liver failure. He underwent liver transplantation at 17 months of age but died at 22 months of age. The younger brother, aged 47 months at the time of this writing, presented with liver dysfunction from 8 months of age. His transaminase levels also fluctuated considerably fluctuations in association with viral infections. At 31 months of age, treatment with succinate and ubiquinone was initiated together with a lipid-rich diet using ketone milk. Thereafter, his transaminase levels normalized and never fluctuated, and the liver histology improved.

CONCLUSIONS

These cases suggested that the clinical courses of patients with MPV17 mutations are greatly influenced by viral infections and that dietary and pharmaceutical treatments targeting the mitochondrial respiratory chain complex II may be beneficial in the clinical management of MPV17 mutant patients.

A succinate-based composition reverses menopausal symptoms without sex hormone replacement therapy

Menopausal transition is often accompanied by a variety of adverse pathological symptoms, currently treated with hormone replacement therapy, which is associated with a number of health risks. This report investigated the role of a food supplement--a composition of energy-exchange metabolites, with succinate as the main component--for treating menopausal syndrome. We studied the impact of a 4-week succinate-based food composition (SBC) treatment on the estral cycle, and bone mass and calcium content of aging mice. The impact of SBC on hormone levels and on the progression of several neurovegetative and psycho-emotional symptoms was further investigated in a randomized, double-blind, placebo-controlled clinical study of early menopausal women. Data were collected from questionnaires, Kupperman index scores, Spielberger-Hanin tests, and blood analysis of hormone levels taken at baseline and throughout the 5-week study. A "rejuvenating" effect of SBC on menopausal animals was observed, expressed as restoration of the estral cycle and an increase in the weight and calcium content of bone tissue. Furthermore, in the randomized, placebo-controlled clinical study in menopausal women, SBC-based monotherapy significantly lowered most subjectively evaluated characteristics of menopausal syndrome and increased blood serum levels of estradiol fourfold. This monotherapy also alleviated symptoms of some neurovegetative and psycho-emotional disorders, such as hot flushes, headache, and anxiety. Succinate-based therapy alleviated many biochemical symptoms of menopause in aging mice and early menopausal women, as well as neurovegetative and psycho-emotional disorders in women. Succinate-based therapy appeared to be free of adverse side effects.

[Effects of silymarin and its combination with succinic acid on brain bioenergetics in rats with experimental inhibition of beta-oxidation of fatty acids]

In the tests on rats with a model of encephalopathy caused by 4-pentenoic acid (inhibitor of the beta-oxidation of fatty acids), the hepatoprotective agent silymarin increases the respiratory activity in brain mitochondria, improves oxidative phosphorylation coupling and energization, and inhibits lipid peroxidation. Succinic acid (a regulator of bioenergetics) improves the damaged Krebs cycle metabolic pathways and produces an antioxidant effect. The combined use of silymarin and succinic demonstrated more expressed cerebroprotective action as compared to that of each agent administered separately.

Succinate and artificial maintenance of normal body temperature synergistically correct lethal disorders in thiopental coma rat

Under modeling of thiopental coma influence of sodium succinate and (or) external warming for the support of normal body temperature (isothermal regimen) on the gas exchange, blood gas content, acid-base status and survival rate was studied in rats. In the absence of therapy hypothermia was developed (-9.4 degrees C), O(2) consumption decreased by a factor 5, oxygenation of arterial blood (pO(2)) did not change while that of venous blood increased, where with arteriovenous oxygen tension gradient decreased by half. Blood tension of carbon dioxide (pCO(2)) increased twice, respiratory and metabolic acidosis was developed. Survival rate under absence of a therapy was 42%, with isolated use of isothermal regimen or succinate therapy alike-50%; with their use in combination drastically increased up to 92%. Succinate increased arteriovenous gradient of pO(2), decreased deficit of buffer bases, increased bicarbonate concentration. At isothermal regimen accumulation of CO(2) in the blood was diminished, its excretion was increased, pH of blood approached normal values. Combined use of both therapy agents increased O(2) consumption and potentiated their positive influence on acid-base status. The implication is that hypothermia restrains effect of succinate in barbiturate coma; prevention of hypothermia in combination with succinate administration is highly effective method of experimental therapy of barbiturate intoxication.

[Effect of amber acid on the kidney function in gentamycin-induced nephropathy in white rats]

The amber acid neutralized by 10 % solution of NaOH in a concentration of 250 mmoL/L was administered subcutaneously simultaneously with intraperitonal injection of gentamycin in a doze of 10 mg/kg(bw) once a day during 7 days to the ten nonlinear white male rats, weight 100-120 g exposed to the water-induced diuresis. In these experiments the positive action of an amber acid as energy substratum on some renal function tests was shown: improvement of reabsorbtion in proximal tubules, proved by proteinuria decrease, subsequent normalization of glomerular filtrations followed by uremia reduction and diminishing of other signs of acute renal failure.

[Cerebral hypoxic lesions in the early phase of acute intoxications with neurotropic poisons: development, course, and ways of correction]

The paper presents the results of examination and treatment of 147 patients in the early phase of severe acute intoxications with neurotropic poisons. The use of the methods of assessing the bioelectrical activity of the brain has been found to objectively evaluate the degree of CNS suppression, to clarify the nature of the damaging action of a toxic agent, and to evaluate the efficiency of therapy. The use of cytoflavin in intensive care for cerebral hypoxic lesions has been shown to substantially decrease the degree of brain lesions.

[Use of the solutions of hydroxyethyl starch and reamberin in the combined treatment of severe gestosis]

The effects of the solutions of hydroethyl starch (HES) and reamberin on hemodynamics, metabolism, and water-sector disorders were studied in patients with severe gestosis. The study covered 42 puerperas who were divided into 3 groups: 1) 10 patients with severe gestosis and normal acid-alkali balance (AAB); 2) 10 with severe gestosis and metabolic acidosis; 3) 22 pueperas with physiological single pregnancy (a control group). Group 1 patients were given infusions of 6% HES solution, 5-6 ml/kg; Group 2 received in addition to 6% HES solution in the above dose infusions of 1.5% reamberin solution, 5 ml/kg. In patients with severe gestosis, hemodynamic, water-sector, and metabolic monitoring on puerperal days 1-5 were found to identify changes in oxygen supply and consumption, water balance, and AAB. In Group 1 patients, HES infusion on days 1-2 after delivery decreased the content of systemic water, extracellular and interstitial fluid, increased oxygen supply; in Group 2, combined infusion therapy with GES and reamberin on puerperal days 1-2 led to an increase in oxygen supply and consumption and a reduction in interstitial hyperhydration and to normalization of AAB.

Intermediates of Krebs cycle correct the depression of the whole body oxygen consumption and lethal cooling in barbiturate poisoning in rat

Rats poisoned with one LD50 of thiopental or amytal are shown to increase oxygen consumption when intraperitoneally given sucinate, malate, citrate, alpha-ketoglutarate, dimethylsuccinate or glutamate (the Krebs cycle intermediates or their precursors) but not when given glucose, pyruvate, acetate, benzoate or nicotinate (energy substrates of other metabolic stages etc). Survival was increased with succinate or malate from control groups, which ranged from 30-83% to 87-100%. These effects were unrelated to respiratory depression or hypoxia as judged by little or no effect of succinate on ventilation indices and by the lack of effect of oxygen administration. Body cooling of comatose rats at ambient temperature approximately 19 degrees C became slower with succinate, the rate of cooling correlated well with oxygen consumption decrease. Succinate had no potency to modify oxygen consumption and body temperature in intact rats. A condition for antidote effect of the Krebs intermediate was sufficiently high dosage (5 mmol/kg), further dose increase made no odds. Repeated dosing of succinate had more marked protective effect, than a single one, to oxygen consumption and tended to promote the attenuation of lethal effect of barbiturates. These data suggest that suppression of whole body oxygen consumption with barbiturate overdose could be an important contributor to both body cooling and mortality. Intermediates of Krebs cycle, not only succinate, may have a pronounced therapeutic effect under the proper treatment regimen. Availability of Krebs cycle intermediates may be a limiting factor for the whole body oxygen consumption in barbiturate coma, its role in brain needs further elucidation.

[Efficacy of derivatives of 3-hydroxypyridine and succinic acid in diabetic patients with the diabetic foot]

A prospective placebo-controlled study was performed to examine the effects of emoxipine, reamberine, and mexidole on the severity of neuropathic and anxiety-depressive symptom clusters, by simultaneously evaluating the parameters of the lipid peroxidation-antioxidative defense protection (LPO-AOD) system in diabetic patients with the diabetic foot. The 14-day use of all the test drugs was found to cause a significant attenuation of diabetic neuropathy and to abolish concomitant anxiety and depression. The positive clinical effect of emoxipine and reamberine was shown to be associated with the stimulation of AOD and with the limitation of LPO. Mexidole is not inferior to emoxipine and reamberine in its clinical efficacy, but it did not change the parameters of the LPO-AOD system as compared with placebo.

[Use of sodium succinate in complex treatment of ischemic stroke]

The results of the study of sodium succinate efficacy in the treatment of 60 patients with ischemic stroke in comparison to the control group, not receiving antioxidants, are presented. The best results of sodium succinate were achieved in regress of local and general brain symptoms. The authors emphasize a possibility of the treatment at home and in outpatient clinic as well as cheaper price of sodium succinate versus other succinates.

[Neuroprotective effect of cytoflavin in closed craniocerebral trauma]

The efficacy of a complex preparation cytoflavin was studied on rats with a model of closed craniocerebral trauma. Cytoflavin produced normalization of the energy exchange, lipid peroxidation, and antioxidant system functioning in nervous tissues. The treatment significantly reduced the degree of posttraumatic edemation in the brain. The cerebroprotective action of cytoflavin was somewhat superior to the effect of the reference drug solcoseryl.

[Method of pharmacological treatment of the consequences of hypoxia in critically ill patients with acute poisoning]

The multi-factor effect of pharmacological preparations reamberine and citotoflavine, which contain succinate, in critical conditions is preconditioned by the impact they produce on a total energy deficit caused by a long-term hypoxia. The correction of energy deficit improves the therapy of patients in coma, which resulted from poisonings by neurotropic substances. The therapeutic effect manifested itself through a shorter state of coma from 25 to 12.5%. However, an analysis of died patients, who received the metabolic antihypoxants, showed that these drugs are not effective, when the time lapse from poisoning to medical aid exceeded 20 hours. When perftoran, a corrector of oxygen transport, and antihypoxant cytoflavin were added to the therapy scheme, it resulted in that 22 of 24 patients, who were also taken to clinic in the state of coma after 20 and more hours, survived, while all patients in the comparison group (20 patients) died despite an intensive therapy.

Inhibitory effects of succinic acid on chemical kindling and amygdala electrical kindling in rats

AIM

To investigate the effects and mechanism of succinic acid on pentylenetetrazol (PTZ) chemical kindling and amygdala electrical kindling in rats.

METHODS

PTZ chemical kindling and amygdala electrical kindling models were established in rats. The effects of succinic acid on the behavior and afterdischarge of kindled rats were observed. The mice were pretreated with succinic acid, 30 min later, picrotoxin, a GABAA receptor antagonist was given by ip, then the effects of succinic acid on mice were observed.

RESULTS

Succinic acid (100-400 mg/kg, ip) dose-dependently inhibited PTZ chemical and amygdala kindled seizure (P<0.05, P<0.01), elevated the afterdischarge threshold, and reduced the Racine's stage of amygdala kindling rats (P<0.05, P<0.01); succinic acid (200-400 mg/kg, ip) inhibited picrotoxin-convulsion in mice (P<0.05, P<0.01).

CONCLUSION

Succinic acid inhibits PTZ chemical and amygdala electrical kindling in rats, and the inhibition mechanism may be related to the enhancement of GABAergic system action in the brain, especially through GABAA receptors.

[Diabetes mellitus in the elderly: succinic acid compounds in treating diabetic neuropathies]

To investigate the influence of the succinic acid treatment on geriatric patients with type 2 diabetes. Succinic Acid has some positive biological properties. One of its is a neglecting of an aerobic glycolysis. In this study we evaluated the efficacy of the combination of the succinic acid ("MITOMIN") on treating of diabetic neuropathy of geriatric patients with type 2 diabetes. The analysis was carried out using 26 patients (aged 60-76 years). The duration of diabetes was 9.15 +/- 1.43 years. Biomedical parameters were measured by standard methods; microalbuminuria was measured by "Micral-Test". Quality of life (psychosocial disorders) was estimated with the help of "SANDOZ"-scale for geriatric assessment. The therapy was assigned 1.5 g of mitomin per day during a month. All patients were examined on having late diabetic complications: 7.69%--had diabetic retinopathy; 11.54%--diabetic nephropathy; 73.08%--diabetic neuropathy; 46.15%--chronic failure of brain vessels; 11.5%--macroangiopathy of lower extremities and 100%--had ischeamic heart disease of different levels. Mitomin therapy improved basal and postprandial glycemic control (NS), variance of pallesthesia (p < 0.001), parameters of quality of life, i.e. depression (p < 0.001), anxiety (p < 0.01), short memory (p < 0.05) and emotionality (p < 0.001). Mitomin therapy plays a positive role in management of elderly patients with type 2 diabetes. It improves glycemic control, pallestesia and quality of life. Combination of succinic acid renders central and peripheral neuropathy protective efficacy.

Modification of radiation-induced changes in the reproductive system of male rats with sodium succinate

We studied the effects of sodium succinate on the reproductive system and blood leukocyte count in rats 30 and 60 days after fractionated irradiation in a dose of 1 Gy. Sodium succinate in concentrations of 0.2 and 0.5% was given ad libitum with water before (1 week) and during irradiation (5 days). The preparation promoted morphofunctional recovery of the testes and epididymides and restored the count of peripheral blood leukocytes.

[Use of cytoflavin for correction of complications of myocardial infarction]

The possibility of using a combined preparation cytoflavine was studied on rats with myocardial infarction induced by coronary artery occlusion. The drug produces a positive action upon the energy exchange and the lipid peroxidation process and normalizes functioning of the system of antioxidant protection of the ischemized myocardium. Cytoflavine treatment led to a more favorable course of ischemic and necrotic processes and optimum organization of the necrosis zones.

[Correction of free radical processes by a succinic acid drug (reamberine) in intensive care of patients with acute neurotropic poisoning]

Sixty-six patients with acute poisonings with neurotropic toxins (soporiphics, neuroleptics, antidepressants, ethanol and its surrogates) were examined and treated. Clinical data and correction of disorders in free-radical processes in acute poisonings with these toxins indicate the efficiency of adding reamberine to combined therapy of this patient population.

[Effect of ammonium succinate on pharmacological effects of acetylsalicylic acid]

Ammonia succinate potentiates the main pharmacological properties and reduces the toxic effects (ulcerogenic action and general toxicity) of acetylsalicylic acid. The new preparation astam, representing a combination of acetylsalicylic acid with ammonia succinate in a 2:1 ratio, is proposed. Astam exhibits antiexudative, capillary-reinforcing, antiproliferative, pain-relieving, antipyretic, antiaggregant, and antioxidant properties. In addition, the drug inhibits the development of structural-metabolic disorders in the case of chronic immune inflammation of joints and various internal organs.

Metabolic correction of cerebral radiation syndrome

DNA strand breaks that occur after irradiation activate the repair enzyme adenosine diphosphoribosyl transferase, which consumes NAD as a substrate and causes depletion first of neuronal NAD and then of the ATP pool. This is considered to be the crucial link in the mechanism underlying the cerebral radiation syndrome (CRS). In this study, two ways to correct the CRS metabolically were examined: (a) prevention of depletion of NAD after irradiation by administration of the enzyme inhibitor nicotinamide and (b) shunting the NAD-dependent oxidative phosphorylation pathway of ATP resynthesis by administration of a substrate of NAD-independent oxidation, succinate. Cerebral lesions induced by radiation were modeled by irradiation of rats or rat brain homogenates with 150 Gy of X rays. The manifestations of CRS in rats (excitement, convulsions, etc.) closely resembled those seen after acute hypoxia. In brain homogenates, pyruvate tetrazolium-reductase activity decreased after irradiation and could be corrected by addition of NAD after irradiation. Succinate tetrazolium-reductase activity was not affected by irradiation. Oxygen consumption by brain homogenates after irradiation in vitro and in situ decreased, as did oxygen consumption by rats in vivo after cranio-caudal irradiation. Administration of nicotinamide or succinate prevented both the postirradiation decrease in respiration (in both rats in vivo and brain homogenates in vitro) and the development of cerebral radiation syndrome. These results help to clarify the mechanisms underlying CRS and its metabolic correction.

Influence of chelating agents on the toxicity and distribution of beryllium in rats

The effect of two new chelating agents-Tiron (4,5-dihydroxy-1,3-benzene disulphonic acid disodium salt) and succinic acid--on the mobilization of beryllium was studied. Animals were exposed to beryllium nitrate (1 mg kg(-1) i.p.) daily for 21 days. Administration of beryllium nitrate showed a marked decrease in haemoglobin percentage, blood sugar, serum alkaline phosphatase and serum protein and a significant increase in the activity of transaminases. Tissue protein and glycogen contents and the activity of alkaline phosphatase, adenosine triphosphatase and succinic dehydrogenase showed significantly decreased values, but beryllium nitrate provoked a considerable increase in the activity of acid phosphatase and glucose-6-phosphatase in the vital and reproductive organs. Significant improvement in the haematological and biochemical parameters was observed with Tiron but no therapeutic effect was seen with succinic acid. Atomic absorption spectrophotometry (AAS) also showed a decreased level of beryllium concentration in the liver and kidney after Tiron therapy.

Improvement of myocardial mitochondrial function after hemodynamic support with left ventricular assist devices in patients with heart failure

OBJECTIVES

Mitochondrial abnormalities have been described in cardiac tissue of patients with heart failure. These changes may result from chronic hypoxia. Our goal was to determine whether mitochondrial functional capacity can be improved in patients with heart failure by means of long-term left ventricular assist device therapy, which improves myocardial oxygen supply by decreasing myocardial work.

METHODS

Mitochondria were isolated from myocardial tissue obtained from 13 patients with heart failure without a left ventricular assist device (HF group) and seven patients with heart failure treated with a left ventricular assist device (LVAD-HF group). Mitochondrial respiratory rates (State 2, State 3, and State 4) were measured by means of polarographic techniques with reduced nicotinamide adenine dinucleotide-dependent (pyruvate/malate, alpha-ketoglutarate, glutamate) and -independent (succinate) substrates. The respiratory control index of Chance (State 3/State 4) and Lardy (State 3/State 2) and phosphorus to oxygen ratios were determined.

RESULTS

The respiratory control index of Chance was higher in LVAD-HF than in HF when using NADH-dependent substrates pyruvate/malate and alpha-ketoglutarate (pyruvate/malate HF: 4.9 +/- 1.0; LVAD-HF: 6.5 +/- 1.5; alpha-ketoglutarate HF: 8.5 +/- 2.4; LVAD-HF: 11.8 +/- 2.9; both p = 0.04). Similarly, the respiratory control index of Lardy was greater in the LVAD-HF than the HF group when alpha-ketoglutarate and glutamate were used as substrates (alpha-ketoglutarate HF: 7.8 +/- 1.7; LVAD-HF: 9.9 +/- 1.5; glutamate HF: 7.6 +/- 2.2; LVAD-HF: 10.7 +/- 2.1; both p = 0.04). The phosphorus to oxygen ratio was comparable for both groups using all substrates. No change in mitochondrial respiration was observed after left ventricular assist device therapy with the NADH-independent substrate, succinate.

CONCLUSION

Cardiomyocyte mitochondrial function is improved by long-term therapy with a left ventricular assist device. This improvement suggests that cardiomyocyte metabolic dysfunction in heart failure may be reversed with left ventricular assist device support.

Prophylaxis of encephalopathies and risk factors of atherogenesis development in the postresuscitation period in rats by means of succinic acid

The effect of oral administration of succinic acid was studied in 66 rats exposed to 10 min cardiac arrest with further resuscitation. A total of 30 mg/kg of the drug were administered daily for 5 days starting with day 3 up to day 7 after resuscitation. The experiments have revealed that treatment with succinic acid caused normalization of the orienting behavior in an 'open field' test, decrease of the intensity of response to electric shock, normalization of free radical formation in the brain and serum and reduced cerebral morphological changes. The succinic acid prevented the increase of cholesterol, triglyceride and low density lipoproteins in the blood. The data suggested that after additional trials the succinic acid could be used to prevent development of postresuscitation encephalopathies (3 months after reanimation).