Efficacy and Safety of the Combination of Superoxide Dismutase, Alpha Lipoic Acid, Vitamin B12, and Carnitine for 12 Months in Patients with Diabetic Neuropathy

Expert opinion on screening, diagnosis and management of diabetic peripheral neuropathy: a multidisciplinary approach

The proposed expert opinion aimed to address the current knowledge on conceptual, clinical, and therapeutic aspects of diabetic peripheral neuropathy (DPN) and to provide a guidance document to assist clinicians for the best practice in DPN care. The participating experts consider the suspicion of the disease by clinicians as a key factor in early recognition and diagnosis, emphasizing an improved awareness of the disease by the first-admission or referring physicians. The proposed "screening and diagnostic" algorithm involves the consideration of DPN in a patient with prediabetes or diabetes who presents with neuropathic symptoms and/or signs of neuropathy in the presence of DPN risk factors, with careful consideration of laboratory testing to rule out other causes of distal symmetric peripheral neuropathy and referral for a detailed neurological work-up for a confirmative test of either small or large nerve fiber dysfunction in atypical cases. Although, the first-line interventions for DPN are currently represented by optimized glycemic control (mainly for type 1 diabetes) and multifactorial intervention (mainly for type 2 diabetes), there is a need for individualized pathogenesis-directed treatment approaches for DPN. Alpha-lipoic acid (ALA) seems to be an important first-line pathogenesis-directed agent, given that it is a direct and indirect antioxidant that works with a strategy targeted directly against reactive oxygen species and indirectly in favor of endogenous antioxidant capacity for improving DPN conditions. There is still a gap in existing research in the field, necessitating well-designed, robust, multicenter clinical trials with sensitive endpoints and standardized protocols to facilitate the diagnosis of DPN via a simple and effective algorithm and to track progression of disease and treatment response. Identification of biomarkers/predictors that would allow an individualized approach from a potentially disease-modifying perspective may provide opportunities for novel treatments that would be efficacious in early stages of DPN, and may modify the natural course of the disease. This expert opinion document is expected to increase awareness among physicians about conceptual, clinical, and therapeutic aspects of DPN and to assist them in timely recognition of DPN and translating this information into their clinical practice for best practice in the management of patients with DPN.

Ranking Alpha Lipoic Acid and Gamma Linolenic Acid in Terms of Efficacy and Safety in the Management of Adults With Diabetic Peripheral Neuropathy: A Systematic Review and Network Meta-analysis

OBJECTIVES

Current medications for diabetic neuropathy (DN) recommended by the American Diabetes Association and American Academy of Neurology do not address the pathologic process of denervation among patients with DN, because ancillary treatments, such as reactive oxygen scavengers, may be needed. The purpose of this work was to summarize the available evidence about the efficacy and safety of alpha lipoic acid (ALA) and gamma linolenic acid (GLA) in the management of DN.

METHODS

Using the search terms [(alpha lipoic acid or ALA or thioctic acid or thioctacid) or (gamma linolenic acid or GLA)] AND [(diabetes or diabetes mellitus) AND (polyneuropathy or neuropathy or sensorimotor polyneuropathy or radiculopathy)], 11 studies were included in this review and combined meta-analysis.

RESULTS

Eight of the 11 articles (73%) reported significant benefit of ALA vs placebo. In the meta-analysis, the Total Symptom Score (TSS) for ALA 600 mg/day (ALA600) was 1.05 points lower (standard mean difference [SMD] -1.05, 95% confidence interval [CI] -2.07 to -0.04, p=0.04, I2=98.18%) compared with control at the end of the study. In the network meta-analysis, ALA600 (SMD -1.68, 95% CI -2.8 to -0.6) and GLA (SMD -2.39, 95% CI -4.3 to -0.5) had significantly lower TSSs compared with placebo. Moreover, GLA had the highest probability of being the best (52.7%) for improving DN symptoms. In all studies, most adverse events include gastrointestinal disturbances. In terms of tolerability, no differences were detected between ALA and control groups.

CONCLUSION

ALA and GLA appear to be safe and efficacious biofactors for improvement of DN symptoms.

Impact of combined alpha-lipoic acid and mitoquinone supplementation on myocardial infarction in aged rats: Heart performance and molecular mechanisms

BACKGROUND

This study aimed to investigate the effects of combined alpha-lipoic acid (ALA) and mitoquinone (Mito Q) supplementation on cardiac function and the underlying mechanisms in aged rats with myocardial infarction (MI).

METHODS

The aged rats underwent left anterior descending artery (LADA) occlusion for 30 min, followed by reperfusion for 24 h. ALA (100 mg/kg, gavage) and Mito Q (10 mg/kg, IP) were administered daily for two weeks before ischemia. Cardiac function, inflammatory, and apoptotic markers were evaluated 24 h after ischemia.

RESULTS

The results of this study indicated that the administration of the combination of ALA and Mito Q significantly improved cardiac function. This improvement was linked to a reduction in the expression of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β (P < 0.001) and apoptotic markers (Bax, caspase-3, and Cyt-c), as well as a decrease in the percentage of TUNEL-positive cells (P < 0.001).

CONCLUSION

The study revealed that combined intervention synergistically mitigated cardiac dysfunction by suppressing inflammatory and apoptotic pathways in aged rats with MI. Further research is needed to validate the potential of ALA and Mito Q as therapeutic options for elderly people at risk of heart attacks.

Acetyllevocarnitine Hydrochloride for the Treatment of Diabetic Peripheral Neuropathy: A Phase 3 Randomized Clinical Trial in China

Diabetic peripheral neuropathy (DPN) is a highly prevalent chronic complication in type 2 diabetes (T2D) for which no effective treatment is available. In this multicenter, randomized, double-blind, placebo-controlled phase 3 clinical trial in China, patients with T2D with DPN received acetyllevocarnitine hydrochloride (ALC; 1,500 mg/day; n = 231) or placebo (n = 227) for 24 weeks, during which antidiabetic therapy was maintained. A significantly greater reduction in modified Toronto clinical neuropathy score (mTCNS) as the primary end point occurred in the ALC group (-6.9 ± 5.3 points) compared with the placebo group (-4.7 ± 5.2 points; P < 0.001). Effect sizes (ALC 1.31 and placebo 0.85) represented a 0.65-fold improvement in ALC treatment efficacy. The mTCNS values for pain did not differ significantly between the two groups (P = 0.066), whereas the remaining 10 components of mTCNS showed significant improvement in the ALC group compared with the placebo group (P < 0.05 for all). Overall results of electrophysiological measurements were inconclusive, with significant improvement in individual measurements limited primarily to the ulnar and median nerves. Incidence of treatment-emergent adverse events was 51.2% in the ALC group, among which urinary tract infection (5.9%) and hyperlipidemia (7.9%) were most frequent.

ARTICLE HIGHLIGHTS

Development and validation of a risk nomogram model for predicting peripheral neuropathy in patients with type 2 diabetes mellitus

Objective

Diabetic peripheral neuropathy frequently occurs and presents severely in individuals suffering from type 2 diabetes mellitus, representing a significant complication. The objective of this research was to develop a risk nomogram for DPN, ensuring its internal validity and evaluating its capacity to predict the condition.

Methods

In this retrospective analysis, Suqian First Hospital's cohort from January 2021 to June 2022 encompassed 397 individuals diagnosed with T2DM. A random number table method was utilized to allocate these patients into two groups for training and validation, following a 7:3 ratio. By applying univariate and multivariable logistic regression, predictive factors were refined to construct the nomogram. The model's prediction accuracy was assessed through metrics like the ROC area, HL test, and an analysis of the calibration curve. DCA further appraised the clinical applicability of the model. Emphasis was also placed on internal validation to confirm the model's dependability and consistency.

Results

Out of 36 evaluated clinicopathological characteristics, a set of four, duration, TBIL, TG, and DPVD, were identified as key variables for constructing the predictive nomogram. The model exhibited robust discriminatory power, evidenced by an AUC of 0.771 (95% CI: 0.714-0.828) in the training cohort and an AUC of 0.754 (95% CI: 0.663-0.845) in the validation group. The congruence of the model's predictions with actual findings was corroborated by the calibration curve. Furthermore, DCA affirmed the clinical value of the model in predicting DPN.

Conclusion

This research introduces an innovative risk nomogram designed for the prediction of diabetic peripheral neuropathy in individuals suffering from type 2 diabetes mellitus. It offers a valuable resource for healthcare professionals to pinpoint those at elevated risk of developing this complication. As a functional instrument, it stands as a viable option for the prognostication of DPN in clinical settings.

Cell metabolism pathways involved in the pathophysiological changes of diabetic peripheral neuropathy

Diabetic peripheral neuropathy is a common complication of diabetes mellitus. Elucidating the pathophysiological metabolic mechanism impels the generation of ideal therapies. However, existing limited treatments for diabetic peripheral neuropathy expose the urgent need for cell metabolism research. Given the lack of comprehensive understanding of energy metabolism changes and related signaling pathways in diabetic peripheral neuropathy, it is essential to explore energy changes and metabolic changes in diabetic peripheral neuropathy to develop suitable treatment methods. This review summarizes the pathophysiological mechanism of diabetic peripheral neuropathy from the perspective of cellular metabolism and the specific interventions for different metabolic pathways to develop effective treatment methods. Various metabolic mechanisms (e.g., polyol, hexosamine, protein kinase C pathway) are associated with diabetic peripheral neuropathy, and researchers are looking for more effective treatments through these pathways.

Disease-modifying therapies for diabetic peripheral neuropathy: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Alpha-lipoic acid, epalrestat, and mecobalamin are widely used as monotherapies for diabetic peripheral neuropathy. However, whether a triple-combination therapy with these three drugs is superior to monotherapy or dual therapy remains debatable.

METHODS

Nine randomized controlled trials were identified through a search on electronic databases such as PubMed, Web of Science, and Cochrane Library. The trial participants (N = 1153) were divided into the experimental group who received the triple-combination therapy and the control group who received conventional or dual therapy with the aforementioned drugs.

RESULTS

Therapeutic outcomes were better in the experimental group than in the control group (odds ratio: 3.74; 95 % confidence interval: 2.57-5.45; I2 = 0 %; p < 0.00001). No statistic difference was noted in adverse effects. Compared with the control group, the experimental group exhibited significant improvements in median motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV), peroneal MNCV, peroneal SNCV, and vibration perception thresholds (VPT) in the left and right lower limbs. In the control group, a subgroup analysis by treatment strategy revealed similar improvements in total efficacy, MNCV, and SNCV.

CONCLUSIONS

For diabetic peripheral neuropathy, the triple-combination therapy may be more effective than monotherapy or dual therapy.

Characteristics of elderly diabetes patients: focus on clinical manifestation, pathogenic mechanism, and the role of traditional Chinese medicine

Diabetes mellitus has become a major public health issue globally, putting an enormous burden on global health systems and people. Among all diseased groups, a considerable part of patients are elderly, while their clinical features, pathogenic processes, and medication regimens are different from patients of other ages. Despite the availability of multiple therapies and techniques, there are still numerous elderly diabetes patients suffering from poor blood glucose control, severe complications, and drug adverse effects, which negatively affect the quality of life in their golden years. Traditional Chinese Medicine (TCM) has been widely used in the treatment of diabetes for several decades, and its relevant clinical practice has confirmed that it has a satisfactory effect on alleviating clinical symptoms and mitigating the progression of complications. Chinese herbal medicine and its active components were used widely with obvious clinical advantages by multiple targets and signaling pathways. However, due to the particular features of elderly diabetes, few studies were conducted to explore Traditional Chinese Medicine intervention on elderly diabetic patients. This study reviews the research on clinical features, pathogenic processes, treatment principles, and TCM treatments, hoping to provide fresh perspectives on the prevention and management strategies for elderly diabetes.

Advantages of omics approaches for elucidating metabolic changes in diabetic peripheral neuropathy

Various animal and cell culture models of diabetes mellitus (DM) have been established and utilized to study diabetic peripheral neuropathy (DPN). The divergence of metabolic abnormalities among these models makes their etiology complicated despite some similarities regarding the pathological and neurological features of DPN. Thus, this study aimed to review the omics approaches toward DPN, especially on the metabolic states in diabetic rats and mice induced by chemicals (streptozotocin and alloxan) as type 1 DM models and by genetic mutations (MKR, db/db and ob/ob) and high-fat diet as type 2 DM models. Omics approaches revealed that the pathways associated with lipid metabolism and inflammation in dorsal root ganglia and sciatic nerves were enriched and controlled in the levels of gene expression among these animal models. Additionally, these pathways were conserved in human DPN, indicating the pivotal pathogeneses of DPN. Omics approaches are beneficial tools to better understand the association of metabolic changes with morphological and functional abnormalities in DPN.

A Mitochondrial Nanoguard Modulates Redox Homeostasis and Bioenergy Metabolism in Diabetic Peripheral Neuropathy

As a major late complication of diabetes, diabetic peripheral neuropathy (DPN) is the primary reason for amputation. Nevertheless, there are no wonder drugs available. Regulating dysfunctional mitochondria is a key therapeutic target for DPN. Resveratrol (RSV) is widely proven to guard mitochondria, yet the unsatisfactory bioavailability restricts its clinical application. Tetrahedral framework nucleic acids (tFNAs) are promising carriers due to their excellent cell entrance efficiency, biological safety, and structure editability. Here, RSV was intercalated into tFNAs to form the tFNAs-RSV complexes. tFNAs-RSV achieved enhanced stability, bioavailability, and biocompatibility compared with tFNAs and RSV alone. With its treatment, reactive oxygen species (ROS) production was minimized and reductases were activated in an in vitro model of DPN. Besides, respiratory function and adenosine triphosphate (ATP) production were enhanced. tFNAs-RSV also exhibited favorable therapeutic effects on sensory dysfunction, neurovascular deterioration, demyelination, and neuroapoptosis in DPN mice. Metabolomics analysis revealed that redox regulation and energy metabolism were two principal mechanisms that were impacted during the process. Comprehensive inspections indicated that tFNAs-RSV inhibited nitrosation and oxidation and activated reductase and respiratory chain. In sum, tFNAs-RSV served as a mitochondrial nanoguard (mito-guard), representing a viable drilling target for clinical drug development of DPN.

α-lipoic acid ameliorates hepatotoxicity induced by chronic ammonia toxicity in crucian carp (Carassius auratus gibelio) by alleviating oxidative stress, inflammation and inhibiting ERS pathway

High environment ammonia (HEA) poses a deadly threat to aquatic animals and indirectly impacts human healthy life, while nutritional regulation can alleviate chronic ammonia toxicity. α-lipoic acid exhibits antioxidative effects in both aqueous and lipid environments, mitigating cellular and tissue damage caused by oxidative stress by aiding in the neutralization of free radicals (reactive oxygen species). Hence, investigating its potential as an effective antioxidant and its protective mechanisms against chronic ammonia stress in crucian carp is highly valuable. Experimental fish (initial weight 20.47 ± 1.68 g) were fed diets supplemented with or without 0.1% α-lipoic acid followed by a chronic ammonia exposure (10 mg/L) for 42 days. The results revealed that chronic ammonia stress affected growth (weight gain rate, specific growth rate, and feed conversion rate), leading to oxidative stress (decreased the activities of antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase; decreased total antioxidant capacity), increased lipid peroxidation (accumulation of malondialdehyde), immune suppression (decreased contents of nonspecific immune enzymes AKP and ACP, 50% hemolytic complement, and decrease of immunoglobulin M), impaired ammonia metabolism (reduced contents of Glu, GS, GSH, and Gln), imbalance of expression of induced antioxidant-related genes (downregulation of Cu/Zu SOD, CAT, Nrf2, and HO-1; upregulation of GST and Keap1), induction of pro-apoptotic molecules (transcription of BAX, Caspase3, and Caspase9), downregulation of anti-apoptotic gene Bcl-2 expression, and induction of endoplasmic reticulum stress (upregulation of IRE1, PERK, and ATF6 expression). The results suggested that the supplementation of α-lipoic acid could effectively induce humoral immunity, alleviate oxidative stress injury and endoplasmic reticulum stress, and ultimately alleviate liver injury induced by ammonia poisoning (50-60% reduction). This provides theoretical basis for revealing the toxicity of long-term ammonia stress and provides new insights into the anti-ammonia toxicity mechanism of α-lipoic acid.

Rehabilitation of Peripheral Neuropathies: From Lexical Analysis of the Literature to Identification of Clinical Protocols

Peripheral nervous system diseases are a complex and heterogenous group of diseases affecting the different nerves with various severity and impact on quality of life. The current literature does not provide a structured guide for the rehabilitation of these conditions. We performed a lexical literature evaluation based on graph theory to clarify this topic. We performed a search on PubMed and calculated the frequencies of the words indicating rehabilitation approaches, nerves, and diseases. We found the usefulness of exercises and different physical agents, like laser and ultrasound therapy and neuromuscular stimulation vibration therapy. Orthoses are useful for entrapment, trauma, and hereditary diseases. Correct knowledge and assessment of the neuropathies are fundamental for the therapeutic decision and to guide rehabilitation. Despite the usefulness shown by the different approaches to modulating pain, improving muscle strength and endurance, and ameliorating balance and the sensory system, further studies are needed to define the best-personalized protocols.

Gait Analysis, Metabolic Parameters and Adherence to the Mediterranean Diet in Patients with Type 2 Diabetes Mellitus Compared with Healthy Controls: A Pilot Study

BACKGROUND AND PURPOSE

Patients with type 2 diabetes mellitus (T2DM) are prone to developing diabetic peripheral neuropathy (DPN) with an increased risk of injuries while walking, potentially leading to plantar ulcers. We aimed to assess the early gait changes in T2DM patients without clinical signs of DPN in comparison to age-matched healthy controls (HC).

SUBJECTS AND METHODS

One hundred T2DM patients (78 women, mean age: 66.4 ± 11.5 years) and 50 age-matched HC (34 women, mean age 62.1 ± 7.9 years) were evaluated with the PODOSmart® gait analysis device. Anthropometric and biochemical data, as well as dietary habits were collected for all participants. T2DM patients also completed the Diabetes Distress (DS) self-report validated questionnaire.

RESULTS

One patient was excluded from the study due to lack of recent biochemical data. Among the T2DM patients, 88.9% reported little or no DS and 11.1% moderate DS. The T2DM group had higher body mass index, waist circumference, systolic blood pressure, glycated hemoglobin A1c, sodium, white blood cell count, triglycerides and low-density lipoprotein cholesterol, but lower high-density lipoprotein cholesterol than HC (p < 0.05 for all comparisons). The MedDiet score was satisfactory in both groups (p > 0.05). Significant differences were found between the two study groups in gaitline heel off, propulsion speed, foot progression angle, time taligrade phase, stride length, walking speed, angle attack, oscillation speed, pronation-supination toe off and clearance.

CONCLUSIONS

The T2DM patients without self-reported DS or clinical signs of DPN may exhibit significant differences in several gait parameters analyzed with PODOSmart®. Whether gait analysis can be used as an early diagnostic tool of T2DM complications should be further explored.

Evaluating treatment options for cardiovascular autonomic neuropathy in patients with diabetes mellitus: a systematic review

Background

Cardiovascular autonomic neuropathy (CAN) is a debilitating complication of diabetes mellitus. To date, there is no systematic review on all the available drug treatments for CAN in diabetic patients, except for one review focusing on aldose reductase inhibitors.

Objective

To evaluate available drug treatment options for CAN in diabetic patients.

Methods

A systematic review was conducted with a search of CENTRAL, Embase, PubMed and Scopus from database inception till 14th May 2022. Randomised controlled trials (RCTs) of diabetic patients with CAN that investigated the effect of treatment on blood pressure, heart rate variability, heart rate or QT interval were included.

Results

Thirteen RCTs with a total of 724 diabetic patients with CAN were selected. There was a significant improvement in the autonomic indices of diabetic patients with CAN given angiotensin-converting enzyme inhibitor (ACEI) for 24 weeks (p<0.05) to two years (p<0.001), angiotensin-receptor blocker (ARB) for one year (p<0.05), single dose of beta blocker (BB) (p<0.05), omega-3 polyunsaturated fatty acids (PUFAs) for three months (p<0.05), alpha-lipoic acid (ALA) for four months (p < 0.05) to six months (p=0.048), vitamin B12 in combination with ALA, acetyl L‑carnitine (ALC), superoxide dismutase (SOD) for one year (p=0.001)  and near significant improvement in the autonomic indices of diabetic patients with CAN given vitamin E for four months (p = 0.05) compared to the control group. However, there was no significant improvement in the autonomic indices of patients given vitamin B12 monotherapy (p ≥ 0.05).

Conclusion

ACEI, ARB, BB, ALA, omega-3 PUFAs, vitamin E, vitamin B12 in combination with ALA, ALC and SOD could be effective treatment options for CAN, while vitamin B12 monotherapy might be unlikely to be recommended for the treatment of CAN due to its lack of efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-023-00629-x.

Clinical Pathobiochemistry of Vitamin B12 Deficiency: Improving Our Understanding by Exploring Novel Mechanisms with a Focus on Diabetic Neuropathy

Vitamin B₁₂ (B₁₂) is an essential cofactor of two important biochemical pathways, the degradation of methylmalonic acid and the synthesis of methionine from homocysteine. Methionine is an important donor of methyl groups for numerous biochemical reactions, including DNA synthesis and gene regulation. Besides hematological abnormalities (megaloblastic anemia or even pancytopenia), a deficiency in B₁₂ may cause neurological symptoms, including symptoms resembling diabetic neuropathy. Although extensively studied, the underlining molecular mechanism for the development of diabetic peripheral neuropathy (DPN) is still unclear. Most studies have found a contribution of oxidative stress in the development of DPN. Detailed immunohistochemical investigations in sural nerve biopsies obtained from diabetic patients with DPN point to an activation of inflammatory pathways induced via elevated advanced glycation end products (AGE), ultimately resulting in increased oxidative stress. Similar results have been found in patients with B₁₂ deficiency, indicating that the observed neural changes in patients with DPN might be caused by cellular B₁₂ deficiency. Since novel results show that B₁₂ exerts intrinsic antioxidative activity in vitro and in vivo, B₁₂ may act as an intracellular, particularly as an intramitochondrial, antioxidant, independent from its classical, well-known cofactor function. These novel findings may provide a rationale for the use of B₁₂ for the treatment of DPN, even in subclinical early states.

Oxidative Stress in Diabetic Peripheral Neuropathy: Pathway and Mechanism-Based Treatment

Diabetic peripheral neuropathy (DPN) is a major complication of diabetes mellitus with a high incidence. Oxidative stress, which is a crucial pathophysiological pathway of DPN, has attracted much attention. The distortion in the redox balance due to the overproduction of reactive oxygen species (ROS) and the deregulation of antioxidant defense systems promotes oxidative damage in DPN. Therefore, we have focused on the role of oxidative stress in the pathogenesis of DPN and elucidated its interaction with other physiological pathways, such as the glycolytic pathway, polyol pathway, advanced glycosylation end products, protein kinase C pathway, inflammation, and non-coding RNAs. These interactions provide novel therapeutic options targeting oxidative stress for DPN. Furthermore, our review addresses the latest therapeutic strategies targeting oxidative stress for the rehabilitation of DPN. Antioxidant supplements and exercise have been proposed as fundamental therapeutic strategies for diabetic patients through ROS-mediated mechanisms. In addition, several novel drug delivery systems can improve the bioavailability of antioxidants and the efficacy of DPN.

A Double-Blind, Randomized, Placebo-Controlled Study to Assess the Efficacy of a Nerve Support Formula on Neuropathic Pain in Individuals Suffering from Type II Diabetes Mellitus

Background

The primary objective of the present study was to evaluate the effects of a Nerve Support Formula NeuropAWAY^® on diabetic neuropathic pain.

Methods

This double-blind, placebo-controlled, randomized trial was conducted between August 2020 and February 2021. Patients aged ≥40 and ≤65 years with a history of type 2 diabetes (T2D) with a confirmed diagnosis of diabetic neuropathic pain were included in the study. The primary efficacy endpoint was to assess the effect of the 42 days administration of the Nerve Support Formula on the neuropathic pain as assessed by the 11 point Pain Intensity Numeric Rating Scale (PI-NRS). The secondary objectives were to assess the effect on plasma vitamin B12 levels, nerve conduction velocity, blood flow velocity, Brief Pain Inventory, Neuropathy Total Symptom Score, and Insomnia Severity Index.

Results

The enrolled study population (n=59) was randomized in two study groups; the Investigational Product (IP) group - Nerve Support Formula (n=27) and placebo group (n=32). The mean age of these participants was 52.63 and 53.72 for IP and placebo group, respectively. The mean (SD) HbA1c levels for IP and placebo group were 8.37 (0.85) and 8.16 (0.86), respectively. By the end of the study (Day 42) the decrease in PI-NRS scores for the IP group was maximal (↓61.32%) and highly significant (p<0.001) in comparison to the placebo group (↑2.47%). Significant improvements (p<0.05) were also noted in the secondary efficacy variables after 42 days of IP intake.

Conclusion

The formula was found to be significantly effective as compared to placebo in reducing pain and other sensory symptoms related to the diabetic peripheral neuropathy.

The impact of oxidative stress-induced mitochondrial dysfunction on diabetic microvascular complications

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycaemia, with absolute insulin deficiency or insulin resistance as the main cause, and causes damage to various target organs including the heart, kidney and neurovascular. In terms of the pathological and physiological mechanisms of DM, oxidative stress is one of the main mechanisms leading to DM and is an important link between DM and its complications. Oxidative stress is a pathological phenomenon resulting from an imbalance between the production of free radicals and the scavenging of antioxidant systems. The main site of reactive oxygen species (ROS) production is the mitochondria, which are also the main organelles damaged. In a chronic high glucose environment, impaired electron transport chain within the mitochondria leads to the production of ROS, prompts increased proton leakage and altered mitochondrial membrane potential (MMP), which in turn releases cytochrome c (cyt-c), leading to apoptosis. This subsequently leads to a vicious cycle of impaired clearance by the body's antioxidant system, impaired transcription and protein synthesis of mitochondrial DNA (mtDNA), which is responsible for encoding mitochondrial proteins, and impaired DNA repair systems, contributing to mitochondrial dysfunction. This paper reviews the dysfunction of mitochondria in the environment of high glucose induced oxidative stress in the DM model, and looks forward to providing a new treatment plan for oxidative stress based on mitochondrial dysfunction.

Mitochondrial Dysfunction and Neurodegenerative Disorders: Role of Nutritional Supplementation

Mitochondrial dysfunction has been implicated in the pathogenesis of a number of neurodegenerative disorders, including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, multisystem atrophy, and progressive supranuclear palsy. This article is concerned specifically with mitochondrial dysfunction as defined by reduced capacity for ATP production, the role of depleted levels of key nutritionally related metabolites, and the potential benefit of supplementation with specific nutrients of relevance to normal mitochondrial function in the above neurodegenerative disorders. The article provides a rationale for a combination of CoQ10, B-vitamins/NADH, L-carnitine, vitamin D, and alpha-lipoic acid for the treatment of the above neurodegenerative disorders.

Syringic Acid Ameliorates Cardiac, Hepatic, Renal and Neuronal Damage Induced by Chronic Hyperglycaemia in Wistar Rats: A Behavioural, Biochemical and Histological Analysis

This study investigated the effects of syringic acid (SA) on renal, cardiac, hepatic, and neuronal diabetic complications in streptozotocin-induced neonatal (nSTZ) diabetic rats. STZ (110 mg/kg i.p) was injected into Wistar rat neonates as a split dose (second and third postnatal day). Diabetes mellitus was diagnosed in adults by measuring fasting blood glucose levels, urine volume, and food and water intake. The treatment of SA (25 mg/kg, 50 mg/kg p.o) was given from the 8th to 18th postnatal week. To assess the development of diabetic complications and the effect of therapy, biochemical indicators in serum and behavioural parameters were recorded at specific intervals during the study period. SA (25 mg/kg, 50 mg/kg p.o) treatment reduced hyperglycaemia, polydipsia, polyphagia, polyuria, relative organ weight, cardiac hypertrophic indices, inflammatory markers, cell injury markers, glycated haemoglobin, histopathological score, and oxidative stress, and increased Na/K ATPase activity. These findings suggest that SA might significantly alleviate diabetic complications and/or renal, neuronal, cardiac, and hepatic damage in nSTZ diabetic rats.

Efficacy and safety of oral alpha-lipoic acid supplementation for type 2 diabetes management: a systematic review and dose-response meta-analysis of randomized trials

Objective

To examine the dose-dependent influence of oral alpha-lipoic acid (ALA) supplementation on cardiometabolic risk factors in patients with type 2 diabetes (T2D).

Design

We followed the instructions outlined in the Cochrane Handbook for Systematic Reviews of Interventions and the Grading of Recommendations, Assessment, Development, and Evaluation Handbook to conduct our systematic review. The protocol of the study was registered in PROSPERO (CRD42021260587).

Method

We searched PubMed, Scopus, and Web of Science to May 2021 for trials of oral ALA supplementation in adults with T2D. The primary outcomes were HbA1c, weight loss, and LDL cholesterol (LDL-C). Secondary outcomes included fasting plasma glucose (FPG), triglyceride (TG), C-reactive protein (CRP), and blood pressure. We conducted a random-effects dose-response meta-analysis to calculate the mean difference (MD) and 95% CI for each 500 mg/day oral ALA supplementation. We performed a nonlinear dose-response meta-analysis using a restricted cubic spline.

Results

We included 16 trials with 1035 patients. Each 500 mg/day increase in oral ALA supplementation significantly reduced HbA1c, body weight, CRP, FPG, and TG. Dose-response meta-analyses indicated a linear decrement in body weight at ALA supplementation of more than 600 mg/day (MD600 mg/day: -0.30 kg, 95% CI: -0.04, -0.57). A relatively J-shaped effect was seen for HbA1c (MD: -0.32%, 95% CI: -0.45, -0.18). Levels of FPG and LDL-C decreased up to 600 mg/day ALA intake. The point estimates were below minimal clinically important difference thresholds for all outcomes.

Conclusion

Despite significant improvements, the effects of oral ALA supplementation on cardiometabolic risk factors in patients with T2D were not clinically important.

A novel approach to alpha-lipoic acid therapy in the treatment of diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a heterogenic disorder prevalent amongst patients suffering from diabetes mellitus (DM), with symptoms comprising neuropathic pain, paresthesia, and numbness in distal lower limbs. Alpha-lipoic acid (ALA) is proposed as a pathogenesis-oriented treatment option, targeting underlying causes of neural lesions such as hyperglycemia, metabolic and microvascular dysfunctions, and cellular oxidative stress. We performed a comprehensive review of controlled clinical trials demonstrating the clinical usefulness of ALA in the treatment of DPN, published in the last 5 years to determine the benefits of ALA monotherapy and combined treatments with other known antioxidants. We also investigated the differential efficacy of oral versus intravenous ALA administration. Clinical trials show the efficacy of ALA treatment, attributed to its anti-inflammatory, anti-hyperglycemic, and antioxidant properties, as well as its function in the endothelial activation and lipid metabolism parameters. ALA supplementation is associated with amelioration in nerve conduction velocity scores, clinically significant reduction of reported neuropathic pain, burning and paresthesia, as well as a decrease in serum triglycerides, improved insulin sensitivity, and quality of life.

Exploring the effectiveness of vitamin B12 complex and alpha-lipoic acid as a treatment for diabetes mellitus/neuropathy: a protocol for systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Diabetic neuropathy (DN) is common in patients diagnosed with diabetes mellitus. This often causes peripheral nerve damage. For many years vitamin B₁₂ and alpha-lipoic acid (ALA) have been regarded as components that can be used in reducing markers of inflammation and oxidative stress. In this study, we will explore the effectiveness of vitamin B₁₂ and ALA as a possible treatment for diabetic mellitus/neuropathy, emphasising markers of inflammation, lipid profile, and glucose metabolism.

METHODS AND ANALYSIS

We will conduct a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocol (PRISMA-P). The search strategies and information sources for the literature will be PubMed, Google Scholar, Web of Science and Science direct. The literature search will include studies published from inception until 30 June 2022. All included studies will be evaluated for quality and risk of bias according to the Cochrane guidelines. To investigate the stability of the results, we will conduct a sensitivity analysis of the outcomes. All data analysis will be performed using Review Manager V.5. 4.

ETHICAL AND DISSEMINATION

This systematic review and meta-analysis will not require ethical approval from an institution committee as it does not have direct participants. We will obtain all our data from previous studies. The findings will be disseminated through publications in peer-reviewed journals and presented at local and international seminars and conferences.

Efficacy of vitamin and antioxidant supplements for treatment of diabetic peripheral neuropathy: systematic review and meta-analysis of randomized controlled trials

ABSTRACTThe results of treatment effect of vitamin or antioxidant intake on diabetic peripheral neuropathy (DPN) was inconsistent. Therefore, we performed a meta-analysis of randomized controlled trials (RCTs) to examine whether these supplements are effective in DPN treatment. We searched seven databases from inception to October 2021. All RCTs of DPN treatments with vitamin and antioxidant supplements were included. We performed sensitivity and subgroup analysis, and also tested for publication bias by the funnel plot and Egger's test. A total of 14 studies with 1384 patients were included in this systematic review. Three high-quality trials showed that vitamin and antioxidant supplements significantly increased sensory nerve conduction velocity (SNCV) of the sural nerve (MD = 2.66, 95%CI (0.60, 4.72), P < 0.05, I²= 0%). Seven studies (758 participants) suggested that these supplements might have improvement on motor nerve conduction velocity (MNCV) of the peroneal nerve in DPN patients with the random-effect model (MD = 0.60, 95%CI (0.28, 0.92), P < 0.05, I²= 65%). In four studies, these supplements could have improved on MNCV of the median nerve with the fixed-effect model (MD = 4.22, 95%CI (2.86, 5.57), P < 0.05, I²= 0%). However, ten studies (841 participants) have suggested that vitamin and antioxidant supplements have not decreased glycosylated haemoglobin (HbA1c). Vitamin and antioxidant supplements may improve the conduction velocity of nerves, including median, sural and peroneal nerves of patients with DPN. But these supplements have not decreased HbA1c in DPN patients. Several trials with a large sample size are needed to provide evidence support for clinical practice in the future.

Application of Sygen® in Diabetic Peripheral Neuropathies—A Review of Biological Interactions

This study investigates the role of Sygen^® in diabetic peripheral neuropathy, a severe disease that affects the peripheral nervous system in diabetic individuals. This disorder often impacts the lower limbs, causing significant discomfort and, if left untreated, progresses into more serious conditions involving chronic ulcers and even amputation in many cases. Although there are management strategies available, peripheral neuropathies are difficult to treat as they often present multiple causes, especially due to metabolic dysfunction in diabetic individuals. Gangliosides, however, have long been studied and appreciated for their role in neurological diseases. The monosialotetrahexosylganglioside (GM1) ganglioside, popularly known as Sygen, provides beneficial effects such as enhanced neuritic sprouting, neurotrophism, neuroprotection, anti-apoptosis, and anti-excitotoxic activity, being particularly useful in the treatment of neurological complications that arise from diabetes. This product mimics the roles displayed by neurotrophins, improving neuronal function and immunomodulation by attenuating exacerbated inflammation in neurons. Furthermore, Sygen assists in axonal stabilization and keeps nodal and paranodal regions of myelin fibers organized. This maintains an adequate propagation of action potentials and restores standard peripheral nerve function. Given the multifactorial nature of this complicated disorder, medical practitioners must carefully screen the patient to avoid confusion and misdiagnosis. There are several studies analyzing the role of Sygen in neurological disorders. However, the medical literature still needs more robust investigations such as randomized clinical trials regarding the administration of this compound for diabetic peripheral neuropathies, specifically.

Mitigating the pro-oxidant state and melanogenesis of Retinitis pigmentosa: by counteracting mitochondrial dysfunction

Retinitis pigmentosa (RP) is a group of mitochondrial diseases characterized by progressive degeneration of rods and cones leading to retinal loss of light sensitivity and, consequently, to blindness. To date, no cure is available according to the clinical literature. As a disease associated with pigmentation-related, pro-oxidant state, and mitochondrial dysfunction, RP may be viewed at the crossroads of different pathogenetic pathways involved in adverse health outcomes, where mitochondria play a preeminent role. RP has been investigated in a number of experimental and clinical studies aimed at delaying retinal hyperpigmentation by means of a number of natural and synthetic antioxidants, as well as mitochondrial cofactors, also termed mitochondrial nutrients (MNs), such as alpha-lipoic acid, coenzyme Q10 and carnitine. One should consider that each MN plays distinct-and indispensable-roles in mitochondrial function. Thus, a logical choice would imply the administration of MN combinations, instead of individual MNs, as performed in previous studies, and with limited, if any, positive outcomes. A rational study design aimed at comparing the protective effects of MNs, separately or in combinations, and in association with other antioxidants, might foresee the utilization of animal RP models. The results should verify a comparative optimization in preventing or effectively contrasting retinal oxidative stress in mouse RP models and, in prospect, in human RP cases.

Management of diabetic neuropathy

Diabetic neuropathy is a neurodegenerative disorder that may alter both the somatic and autonomic peripheral nervous systems in the context of diabetes mellitus (DM). It is a prevalent and burdensome chronic complication of DM, that requires timely management. Optimized glycemic control (mainly for type 1 DM), multifactorial intervention (mainly for type 2 DM), with lifestyle intervention/physical exercise, and weight loss represent the basis of management for diabetic distal symmetrical polyneuropathy, and should be implemented early in the disease course. Despite better understanding of the pathogenetic mechanisms of diabetic peripheral neuropathy, there is still a stringent need for more pathogenetic-based agents that would significantly modify the natural history of the disease. The paper reviews the available drugs and current recommendations for the management of distal symmetrical polyneuropathy, including pain management, and for diabetic autonomic neuropathy. Evaluation of drug combinations that would perhaps be more efficient in slowing the progression of the disease or even reversing it, and that would provide a better pain management is still needed.

Interventional Clinical Trials on Diabetic Peripheral Neuropathy: A Retrospective Analysis

Aims/Introduction

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes. At present, there is no comprehensive summary of the clinical trials related to DPN. In this article, we summarized the basic characteristics of the interventional clinical trials pertaining to DPN to determine the current status of research in this field and the existing issues.

Materials and Methods

We searched the World Health Organization International Clinical Trial Registration Platform (ICTRP), PubMed and Web of Science for clinical trials from 2005 to April 2021 and extracted 149 registered and 459 published clinical trials on DPN. We summarized the characteristics of the clinical trials, including the source registration, recruitment status, stage, age group, allocation method, intervention, end point classification, funding source, and treatment.

Results

After excluding noninterventional and nontreatment trials, 149 registered clinical trials out of 292 records from 12 registration centers and 459 published articles were included in this study. Among the registered trials, 43% had been completed, and 34.4% had been published in peer-reviewed journals. Among these trials, more than half used random allocation and blinded placebo-controlled methodologies. A total of 40.3% of the trials were multicenter studies, 63.8% of the treatments were drug therapies, and the endpoint classifications of 49% were efficacy and safety. Of the 459 published interventional clinical trials on DPN, 69.7% of the trials used drug treatments; more than half were randomized, double-blind, placebo-controlled clinical trials; 94.1% had positive outcomes; 46.4% had a target size of 50; and 22.9% were multicenter.

Conclusion

This paper systematically summarizes the current status of interventional trials on DPN registered in the ICTRP and published clinical trials and provides a reference for the development of high-quality intervention strategies for DPN in the future.

New monoterpenoids from the stigmas of Crocus sativus

One new compound, crocusatin M (1), and three new glycosidic compounds, crocusatins N-P (2-4), along with nine known compounds were isolated from the dried stigmas of Crocus sativus. The structures of new compounds were elucidated on the basis of spectroscopic analysis, and the absolute configurations of 1, 2, and 3 were unambiguously assigned by the comparison of experimental and calculated ECD data. This is the first report of the isolation of 4 with the HMG moiety from the genus Crocus. Compounds 1 and 4 exhibited weak anti-inflammatory activities on inhibiting lipopolysaccharide (LPS)-induced NO production.

Vitamin B12 Supplementation in Diabetic Neuropathy: A 1-Year, Randomized, Double-Blind, Placebo-Controlled Trial

AIM

To investigate the effect of normalizing vitamin B12 (B12) levels with oral B12 (methylcobalamin) 1000 μg/day for one year in patients with diabetic neuropathy (DN).

PATIENTS AND METHODS

In this prospective, double-blind, placebo-controlled trial, 90 patients with type 2 diabetes on metformin for at least four years and both peripheral and autonomic DN were randomized to an active treatment group (n = 44) receiving B12 and a control group (n = 46) receiving a placebo. All patients had B12 levels less than 400 pmol/L. Subjects underwent measurements of sural nerve conduction velocity (SNCV), sural nerve action potential (amplitude) (SNAP), and vibration perception threshold (VPT), and they performed cardiovascular autonomic reflex tests (CARTs: mean circular resultant (MCR), Valsalva test, postural index, and orthostatic hypotension). Sudomotor function was assessed with the SUDOSCAN that measures electrochemical skin conductance in hands and feet (ESCH and ESCF, respectively). We also used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE, respectively) and questionnaires to evaluate quality of life (QoL) and level of pain (pain score).

RESULTS

B12 levels increased from 232.0 ± 71.8 at baseline to 776.7 ± 242.3 pmol/L at follow-up, p < 0.0001, in the active group but not in the control group. VPT, MNSIQ, QoL, pain score, SNCV, SNAP, and ESCF significantly improved in the active group (p < 0.001, p = 0.002, p < 0.0001, p < 0.000, p < 0.0001, p < 0.0001, and p = 0.014, respectively), whereas CARTS and MNSIE improved but not significantly. MCR, MNSIQ, SNCV, SNAP, and pain score significantly deteriorated in the control group (p = 0.025, p = 0.017, p = 0.045, p < 0.0001, and p < 0.0001, respectively).

CONCLUSIONS

The treatment of patients with DN with 1 mg of oral methylcobalamin for twelve months increased plasma B12 levels and improved all neurophysiological parameters, sudomotor function, pain score, and QoL, but it did not improve CARTS and MNSIE.