Treatment of platelet concentrates with the L-carnitine modulates platelets oxidative stress and platelet apoptosis due to mitochondrial reactive oxygen species reduction and reducing cytochrome C release during storage

Diet and Nutraceuticals for treatment and prevention of primary and secondary stroke: Emphasis on nutritional antiplatelet and antithrombotic agents

Ischemic stroke is a devastating disease that causes morbidity and mortality. Malnutrition following ischemic stroke is common in stroke patients. During the rehabilitation, the death rates of stroke patients are significantly increased due to malnutrition. Nutritional supplements such as protein, vitamins, fish, fish oils, moderate wine or alcohol consumption, nuts, minerals, herbal products, food colorants, marine products, fiber, probiotics and Mediterranean diets have improved neurological functions in stroke patients as well as their quality of life. Platelets and their mediators contribute to the development of clots leading to stroke. Ischemic stroke patients are treated with thrombolytics, antiplatelets, and antithrombotic agents. Several systematic reviews, meta-analyses, and clinical trials recommended that consumption of these nutrients and diets mitigated the vascular, peripheral, and central complications associated with ischemic stroke (Fig. 2). Particularly, these nutraceuticals mitigated the platelet adhesion, activation, and aggregation that intended to reduce the risks of primary and secondary stroke. Although these nutraceuticals mitigate platelet dysfunction, there is a greater risk of bleeding if consumed excessively. Moreover, malnutrition must be evaluated and adequate amounts of nutrients must be provided to stroke patients during intensive care units and rehabilitation periods. In this review, we have summarized the importance of diet and nutraceuticals in ameliorating neurological complications and platelet dysfunction with an emphasis on primary and secondary prevention of ischemic stroke.

Nanomedicine-mediated recovery of antioxidant glutathione peroxidase activity after oxidative-stress cellular damage: Insights for neurological long COVID

Nanomedicine for treating post-viral infectious disease syndrome is at an emerging stage. Despite promising results from preclinical studies on conventional antioxidants, their clinical translation as a therapy for treating post-COVID conditions remains challenging. The limitations are due to their low bioavailability, instability, limited transport to the target tissues, and short half-life, requiring frequent and high doses. Activating the immune system during coronavirus (SARS-CoV-2) infection can lead to increased production of reactive oxygen species (ROS), depleted antioxidant reserve, and finally, oxidative stress and neuroinflammation. To tackle this problem, we developed an antioxidant nanotherapy based on lipid (vesicular and cubosomal types) nanoparticles (LNPs) co-encapsulating ginkgolide B and quercetin. The antioxidant-loaded nanocarriers were prepared by a self-assembly method via hydration of a lyophilized mixed thin lipid film. We evaluated the LNPs in a new in vitro model for studying neuronal dysfunction caused by oxidative stress in coronavirus infection. We examined the key downstream signaling pathways that are triggered in response to potassium persulfate (KPS) causing oxidative stress-mediated neurotoxicity. Treatment of neuronally-derived cells (SH-SY5Y) with KPS (50 mM) for 30 min markedly increased mitochondrial dysfunction while depleting the levels of both glutathione peroxidase (GSH-Px) and tyrosine hydroxylase (TH). This led to the sequential activation of apoptotic and necrotic cell death processes, which corroborates with the crucial implication of the two proteins (GSH-Px and TH) in the long-COVID syndrome. Nanomedicine-mediated treatment with ginkgolide B-loaded cubosomes and vesicular LNPs showed minimal cytotoxicity and completely attenuated the KPS-induced cell death process, decreasing apoptosis from 32.6% (KPS) to 19.0% (MO-GB), 12.8% (MO-GB-Quer), 14.8% (DMPC-PEG-GB), and 23.6% (DMPC-PEG-GB-Quer) via free radical scavenging and replenished GSH-Px levels. These findings indicated that GB-LNPs-based nanomedicines may protect against KPS-induced apoptosis by regulating intracellular redox homeostasis.

L-carnitine contributes to enhancement of viability and quality of platelet concentrates through changing the apoptotic and anti-apoptotic associated microRNAs

BACKGROUND

Micro RNAs are known as the main regulator of messenger RNA translation in platelets and have a vital role in process of apoptosis during platelet storage. Our pervious study revealed that the expression of miR-145 and miR-326 changed significantly in platelets under maintenance conditions. This study aimed to evaluate the effect of L-carnitine (LC) as an additive to augment platelet quality by changing the microRNA expression.

METHODS

We used ten platelet concentrate (PC) bags and divided each into two equal parts, LC- treated, and LC free PC. The expression of miR-145 and miR-326 were determined using real-time PCR. Moreover, we measured platelet count, platelet aggregation, platelet viability, and lactate dehydrogenase activity in all samples.

RESULTS

The miR-326 expression significantly increased during platelet storage with mean fold changes of 3.2 for the control and 2.5 for LC- treated PC. The mean fold changes in miR-145 expression was less in the control PC (0.52) compared to the LC- treated PC (0.79). Increased levels of platelet count, platelet aggregation, and platelet viability were found in the LC-treated compared to the untreated PC.

CONCLUSION

LC has a protective effect on platelet apoptosis, reduces the expression of apoptotic microRNA, and prevents the reduction of anti-apoptotic microRNA.

A tight interplay between platelet activation and mitochondrial DNA release promotes platelet storage lesion in platelet concentrates

BACKGROUND AND OBJECTIVES

Platelet storage lesion (PSL) adversely affects the quality of platelet concentrates (PCs). Platelets are prone to activation during storage. Moreover, elevated free mitochondrial DNA (mtDNA) levels in PCs are associated with a higher risk of adverse transfusion reactions. Therefore, we aimed to evaluate the correlation between platelet activation markers and mtDNA release during PC storage.

MATERIALS AND METHODS

Six PCs prepared by the platelet-rich plasma method were assessed for free mtDNA copy number using quantitative real-time PCR and CD62P (P-selectin) expression by flow cytometry on days 0 (PC collection day), 3, 5 and 7 of storage. Lactate dehydrogenase (LDH) activity, pH, platelet count, mean platelet volume (MPV) and platelet distribution width (PDW) were measured as well. The correlation between free mtDNA and other PSL parameters, and the correlation between all parameters, was determined.

RESULTS

Significant increases in free mtDNA, MPV and PDW, and a significant decrease in platelet count and pH were observed. CD62P expression and LDH activity elevated significantly, particularly on storage days 5-7 and 0-3, respectively. Moreover, a moderate positive correlation (r = 0.61) was observed between free mtDNA and CD62P expression. The r values between free mtDNA and LDH, pH, platelet count, MPV and PDW were 0.81, -0.72, -0.49, 0.81 and 0.77, respectively.

CONCLUSION

The interplay between platelet activation and mtDNA release in promoting PSL in PCs may serve as a promising target for future research on applying additive solutions and evaluating the quality of PCs to improve transfusion and clinical outcomes.

Liposomal Resveratrol Alleviates Platelet Storage Lesion via Antioxidation and the Physical Buffering Effect

Platelet transfusion is essential in the treatment of platelet-related diseases and the prevention of bleeding in patients with surgical procedures. Platelet transfusion efficacy and shelf life are limited mainly by the development of platelet storage lesion (PSL). Mitigating PSL is the key to prolonging the platelet shelf life and reducing wastage. Excess intracellular reactive oxygen species (ROS) are one of the main factors causing PSL. In this study, we explored a nanomedicine strategy to improve the quality and functions of platelets in storage. Resveratrol (Res), a natural plant product, is known for its antioxidative effect. However, medical applications of Res are limited due to its low water solubility and stability. Therefore, we used a resveratrol-loaded liposomal system (Res-Lipo) to better utilize the antioxidant effect of the drug. This study aimed to evaluate the effect of Res-Lipo on platelet oxidative stress and alleviation of PSL during the storage time. Res-Lipo scavenged intracellular ROS and inhibited platelet apoptosis and activation during storage. Res-Lipo not only maintained mitochondrial function but also improved platelet aggregation in response to adenosine 5'-diphosphate. These results revealed that Res-Lipo ameliorated PSL and prolonged the platelet survival time in vivo. The strategy provides a potential method for extending the platelet storage time and might be considered a potential and safe additive to alleviate PSL.

Resveratrol reduces platelet storage lesion by preventing free mitochondrial DNA (mtDNA) accumulation in platelet concentrates during storage

Platelet activation and mitochondrial damage are among the crucial events leading to the quality reduction of platelet concentrates (PCs) during preparation and storage, called platelet storage lesion. Platelet activation results in the clearance of transfused platelets. Oxidative stress and platelet activation trigger mitochondrial DNA (mtDNA) release into the extracellular milieu which is associated with adverse transfusion reactions. Therefore, we aimed to investigate the effects of resveratrol, an antioxidant polyphenol, on platelet activation markers and mtDNA release. Ten PCs were divided equally into two bags each, one of them was allocated to the control group (n = 10) and another to the case group (resveratrol-treated, n = 10). Free mtDNA level and CD62P (P-selectin) expression level were measured by absolute quantification Real-Time PCR, and flow cytometry on days 0 (the receiving day), 3, 5, and 7 of storage respectively. Moreover, Lactate dehydrogenase (LDH) enzyme activity, pH, platelet count, mean platelet volume (MPV), and platelet distribution width (PDW) were assessed as well. Treatment of PCs with resveratrol can significantly decrease mtDNA release during storage compared to the control. In addition, platelet activation was significantly mitigated. We also observed significantly lower MPV, PDW, and LDH activity in resveratrol-treated PCs compared to the control group on days 3, 5, and 7. Furthermore, resveratrol maintained the pH of PCs on day 7. Resveratrol diminished free mtDNA and maintained biochemical parameters in PCs, possibly by reducing platelet activation. Therefore, resveratrol might be a possible additive solution for improving the quality of stored PCs.

Platelet storage: Progress so far

There is a crucial need for platelet transfusion during an emergency-surgery and treatment of platelet disorders. The unavailability of donors has furthermore increased the demand for platelet storage. Platelets have limited shelf life due to bacterial contamination and storage lesions. Temperature, materials, oxygen availability, media, platelet processing and manufacturing methods influence the platelet quality and viability during storage. The conception of various platelet additive solutions along with the advent of plastic storage during the 1980s led to enormous developments in platelet storage strategies. Cold storage of platelets gained attention despite its inability to contribute to platelet survival post-transfusion as it offers faster haemostasis. Several developments in platelet storage strategies over the years have improved the quality and shelf-life of stored platelets. Despite the progress, the efficacy of platelets during storage beyond a week has not been achieved. Antioxidants as additives have been explored in platelet storage and have proven to enhance the efficacy of platelets during prolonged storage. However, the molecular interactions of antioxidants in platelets can provide a better understanding of their mechanism of action. Optimization of dosage concentrations of antioxidants is also a critical parameter to be considered as they tend to exhibit toxicity at certain levels. This review provides comprehensive insights into the critical factors affecting platelet storage and the evolution of platelet storage. It also emphasizes the role of antioxidants as additives in platelet storage solutions and their future prospects towards better platelet banking.

L-carnitine modulates free mitochondrial DNA DAMPs and platelet storage lesions during storage of platelet concentrates

Platelet storage lesions may occur in Platelet concentrates (PCs) storage time, reducing PCs' quality. Mitochondrial damage causes mitochondrial DNA (mtDNA) to be released into the extracellular space. In this study, we evaluated the effect of L-carnitine (LC) as an antioxidant on free mtDNA DAMPs release in PCs during storage. Ten PCs prepared by the PRP method were studied. The copy numbers of free mtDNA, total reactive oxygen species (ROS), lactate dehydrogenase (LDH) enzyme activity, pH, and platelet counts were measured on days 0, 3, 5, and 7 of PCs storage in LC-treated and untreated platelets. LDH activity was significantly lower than the control group during 7 days of PCs storage (p = 0.041). Also, ROS production decreased in LC-treated PCs compared to the control group during storage (p = 0.026), and the difference mean of ROS between the two groups was significant on day 3, 5, and 7 (P_day3 = 0.02, P_day5 = 0.0001, P_day7 = 0.031). Moreover, LC decreased the copy numbers of free mtDNA during 7 days of storage (p = 0.021), and the difference mean of the copy numbers of free mtDNA in LC-treated PCs compared to the control group was significant on day 5 and 7 (P_day5 = 0.041، P_day7 = 0.022). It seems that LC can maintain the metabolism and antioxidant capacity of PCs and thus can reduce mitochondrial damage and mtDNA release; consequently, it can decrease DAMPs in PCs. Therefore, it may be possible to use this substance as a platelet additive solution in the future.

Dietary L-Carnitine Affects Leukocyte Count and Function in Dairy Cows Around Parturition

In early lactation, an energy deficit leading to a negative energy balance (NEB) is associated with increased susceptibility to disease and has been shown to be an important factor during transition in dairy cows. L-carnitine as a key factor in the mitochondrial transport of fatty acids and subsequently for β-oxidation and energy release is known to modulate mitochondrial biogenesis and thus influence metabolism and immune system. In the current study, we characterized hematological changes around parturition and investigated the potential effects of dietary L-carnitine supplementation on immune cell functions. For this approach, dairy cows were assigned either to a control (CON, n = 30) or an L-carnitine group [CAR, n = 29, 25 g rumen-protected L-carnitine per cow and day (d)]. Blood samples were taken from d 42 ante partum (ap) until d 110 post-partum (pp), with special focus and frequent sampling from 0.5 to72 h post-calving to clarify the impact of L-carnitine supplementation on leukocyte count, formation of reactive oxygen species (ROS) in polymorphonuclear cells (PMN) and peripheral mononuclear cells (PBMC) and their phagocytosis activity. Blood cortisol concentration and the capacity of PBMC proliferation was also investigated. All populations of leukocytes were changed during the peripartal period, especially granulocytes showed a characteristic increase up to 4 h pp. L-carnitine supplementation resulted in increased levels of eosinophils which was particularly pronounced one day before to 4 h pp, indicating a possible enhanced support for tissue repair and recovery. Non-supplemented cows showed a higher phagocytic activity in PBMC as well as a higher phagocytic capacity of PMN during the most demanding period around parturition, which may relate to a decrease in plasma levels of non-esterified fatty acids reported previously. L-carnitine, on the other hand, led to an increased efficiency to form ROS in stimulated PMN. Finally, a short period around calving proved to be a sensitive period in which L-carnitine administration was effective.

Effects of l-carnitine supplementation in patients with childhood-onset epilepsy prescribed valproate

BACKGROUND

The benefits of carnitine supplementation in patients treated with valproate (VPA) are not clear. Therefore, we retrospectively explored the benefits of carnitine supplementation by analyzing laboratory data.

METHODS

We measured the serum-free carnitine (FC), VPA, aspartate aminotransferase, alanine aminotransferase, amylase, and ammonia levels, and the platelet count, in 69 patients with childhood-onset epilepsy treated with VPA. Eight patients had received carnitine supplementation. The serum FC and acylcarnitine levels were measured using an enzyme cycling method. We compared laboratory values between patients with and without carnitine supplementation and analyzed the correlations between serum FC levels and laboratory values.

RESULTS

The serum FC levels were normal (median, 48.8 μmol/L; range: 41.9-68.3 μmol/L) in all eight patients with carnitine supplementation, but below normal in 32 of 61 patients without supplementation. The median serum amylase levels were lower in the patients with carnitine supplementation (median, 48 U/L; range: 27-149 U/L) than in those without (median, 7 U/L; range: 14-234 U/L). The platelet count and serum ammonia levels did not differ significantly between patients with and without supplementation. There was no significant correlation between the serum FC level and the platelet count, serum amylase level, or ammonia level.

CONCLUSIONS

Carnitine supplementation helps maintain serum FC levels in patients treated with VPA. The lower serum amylase levels in patients with carnitine supplementation may reflect protective effects of carnitine against latent pancreatic injury.