Key Developments in the Potential of Curcumin for the Treatment of Peripheral Neuropathies

Peripheral neuropathies (PN) can be triggered after metabolic diseases, traumatic peripheral nerve injury, genetic mutations, toxic substances, and/or inflammation. PN is a major clinical problem, affecting many patients and with few effective therapeutics. Recently, interest in natural dietary compounds, such as polyphenols, in human health has led to a great deal of research, especially in PN. Curcumin is a polyphenol extracted from the root of Curcuma longa. This molecule has long been used in Asian medicine for its anti-inflammatory, antibacterial, and antioxidant properties. However, like numerous polyphenols, curcumin has a very low bioavailability and a very fast metabolism. This review addresses multiple aspects of curcumin in PN, including bioavailability issues, new formulations, observations in animal behavioral tests, electrophysiological, histological, and molecular aspects, and clinical trials published to date. The, review covers in vitro and in vivo studies, with a special focus on the molecular mechanisms of curcumin (anti-inflammatory, antioxidant, anti-endoplasmic reticulum stress (anti-ER-stress), neuroprotection, and glial protection). This review provides for the first time an overview of curcumin in the treatment of PN. Finally, because PN are associated with numerous pathologies (e.g., cancers, diabetes, addiction, inflammatory disease...), this review is likely to interest a large audience.

Impact of high dose vitamin C on platelet function

AIM

To examine the effect of high doses of vitamin C (VitC) on ex vivo human platelets (PLTs).

METHODS

Platelet concentrates collected for therapeutic or prophylactic transfusions were exposed to: (1) normal saline (control); (2) 0.3 mmol/L VitC (Lo VitC); or (3) 3 mmol/L VitC (Hi VitC, final concentrations) and stored appropriately. The VitC additive was preservative-free buffered ascorbic acid in water, pH 5.5 to 7.0, adjusted with sodium bicarbonate and sodium hydroxide. The doses of VitC used here correspond to plasma VitC levels reported in recently completed clinical trials. Prior to supplementation, a baseline sample was collected for analysis. PLTs were sampled again on days 2, 5 and 8 and assayed for changes in PLT function by: Thromboelastography (TEG), for changes in viscoelastic properties; aggregometry, for PLT aggregation and adenosine triphosphate (ATP) secretion in response to collagen or adenosine diphosphate (ADP); and flow cytometry, for changes in expression of CD-31, CD41a, CD62p and CD63. In addition, PLT intracellular VitC content was measured using a fluorimetric assay for ascorbic acid and PLT poor plasma was used for plasma coagulation tests [prothrombin time (PT), partial thrombplastin time (PTT), functional fibrinogen] and Lipidomics analysis (UPLC ESI-MS/MS).

RESULTS

VitC supplementation significantly increased PLTs intracellular ascorbic acid levels from 1.2 mmol/L at baseline to 3.2 mmol/L (Lo VitC) and 15.7 mmol/L (Hi VitC, P < 0.05). VitC supplementation did not significantly change PT and PTT values, or functional fibrinogen levels over the 8 d exposure period (P > 0.05). PLT function assayed by TEG, aggregometry and flow cytometry was not significantly altered by Lo or Hi VitC for up to 5 d. However, PLTs exposed to 3 mmol/L VitC for 8 d demonstrated significantly increased R and K times by TEG and a decrease in the α-angle (P < 0.05). There was also a fall of 20 mm in maximum amplitude associated with the Hi VitC compared to both baseline and day 8 saline controls. Platelet aggregation studies, showed uniform declines in collagen and ADP-induced platelet aggregations over the 8-d study period in all three groups (P > 0.05). Collagen and ADP-induced ATP secretion was also not different between the three groups (P > 0.05). Finally, VitC at the higher dose (3 mmol/L) also induced the release of several eicosanoids including thromboxane B₂ and prostaglandin E₂, as well as products of arachidonic acid metabolism via the lipoxygenases pathway such as 11-/12-/15-hydroxyicosatetraenoic acid (P < 0.05).

CONCLUSION

Alterations in PLT function by exposure to 3 mmol/L VitC for 8 d suggest that caution should be exerted with prolonged use of intravenous high dose VitC.

Unsupervised analysis of combined lipid and coagulation data reveals coagulopathy subtypes among dialysis patients

Hemodialysis (HD) and peritoneal dialysis (PD) are the primary means of managing end stage renal disease (ESRD). However, these treatment modalities are associated with the onset of coagulation abnormalities. Effective management of coagulation risk among these patients requires the identification of surrogate markers that provide an early indication of the coagulation abnormalities. The role of sphingolipids in the manifestation and prediction of coagulation abnormalities among dialysis patients have never been investigated. Herein, we report the first instance of an in depth investigation into the sphingolipid changes among ESRD patients undergoing HD and PD. The results reveal distinct differences in terms of perturbations to specific sphingolipid biosynthetic pathways that are highly dependent on the treatment modality. Our studies also demonstrated strong correlation between specific sphingolipids and coagulation parameters, such as HexCer(d18:1/26:0) and maximal amplitude (MA), SM(d18:1/24:1) and tissue factor pathway inhibitor, and sphingosine 1-phosphate d18:1 and FX (Spearman ρ of 0.93, 0.89, and -0.89, respectively). Furthermore, our study revealed the potential for using HexCer(d18:1/22:0), HexCer(d18:1/24:0), and HexCer(d18:1/26:0) (r² = 0.71, 0.82, and 0.63, respectively) and coagulation parameter MA (r² = 0.7) for successful diagnosis of differential coagulopathies among ESRD patients undergoing HD, providing an opportunity toward personalized disease management.

Human as the Ultimate Wound Healing Model: Strategies for Studies Investigating the Dermal Lipidome

PURPOSE OF REVIEW

Educate the reader of the multiple roles undertaken by the human epidermal lipidome and the experimental techniques of measuring them.

RECENT FINDINGS

Damage to skin elicits a wound healing process that is capped by the recreation of the lipid barrier. In addition to barrier function, lipids also undertake an active signaling role during wound healing. Achievement of these multiple functions necessitates a significant complexity and diversity in the lipidome resulting in a composition that is unique to the human skin. As such, any attempts to delineate the function of the lipidome during the wound healing process in humans need to be addressed via studies undertaken in humans.

SUMMARY

The human cutaneous lipidome is unique and play a functionally significant role in maintaining barrier and regulating wound healing. Modern mass spectrometry and Raman spectroscopy based methods enable the investigation epidermal lipidome with respect to those functions.