Modulation of neuropathic pain in experimental diabetes mellitus

Exploring Zn(II)-Acetyl l-carnitine complex for simultaneous management of depression, chronic pain, and neuroprotection

Acetyl-l-carnitine (ALC) is synthesized in the brain, liver, and kidneys and plays crucial roles in energy metabolism, acetylcholine production, protein synthesis, and neuronal protection, contributing to its antidepressant and neuroprotective properties. Zinc, a vital biometal, is essential for depression and neuroprotection, exhibiting antidepressive effects alone or combined with classical antidepressants. The pharmacological benefits of metal coordination complexes often result from synergistic or additive effects. In this study, we present a novel multifunctional zinc complex, Zn(ALC)Cl2(H2O), which crystallizes in the monoclinic chiral space group P21, featuring a distorted tetrahedral Zn(II) environment. This new compound demonstrates significantly higher antidepressant activity, reducing immobility in the forced swimming test by 54 % compared to commercial ALC. Additionally, it exhibits in vivo antinociceptive properties, increases latency time, and proves effective in a diabetic neuropathy model by preventing the glucose-induced decrease in intracellular GSH levels. In vitro studies indicate that the complex can cross the blood-brain barrier and offer neuroprotection against glutamate-induced excitotoxicity and oxygen-glucose deprivation, with a drug classification of 10 versus 5 for ALC. Furthermore, under astrocytosis conditions, the Zn complex neutralizes the toxic effects of TGFβ-treated astrocytes. These findings highlight Zn(ALC)Cl2(H2O) as a promising candidate for treating depression and neurodegenerative diseases.

Activation of G-protein-coupled receptor 39 reduces neuropathic pain in a rat model

Activated G-protein-coupled receptor 39 (GPR39) has been shown to attenuate inflammation by interacting with sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α). However, whether GPR39 attenuates neuropathic pain remains unclear. In this study, we established a Sprague-Dawley rat model of spared nerve injury-induced neuropathic pain and found that GPR39 expression was significantly decreased in neurons and microglia in the spinal dorsal horn compared with sham-operated rats. Intrathecal injection of TC-G 1008, a specific agonist of GPR39, significantly alleviated mechanical allodynia in the rats with spared nerve injury, improved spinal cord mitochondrial biogenesis, and alleviated neuroinflammation. These changes were abolished by GPR39 small interfering RNA (siRNA), Ex-527 (SIRT1 inhibitor), and PGC-1α siRNA. Taken together, these findings show that GPR39 activation ameliorates mechanical allodynia by activating the SIRT1/PGC-1α pathway in rats with spared nerve injury.

Using polyphenols as a relevant therapy to diabetes and its complications, a review

Diabetes is currently a worldwide health concern. Hyperglycemia, hypertension, obesity, and oxidative stress are the major risk factors that inevitably lead to all the complications from diabetes. These complications severely impact the quality of life of patients, and they can be managed, reduced, or even reverted by several polyphenols, plant extracts and foods rich in these compounds. The goal of this review is to approach diabetes not as a single condition but rather an interconnected combination of risk factors and complications. This work shows that polyphenols have multi target action and effects and they have been systematically proven to be relevant in the reduction of each risk factor and improvement of associated complication.

Photobiomodulation (Laser and LED) on Sternotomy Healing in Hyperglycemic and Normoglycemic Patients Who Underwent Coronary Bypass Surgery with Internal Mammary Artery Grafts: A Randomized, Double-Blind Study with Follow-Up

BACKGROUND AND OBJECTIVE

This study aimed at analyzing the healing effects of low-level laser therapy (LLLT) (λ620 nm, 6 J/cm²) and light-emitting diode (LED) therapy (λ640 nm, 6 J/cm²) on the longitudinal sternotomy incisions of hyperglycemic and normoglycemic patients who underwent coronary artery bypass grafting (CABG).

MATERIALS AND METHODS

120 volunteers were electively submitted to CABG and were randomly allocated into four different groups of equal size (n = 30): control, placebo, laser (λ of 640 nm and spatial average energy fluency [SAEF] of 1.06 J/cm²), and LED (λ of 660 ± 20 nm and SAEF of 0.24 J/cm²). Laser and LED groups were irradiated from the second to eighth day postsurgery, and sternotomy incision was photographically registered. Then, participants were also separated into hyperglycemic and normoglycemic groups, according to their fasting blood glucose test before surgery. Three researchers blindly analyzed the incision photographs to determine hyperemia and wound closure at the first day of hospital discharge (eighth postoperative day).

RESULTS

LLLT and LED groups had similarly less hyperemia and less incision bleeding or dehiscence (p ≤ 0.005) and the outcomes were also analogous between hyperglycemic and normoglycemic patients, which indicates no difference observed in an intragroup analysis (p ≥ 0.05).

CONCLUSIONS

With the present therapy parameters, it may be assumed that both coherent light (laser) and non-coherent light (LED) are effective in promoting sternotomy and healing acceleration, which are evident on the eighth day postsurgery.

Low-Level Laser and Light-Emitting Diode Therapy for Pain Control in Hyperglycemic and Normoglycemic Patients Who Underwent Coronary Bypass Surgery with Internal Mammary Artery Grafts: A Randomized, Double-Blind Study with Follow-Up

OBJECTIVE

This study aimed to evaluate the efficacy of low-level laser therapy (LLLT) and light-emitting diodes (LEDs) for reducing pain in hyperglycemic and normoglycemic patients who underwent coronary artery bypass surgery with internal mammary artery grafts.

METHODS

This study was conducted on 120 volunteers who underwent elective coronary artery bypass graft (CABG) surgery. The volunteers were randomly allocated to four different groups of equal size (n = 30): control, placebo, LLLT [λ = 640 nm and spatial average energy fluence (SAEF) = 1.06 J/cm(2)], and LED (λ = 660 ± 20 nm and SAEF = 0.24 J/cm(2)). Participants were also divided into hyperglycemic and normoglycemic subgroups, according to their fasting blood glucose test result before surgery. The outcome assessed was pain during coughing by a visual analog scale (VAS) and the McGill Pain Questionnaire.

RESULTS

The patients were followed for 1 month after the surgery. The LLLT and LED groups showed a greater decrease in pain, with similar results, as indicated by both the VAS and the McGill questionnaire (p ≤ 0.05), on the 6th and 8th postoperative day compared with the placebo and control groups. The outcomes were also similar between hyperglycemic and normoglycemic patients. One month after the surgery, almost no individual reported pain during coughing.

CONCLUSIONS

LLLT and LED had similar analgesic effects in hyperglycemic and normoglycemic patients, better than placebo and control groups.