Self-emulsifying drug delivery system of (R)-α-lipoic acid to improve its stability and oral absorption

Orally fast dissolving α-lipoic acid electrospun nanofibers mitigates lipopolysaccharide induced inflammation in RAW 264.7 macrophages

α-Lipoic acid (LA), a dietary supplement known for its strong antioxidant and anti-inflammatory potential, faces challenges due to its poor aqueous solubility and thermal instability. To address these issues, herein methyl-beta-cyclodextrin (M-β-CD) was utilized to create inclusion complex (IC) of LA in 1:1 M stoichiometric ratio of M-β-CD to LA. The LA-M-β-CD-IC was further combined with pullulan (PUL), a non-toxic and water-soluble biopolymer, for the development of electrospun nanofibers (NF) by green and sustainable approach. The resulting PUL/LA/M-β-CD NF formed as a self-standing and flexible material with an average diameter of 569 ± 129 nm and encapsulation efficiency of ∼86.90 %. The developed NF demonstrated an accelerated release, quick dissolution, and disintegration when exposed to artificial saliva replicating the conditions of oral cavity. PUL/LA/M-β-CD NF attenuated the production of ROS and NO by downregulating pro-inflammatory enzymes (iNOS and COX-2) in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Moreover, PUL/LA/M-β-CD NF also significantly downregulated the expression of pro-inflammatory cytokines including TNF-α, IL-6, and IL-1β along with suppression of NF-ĸB nuclear translocation in comparison to LA (at 250 μM). In nutshell, PUL/LA/M-β-CD NF demonstrated great potential as a rapid disintegrating delivery system for oral anti-inflammatory treatment due to the enhanced physicochemical characteristics of LA.

Potential of Plant-Derived Compounds in Preventing and Reversing Organ Fibrosis and the Underlying Mechanisms

Increased production of extracellular matrix is a necessary response to tissue damage and stress. In a normal healing process, the increase in extracellular matrix is transient. In some instances; however, the increase in extracellular matrix can persist as fibrosis, leading to deleterious alterations in organ structure, biomechanical properties, and function. Indeed, fibrosis is now appreciated to be an important cause of mortality and morbidity. Extensive research has illustrated that fibrosis can be slowed, arrested or even reversed; however, few drugs have been approved specifically for anti-fibrotic treatment. This is in part due to the complex pathways responsible for fibrogenesis and the undesirable side effects of drugs targeting these pathways. Natural products have been utilized for thousands of years as a major component of traditional medicine and currently account for almost one-third of drugs used clinically worldwide. A variety of plant-derived compounds have been demonstrated to have preventative or even reversal effects on fibrosis. This review will discuss the effects and the underlying mechanisms of some of the major plant-derived compounds that have been identified to impact fibrosis.

The efficacy of alpha‐lipoic acid in the management of burning mouth syndrome: An updated systematic review of randomized controlled clinical trials

Background and Aims

Burning mouth syndrome (BMS) causes burning or uncomfortable feelings in the oral cavity without any obvious injuries. This condition's etiopathogenesis is still unknown, consequently, BMS management is very challenging. Alpha‐lipoic acid (ALA) is a naturally occurring potent bioactive compound that has been found to be useful in the management of BMS in many studies. Therefore, we conducted a comprehensive systematic review to investigate the usefulness of ALA in the management of BMS based on randomized controlled trials (RCTs).

Methods

Different electronic databases, including PubMed, Scopus, Embase, Web of Science, and Google Scholar, were extensively searched to find relevant studies.

Results

This study included nine RCTs that matched the inclusion criteria. In most studies, ALA was given at a dose of 600–800 mg/day, with up to two months of follow‐up. The majority of studies (six out of nine studies) indicated that ALA was more effective in BMS patients than in the placebo‐controlled group.

Conclusions

This comprehensive systematic review provides evidence of the positive outcomes of the treatment of BMS with ALA. However, more research might be needed before ALA can be considered the first‐line therapy for BMS.

R-α-Lipoic Acid Conjugated to d-α-Tocopherol Polyethylene Glycol 1000 Succinate: Synthesis, Characterization, and Effect on Antiseizure Activity

α-Lipoic acid (LA), a dithiol micronutrient, acts as a vital cofactor in various cellular catabolic reactions and is also known as a universal antioxidant. The therapeutic efficacy of LA is compromised by a poor aqueous solubility as well as a short half-life. In the present study, LA was conjugated to d-α-tocopherol polyethylene glycol succinate (TPGS) using carbodiimideacid-alcohol coupling reaction. The synthesized conjugate (TPGS-LA) was characterized using ¹H and ¹³C nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), UV-vis spectroscopy, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The TPGS-LA conjugate was demonstrated to be biocompatible and to have better anticonvulsion activity as compared to native LA in pentylenetetrazol (PTZ)-induced convulsions in zebrafish. Moreover, zebrafish larvae pretreated with TPGS-LA conjugate demonstrated a significant (p < 0.05) reduction of protein carbonylation levels and downregulation of c-fos expression during seizures as compared to native LA. Conclusively, the present findings demonstrate that the TPGS-LA conjugate can be a promising approach for the delivery of LA.

Self-Emulsifying Systems for Delivery of Bioactive Compounds from Natural Origin

Nature has been used as therapeutic resources in the treatment of diseases for many years. However, some natural compounds have poor water solubility. Therefore, physicochemical strategies and technologies are necessary for development of systems for carrying these substances. The self-emulsifying drug delivery systems (SEDDS) have been used as carriers of hydrophobic compounds in order to increase the solubility and absorption, improving their bioavailability. SEDDS are constituted with a mixture of oils and surfactants which, when come into contact with an aqueous medium under mild agitation, can form emulsions. In the last years, a wide variety of self-emulsifying formulations containing bioactive compounds from natural origin has been developed. This review provides a comprehensive overview of the main excipients and natural bioactive compounds composing SEDDS. In addition, applications, new technologies and innovation are reviewed as well. Examples of self-emulsifying formulations administered in different sites are also considered for a better understanding of the use of this strategy to modify the delivery of compounds from natural origin.

Estimation of pharmacokinetic parameters of alpha-lipoic acid in the chicks model

Background and objective: Alpha-lipoic acid is a drug used to treat diabetic neuropathy, and it has other uses as a dietary supplement. The target of the study was to investigate the concentration of therapeutic doses of Alpha-lipoic acid in the blood plasma of broiler chicks to define the pharmacokinetic parameters. Methods: A randomized controlled study was performed on thirty-five healthy broiler chicks of seven days old, chicks were injected into the peritoneum with a single dose of analgesic ED50 80mg /kg b.wt, following injection of the drug, blood samples were collected at 0.25, 0.5, 1, 2, 4, 24 h (five chicks per time) from the jugular vein. Then the  blood plasma was obtained, the concentrations of Alpha-lipoic acid  in blood  plasma samples were determined utilizing UV Spectrometric Method, the pharmacokinetic parameters were determined by the PKSolver program. Time versus concentration curve for Alpha-lipoic acid was obtained from the program. The pharmacokinetic parameters were determined with non-compartmental models. Results: The concentration of Alpha-lipoic acid  in the blood plasma of chicks injected with Alpha lipoic at a dose (80 mg/kg) were 134.6±7.17, 178.5±4.10 ,192.4±7.83  ,158.5±11.05  ,147.1±10.16, 122.8±7.09  µg/ml at times   0.25, 0.5, 1, 2, 4, and 24 hours respectively. The maximum plasma concentration was 192.4µg/ml during a period of 1 hour of injection. The terminal elimination half-life was 65hours, the terminal phase elimination rate constant was 0.011 h-1 , the mean residence time was 94h, and the area under the curve from time 0 to infinity was 14960 µg.h/ml. Conclusions:  Our study concluded that the peak of the analgesic effect of alpha lipoic acid was one hour after treatment; furthermore, it is characterized by a long elimination half-life and a poor clearance from the chick’s body, which is reflected in the long effects of its pharmacological properties