Characteristics, Properties and Analytical/Bioanalytical Methods of 5-Aminosalicylic Acid: A Review

Lab-on-a chip electrochemical sensing platform for simultaneous, ultra-sensitive and on-spot detection of 4-aminosalicylic acid and 5-aminosalicylic acid based on synergistic potential of chitosan functionalized MWCNTs supported on Ni doped Bi2S3

Mesalamine or 5-aminosalicylic acid (5-ASA) and its isomer 4-aminosalicylic acid (4-ASA), well known key therapeutic agents used to treat inflammatory bowel diseases (IBDs) can pose toxicity risks upon unregulated consumption. However, their simultaneous real-time detection from physiological fluids like urine remains unexplored. This study presents an innovative electrochemical sensing platform using modified screen-printed electrodes capable of simultaneous detection of both the drugs by harnessing the synergistic potential of a novel nanocomposite comprising chitosan functionalized multi-walled carbon nanotubes and nickel doped bismuth sulphide. Comprehensive optical and microstructural characterization validate the modified sensor platform's morphological characteristics. The sensor was evaluated using CV and DPV, exhibiting notably low detection limits which is of the value 39.559 μM for 5-ASA and 85.21 μM for 4-ASA. Sensitivity was found to be 0.174 μA μM-1cm-2 for the linear dynamic range (LDR) of 50 μM-5750 μM for 5-ASA and 0.139 μA μM-1cm-2 for the linear dynamic range (LDR) of 100 μM-2200 μM for 4-ASA. Moreover, the adaptability of the sensor for integration into hand-held point-of-care devices for practical application has been demonstrated in this paper. Experimental validation using real urine samples underscores the sensor's impressive recovery rate of 98-99.6 % for 5-ASA and 95.12-99.24 % for 4-ASA and its capability of detecting target drugs even when present with typical urinary constituents as interferences. The real-world applicability of this sensing platform is further emphasized by conducting experiments on miniaturized hand-held device thus making it a promising tool for on-the-spot detection, offering substantial potential for future integration into point-of-care diagnostic devices to monitor patients requiring precise medical monitoring. Our approach offers unprecedented real-time identification capabilities of 4-ASA and 5-ASA which has not been explored before.

Overexpression of PtNRPS1 enhances diatom-mediated bioremediation of salicylate pollution

The accumulation of the emerging pollutant salicylic acid (SA) in the environment has gained much attention. In this study, overexpression of the non-ribosomal peptide synthase (NRPS) gene, PtNRPS1 in the marine diatom Phaeodactylum tricornutum (PtNRPS1-OE) increased resistance to SA pollutants. It was assumed that the enhanced tolerance was due to the high binding affinity between recombinant PtNRPS1 (rNRPS1) and SA pollutants. Moreover, tandem mass spectrometry analysis determined the amino acids that participated in the covalently binding of SA. The removal efficiency of SA pollutants by PtNRPS1-OE cells was found to be markedly elevated. The mechanism underlying the removal of SA and 5-substituted SA (5-sSA) was proposed, following the co-localization analysis of rNRPS1 and SA. The purpose of this study was not about using PtNRPS1 as an enzyme to catalyze the synthesis of metabolite. Rather, it explored the possibility of using PtNRPS1 to remove pollutants, which further improves practical feasibility of microalgae-mediated bioremediation.

[α-Cyperone Antagonizes Intestinal Mucosal Inflammatory Response Through Modulation of TLR4/NF-κB Signaling Pathway to Alleviate Crohn's Disease-Like Colitis in Mice]

Objective

To investigate the effect and potential mechanisms of α-cyperone (CYP) on Crohn's disease (CD) -like colitis induced by 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) in mice.

Methods

The mice were randomly and evenly divided into wild type (WT), TNBS, CYP and 5-aminosalicylic acid (5-ASA) groups, with 10 mice in each group. The symptoms of enteritis, the function and structure of the intestinal barrier, and the expression levels of inflammatory factors, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and gamma-interferon (IFN-γ), in the colon were assessed. The lipopolysaccharide (LPS)-induced inflammation model of Caco2 cells was constructed and the cells were divided into Control, LPS and LPS+CYP groups. The expression levels of tight junction protein and inflammatory factors in each group were assessed. Gene Ontology (GO) functional enrichment analysis was conducted to predict the possible pathways of action and potential molecular mechanisms of CYP, and to verify them in vivo and in vitro.

Results

In the in vivo study, compared with those of the TNBS group, the body mass and colon length of mice in the CYP group and the 5-ASA group were significantly increased, while the disease activity scores and histological inflammation scores were significantly decreased (P<0.05). The level of lucifcein-glucan isothiocyanate and the bacterial translocation rate (in the liver, the spleen, and mesenteric lymph nodes) were significantly decreased, while the transepithelial electric resistance (TEER) value and the expression levels of zonula occluden protein-1 (ZO-1), and claudin-1 were significantly increased (P<0.05). The expression of inflammatory factors was significantly decreased (P<0.05). In the in vitro study, compared with those of the LPS group, the TEER value and the expression of ZO-1 and claudin-1 in the Caco2 cells in the LPS+CYP group were significantly increased (P<0.05). The expression of inflammatory factors was significantly decreased (P<0.05). Enrichment analysis showed that CYP was correlated with inflammatory response (P<0.001). Western blot results showed that CYP could significantly reduce the expression of key proteins in toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway in vivo and in vitro (P<0.05).

Conclusion

CYP may protect the intestinal barrier by antagonizing the inflammatory response of the intestinal mucosa through regulating the expression of the TLR4/NF-κB signaling pathway, thereby alleviating TNBS-induced CD-like colitis in mice.

Downregulation of OATP2B1 by proinflammatory cytokines leads to 5-ASA hyposensitivity in Ulcerative colitis

5-Aminosalicylic acid (5-ASA) is a first-line agent in both remission and maintenance therapy for ulcerative colitis (UC). However, the mucosal concentration of 5-ASA was significantly lower in patients with severe histological inflammation, which further led to a poor response to 5-ASA treatment. Our study aimed to clarify the mechanism of 5-ASA uptake into colonic epithelial cells and to further explore the reason for the decreased colonic mucosal 5-ASA concentration in UC patients. Our results demonstrated that the colonic 5-ASA concentration was notably reduced in DSS-induced colitis mice and inversely correlated with colonic inflammation. 5-ASA was not a substrate of carnitine/organic cation transporter 1/2 (OCTN1/2) or multidrug resistance protein 1 (MDR1), whereas organic anion transporting polypeptide 2B1 (OATP2B1) and sodium-coupled monocarboxylate transporter 1 (SMCT1) mediated the uptake of 5-ASA, with a greater contribution from OATP2B1 than SMCT1. Inhibitors and siRNAs targeting OATP2B1 significantly reduced 5-ASA absorption in colonic cell lines. Moreover, OATP2B1 expression was dramatically downregulated in colon tissues from UC patients and dextran sodium sulfate (DSS)-induced colitis mice, and was also negatively correlated with colonic inflammation. Mechanistically, mixed proinflammatory cytokines downregulated the expression of OATP2B1 in a time- and concentration-dependent manner through the hepatocyte nuclear factor 4 α (HNF4α) pathway. In conclusion, OATP2B1 was the pivotal transporter involved in colonic 5-ASA uptake, which indicated that inducing OATP2B1 expression may be a strategy to promote 5-ASA uptake and further improve the concentration and anti-inflammatory efficacy of 5-ASA in UC.

Metabolomic profiling of the aqueous humor in patients with pediatric cataract

Pediatric cataract, including congenital and developmental cataract, is a kind of pediatric vision-threatening disease with extensive phenotypic heterogeneity and multiple mechanisms. We aimed to investigate the metabolite profile of aqueous humor (AH) in patients with pediatric cataracts, and identify underlying mutual correlations between differential metabolites. Metabolomic profiles of AH were analyzed and compared between pediatric cataract patients (n = 33) and age-related cataract patients without metabolic diseases (n = 29), using global untargeted metabolomics with ultra-high-performance liquid chromatography tandem mass spectrometry. Principal component analysis, partial least squares discriminant analysis and heat map were applied. Enriched pathway analysis was conducted using Kyoto Encyclopedia of Genes and Genomes. Receiver-operating characteristic (ROC) analyses were employed to select potential biomarkers. A total of 318 metabolites were identified, of which 54 differential metabolites (25 upregulated and 29 downregulated) were detected in pediatric cataract group compared with controls (variable importance of projection >1.0, fold change ≥1.5 or ≤ 0.667 and P < 0.05). A significant accumulation of N-Acetyl-Dl-glutamic acid was observed in pediatric cataract group. The differential metabolites were mainly enriched in histidine metabolism (increased L-Histidine and decreased 1-Methylhistamine) and the tryptophan metabolism (increased N-Formylkynurenine and L-Kynurenine). 5-Aminosalicylic acid showed strong positive mutual inter-correlation with L-Tyrosinemethylester and N,N-Diethylethanolamine, both of which were down-regulated in pediatric cataract group. The ROC analysis implied 11 metabolites served as potential biomarkers for pediatric cataract patients (all area under the ROC curve ≥0.900). These results illustrated novel potential metabolites and metabolic pathways in pediatric cataract, which provides new insights into the pathophysiology of pediatric cataract.

Efficacy and safety of Chinese patent medicine combined with 5-aminosalicylic acid for patients with ulcerative colitis: A network meta-analysis of randomized controlled trials

Objectives

Given the widespread use of Chinese patent medicines (CPMs) in combination with 5-aminosalicylic acid (5-ASA) for Ulcerative colitis (UC) patients, this study aimed to evaluate the efficacy and safety of nine CPMs combined with 5-ASA in the treatment of UC.

Methods

A systematic literature search was conducted in eight databases from inception to May 2023 to identify eligible RCTs evaluating the effects of CPM combined with 5-ASA for the treatment of UC. The methodological quality of the included RCTs was assessed using the Cochrane risk of bias tool in Review Manager 5.4. The primary outcome of the meta-analysis was the overall response rate. The secondary outcomes included excellent rate, disease activity index (DAI), IL-6, IL-8, and TNF-α levels, mean platelet volume (MPV), fibrinogen (FIB) levels, recurrence rate, and adverse event rate. Network meta-analysis was performed using Review Manager 5.4 and Stata 15.0.

Results

In total, 70 RCTs including 5973 patients and 10 treatment regimens were included. The combination of Kangfuxin Liquid (KFL) and 5-ASA showed the greatest efficacy in improving FIB levels and the overall response rate. Bupi Yichang Pill (BYP) combined with 5-ASA was associated with the fewest adverse events and the lowest recurrence rate. Hudi Enteric-coated Capsule (HEC) combined with 5-ASA ranked first in improving DAI. ZhiKang Capsule (ZKC), ChangYanNing Capsule (CYN), and Danshen Injection (DSI) combined with 5-ASA ranked first in improving IL-6, IL-10, and TNF-α levels, respectively. Shenling Baizhu Powder (SBP) combined with 5-ASA was associated with the highest excellent rate.

Conclusions

CPM combined with 5-ASA may be more effective than 5-ASA alone for treating UC. Besides, CPM combined with 5-ASA could better reduce the recurrence rate and adverse event rate in UC patients. The current meta-analysis provides statistical evidence for clinical application.Systematic Review Registration: International Prospective Register of Systematic Reviews (PROSPERO), No. CRD42023433672.

Electroanalytical Overview: The Sensing of Mesalamine (5-Aminosalicylic Acid)

Mesalamine, known as 5-aminosalicylic acid, is a medication used primarily in the treatment of inflammatory bowel disease, including ulcerative colitis and Crohn's disease. 5-Aminosalicylic acid can be measured using various benchtop laboratory techniques which involve liquid chromatography-mass spectroscopy, but these are sophisticated and large, meaning that they cannot be used on-site because transportation of the samples, chemicals, and physical and biological reactions can potentially occur, which can affect the sample's composition and potentially result in inaccurate results. An alternative approach is the use of electrochemical based sensing platforms which has the advantages of portability, cost-efficiency, facile miniaturization, and rapid analysis while nonetheless providing sensitivity and selectivity. We provide an overview of the use of the electroanalytical techniques for the sensing of 5-aminosalicylic acid and compare them to other laboratory-based measurements. The applications, challenges faced, and future opportunities for electroanalytical based sensing platforms are presented in this review.

Topical drug delivery strategies for enhancing drug effectiveness by skin barriers, drug delivery systems and individualized dosing

Topical drug delivery is widely used in various diseases because of the advantages of not passing through the gastrointestinal tract, avoiding gastrointestinal irritation and hepatic first-pass effect, and reaching the lesion directly to reduce unnecessary adverse reactions. The skin helps the organism to defend itself against a huge majority of external aggressions and is one of the most important lines of defense of the body. However, the skin's strong barrier ability is also a huge obstacle to the effectiveness of topical medications. Allowing the bioactive, composition in a drug to pass through the stratum corneum barrier as needed to reach the target site is the most essential need for the bioactive, composition to exert its therapeutic effect. The state of the skin barrier, the choice of delivery system for the bioactive, composition, and individualized disease detection and dosing planning influence the effectiveness of topical medications. Nowadays, enhancing transdermal absorption of topically applied drugs is the hottest research area. However, enhancing transdermal absorption of drugs is not the first choice to improve the effectiveness of all drugs. Excessive transdermal absorption enhances topical drug accumulation at non-target sites and the occurrence of adverse reactions. This paper introduces topical drug delivery strategies to improve drug effectiveness from three perspectives: skin barrier, drug delivery system and individualized drug delivery, describes the current status and shortcomings of topical drug research, and provides new directions and ideas for topical drug research.

Spectrophotometric determination of Mesalazine in Pure Form and Pharmaceuticals formulations via Diazotization and Coupling Reaction

An accurate, simple, and precise spectrofluorimetric method is presented for the determination of Mesalazine (MZN) based on Diazotization in acidic medium through reaction it with Sodium nitrite (NaNO2) to result diazonium salt that Coupling Reaction in medium base with 2,7-Dihydroxynaphthalene (DHNP) to formed azo dye. The intensity of the dye was measured at 501 nm after optimization of the experimental parameters. Beer’s law was applied to the proposed method and it was valid within a concentration range of 0.25–10 μg/mL and the linear regression was R2 = 0.9974. The limit of quantitation was 0.0241 μg/mL, and the molar absorptivity coefficient 1.85x104 L.mol−1.cm−1. Sandal's sensitivity was 0.0082 μg.cm-2 There is no interference from excipients found in the tablet. The data were statistically compared with British Pharmacopoeia methods asstandard reference using Student's t-and F-test.

Temozolomide: an Overview of Biological Properties, Drug Delivery Nanosystems, and Analytical Methods

Temozolomide (TMZ) is an imidazotetrazine prodrug used to treat glioblastoma multiforme. Its physicochemical prop-erties and small size confer the ability to cross the blood-brain barrier. The antitumor activity depends on pH-dependent hydrolysis of the methyldiazonium cation, which is capable of methylating purine bases (O6-guanine; N7-guanine, and N3-adenine) and causing DNA damage and cell death. TMZ is more stable in acidic media (pH ≤ 5.0) than in basic media (pH ≥ 7.0) due to the protonated form that minimizes the catalytic process. Because of this, TMZ has high oral bioavailability, but it has a half-life of 1.8 h and low brain distribution (17.8%), requiring a repeated dos-ing regimen that limits its efficacy and increases adverse events. Drug delivery Nanosystems (DDNs) improve the phys-icochemical properties of TMZ and may provide controlled and targeted delivery. Therefore, DDNs can increase the efficacy and safety of TMZ. In this context, to ensure the efficiency of DDNs, analytical methods are used to evaluate TMZ pharmacokinetic parameters, encapsulation efficiency, and the release profile of DDNs. Among the methods, high-performance liquid chromatography is the most used due to its detection sensitivity in complex matrices such as tissues and plasma. Micellar electrokinetic chromatography features fast analysis and no sample pretreatment. Spec-trophotometric methods are still used to determine encapsulation efficiency due to their low cost, despite their low sen-sitivity. This review summarizes the physicochemical and pharmacological properties of free TMZ and TMZ-loaded DDNs. In addition, this review addresses the main analytical methods employed to characterize TMZ in different ma-trices.

An updated review on properties, nanodelivery systems, and analytical methods for the determination of 5-fluorouracil in pharmaceutical and biological samples

Abstract:

5-Fluorouracil (5-FU) is an antimetabolite drug used for over 70 years as first-line chemotherapy to treat various types of cancer, such as head, neck, breast and colorectal cancer. 5-FU acts mainly by inhibiting thymidylate synthase, thereby interfering with deoxyribonucleic acid (DNA) replication or by 5-FU incorporating into DNA, causing damage to the sequence of nucleotides. Being analogous to uracil, 5-FU enters cells using the same transport mechanism, where a is converted into active metabolites such as fluorouridine triphosphate (FUTP), fluorodeoxyuridine monophosphate (FdUMP), and fluorodeoxyuridine triphosphate (FdUTP). Currently, there are several nanodelivery systems being developed and evaluated at the preclinical level to overcome existing limitations to 5-FU chemotherapy, including liposomes, polymeric nanoparticles, polymeric micelles, nanoemulsions, mesoporous silica nanoparticles, and solid lipid nanoparticles. Therefore, it is essential to choose and develop suitable analytical methods for the quantification of 5-FU and its metabolites (5-fluorouridine and 5-fluoro-2-deoxyuridine) in pharmaceutical and biological samples. Among the analytical techniques, chromatographic methods are commonly the most used for the quantification of 5-FU from different matrices. However, other analytical methods have also been developed for the determination of 5-FU, such as electrochemical methods, a sensitive, selective, and precise technique, in addition to having a reduced cost. Here, we first review the physicochemical properties, mechanism of action, and advances in 5-FU nanodelivery systems. Next, we summarize the current progress of other chromatographic methods described to determine 5-FU. Lastly, we discuss the advantages of electrochemical methods for the identification and quantification of 5-FU and its metabolites in pharmaceutical and biological samples.

The Communication Between Intestinal Microbiota and Ulcerative Colitis: An Exploration of Pathogenesis, Animal Models, and Potential Therapeutic Strategies

Ulcerative Colitis (UC) is a chronic inflammatory bowel disease. The prolonged course of UC and the lack of effective treatment management make it difficult to cure, affecting the health and life safety of patients. Although UC has received more attention, the etiology and pathogenesis of UC are still unclear. Therefore, it is urgent to establish an updated and comprehensive understanding of UC and explore effective treatment strategies. Notably, sufficient evidence shows that the intestinal microbiota plays an important role in the pathogenesis of UC, and the treating method aimed at improving the balance of the intestinal microbiota exhibits a therapeutic potential for UC. This article reviews the relationship between the genetic, immunological and microbial risk factors with UC. At the same time, the UC animal models related to intestinal microbiota dysbiosis induced by chemical drugs were evaluated. Finally, the potential value of the therapeutic strategies for restoring intestinal microbial homeostasis and treating UC were also investigated. Comprehensively, this study may help to carry out preclinical research, treatment theory and methods, and health management strategy of UC, and provide some theoretical basis for TCM in the treatment of UC.