Anti-inflammatory efficacy and relevant SAR investigations of novel chiral pyrazolo isoquinoline derivatives: Design, synthesis, in-vitro, in-vivo, and computational studies targeting iNOS

Discovery of novel CXCR4 inhibitors for the treatment of inflammation by virtual screening and biological evaluation

C-X-C chemokine receptor type 4 (CXCR4) exerts considerable influence on the pathogenesis of inflammatory disorders and offers a potent avenue for drug intervention. This research utilizes a hybrid virtual screening methodology constructed using computer-aided drug design to discover novel CXCR4 inhibitors for the treatment of inflammation. First, a compound library was screened by Lipinski's five rules and adsorption, distribution, metabolism, excretion and toxicity properties. Second, the HypoGen algorithm was used in constructing a 3D-QSAR pharmacophore model and verify it layer by layer, and the obtained optimal pharmacophore 1 (Hypo 1) was used as a 3D query for compound screening. Then, hit compounds were obtained through molecular docking (Libdock and CDOCKER). The toxicity of the compounds to MDA-MB-231 cells was evaluated in vitro, and their binding affinity to the target was evaluated according to how they compete with 12G5 antibody for CXCR4 on the surfaces of the MDA-MB-231 cells. Compound Hit14 showed the strongest binding affinity among the hit compounds and inhibited cell migration and invasion in Matrigel invasion and wound healing assay at a concentration of 100 nM, demonstrating a better effect than AMD3100. Western Blot experiments further showed that Hit14 blocked the CXCR4/CXCL12-mediated phosphorylation of Akt. Meanwhile, cellular thermal displacement assay analysis showed that CXCR4 protein bound to Hit14 had high thermal stability. Finally, through in vivo experiments, we found that Hit14 inhibited mouse ear inflammation and reduced ear swelling and damage. Therefore, Hit14 is a promising drug for the further development of CXCR4 inhibitors for inflammation treatment.

Synthesis and anti-inflammatory activity of mogrol derivatives modified at C24 site

Mogrol, the aglycone of well-known sweeter mogrosides, shows potent anti-inflammatory activity. In this study, forty-two mogrol derivatives bearing various pharmacophores with oxygen or nitrogen atoms were designed and synthesized via structural modification at C24 site, and their anti-inflammatory activity were screened against lipopolysaccharide (LPS)-induced RAW264.7 cells. Compared with mogrol, most of derivatives exhibited stronger inhibition of NO production without cytotoxicity. In particular, compound B5 that contained an indole motif effectively suppressed the secretion of inflammatory mediators including TNF-α and IL-6, and inhibited the expression levels of TLR4, p-p65 and iNOS proteins. Molecular docking showed that the active B5 interacted with amino acid residues of iNOS protein through π-π stacking and hydrophobic interactions with binding affinity value of -12.1 kcal/mol, which was much stronger than mogrol (-8.9 kcal/mol). These results suggest that derivative B5 is a promising anti-inflammatory molecule and the strategy of hybridizing indole skeleton on mogrol is worthy for further attention.

The STAT3 inhibitor B9 alleviates lipopolysaccharide-induced acute lung injury through its anti-inflammatory effects

The development of acute lung injury (ALI), a common respiratory condition with multiple causes, is significantly influenced by the pro-inflammatory environment of signal transducer and activator of transcription 3 (STAT3) in macrophages. Our study aimed to evaluate the anti-inflammatory effects of B9 (N-(4-hydroxyphenyl)-9, 10-dioxo-9, 10-dihydroanthracene-2-sulfonamide), a novel inhibitor targeting the STAT3 SH2 domain, in macrophages and to assess its therapeutic potential for ALI using a mouse model of lipopolysaccharide (LPS)-induced ALI. We found that B9 (30 mg/kg) significantly reduced lung pathological damage and neutrophil infiltration caused by the intratracheal administration of LPS. Additionally, the high expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in alveolar lavage fluid was also inhibited by B9 treatment. The decreased expression of CD86 and increased CD206 in lung tissue demonstrated the anti-inflammatory effect of B9, which was due to its inhibition of the STAT3 signaling pathway in macrophages of ALI mice. Furthermore, B9 suppressed the activation of RAW264.7 cells induced by LPS, characterized by its ability to inhibit the activation of iNOS and STAT3 in a dose-dependent manner, as well as reduce the secretion of IL-6 and IL-1β. The in vivo preliminary safety evaluation indicated that B9 had a favorable safety profile at the administered doses. These results suggest that B9 exerts a therapeutic effect on LPS-induced ALI, potentially by preventing the phosphorylation of STAT3 Y705 and S727 without affecting the STAT3 protein level. Taken together, these findings provide a foundation for developing B9 as a novel anti-inflammatory agent for ameliorating LPS-induced ALI.

A series of indole-derived γ-hydroxy propiolate esters as potent anti-inflammatory agents: Design, synthesis, in-vitro and in-vivo biological studies

A variety of novel indole-derived γ-hydroxy propiolate esters were designed, synthesized, and evaluated for their anti-inflammatory activity in-vitro and in-vivo. According to the nitric oxide (NO) inhibitory analysis, all compounds showed potent NO inhibitory ability in a dose-dependent manner, with no apparent cytotoxicity. The model compound, L-37, also exhibited significant potency in PGE2 inhibition. In addition, compounds L-37 and L-39 can downregulate the expression of COX-2 enzyme at 5 μM via ELISA experiment. Compound L-37 (1 μM) also inhibited the PGF1 production as well as the expression of COX-1, but displayed weak inhibition activity towards the Leukotrienes (LT) and Thromboxane-B2 (TXB-2) production. However, the expression of 5-LOX was significantly inhibited by compound L-39 at 5 μM. Xylene-induced ear edema model was explored for in-vivo anti-inflammatory evaluation, compound L-37 showed similar inhibitory activity compared with celecoxib, approximately 80% at 50 mg/kg dosage. Every outcome showed that the newly synthesized compounds can effectively inhibit inflammation.

New Insight into the Possible Roles of L-Carnitine in a Rat Model of Multiple Sclerosis

OBJECTIVE

We investigated the effect of L-carnitine (LC) on cuprizone (Cup) demyelinating rat model and its possible underlying mechanisms.

METHODS

Thirty male Sprague-Dawley (SD) rats were randomly allocated to three groups: the normal control group; the Cup group, in which Cup was administrated at a dose of 450 mg/kg per day orally via gastric gavage for 5 weeks; and the Cup + LC group, which received the same dose of Cup as the Cup group, except that the rats were treated additionally with LC 100 mg/kg/day orally for 5 weeks. The nerve conduction (NCV) in isolated sciatic nerves was measured; then, the sciatic nerves were isolated for H&E staining and electron microscope examination. The expression of myelin basic protein (MBP), IL-1β, p53, iNOS, and NF-KB by immunohistochemistry was detected in the isolated nerves. A PCR assay was also performed to detect the expression of antioxidant genes Nrf2 and HO-1. In addition, the level of IL-17 was measured by ELISA.

RESULTS

There was a significant reduction in NCV in the Cup group compared to normal rats (p < 0.001), which was significantly improved in the LC group (p < 0.001). EM and histopathological examination revealed significant demyelination and deterioration of the sciatic nerve fibers, with significant improvement in the LC group. The level of IL-17 as well as the expression of IL-1β, p53, iNOS, and NF-KB were significantly increased, with significant reduction expression of MBP in the sciatic nerves (p < 0.01), and LC treatment significantly improved the studied parameters (p < 0.01).

CONCLUSION

The current study demonstrates a neuroprotective effect of LC in a Cup-induced demyelinating rat model. This effect might be due to its anti-inflammatory and antioxidant actions.