Rebamipide, an Amino Acid Analog of 2(1H)-Quinolinone, Inhibits the Formation of Human Osteoclasts

The combined use of anti-peptic agents is associated with an increased risk of osteoporotic fracture: a nationwide case-control study

BACKGROUND/AIMS

Long-term use of acid suppressants such as proton pump inhibitors (PPIs) and histamine 2 receptor antagonist (H2RA) has been associated with the risk of osteoporotic fracture. Acid suppressants and muco-protective agents (MPAs) are often used together as anti-ulcer agents. We evaluated the association between the risk of osteoporotic fracture and the combined use of these anti-peptic agents.

METHODS

A population-based case-control study was conducted by analyzing the Korean National Health Insurance Data from 2014 to 2020. Patients who had been prescribed anti-peptic agents, such as PPI, H2RA, or MPA, were included. Considering the incidence of osteoporotic fractures, the case group (n = 14,704) and control group (n = 58,816) were classified by 1:4 matching based on age and sex.

RESULTS

The use of all types of anti-peptic agents was associated with an increased risk of osteoporotic fractures (PPI: hazard osteoratio [HR], 1.31; H2RA: HR, 1.44; and MPA: HR, 1.33; all p < 0.001). Compared to PPI alone, the combined use of "PPI and H2RA" (HR, 1.58; p = 0.010) as well as "PPI, H2RA, and MPA" (HR, 1.71; p = 0.001) was associated with an increased risk of osteoporotic fracture. However, compared with PPI alone, "MPA and PPI or H2RA" was not associated with an increased risk of osteoporotic fracture.

CONCLUSION

This study found that the combined use of "PPI and H2RA" was associated with a higher risk of osteoporotic fractures. In cases where deemed necessary, the physicians may initially consider prescribing the combination use of MPA.

Intra-Articular Injection of Rebamipide-Loaded Nanoparticles Attenuate Disease Progression and Joint Destruction in Osteoarthritis Rat Model: A Pilot Study

OBJECTIVE

Rebamipide has antioxidant effects and is a drug with a local rather than systemic mechanism of action. Oxidative stress and inflammation in chondrocytes are the major factors contributing to the development and progression of osteoarthritis (OA). Since OA is mainly developed in weight bearing or overused joints, the locally sustained therapy is effective for targeting inflammatory component of OA. We investigated the effects of intra-articular injection of rebamipide loaded nanoparticles (NPs) in OA rat model.

DESIGN

We fabricated rebamipide-loaded methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (mPEG-PDLLA) and poly(D, L-lactide-co-glycolide) (PLGA) NPs that allow the sustained release of rebamipide. In vitro, chondrocytes from rat were used to investigate the cytotoxicity and anti-inflammatory effect of rebamipide-loaded NPs. In vivo, monosodium iodoacetate (MIA)-induced OA rats were divided into 7 groups, consisting of healthy control rats and rats injected with MIA alone or in combination with NPs, rebamipide (1 mg)/NPs, rebamipide (10 mg)/NPs, rebamipide (10 mg) solution, or oral administration.

RESULTS

In vitro, rebamipide/NPs dose-dependently suppressed the mRNA levels of pro-inflammatory mediators, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, matrix metalloproteinase (MMP)-3, MMP-13, and cyclo-oxygenase-2. In vivo, the mRNA levels of pro-inflammatory components most markedly decreased in the intra-articularly injected rebamipide (10 mg)/NP group compared to other groups. Macroscopic, radiographic, and histological evaluations showed that the intra-articular injection of rebamipide/NPs inhibited cartilage degeneration more than rebamipide solution or rebamipide administration.

CONCLUSIONS

Using a chemically induced rat model of OA, intra-articular delivery of rebamipide was associated with decreased local and systemic inflammatory response decreased joint degradation and arthritic progression.

Hydrogel Formulations Incorporating Drug Nanocrystals Enhance the Therapeutic Effect of Rebamipide in a Hamster Model for Oral Mucositis

A mouthwash formulation of rebamipide (REB) is commonly used to treat oral mucositis; however, this formulation does not provide sufficient treatment or prevention in cases of serious oral mucositis. To improve treatment, we attempted to design a hydrogel incorporating REB nanocrystals (R-NPs gel). The R-NPs gel was prepared by a bead mill method using carbopol hydrogel, methylcellulose and 2-hydroxypropyl-β-cyclodextrin, and another hydrogel incorporating REB microcrystals (R-MPs gel) was prepared following the same protocol but without the bead mill treatment. The REB particle size in the R-MPs gel was 0.15–25 μm, and while the REB particle size was 50–180 nm in the R-NPs gel. Next, we investigated the therapeutic effect of REB nanocrystals on oral mucositis using a hamster model. Almost all of the REB was released as drug nanocrystals from the R-NPs gel, and the REB content in the cheek pouch of hamsters treated with R-NPs gel was significantly higher than that of hamsters treated with R-MPs gel. Further, treatment with REB hydrogels enhanced the healing of oral wounds in the hamsters. REB accumulation in the cheek pouch of hamsters treated with the R-NPs gel was prevented by an inhibitor of clathrin-dependent endocytosis (CME) (40 μM dynasore). In conclusion, we designed an R-NPs gel and found that REB nanocrystals are taken up by tissues through CME, where they provide a persistent effect resulting in an enhancement of oral wound healing.

Solid Nanocrystals of Rebamipide Promote Recovery from Indomethacin-Induced Gastrointestinal Bleeding

Indomethacin (IMC)-induced gastrointestinal (GI) injuries are more common in rheumatoid arthritis (RA) patients than in other IMC users, and the overexpression of nitric oxide (NO) via inducible NO synthase (iNOS) is related to the seriousness of IMC-induced GI injuries. However, sufficient strategies to prevent IMC-induced GI injuries have not yet been established. In this study, we designed dispersions of rebamipide (RBM) solid nanocrystals (particle size: 30–190 nm) by a bead mill method (RBM-NDs), and investigated whether the oral administration of RBM-NDs is useful to prevent IMC-induced GI injuries. The RBM nanocrystals were spherical and had a solubility 4.71-fold greater than dispersions of traditional RBM powder (RBM-TDs). In addition, the RBM-NDs were stable for 1 month after preparation. The RBM contents in the stomach, jejunum, and ileum of rats orally administered RBM-NDs were significantly higher than in rats administered RBM-TDs. Moreover, the oral administration of RBM-NDs decreased the NO levels via iNOS and area of the GI lesions in IMC-stimulated RA (adjuvant-induced arthritis rat) rats in comparison with the oral administration of RBM-TDs. Thus, we show that the oral administration of RBM-NDs provides a high drug supply to the GI mucosa, resulting in a therapeutic effect on IMC-induced GI injuries. Solid nanocrystalline RBM preparations may offer effective therapy for RA patients.

Analysis of two novel 1-4 quinolinone structures with bromine and nitrobenzyl ligands

The scientific community has shown particular interest in the study of quinolinones-a class of bicyclic organic compounds. An example of these compounds are the 4-quinolinones, considered to be very useful building blocks, since they can adapt their molecular structures with different ligands for applications in various fields such as pharmacy, medicine, physics and engineering. The compounds (E)-3-(benzylidene)-2-(3-nitrophenyl)-2,3-dihydro-1-(phenylsulfonyl)-quinolin-4-(1H)-one (NFQ) and (E)-3-(benzylidene)-2-(4-bromophenyl)-2,3-dihydro-1-(phenylsulfonyl) quinolin-4-(1H)-one (BFQ) were synthesized and characterized by infrared spectroscopy, ¹H and ¹³C NMR, and melting point. NFQ crystallized in the orthorhombic Pbca space group while BFQ appears in the monoclinic P2₁/n space group. X-ray diffraction was used to evaluate their crystallographic structures, and Hirshfeld surface evaluates the intermolecular interactions, supramolecular arrangement and packaging. Theoretical vibrational assignments and calculated electronic properties also demonstrate acceptable agreement between experimental and theoretical results.

Potential Role of Rebamipide in Osteoclast Differentiation and Mandibular Condylar Cartilage Homeostasis

Background:

Temporomandibular joint osteoarthritis (TMJ-OA) is a degenerative disease that involves changes in subchondral bone and progressive degradation of cartilage. Currently, rebamipide, a gastroprotective drug, is administered to protect gastric mucosa and accelerate ulcer healing.

Objectives:

Recent studies have shown that rebamipide also attenuates cartilage degeneration by suppressing oxidative damage and inducing homeostasis of the extracellular matrix of articular chondrocytes. Regarding the latter, reduced expression of cathepsin K, NFATc1, c-Src, and integrin β3, and increased expression of nuclear factor-kappa B, have been found to be mediated by the transcription factor, receptor activator of nuclear factor kappa-B ligand (RANKL).

Methods:

Treatment with rebamipide was also found to activate, mitogen-activated protein kinases such as p38, ERK, and JNK to reduce osteoclast differentiation. Taken together, these results strongly indicate that rebamipide mediates inhibitory effects on cartilage degradation and osteoclastogenesis in TMJ-OA.

Results and Conclusion:

Here, we highlight recent evidence regarding the potential for rebamipide to affect osteoclast differentiation and TMJ-OA pathogenesis. We also discuss the potential role of rebamipide to serve as a new strategy for the treatment of TMJ-OA.