Role of Ketotifen on metabolic profiles, inflammation and oxidative stress in diabetic rats

Ketotifen counteracts cisplatin-induced acute kidney injury in mice via targeting NF-κB/NLRP3/Caspase-1 and Bax/Bcl2/Caspase-3 signaling pathways

Cisplatin (CIS) stands as one of the most effective chemotherapy drugs currently available. Despite its anticancer properties, the clinical application of CIS is restricted due to nephrotoxicity. Our research aimed to specify the impact of ketotifen fumarate (KET) against nephrotoxicity induced by CIS in mice. Male NMRI mice were treated with KET (0.4, 0.8, and 1.6 mg/kg, ip) for seven days. On the fourth day of the study, a single dose of CIS (13 mg/kg, ip) was administered, and the mice were sacrificed on the eighth day. The results indicated that administration of KET attenuated CIS-induced elevation of BUN and Cr in the serum, as well as renal KIM-1 levels. This improvement was accompanied by a significant reduction in kidney tissue damage, which was supported by histopathological examinations. Likewise, the decrease in the ratio of GSH to GSSG and antioxidant enzyme activities (CAT, SOD, and GPx), and the increase in lipid peroxidation marker (TBARS) were reversed in KET-treated mice. The ELISA results revealed that KET-treated mice ameliorated CIS-induced elevation in the renal levels of TNF-α, IL-1β, and IL-18. Western blot analysis exhibited that KET suppressed the activation of the transcription factor NF-κB and the NLRP3 inflammasome in the kidney of CIS-treated mice. Moreover, KET treatment reversed the changes in the protein expression of markers related to apoptosis (Bax, Bcl2, Caspase-3, and p53). Interestingly, KET significantly enhanced the cytotoxicity of CIS in HeLa cells. In conclusion, this study provides valuable insights into the promising effects of KET in mitigating CIS-induced nephrotoxicity.

Repurposing ketotifen as a therapeutic strategy for neuroendocrine prostate cancer by targeting the IL-6/STAT3 pathway

PURPOSE

Neuroendocrine prostate cancer (NEPC), a highly aggressive subtype of prostate cancer displaying resistance to hormone therapy, presents a poor prognosis and limited therapeutic options. Here, we aimed to find novel medication therapies for NEPC and explore the underlying mechanism.

METHODS

A high-throughput drug screening utilizing an FDA-approved drug library was performed and ketotifen, an antihistamine agent, was identified as a potential therapeutic candidate for NEPC. The whole-transcriptome sequencing analysis was conducted to explore mechanism of ketotifen inhibitory in NEPC. Multiple cell biology and biochemistry experiments were performed to confirm the inhibitory effect of ketotifen in vitro. A spontaneous NEPC mice model (PBCre4:Ptenf/f;Trp53f/f;Rb1f/f) was used to reveal the inhibitory effect of ketotifen in vivo.

RESULTS

Our in vitro experiments demonstrated that ketotifen effectively suppressed neuroendocrine differentiation, reduced cell viability, and reversed the lineage switch via targeting the IL-6/STAT3 pathway. Our in vivo results showed that ketotifen significantly prolonged overall survival and reduced the risk of distant metastases in NEPC mice model.

CONCLUSION

Our findings repurpose ketotifen for antitumor applications and endorse its clinical development for NEPC therapy, offering a novel and promising therapeutic strategy for this formidable cancer subtype.

Calming Down Mast Cells with Ketotifen: A Potential Strategy for Multiple Sclerosis Therapy?

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by extensive inflammation, demyelination, axonal loss and gliosis. Evidence indicates that mast cells contribute to immunopathogenesis of both MS and experimental autoimmune encephalomyelitis (EAE), which is the most employed animal model to study this disease. Considering the inflammatory potential of mast cells, their presence at the CNS and their stabilization by certain drugs, we investigated the effect of ketotifen fumarate (Ket) on EAE development. EAE was induced in C57BL/6 mice by immunization with MOG35-55 and the animals were injected daily with Ket from the seventh to the 17th day after disease induction. This early intervention with Ket significantly reduced disease prevalence and severity. The protective effect was concomitant with less NLRP3 inflammasome activation, rebalanced oxidative stress and also reduced T cell infiltration at the CNS. Even though Ket administration did not alter mast cell percentage at the CNS, it decreased the local CPA3 and CMA1 mRNA expression that are enzymes typically produced by these cells. Evaluation of the CNS-barrier permeability indicated that Ket clearly restored the permeability levels of this barrier. Ket also triggered an evident lymphadenomegaly due to accumulation of T cells that produced higher levels of encephalitogenic cytokines in response to in vitro stimulation with MOG. Altogether these findings reinforce the concept that mast cells are particularly relevant in MS immunopathogenesis and that Ket, a known stabilizer of their activity, has the potential to be used in MS control.

Ketotifen fumarate attenuates feline gingivitis related with gingival microenvironment modulation

Gingivitis is evidenced by inflammation of the free gingiva, and still reversible. If left untreated, it may then progress to periodontitis. In the present study, the therapeutical effect of ketotifen fumarate on gingivitis was explored. Domestic cats with varying degrees of gingivitis naturally were enrolled in this study. Subgroups of animals were treated twice daily for one week with or without ketotifen fumarate (5 mg/kg). Effects of ketotifen fumarate were measured on gingival index, cells accumulation, mediators release, receptor-ligand interaction, oxidative stress, MAPK and NF-κB pathways, epithelial barrier and apoptosis. Ketotifen fumarate attenuated the initiation and progression of gingivitis, inhibited the infiltrations of mast cells, B lymphocytes, T lymphocytes, macrophages, neutrophils and eosinophils as well as the release of IgE, β-hexosaminidase, tryptase, chymase, TNF-α, IL-4, and IL-13, influenced endothelial cells, fibroblasts and epithelial cells proliferation and apoptosis, and induced Th2 cells polarization, where ketotifen fumarate also might affect their interactions. Ketotifen fumarate reduced the oxidative stress, and inhibited NF-κB and p38 MAPK related with mast cells and macrophages accumulation. Ketotifen fumarate improved the aberrant expression of ZO-1 and inhibits the following apoptosis. On the other hand, these cells and mediators augmented functional attributes of them involving SCF/c-Kit, α4β7/VCAM-1 and IL-8/IL-8RB interactions, thus creating a positive feedback loop to perpetuate gingivitis, where an inflammation microenvironment was modeled. Our results showed a previously unexplored therapeutic potential of ketotifen fumarate for gingivitis and further suggest that, in addition to biofilms, targeting inflammation microenvironment could be new strategy for the treatment of gingivitis/periodontitis.