SP-8356 inhibits acute lung injury by suppressing inflammatory cytokine production and immune cell infiltration

This study investigated the anti-inflammatory and protective properties of SP-8356, a synthetic derivative of (1S)-(-)-verbenone, in a mouse model of LPS-induced acute lung injury (ALI). By targeting intracellular signaling pathways and inflammatory responses, SP-8356 demonstrated a potent ability to attenuate deleterious effects of proinflammatory stimuli. Specifically, SP-8356 effectively inhibited the activation of crucial signaling molecules such as NF-κB and Akt, and subsequently dampened the expression of inflammatory cytokines in various lung cellular components. Intervention with SP-8356 treatment also preserved the structural integrity of the epithelial and endothelial barriers. By reducing immune cell infiltration into inflamed lung tissue, SP-8356 exerted a broad protective effect against ALI. These findings position SP-8356 as a promising therapeutic candidate for pulmonary inflammatory diseases that cause ALI.

Intervention with extracellular matrix metalloproteinase inducer in osteoclasts attenuates periodontitis-induced bone resorption

Extracellular matrix metalloproteinase inducer (EMMPRIN) plays critical roles in the regulation of inflammation and bone metabolism. The roles of EMMPRIN signaling in osteoclasts are worthy of deep study. The present study aimed to investigate bone resorption in periodontitis through the intervention of EMMPRIN signaling. The distribution of EMMPRIN in human periodontitis was observed. RANKL-induced osteoclast differentiation of mouse bone marrow-derived macrophages (BMMs) were treated with EMMPRIN inhibitor in vitro. Rats with ligation-induced periodontitis were treated with EMMPRIN inhibitor and harvested for microcomputed tomography scanning, histologic observation, immunohistochemistry, and double immunofluorescence analysis. Positive expressions of EMMPRIN could be found in the CD68+-infiltrating cells. Downregulated EMMPRIN restrained osteoclast differentiation of BMMs in vitro, which also inhibited MMP-9 expression (*P < 0.05). In vivo, EMMPRIN inhibitor restrained ligation-induced bone resorption by decreasing tartrate-resistant acid phosphatase-positive osteoclasts. Both EMMPRIN-positive and MMP-9-positive osteoclasts were less common in the EMMPRIN inhibitor groups than in the control groups. Intervention of EMMPRIN signaling in osteoclasts could probably provide a potential therapeutic target for attenuating ligation-induced bone resorption.

SP-8356: A Novel Verbenone Derivative Exerts In Vitro Anti-Non-Small Cell Lung Cancer Effects, Promotes Apoptosis via The P53/MDM2 Axis and Inhibits Tumor Formation in Mice

OBJECTIVE

Non-small cell lung cancer (NSCLC) stands as a prominent contributor to cancer-related fatalities on a global scale, necessitating the search for novel therapeutic agents. SP-8356, a derivative of (1S)-(-)-verbenone, has shown promise as an anticancer agent in preclinical studies. However, specific mechanisms underlying its effects in NSCLC remain to be elucidated. The aim of this research was to explore the in vitro anti-NSCLC effects of SP-8356, elucidate its mechanisms of action, and assess its efficacy in inhibiting tumor formation in a murine model.

MATERIALS AND METHODS

In this experimental study, NSCLC cell lines were treated with various concentrations of SP- 8356. Cell viability and proliferation were assessed using MTT and colony formation assays, respectively. Cell cycle distribution was analyzed by flow cytometry, and apoptosis was evaluated by determining apoptotic protein expression. Western blot analysis was conducted to assess protein expression levels of the both p53 and MDM2. Additionally, we evaluated efficacy of the SP-8356 in inhibiting tumor formation of the nude mouse model.

RESULTS

SP-8356 demonstrated a concentration-dependent inhibition of cell proliferation in the NSCLC cell lines. Flow cytometric analysis showed that SP-8356 led to cell cycle arrest at the G2/M phase, indicating its potential influence on regulating the cell cycle. SP-8356 treatment was associated with the downregulation of CDK1 and Cyclin B1. Additionally, SP-8356 significantly enhanced apoptosis in NSCLC cells. SP-8356 treatment was associated with the downregulation of Bcl-2, while Bax expression was upregulated. Mechanistically, SP-8356 led to accumulation of the p53 protein levels within the NSCLC cells. This accumulation was mediated through inhibition of its negative regulator, MDM2. Using a nude mouse model demonstrated that SP-8356 effectively inhibited tumor formation in vivo.

CONCLUSION

Our findings shed light on the molecular mechanisms underlying anticancer activity of SP-8356 and highlight its potential as a promising therapeutic candidate for NSCLC treatment.

SP-8356 (A Verbenone Derivative) Inhibits Proliferation, Suppresses Cell Migration and Invasion and Decreases Tumor Growth of Osteosarcoma: Role of PGC-1α/TFAM and AMPK-Activation

OBJECTIVE

Osteosarcoma (OS) is an uncommon sarcoma with osteoid formation in conjunction with malignant mesenchymal cells on histological examination. SP-8356 has been reported to exhibit anti-cancer properties in human cancers. However the impact of SP-8356 on OS is largely unknown. The metabolic pathways are coordinated by AMPactivated protein kinase (AMPK), which maintains a balance between the supply and demand of nutrients and energy. This study aimed to investigate effect of SP-8356 on proliferation and apoptosis of OS cells and tumor growth in mice. Furthermore, involvement of PGC-1α/TFAM and AMPK-activation was studied.

MATERIALS AND METHODS

In the experimental study, Saos-2 and MG63 cells were cultured with SP-8356 for 24 hours and analysed for cellular proliferation using MTT assay. DNA fragmentation was studied using ELISA based kit. Furthermore, transwell chambers assay was used to determine cell migration and cell invasion. Targeted protein expression levels were assessed using western blotting. For in vivo studies, mice (5-6 weeks old) were implanted with either Saos-2 or MG63 cells on dorsal surface subcutaneously and they were administered with SP-8356 (10 mg/kg) for two weeks prior to bone tumor induction.

RESULTS

We found that SP-8356 exerted anti-proliferative effects on Saos-2 and MG63 cells. Furthermore, SP-8356 treatment significantly restricted migration and invasion of Saos-2 and MG63 cells. Compared to the control, SP-8356 significantly reduced apoptotic cell death, while it increased PGC-1α and TFAM expressions. Without affecting body weight, SP-8356 significantly reduced tumor development in mice, as compared to the control group.

CONCLUSION

SP-8356 was found to inhibit proliferation, suppressed cells migration and invasion and decreased OS tumor growth. Furthermore, SP-8356 was found to act through PGC-1α/TFAM and AMPK activations. SP-8356 can be therefore used as therapeutic agent for OS treatment.

Therapeutic effect of SP-8356 on pulmonary embolism-associated cardiac injury is mediated by its ability to suppress apoptosis and inflammation

The cyclophilin A–CD147 interaction has been reported to be one of the most potential therapeutic targets for the treatment of acute pulmonary embolism. The signalling of extracellular signal‐regulated kinase 1/2 (ERK1/2) was also reported in the pathogenesis of cardiac injury. Since SP‐8356 is regarded as a novel Inhibitor of CD147‐Cyclophilin, the study aimed to evaluate potential therapeutic effects of SP‐8356 for pulmonary embolism‐associated cardiac injury. Western blot and immunohistochemistry were carried out to analyse the expression of MMP‐9, ERK1/2, phosphorylated ERK1/2 (p‐ERK1/2), P65, p‐P65, and CyA protein in PE cell and rat models under distinct conditions. Flow cytometry and TUNEL were carried out to examine the apoptosis of primary rat myocardiocytes and PE rat models under distinct conditions. CyA treatment on primary rat myocardiocytes remarkably raised the expression of MMP‐9, p‐ERK1/2 and p‐P65 protein expression; SP8536 treatment effectively restored the CyA‐induced up‐regulation of MMP‐9, p‐ERK1/2 and p‐P65 protein expression in primary rat myocardiocytes. Besides, flow cytometry analysis showed that SP8536 remarkably suppressed the CyA‐induced elevation of cell apoptosis rate of primary rat myocardiocytes. Moreover, SP8536 notably diminished the abnormal elevation of right ventricular systolic pressure (RVSP), Troponin I and Myeloperoxidase activity in PE rat models. Furthermore, SP‐8536 significantly restored the up‐regulation of MMP‐9, p‐ERK1/2, p‐P65, CyA protein and the cellular apoptosis in the PE rat model. Our study validated that SP‐8356 could suppress cell apoptosis and inflammatory response via down‐regulating the highly expressed MMP‐9, p‐ERK1/2, and p‐P65 and MMP‐9 in PE‐associated cardiac injury in a dose‐dependent manner.

SP-8356, a (1S)-(-)-Verbenone Derivative, Inhibits the Growth and Motility of Liver Cancer Cells by Regulating NF-κB and ERK Signaling

Liver cancer is a common tumor and currently the second leading cause of cancer-related mortality globally. Liver cancer is highly related to inflammation as more than 90% of liver cancer arises in the context of hepatic inflammation, such as hepatitis B virus and hepatitis C virus infection. Despite significant improvements in the therapeutic modalities for liver cancer, patient prognosis is not satisfactory due to the limited efficacy of current drug therapies in anti-metastatic activity. Therefore, developing new effective anti-cancer agents with anti-metastatic activity is important for the treatment of liver cancer. In this study, SP-8356, a verbenone derivative with anti-inflammatory activity, was investigated for its effect on the growth and migration of liver cancer cells. Our findings demonstrated that SP-8356 inhibits the proliferation of liver cancer cells by inducing apoptosis and suppressing the mobility and invasion ability of liver cancer cells. Functional studies revealed that SP-8356 inhibits the mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways, which are related to cell proliferation and metastasis, resulting in the downregulation of metastasis-related genes. Moreover, using an orthotopic liver cancer model, tumor growth was significantly decreased following treatment with SP-8356. Thus, this study suggests that SP-8356 may be a potential agent for the treatment of liver cancer with multimodal regulation.

Metabolism and Pharmacokinetics of SP-8356, a Novel (1S)-(-)-Verbenone Derivative, in Rats and Dogs and Its Implications in Humans

(1S,5R)-4-((E)-3,4-dihydroxy-5-methoxystryryl)-6,6-dimethylbicylco[3.1.1]hept-3-en-2-one (SP-8356) is a novel (1S)-(−)-verbenone derivative that is currently in preclinical development for the treatment of ischemic stroke and atherosclerosis. This report aimed at characterization of the metabolism and pharmacokinetic properties of SP-8356. Following intravenous dose in rats and dogs, plasma concentrations of SP-8356 declined rapidly with high clearance (CL) and short half-life; after oral administration in both species, its plasma levels were below the quantitation limit. Fourteen circulating metabolites, formed by mono-oxygenation, demethylation, glucuronidation, catechol O-methylation, sulfation and oxidation (bioactivation) followed by glutathione (GSH) conjugation, were tentatively identified in both species. Urinary excretion of SP-8356 appeared to be minimal in rats, compared to its metabolites. GSH conjugate of SP-8356 was also formed during incubation with rat liver S9 fraction consistent with oxidative bioactivation; this bioactivation was almost completely inhibited by the cofactors for glucuronidation, sulfation and methylation, indicating that it may be abolished by competing metabolic reactions in the body. The human pharmacokinetics of SP-8356 was predicted to be similar to that of the animals based on the current in vitro metabolic stability results. In summary, rapid phase II metabolism appears to be mainly responsible for its suboptimal pharmacokinetics, such as high CL and low oral absorption. Because of competing metabolic reactions, potential safety risks related to SP-8356 bioactivation may be low.