Pharmacology/Drug Development

Postoperative pain management in breast surgery and video-assisted thoracic surgeries (VATS) remains challenging. Oral or intravenous infusion of opioids were early treatments, but they can result in gastrointestinal reactions, respiratory inhibition, and other adverse reactions. In recent years, various regional block techniques have been employed for postoperative analgesia of these surgeries. However, a pair-wise meta-analysis cannot comprehensively rank and evaluate the analgesic effects and adverse events of various regional blocks.

Endocannabinoids have an important role for the regulation of neuropathic pain. In our previous study, we observed that preventing the degradation of a endocannabinoid, 2-arachidonoylglycerol (2-AG), using an inhibitor of monoacylglycerol lipase (JZL184), attenuated neuropathic orofacial pain (NOP). The present study aimed to investigate mechanisms underlying JZL184-induced attenuation of NOP. We hypothesized that JZL184 may suppress microglial reactivity in the trigeminal spinal subnucleus caudalis (Vc) under NOP. The infraorbital nerve (ION) was hemisected to model NOP in mice, resulting in a significant reduction of mechanical head-withdrawal threshold (MHWT) on day 4 following the ION hemisection. Chronic systemic application of JZL184 at a concentration of 8 or 16 mg/kg/day for 4 days significantly attenuated the reduction of MHWT in mice exposed to NOP. Administering JZL184 at 4 mg/kg/day or its vehicle, however, did not attenuate the MHWT of mice with NOP. The reactivity of microglial cells in the Vc increased in mice with NOP compared to sham-operated controls. The application of JZL184 at 8 or 16 mg/kg/day for 4 days significantly reduced the increased microglial reactivity in the Vc. The changes of microglia under NOP were, by contrast, not reduced by application of the drug at 4 mg/kg/day or its vehicle. The results indicate that preventing 2-AG degradation may increase its accumulation in the Vc and normalize microglial reactivity under NOP, which may contribute to suppressing NOP.

Natural compounds and their synthesized analogues continue to be valuable sources in the discovery and development of novel anti-inflammatory agents. AL-04 is a thiol analogue derived from a natural sesquiterpene alantolactone, that demonstrated potential anti-inflammatory activity in vitro in comparison to its parent compound. However, the anti-inflammatory mechanism of action of AL-04 has not been elucidated. In this context, we investigated the signaling pathway that primarily mediate the anti-inflammatory activity of AL-04 and its effect on principal inflammatory mediators including iNOS, COX-2 and ROS. Furthermore, the anti-inflammatory activity was investigated in vivo in carrageenan induced paw oedema model in addition to the exploration of anti-nociceptive activity and acute toxicity. The results suggested that treatment with AL-04 significantly decreased the LPS-induced upregulation of pro-inflammatory cytokines and mediators in addition to the downregulated transcription of TNF-α and IL-6 in RAW 264.7 cell line. Furthermore, mRNA and the protein expression of COX-2 and iNOS were also significantly attenuated with AL-04 at a concentration of 10 µM. Western blot studies further suggested that AL-04 downregulated LPS-stimulated NF-κB p65 expression. In addition to this the anti-inflammatory activity of AL-04 was demonstrated in carrageenan induced paw oedema model with significant inhibition of oedema in a dose-dependent manner. The anti-inflammatory activity of AL-04 was further demonstrated in balb/c mice by inhibition of leukocyte migration and vascular permeability. Besides, AL-04 also inhibited thermally and chemically induced pain in tail-flick and acetic acid induced writing assays respectively in balb/c mice suggesting the analgesic potential of the compound. Acute toxicity studies further suggested the appreciable safety of AL-04 at high dose of 2000 mg/kg with no indications of toxicity or changes in biochemical and haematological parameters. Overall, the study insinuates the anti-inflammatory potential of AL-04 and paves way for further exploration of the compound as a safer therapeutic anti-inflammatory agent.

Accurate specification of the drugs' solubility is known as an important activity to appropriately manage the supercritical impregnation process. Over the last decades, the application of supercritical fluids (SCFs), mainly CO, has found great interest as a promising solution to dominate the limitations of traditional methods including high toxicity, difficulty of control, high expense and low stability. Oxaprozin is an efficient off-patent nonsteroidal anti-inflammatory drug (NSAID), which is being extensively used for the pain management of patients suffering from chronic musculoskeletal disorders such as rheumatoid arthritis. In this paper, the prominent purpose of the authors is to predict and consequently optimize the solubility of Oxaprozin inside the COSCF. To do this, the authors employed two basic models and improved them with the Adaboost ensemble method. The base models include Gaussian process regression (GPR) and decision tree (DT). We optimized and evaluated the hyper-parameters of them using standard metrics. Boosted DT has an MAE error rate, an R2-score, and an MAPE of 6.806E-05, 0.980, and 4.511E-01, respectively. Also, boosted GPR has an R2-score of 0.998 and its MAPE error is 3.929E-02, and with MAE it has an error rate of 5.024E-06. So, boosted GPR was chosen as the best model, and the best values were: (T = 3.38E + 02, P = 4.0E + 02, Solubility = 0.001241).

Chronic inflammation is implicated in numerous human pathologies. In particular, low-grade inflammation is currently recognized as an important mechanism of osteoarthritis (OA), at least in some patients. Among the signs of the inflammatory process are elevated macrophage numbers detected in the OA synovium compared to healthy controls. High macrophage counts also correlate with clinical symptoms of the disease. Macrophages are central players in the development of chronic inflammation, pain, cartilage destruction, and bone remodeling. However, macrophages are also involved in tissue repair and remodeling, including cartilage. Therefore, reduction of macrophage content in the joints correlates with deleterious effects in OA models. Macrophage population is heterogeneous and dynamic, with phenotype transitions being induced by a variety of stimuli. In order to effectively use the macrophage inflammatory circuit for treatment of OA, it is important to understand macrophage heterogeneity and interactions with surrounding cells and tissues in the joint. In this review, we discuss functional phenotypes of macrophages and specific targeting approaches relevant for OA treatment development.