Design, Synthesis and Preliminary Bioactivity Evaluation of N-acetylcysteine Derivatives as Antioxidative and Anti-inflammatory Agents.

N-acetylcysteine (NAC) is a commonly used mucolytic agent and antidote for acetaminophen overdose. For pulmonary diseases, NAC exhibits antioxidative properties, regulates cytokine production, reduces apoptosis of lung epithelial cells, and facilitates the resolution of inflammation. However, the efficacy of NAC in clinical trials targeting different pathological conditions is constrained by its short half-life and low bioavailability. In the present study, a series of NAC derivatives were designed and synthesized to further enhance its pharmacological activity. Structure-activity relationship (SAR) studies were conducted to optimize the activating groups. In vitro evaluations revealed that compounds 4r, 4t, 4w, and 4x exhibited superior antioxidative and anti-inflammatory activities compared to the positive controls of NAC and fudosteine. The ADME prediction analysis indicated that these compounds exhibited a favorable pharmacological profile. In-vivo experiments with compound 4r demonstrated that the high-dose group (80 mg/kg) exhibited improved therapeutic effects in reversing the HPY level in mice with pulmonary fibrosis compared to the NAC group (500 mg/kg), further proving its superior oral bioavailability and therapeutic effect compared to NAC.

S-allylmercapto-N-acetylcysteine ameliorates pulmonary fibrosis in mice via Nrf2 pathway activation and NF-κB, TGF-ß1/Smad2/3 pathway suppression.

Pulmonary fibrosis (PF) is a chronic lung disease characterised by alveolar inflammatory injury, alveolar septal thickening, and eventually fibrosis. Patients with severe Coronavirus Disease 2019 (COVID-19) may have left a certain degree of pulmonary fibrosis. PF is commonly caused by oxidative imbalance and inflammatory damage. S-allylmercapto-N-acetylcysteine (ASSNAC) exhibits anti-oxidative and anti-inflammatory effects in other diseases. However, the pharmacodynamics of ASSNAC remain unclear for PF. This investigation aimed to evaluate the efficacy and mechanism of ASSNAC against PF. The PF model was established by TGF-ß1 stimulating HFL-1 cells in vitro. ASSNAC exhibited the potential to inhibit fibroblast transformation into myofibroblasts. Also, in the PF mice model with bleomycin (BLM), the sodium salt of ASSNAC (ASSNAC-Na) inhalation was treated. ASSNAC remarkably improved mice's lung tissue structure and collagen deposition. The important indicator proteins of PF, collagen Ⅰ, collagen Ⅲ, and α-SMA significantly decreased in the ASSNAC treated groups. Besides, ASSNAC attenuated oxidative stress by reversing glutathione (GSH), superoxide dismutase (SOD) levels and interfering with Nrf2/NOX4 signaling pathways. ASSNAC showed an anti-inflammatory effect by reducing the number of inflammatory cells and inflammatory cytokines, such as TNF-α and IL-6, and blocking the NF-κB signaling pathway. ASSNAC inhibited fibroblast differentiation by blocking the TGF-ß1/Smad2/3 signaling pathway. This study implicates that ASSNAC alleviates pulmonary fibrosis through fighting against oxidative stress, reducing inflammation and inhibiting fibroblast differentiation.

Smart and Generalizable Cytarabine Derivative-Triggered Nanoparticles for Synergistic Therapy of Relapsed/Refractory Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is rapidly progressed hematologic malignancy with relapsed and refractory characteristics. Cytarabine combined with the BCL2 inhibitor venetoclax showed impressive response rates in the treatment of relapsed/refractory acute myeloid leukemia (R/R AML), while it requires complicated administration regimens and brings added toxicity. In this work, we synthesized a mercaptopropionic acid-substituted derivative of Ara-C (Ara-SH) and used it as the trigger to fabricate a smart cytarabine and venetoclax-coloaded nanoparticle (AV-NP) through self-assembly. The AV-NP characterized with redox-responsive drug release, rapid uptake by leukemia cells, and long retention in circulation had the potential to accumulate in leukemia-enriched sites. It generated a remarkable synergistic effect with higher antileukemia activity in vitro and better safety in the hematologic system compared with free drugs and significantly improved the therapeutic effect on orthotopic AML mice in vivo. These similar results were also confirmed in primary cells from R/R-AML patients. Besides, the AV-NP has the superiority of facile fabrication and generalizability, rendering it easy for clinical translation.