A class of drugs known as histone deacetylase inhibitors (HDACis) targets the enzymes known as histone deacetylases, which are essential for controlling gene expression. Due to these inhibitors' potential therapeutic implications in a variety of diseases, such as cancer, neurological disorders, and inflammatory conditions, they have drawn a great deal of attention in both fundamental research and clinical settings. Histone proteins lose their acetyl groups due to the action of HDAC enzymes, which causes chromatin condensation and transcriptional suppression. Histone acetylation is encouraged by HDACis by suppressing HDAC activity, which relaxes chromatin structure and improves gene transcription. Thanks to this mode of action, HDACis can control the expression of genes involved in important cellular functions as differentiation, apoptosis, and cell cycle regulation. Numerous substances, both synthetic and natural, have been found as HDACis. These include belinostat (PXD101), trichostatin A (TSA), romidepsin (FK228), and suberoylanilide hydroxamic acid (SAHA or vorinostat). These substances have a variety of biological effects, which can be attributed to their differing degrees of selectivity towards distinct HDAC isoforms. HDACis have demonstrated potential as anticancer drugs in cancer therapy through their ability to induce cell cycle arrest, promote apoptosis, and inhibit angiogenesis and metastasis. The FDA approved romidepsin and vorinostat as among the first HDACis for the treatment of cutaneous T-cell lymphoma, demonstrating the therapeutic promise of this family of medications. HDACis have shown therapeutic promise not only for cancer but also for neurological diseases including Parkinson's and Alzheimer's. Through the regulation of genes linked to the survival and functionality of neurons, HDACis may provide neuroprotective benefits and slow down the advancement of illness. By inhibiting the synthesis of pro-inflammatory cytokines and chemokines, HDACis show anti-inflammatory effects in inflammatory situations. For the treatment of autoimmune illnesses and chronic inflammatory disorders, this makes them appealing candidates. HDACis have the potential to be therapeutic agents, but they can also have unfavorable side effects such as heart toxicities, hematological abnormalities, and gastrointestinal problems. Thus, current research endeavors to create more precisely targeted HDACis that exhibit enhanced safety characteristics and therapeutic effectiveness. To sum up, histone deacetylase inhibitors are a potential family of drugs with a variety of therapeutic uses in neurological illnesses, inflammatory disorders, and cancer. To fully utilize HDACis' therapeutic potential in clinical practice, more clarification of their mechanisms of action and improved drug design are necessary.
