Dexamethasone is a glucocorticoid receptor agonist and IL receptor modulator with anti-inflammatory, immunosuppressive, and apoptosis-inducing activities. It inhibits the production of inflammatory miRNA-155 exosomes in macrophages, significantly reduces inflammatory cytokine expression in neutrophils and monocytes, suppresses LPS-induced macrophage inflammation, and induces autophagy. It is commonly used to induce animal models of depression, muscle atrophy, and hypertension, and holds potential in COVID-19 research.

5-Hydroxytryptophan (NSC-92523) is a metabolite of tryptophan and a direct precursor of serotonin. It is a substrate of aromatic amino acid decarboxylase and can be used to induce depression models.

Penitrem A is an indole-diterpenoid neurotoxic alkaloid produced by *Penicillium* species. As a selective BK channel antagonist, it exhibits antiproliferative and anti-invasive activities against various malignancies, and stimulates the spontaneous release of endogenous glutamate, GABA, and aspartate from cortical synaptosomes. It is commonly used to induce tremor models in animals.