Minocycline hydrochloride (Minocycline HCl) is a tetracycline antibiotic with excellent absorption and tissue penetration that is used for several bacterial infections as well as treatment of acne. Minocycline hydrochloride can cause both an acute hepatitis-like syndrome occurring within 1 to 3 months of starting therapy or a more insidious chronic hepatitis with autoimmune features typically after long-term treatment.

Minocycline exhibits significant neuroprotective effects in models of cerebral ischemia, traumatic brain injury, Huntington's disease, and Parkinson's disease. Its neuroprotective properties may involve the inhibition of 5-lipoxygenase (an inflammatory enzyme associated with brain aging). Additionally, Minocycline's activity is linked to the inhibition of protein synthesis.

Minocycline inhibits the release of cytochrome c mediated by the permeability transition in mitochondria. This inhibition by minocycline on cytochrome c release has been demonstrated in vivo, in cells, and isolated mitochondria. Additionally, minocycline suppresses the activity of inducible caspase-1 and caspase-3, inducible nitric oxide synthase (iNOS), and p38 mitogen-activated protein kinase (MAPK). Following experimental focal ischemia, minocycline reduces the upregulation of caspase-1 and iNOS, thereby decreasing infarct size.