Mefloquine (hydrochloride)

Mefloquine hydrochloride (Mefloquin hydrochloride), a quinoline antimalarial agent, is an anti-SARS-CoV-2 entry inhibitor. Mefloquine hydrochloride is also a K⁺ channel (KvQT1/minK) antagonist with an IC₅₀ of ~1 μM. Mefloquine hydrochloride can be used for malaria, systemic lupus erythematosus and cancer research^[1][2][3]. In Vitro: Mefloquine hydrochloride selectively inhibits prostate cancer (PCa) cell growth with an IC₅₀ of ~10 μM. Mefloquine hydrochloride also induces hyperpolarization of the mitochondrial membrane potential (MMP), as well as ROS generation^[2].
Mefloquine hydrochloride (10 μM)-mediated ROS simultaneously downregulated Akt phosphorylation and activated ERK, JNK and AMPK signaling in PC3 cells^[2].
Mefloquine shows higher anti-SARS-CoV-2 activity than Hydroxychloroquine in VeroE6/TMPRSS2 and Calu-3 cells, with IC₅₀ of 1.28 μM, IC₉₀ of 2.31 μM, and IC₉₉ of 4.39 μM in VeroE6/TMPRSS2 cells. Mefloquine inhibits viral entry after viral attachment to the target cell^[3]. In Vivo: Mefloquine hydrochloride (5 mg/kg; i.p.; daily; 14 days) reverses the lower vertebral cancellous bone volume and bone formation; and has modest effects on cortical bone volume, thickness, and moment of inertia in old mice^[4].