Cephaeline dihydrochloride is primarily used in the treatment of amoebiasis, a parasitic infection caused by Entamoeba histolytica. It acts by targeting and killing the amoebae in the intestinal tract, helping to alleviate symptoms such as diarrhea and abdominal pain. Additionally, it is employed as an emetic agent in cases of poisoning, inducing vomiting to expel toxic substances from the stomach. Its application extends to laboratory research, where it is used to study its mechanisms of action and potential therapeutic effects in various diseases.