Apoptosis of human breast cancer cells induced by microencapsulated betulinic acid from sour jujube fruits through the mitochondria transduction pathway

► We isolated betulinic acid from sour jujube fruits for the first time. ► Microencapsulated betulinic acid was formed to improve its dissolution. ► We investigated the apoptosis mechanisms of betulinic acid on MCF-7 cells. ► The apoptosis mechanism was induced through the mitochondria transduction pathway. ► Microencapsulated betulinic acid as a potent apoptosis inducer in MCF-7 cells. Betulinic acid (BA), a natural pentacyclic triterpenoid, was isolated from sour jujube fruits for the first time. An inclusion complex comprising BA and β-cyclodextrin (β-CD) was formed to improve the dissolution of BA, but little is known about its anticancer effect. In this study, the anti-proliferative and apoptosis mechanisms of BA–β-CD on human breast cancer MCF-7 cells were further investigated. Experimental results confirmed that the complexation model inhibited the growth of MCF-7 cells in a dose-dependent manner, arrested cell cycle in the G2/M phase and induced apoptosis via the mitochondria transduction pathway. Gene and protein analyses showed that the complexation model significantly inhibited Bcl-2 expression and promoted Bax expression, causing caspase-3 and caspase-9 cascade activation. These findings corroborated evidence on microencapsulated BA as an apoptosis inducer in MCF-7 cells. Thus, sour jujube fruits may have potential use as a breast cancer chemotherapeutic agent.