Bioactive compounds from edible plants have limited efficacy in treating advanced cancers, but they have potential to increase the efficacy of chemotherapy drugs in a combined treatment. An aqueous extract of berries of Pimenta dioica (Allspice) shows promise as one such candidate for combination therapy or chemoprevention. An aqueous extract of Allspice (AAE) was tested against human breast cancer (BrCa) cells in vitro and in vivo. AAE reduced the viability and clonogenic growth of several types of BrCa cells (IC50 ≤ 100 μg/ml) with limited toxicity in non-tumorigenic, quiescent cells (IC50 >200 μg/ml). AAE induced cytotoxicity in BrCa was inconsistent with apoptosis, but was associated with increased levels of autophagy markers LC3B and LC3B-positive puncta. Silencing the expression of autophagy related genes (ATGs) prevented AAE-induced cell death. Further, AAE caused inhibition of Akt/mTOR signaling, and showed enhanced cytotoxicity when combined with rapamycin, a chemotherapy drug and an inhibitor of mTOR signaling. Oral administration (gavage) of AAE into athymic mice implanted with MDA-MB231 tumors inhibited tumor growth slightly but not significantly (mean decrease ~ 14%, p ≥ 0.20) if mice were gavaged post-tumor implant. Tumor growth showed a significant delay (38%) in tumor palpability and growth rate (time to reach tumor volume ≥ 1,000 mm3) when mice were pre-dosed with AAE for two weeks. Analysis of tumor tissues showed increased levels of LC3B in AAE treated tumors, indicating elevated autophagic tumor cell death in vivo in treated mice. These results demonstrate antitumor and chemo-preventive activity of AAE against BrCa and potential for adjuvant to mTOR inhibition.
Pubmed ID: 25945840 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
Cell line MCF-7 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line MDA-MB-231 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line MCF-12A is a Spontaneously immortalized cell line with a species of origin Homo sapiens
View all literature mentionsCell line MCF-10A is a Spontaneously immortalized cell line with a species of origin Homo sapiens
View all literature mentionsCell line MCF-10A is a Spontaneously immortalized cell line with a species of origin Homo sapiens
View all literature mentionsCell line MDA-MB-231 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line BT-474 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line MCF-10A is a Spontaneously immortalized cell line with a species of origin Homo sapiens
View all literature mentionsCell line SK-BR-3 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentions