Comparative Efficacy of Extracts from Lycium Barbarum Bark and Fruit on Estrogen Receptor Positive Human Mammary Carcinoma MCF-7 Cells

Abstract

Chemo-endocrine therapy for estrogen receptor positive (ER⁺) breast cancer exhibits acquired tumor resistance. Herbal medicines provide integrative support for breast cancer patients. Present study compared the efficacy of aqueous extracts from Lycium barbarum bark (LBB) and Lycium barbarum fruit (LBF) on ER⁺ MCF-7 cells. Cellular growth and 17ß-estradiol (E₂) metabolism quantified the efficacy. MCF-7 cells maintained in serum depleted medium+ E₂ exhibited increased anchorage-dependent and anchorage-independent growth. LBB exhibited greater potency than LBF (95% reduction in IC₅₀). LBB produced a 6.8-fold increase, 40% decrease, and a 3.7-fold increase in 2-hydroxyestrone (2-OHE₁), 16α-hydroxyestrone (16α-OHE₁), and estriol (E₃) formation. The corresponding values for LBF were 3.9, 33, and 10.5. LBB produced a16.3-fold and a twofold increase in 2-OHE₁:16α-OHE₁ and E₃:16α-OHE₁ ratios, whereas LBF produced a sixfold and a 2.9-fold increase. The efficacy of LBB is due to increased 2-OHE₁ formation, whereas that of LBF is due to accelerated conversion of 16α-OHE₁ to E₃. Specific growth inhibitory profiles of LBB and LBF may be due to their distinct chemical composition and their complementary actions on E₂ metabolism. This study validates a mechanistic approach to identify efficacious herbal extracts for clinical ER⁺ breast cancer.

ACKNOWLEDGMENTS

This study is dedicated to the memory of Laurie Mezzalingua (1968–2009). During that period, Laurie selflessly and generously devoted herself to helping many others suffering from breast cancer.

FUNDING

Major funding for this study was provided by the philanthropic contributions to the American Foundation for Chinese Medicine by Peter Cheney, Suzanne Hoyt, The family of Daniel and Kathleen Mezzalingua, The family of Hakan and Marie Ledin and the Issac and Laura Perlmutter Fund.