Effect of a Stabilized Fermented Broccoli Sprout Extract on Cultured Human Colon Carcinoma Cell Viability,Cell Death,and Apoptosis

Abstract

Introduction:

Sulforaphane inhibits tumor cell growth in vitro. A recently patented broccoli sprouts extract from Clojjic, LLC, contains sulforaphane stabilized by lactic acid fermentation driven by 12 specifically targeted gut microbiota, which also produce bacteriocins with cytotoxic effects. Here, we examined the cytotoxic effect of Clojjic extract on cultured human colorectal tumor cells.

Materials and Methods:

HCT-116 human colorectal tumor cell monolayers were treated with serial dilutions of Clojjic extract preparations for up to 48 hours. Cytotoxicity, viability, and apoptosis were measured with bioluminescence- and fluorescence-based assays. The effect of Clojjic extract on histone deacetylase (HDAC) enzyme was measured in HeLa cell nuclear extracts.

Results:

Clojjic extract was cytotoxic to HT-116 cells at high concentrations (1:4 dilution of the extract containing up to 130 μg/g¹ of sulforaphane), as evidenced by increased CellTox Green fluorescence; however, the culture medium pH was substantially reduced and may have contributed to the observed cytotoxic effects. Exposure to Clojjic extract, but not purified sulforaphane, showed a modest dose-dependent cytotoxic effect on HT-116 cells at 24 and 48 hours, with reduced viability per CellTiter-Fluor assay and increased markers of apoptosis. The Clojjic extract also demonstrated HDAC inhibitory activity in HeLa cell extracts, suggesting that it contains an HDAC inhibitor(s), possibly a sulforaphane metabolite or probiotic byproduct.

Conclusion:

Clojjic extracts have a powerful cytotoxic effect via dual bioactive components: lactobacilli metabolites (bacteriocins) and stabilized sulforaphane from broccoli sprouts. Further in vitro and in vivo studies are warranted to investigate the utility of the Clojjic extract as a potential cancer therapeutic.