Crude Edible Fig (Ficus carica) Leaf Extract Prevents Diethylstilbestrol (DES)-Induced DNA Strand Breaks in Single-Cell Gel Electrophoresis (SCGE)/Comet Assay: Literature Review and Pilot Study.

Alrena V Lightbourn,Ronald D Thomas

doi:10.35248/0975-0851.19.11.389

Abstract

Fig (Ficus carica) trees are among the oldest plants on earth. The chemopreventive properties of constituent polyphenols and fiber that implicate figs in having a functional role in averting cancer have not been fully elucidated. We therefore hypothesized that fig leaf extract would inhibit (or attenuate) DES-induced DNA single-strand breakage in MCF10A human breast epithelial cells. To test this hypothesis, MCF10A cells were treated with DES (1, 10, 100 μM), crude fig leaf extract (5, 10, 15 μL), or concomitant doses of DES (100 μM)/fig leaf extract (5, 10, 15 μL). The cells were analyzed for DNA strand breakage using the SCGE/COMET assay with mean olive tail moment as a marker of DNA damage. DES induced DNA strand breaks at all treatment levels compared to DMSO and non-treatment controls. DES at concentrations of 1, 10, and 100 μM produced mean olive tail moments of 1.2082 (177.6%), 1.2702 (186.7%), and 1.1275 (165.7%), respectively, which were statistically significantly (p<0.05) higher than the DMSO control value (0.6803). Exposure to fig leaf extract produced no DNA damage. Rather, a desirable dose-dependent reduction in DES-induced DNA strand breaks was observed. Composite treatment of MCF10A cells with DES and fig leaf extract attenuated DES-induced DNA strand breaks. Taken together, these results suggest a potential mechanism for cancer chemoprevention. Additional studies are necessary to identify relevant active ingredients, confirm the mechanism of action, and further elucidate the therapeutic potential of fig leaf extract for early-stage breast cancer chemoprevention.

Highlights

Cancer, ranked the second leading cause of mortality in the United States [1] and Florida [2], is further segregated to attribute to breast cancer the designation of No 1 cause of death among women [3,4]
The Single-cell gel electrophoresis (SCGE)/COMET assay is a sensitive, non-radiometric procedure. This technique was effective in assessing DES-induced deoxyribonucleic acid (DNA) damage in benign human breast epithelial (MCF10A) cells as well as measuring the extent of nuclear insult imposed on MCF10A by environmental estrogens and their metabolites
Microliter quantities of fig leaf extract were sufficiently potent to evoke cellular changes resulting in DNA repair that was detectable by COMET analysis

Summary

Introduction

Cancer, ranked the second leading cause of mortality in the United States [1] and Florida [2], is further segregated to attribute to breast cancer the designation of No 1 cause of death among women [3,4]. 18.1 million new cases and 9.6 million cancer deaths are expected globally in 2018 alone. Of these cases, the incidence and mortality of cancer in the Americas (North, South and Central America, and the Caribbean), is estimated at 21.0% (~3.8 million) and 14.4% (~1.4 million) cases, respectively. Female victims of cancer represent 24.2% (8.6 million) of new cases and roughly 15.0% (4.2 million) of deaths [5]. From 2017-2018, in situ cases are the primary form (28%) of breast cancer in women between 50-69 years old; invasive cases prevail (27%) between 60-69 years old; and deaths are most prevalent (27%) ≥ 80 years old [1,6,7]

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Conclusion