Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
SaDazia Driffin - Claflin University
Co-Author(s): Omar Bagasra, M.D., Ph.D., Claflin University, SC
D-limonene is a chemical that is predominantly used in fragrances and is used as an additive for a lemon-like flavor. Common consumer goods that have synthetic D-Limonene an additive include fragrances, soaps, automobile tire cleaner, cleaning products (degreasers), shampoo, beverages (such as orange juice), and chewing gum. This chemical structure of D- limonene is a monocyclic monoterpene. Currently, widespread use of synthetic limonene is due to its easy biosynthetic. These are not natural chemicals but are synthesized chemically on a mass scale. Dietary intake from food ingredients is an alternative route of exposure; thus, limonene is found as a flavoring compound in tea resulting in both dietary and inhalative exposure. Since, most of the women are exposed to limonene during pregnancy we explored the effects of limonene on human developing neurons. Methods: To determine the potential adverse effects of D-limonene, we utilized four neuroblastoma cell lines (NBC’s): two of male origin (CRL-2267& 2142) and two from female origin (CRL-2266 & 2149). The NBCs were exposed to low amounts of D-Limonene (i.e. from 20 nM to 0.2 nM). After exposure for 48-96 hours in these chemicals the cells were fixed and stained with hematoxylin and eosin (H&E). We carried out a detailed histological analysis of the NBCs that were exposed to D-limonene and compared them to unexposed controls for cell growth, growth pattern changes, central chromatolysis, axonal length, axon degeneration, and syncytia formation. The morphologic analyses showed significant changes in the NBCs for both male and female cell lines that were exposed to limonene. The exposures to the chemical at all concentration imparted profound morphologic adverse effects including significant decline in cell growth, changes in axonal lengths, increased degeneration of neurons and increased central chromatolysis, and syncytia formation. We concluded that exposures to D-limonene even at very low concentrations induce significant neuro modifications in male and female NBCs. Our observations are first of show a potential link between exposures to D-limonene and neurodevelopmental disorder in human developing neurons that represent fetal brain development in utero. Molecular and immunological analyses are in progress.
Funder Acknowledgement(s): Findings reported in this publication were supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R25GM113740. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Faculty Advisor: Omar Bagasra, M.D., Ph.D., firstname.lastname@example.org
Role: I executed the plans of this research that was designed and advised by my mentor.