The Pursuit of Happiness: The Effect of Herbs on Serotonin-Deficient C. Elegans

Overview

Serotonin is a neurotransmitter that is thought to affect mood in humans. A common class of prescription drugs used to treat symptoms of depression are selective serotonin reuptake inhibitors (SSRIs). These drugs are thought to act by increasing serotonin levels, but they do not work for some individuals and can have debilitating side effects. Herbal remedies, such as lavender and St. John’s Wort, are thought to be natural alternatives to these drugs, but they may not have the same efficacy as prescription medications. This study was conducted to test the efficacy of these herbal remedies in increasing serotonin production in C. elegans. C. elegans, a non-parasitic nematode, was used for this experiment because it is easily propagated and has a completely mapped genome. Both wild type and tph-1 mutant (serotonin-deficient) C. elegans were used. For the herbal remedies, decoctions were made of either lavender (Lavandula stoechas) and St. John’s Wort (Hypericum perforatum). A chemotaxis experiment was used to determine the preference of living area of both tph-1 and wild type C. elegans, given an option between a control and three concentrations of each decoction (lavender and St. John’s Wort). A dose response experiment with 2%, 0.2% and 0.02% dilutions of the original decoction was conducted to test the effects of herbal remedies on the worms. Fecundity, behavior and mortality were monitored for two days for control and experimental groups. These worms were then harvested into worm pellets and analyzed using quantitative real-time PCR to determine the genetic efficacy of these herbal remedies. Results with the lavender decoction and St. John’s Wort decoction suggested an increase of serotonin levels as observed by increases in tph-1 mutant fecundity when compared to the untreated tph-1 worms. Both solutions also showed effectiveness at the genetic level when analyzed with qPCR because both caused an upregulation of the tph-1 gene. The effectiveness of these solutions suggests ramifications for humans who are affected by the side effects or ineffectiveness of SSRIs and other serotonin targeting medications because it suggests that there may be viable alternatives with less risks.

Competition history

AJAS 2020 Category not listed

Related projects

AJAS · 2019