Investigation of the cytotoxic potential and anti-inflammatory properties of Euphorbia hirta alone and in combination with Selenium in vitro

Abstract

Euphorbia hirta (E. hirta) is a medicinal plant used for the traditional treatment of respiratory disorders such as asthma and chronic bronchitis in parts of the world where it grows naturally, for example East and West Africa and Australia. It is a shrub belonging to the Euphorbiaceae (spurge) family of plants with anti-inflammatory and possible anti-oxidant properties. A combination of the plant material with another anti-oxidant could possibly lead to enhanced effects of the properties of E. hirta, one such anti-oxidant is selenium. Selenium is a micro-nutrient that helps to maintain a good immune system in the body by its anti-inflammatory action in the cyclooxygenase–lipoxygenase pathway. The aim of this study was to investigate the cellular effects of E. hirta and selenium, alone and in combination, on primary chick embryo lung cell cultures. The primary lung cell cultures were established by harvesting lungs from 13 day old chicken embryos. After the cell culture was established, the concentrations of E. hirta and selenium were tested for cytotoxicity using the Neutral Red (NR) and Crystal Violet (CV) assays. Neither of the substances, either alone or in combination, had an effect on the lysosomal membrane integrity as measured by NR, or on the amount of cellular proteins, as measured by CV. Light microscopy and scanning electron microscopy were used to observe the effect of E. hirta and selenium on cellular morphology. A mixture of cellular shapes was observed in the control and exposed cells. Cell membranes remained smooth and undamaged after exposure, with no apoptotic morphologies such as membrane blebbing. Cells with a number of pseudopodia were observed suggesting that the cells were possibly in a state of migration. Confocal microscopy was done to investigate certain internal cellular mechanisms possibly affected by E. hirta and selenium. Staining with Mito Tracker Red 580 showed that there was no significant effect on mitochondria. Nuclear staining with DAPI showed that neither E. hirta nor selenium had a detrimental effect on the nucleus. FDA and PI staining showed that selenium caused possible increased membrane permeability. Detection of ROS production with DCH2FDA indicated that E. hirta protected the cell from H2O2. The study draws one to the conclusion that E. hirta and selenium, alone and in combination, is not toxic at the concentrations tested to chicken embryo lung cells. The anti-oxidant activity of E. hirta was confirmed, as it prevented the production of H2O2. Copyright