Cytotoxicity in HUVEC Cells Exposed to Methanol Extracts of Four Medicinal Plants Combined with and without Boron

Medicinal plants synthesize many types of biologically active compounds, and these molecules play an important role in pharmacy and provide the raw material for some drugs. Although some plants are used because they are easily accessible at very low costs and are thought to have fewer side effects than synthetic products, it is also frequently reported that high doses of these plants can have toxic side effects rather than benefits. In this study, the cytotoxic effects of low (25 μg/mL), medium (50 μg/mL), and high doses (100 μg/mL) of methanol extracts from four different medicinal plants commonly used by the public, stinging nettle (Urtica dioica L.), purslane (Portulaca oleracea L.), bitter melon (Ecballium elaterium L.), and wild thyme (Thymus serpyllum L.) with and without boric acid co-treatment for 24 hours on human umbilical cord vein endothelial cells (HUVEC) were investigated using a cell viability assay and light microscopy techniques. It has been determined that adding medium doses of boric acid (500  to these plant extracts decreased cytotoxicity in HUVEC and increased cell viability. This study demonstrates the potential of adding boric acid to plant extracts that are highly toxic or have adverse side effects, in order to mitigate these effects.