Context: Pluchea indica (L.) Less (Asteraceae) is an herb used as a traditional medicine for wound healing. The chemical compounds found in Pluchea indica leaves are phenolic acids, flavonoids, anthocyanins and carotenoids.
Objective: This study investigates the effect of Pluchea indica leaf ethanol extract and its nanoparticles (NPs) on cytotoxicity, cell survival and migration of human oral squamous carcinoma cell line.
Materials and methods: Cell viability was measured using MTT assay to assess the effect of Pluchea indica leaf extract and NPs (1-500 μg/mL) on cytotoxicity and cell survival. The effect of Pluchea indica leaf extract and NPs on cell migration was determined by scratch assay. The % relative migration was calculated after 24, 48 and 72 h of treatment.
Results: The sizes of Pluchea indica leaf extract NPs were in a range of nanometers. NPs possessed negative charge with the polydispersity index (PDI) smaller than 0.3. After the treatment for 24, 48 and 72 h, Pluchea indica leaf extract had IC50 value of 443.2, 350.9 and 580.5 μg/mL, respectively, whereas the IC50 value of NPs after the treatment for 24, 48 and 72 h were 177.4, 149.2 and 185.1 μg/mL, respectively. The % relative migration of cells was significantly increased when the cells were treated with 62.5 and 125 μg/mL of the extract and 62.5 μg/mL of NPs.
Discussion and conclusions: NPs increased cytotoxicity of the Pluchea indica leaf extract, increased the migration of cells at low concentration and increased colloidal stability of the extract in an oral spray formulation.
Keywords: Cytotoxicity; HO-1-N-1; cell survival; colloidal stability study; migration; scratch assay; solvent displacement method.