An in vitro evaluation of cytotoxicity of curcumin against human periodontal ligament fibroblasts

INTRODUCTION: Curcumin, a component of turmeric (Curcuma longa L.), is a molecule of multitude of medicinal properties. Although curcumin has found a place in the treatment of gingival and periodontal diseases, there are no reported cytotoxicity studies on the cells of clinical significance (i.e., periodontal ligament [PDL] fibroblasts). AIMS: The objective of this research was to assess the in vitro cytotoxicity of curcumin against human PDL fibroblasts. MATERIALS AND METHODS: Human PDL fibroblasts from premolar teeth were cultured and used for cytotoxicity tests from healthy children presented for orthodontic extractions. Test concentrations of curcumin (100%, 50%, and 25%) were prepared by diluting 95% curcumin with di‑methyl‑sulfoxide and added to 96‑well microtiter plate (in triplicate) containing the fibroblast culture (approximately 2 × 104 cells/well). Fibroblast cells without treatment (without curcumin) acted as a control group. The viability of cells after 48 h of incubation at 37°C in a humidified atmosphere of 5% CO(2) and 95% air was ascertained by the 3‑(4, 5‑dimethyl‑thiazol‑2‑yl)‑2, 5‑diphenyl‑tetrazolium bromide (MTT) assay. The viability of PDL fibroblast cells of experimental wells was expressed relative to that of control, in terms of change in the color intensity. Absorbencies were recorded at 450 nm on a microplate reader with background subtraction at 620 nm. The cell viability at various concentrations of curcumin against the PDL fibroblasts was calculated as mean absorbance (optical density) and percentage values. RESULTS: Cell viability of PDL fibroblasts to 100%, 50%, and 25% curcumin concentration was 111.75%, 112.50%, and 114.40%, respectively. CONCLUSIONS: No in vitro cytotoxicity was detected for curcumin against human PDL fibroblasts, at any of the concentrations used (100%, 50%, and 25%) by MTT assay at the end of 48 h.