Cytotoxic Effects of Juglans Regia L. and Coffea Canephora on Human Gingival Fibroblasts

Abstract

BACKGROUND:
Juglans regia L. (English walnut) and Coffea canephora (robusta coffee) are widely recognized for their rich composition of bioactive compounds, including polyphenols, flavonoids, tannins, and alkaloids. These natural compounds exhibit various pharmacological properties, such as antioxidant, anti-inflammatory, and antimicrobial activities, which make them valuable candidates for therapeutic applications. Human gingival fibroblasts (HGF), crucial in maintaining gingival tissue integrity and oral health, are a focus of interest in evaluating the cytotoxicity and biocompatibility of these natural products. This study aimed to investigate the cytotoxic effects of walnut powder and coffee extracts on HGF cells, providing insights into their potential applications in dental formulations.

MATERIALS AND METHODS:
The cytotoxic effects of Juglans regia L. and Coffea canephora were assessed using the MTT assay. Human gingival fibroblasts were cultured in 96-well plates and treated with varying concentrations (0 µg/ml to 500 µg/ml) of the extracts for 24 hours. The MTT dye (10 mg/ml) was added to each well, and the plates were incubated at 37°C for 4 hours. After incubation, the medium was replaced with DMSO to dissolve the formazan crystals, and absorbance was measured at 570 nm using a Synergy Hybrid Multi-Mode Reader. Cell viability was calculated and analyzed using one-way ANOVA with Tukey’s multiple comparisons. Morphological changes were assessed using phase-contrast microscopy at 20X magnification.

RESULTS:
The study revealed a concentration-dependent cytotoxic effect of the extracts on HGF cells. At lower concentrations (0–50 µg/ml), cell viability remained high, indicating minimal cytotoxicity. However, at higher concentrations (200 µg/ml and above), a significant reduction in cell viability was observed (p < 0.001). Morphological assessments showed clear cellular alterations, including changes in shape and density, particularly at higher extract concentrations. Control samples maintained normal morphology and viability, providing a baseline for comparison. 

CONCLUSION:
This study demonstrated that Juglans regia L. and Coffea canephora exhibit concentration-dependent cytotoxic effects on human gingival fibroblasts. While lower concentrations were well-tolerated, higher concentrations significantly impacted cell viability and morphology. These findings underscore the need to optimize extract concentrations for safe and effective use in dental applications. Further research is recommended to explore the mechanisms underlying these effects and evaluate their potential therapeutic benefits in oral health.