EP_085. In vitro micronucleus assay for Dioscorea hispida genotoxicity assessment

Siti Khadijah Mustapha Kamal¹, Norizah Awang¹, Nur Liana Md Nasir¹, Nik Aina Syazana Nik Zainuddin¹, Lau Mei Siu¹, Mohd Rahimi Ashraf Abd Rahman¹, Poo Chin Long¹, Siti Soleha Ab dullah¹, Elda Nurafnie Ibnu Rasid¹, Hussin Muhammad^1*

1. Toxicology and Pharmacology Unit, Herbal Medicine Research Centre, Institute for Medical Research, National Institute of Health, Persiaran Setia Murni, Setia Alam, Seksyen U13, 40170 Shah Alam, Selangor, Malaysia

*Corresponding author: Hussin Muhammad. This email address is being protected from spambots. You need JavaScript enabled to view it.

ABSTRACT

INTRODUCTION: Dioscorea hispida or “ubi gadong”, traditionally used for its medicinal properties, contains bioactive compounds like diosgenin and dioscorine, the latter being toxic without proper detoxification. While Dioscorea hispida shows antioxidant, antimicrobial, and anti-inflammatory effects, scientific data on its genotoxic safety continues to be limited. This highlights the need for further assessment to establish the safety profile of this plant.

OBJECTIVE(S): The purpose of this study is to investigate the genotoxicity of Dioscorea hispida aqueous extract (DHAE) through the in vitro micronucleus assay.

MATERIALS & METHODS: V79B cells were cultured in Dulbecco’s Modified Eagle’s Medium supplemented with 10% FBS and 1% antibiotic/antimycotic, maintained at 37°C with 5% CO₂. Cytotoxicity of DHAE was evaluated using MTS assay. The in vitro micronucleus assay was conducted according to OECD TG487, with and without metabolic activation of S9 mix. Cells were exposed to DHAE at concentrations of 1.25, 2.5, and 5 mg/mL along with controls for 3 hours, followed by 21 ± 0.5 hours recovery. After fixation with Carnoy’s fixative, slides were stained with acridine orange, and 1,000 binucleated cells were scored per treatment group using fluorescence microscopy.

RESULTS: No significant increase in micronucleated cell frequency was observed at any DHAE concentration, with or without metabolic activation, compared to the negative control. In contrast, the positive controls induced marked increase in micronucleus formation under both conditions.

CONCLUSION: DHAE did not induce significant increase in micronuclei formation at any tested dose, with or without metabolic activation, suggesting no genotoxic potential in the in vitro micronucleus assay.

KEYWORDS: Dioscorea hispida, Genotoxicity, In vitro Micronucleus Assay