Preventive Role of Methanolic Extract of Ocimum sanctum L., Camellia sinensis (L.) Kuntze and Their Combined Formulation against Sublethal Concentration of Sodium Fluoride Exposed to Channa punctatus (Bloch.)

ABSTRACT: In the recent years, Fluoride has emerged as one of the most harmful pollutants in the world and its presence has been shown to negatively impact the quality of groundwater in many countries. According to World Health Organization (WHO), when its concentration exceeds 1.5 mg/L limit, it may cause threats to the health. Exposure to high concentrations of fluoride has been known to have deleterious effects on the biological system of human as well as other animals. Based on this background, a study has been conducted to show the effects of sodium fluoride induced toxicity in the freshwater fish Channa punctatus (Bloch.). The fishes were exposed to sublethal doses of 25 ppm and 50 ppm of sodium fluoride for a period of 3 and 7 days. The damaging effects of sodium fluoride were manifested in the morphological, behavioural, haematological, biochemical and histological parameters of the fishes. The fishes were then further exposed to 100 mg/L of methanolic leaf extracts of tulsi, tea and a combined formulation of the two extracts to investigate the ameliorative properties in the revival of fluoride toxicity in the fishes. However, the results showed that the impact of toxicity caused by exposure to 25 ppm was much less pronounced as compared to 50 ppm of sodium fluoride. These effects were revealed to be effectively reduced by the addition of the plant extracts. Both the selected plant extracts showed positive results. However, their combined formula revealed the highest level of effectiveness in the remedial activity of fluoride induced toxicity.  Keywords: Fluoride, Sublethal, Toxicity, Channa punctatus, Leaf Extract, Remediation