Plant extracts as potential phytotherapeutic products are supposed to be safe. However, adverse and untoward fatal effects have been reported.  Study aimed to evaluate the safety and toxicity of aqueous extracts of Camellia sinensis, Parquetina nigrescens and Telfairia occidentalis leaves. The extracts were subjected to brine shrimp lethality bioassay and toxicities by Lorke’s method. Mice were given oral leaves extracts of C. sinensis (1000, 2000, 4000 mg/kg and 700, 1400, 2800 mg/kg); P. nigrescens (3000, 6000, 12000 mg/kg and 2000, 4000, 8000 mg/kg) and T. occidentalis (2500, 5000, 10,000 mg/kg and 1750, 3500, 7000 mg/kg) for acute and Sub-acute toxicity studies respectively. Toxicity was observed for the first 4hrs, then over a period of 24hrs and at least once daily for 14 days extended to 28 days. General behavior, adverse effects and mortality observed and evaluated throughout the experimental period. Camellia sinensis (LC50=418.6 µg/mL) with least toxicity on the brine shrimps compared to P. nigrescens (LC50=32.34 µg/mL) and T. occidentalis (LC50=8.32 µg/mL). LD50 of the extracts; 2800, 8000 and 7000 mg/kg for C. sinensis, P. nigrescens and T. occidentalis respectively. No death, No changes in body and relative organ weights. However, C. sinensis and T. occidentalis significantly increased in Haemoglobin (C. sinensis: 15.90 ± 0.33 (p < 0.00) and T. occidentalis: 14.67 ± 0.22 (p < 0.01)), PCV (C. sinensis: 46.20 ± 1.02  and T. occidentalis: 44.00 ± 0.71 (p < 0.00)), RBC (C. sinensis: 5.55 ± 0.12 and T. occidentalis: 5.49 ± 0.12 (p < 0.00)). No histomorphological changes in the vital organs except P. nigrescens with mild kidney interstitial fibrosis, mild glomerular hypercellularity and mild liver microhemorrhages. Various doses of the extracts did not cause mortality or serious signs of toxicity in mice.    

 

Key words: Camellia sinensis, Parquetina nigrescens, Telfairia occidentalis, acute and sub-acute toxicities, No Observed Adverse Effect Level.