Toxicity evaluation of Xanthorrhoea johnsonii leaf methanolic extract using the Artemia franciscana bioassay
IE Cock1, FR Kalt2
1 Biomolecular and Physical Sciences, Nathan Campus, Griffith University, 170 Kessels Road, Nathan, Queensland 4111; Genomics Research Centre, Gold Coast Campus, Griffith University, Parklands Drive, Southport, Queensland 4222, Australia
2 Biomolecular and Physical Sciences, Nathan Campus, Griffith University, 170 Kessels Road, Nathan, Queensland 4111, Australia
I E Cock
Biomolecular and Biomedical Sciences, Griffith University, Nathan Campus, 170 Kessels Road, Nathan, Queensland 4111
Source of Support: School of Biomolecular and Physical Sciences, Griffith University, Australia, Conflict of Interest: None
The toxicity of Xanthorrhoea johnsonii methanolic leaf extract was investigated using the Artemia franciscana nauplii bioassay. At 24 h, the extract produced an EC 50 of 361.0 ± 41.8 μg/ml, indicating that it was substantially more toxic than the pesticide Mevinphos (1346.2 ± 80.1 ΅g/ml) and approximately 4 fold less toxic than potassium dichromate (87.1 ± 5.2 μg/ml). Whilst potassium dichromate LC 50 values remained constant across the 72-h test period, these values decreased for the extract and Mevinphos to similar values (199.8 ± 60.5 and 114 ± 12.8 μg/ml, respectively), indicating their similar level of efficacy. Noteworthy was the apparent anesthetic effect of X. johnsonii leaf extract. Although the extract initially appeared to kill the A. franciscana nauplii, they were seen to temporarily recover by 48 h only to die by 72 h.