bRecommended for use in environmental risk assessments of pharmaceuticals (EMA, 2006); cThe highest tested concentration.
In fact, lethal effects only occurred at the highest tested concentration.
In ABTS free radicals scavenging assay compound 1 exhibited 88.51 ± 0.62 % inhibition at highest tested concentration i.e., 1000 μg/mL.
For all the inhibitors, the inhibition efficiency increased with increasing concentration, reaching a maximum at the highest tested concentration.
Highest tested concentration of arsenite (20 ppm) was found to be detrimental in both IEC and IEC-6.
Most of these nucleoside analogs exhibited potent anti-HIV-1 activity with no cytotoxicity observed at the highest tested concentration up to 25 μM.
In DPPH free radicals scavenging assay (Table 4), compound 1 showed a better activity (72.41 ± 0.45 %) followed by 2, 3 and 4 with 70.32 ± 0.61, 60.40 ± 0.49 and 45.80 ± 0.61 % free radicals scavenging respectively at highest tested concentration.
In larvae of the sea urchin T. gratilla exposed for 5 days to fluorescent PE microspheres (10 45 µm, 103 3 × 105 items/L), effects were only observed at the highest tested concentration.
As stated by the guidance for the implementation of REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), the NOEC is 'the highest tested concentration for which there is no statistical significant difference of effect when compared to the control group' [12].
The 28-day, 90-day and developmental studies were performed using nominal HFPE concentrations of 1000, 3300, and 10,000 ppm (6 h/day: actual exposures confirmed by test atmosphere analysis), and the highest tested concentration proved to be an NOAEL in each study.
No activity at the highest tested concentration denoted as EC50 > 15.70 μg/ml.
