Table 2.
Effect of 20-hydroxyecdysone on detoxification enzyme activities of Tribolium castaneum larvae after 7 d of treatment
| Specific activitya | |||
|---|---|---|---|
| EST (1-NA) | GST (CDNB) | P450 (cytochrome c) | |
| Control | 0.31 ± 0.04a | 10.2 ± 5.1a | 0.72 ± 0.12a |
| 300 ppm | 0.5 ± 0.05b | 43.1 ± 7.3d | 1.18 ± 0.13d |
| 600 ppm | 0.42 ± 0.02b | 74.2 ± 5.4d | 0.77 ± 0.1a |
| 900 ppm | 0.39 ± 0.07b | 228.9 ± 6.8d | 0.64 ± 0.12a |
| 1,200 ppm | 0.29 ± 0.05c | 337.4 ± 4.6d | 0.33 ± 0.06c |
| Starved | 0.37 ± 0.04a | 53.15 ± 7.2b | 0.49 ± 0.09b |
Means in the same column followed by different letters indicate that the difference between controls and treated or starved larvae is statistically significant as determined by the Tukey’s HSD test. Between the letters ‘a’ and ‘b’, the effect is significant (P < 0.05). Between the letters ‘a–c’, the effect is very significant (P < 0.01). Between the letters ‘a–d’, the effect is very highly significant (P < 0.001).
aSpecific activity: EST (1-NA): mmol of β-naphtol formed per minute per milligrams of proteins; GST (CDNB): nanomoles of substrate conjugated per minute per milligram of protein; P450 (cytochrome c): nanomoles of cytochrome c reduced per minute per milligram of protein.