Table 3. Effect of pure compounds on catalase and haemolytic activity of test bacteria.
| Organism | Compound | Concentration of
extract, µg/ml |
Change in catalase
activity, % † |
Inhibition in
haemolysis, % † |
|---|---|---|---|---|
| C. violaceum | Gallic acid | 100 | 11.53 *** ± 1.51 | 14.28 * ±4.73 |
| 150 | 12.30 *** ± 0.65 | 22.85 *** ± 5.22 | ||
| 200 | 10.25 *** ± 0.51 | 18.57 * ± 2.78 | ||
| Quercetin | 100 | 1.79 * ± 0.30 | 9.52 ** ± 3.55 | |
| 150 | 2.09 * ± 0.75 | 13.09 ** ± 1.11 | ||
| 200 | 2.39 * ± 0.62 | 19.04 *** ± 2.61 | ||
| Cinnamic acid | 100 | -2.68 * ± 1.47 | 8.47 * ± 4.90 | |
| Chlorogenic acid | 75 | -3.84 * ± 0.64 | 10.16 * ± 5.80 | |
| Catechin | 50 | 4.93 *** ± 1.00 | 17.54 * ± 3.91 | |
| P. aeruginosa | Gallic acid | 100 | 0.31 ± 0.67 | 9.64 ± 5.59 |
| 150 | 0.62 ± 0.47 | 9.41 ± 1.18 | ||
| 200 | 0.62 ± 0.45 | 9.52 ± 2.10 | ||
| Quercetin | 100 | -2.84 ** ± 0.50 | 2.82 * ± 0.009 | |
| 150 | -1.26 * ± 0.30 | 9.73 *** ± 0.30 | ||
| 200 | -2.61 *** ± 0.47 | 12.34 ** ± 1.97 | ||
| Cinnamic acid | 100 | 1.18 ± 0.41 | 19.11 * ± 6.23 | |
| Chlorogenic acid | 75 | 1.47 * ± 0.83 | 35.29 *** ± 3.70 | |
| Catechin | 50 | -9.00 ** ± 1.91 | 15.06 *** ± 3.66 |
* p<0.05, ** p<0.01, *** p<0.001. †Mean ± SD. Catalase assay was done by monitoring disappearance of H 2O 2 at 240 nm; Hemoglobin concentration was measured at OD 540; DMSO in ‘vehicle control’ tube had no effect on catalase and haemolytic activity of any of the three bacteria; Chloramphenicol (0.5 μg/mL) enhanced catalase activity of C. violaceum by 11.23%*. ± 0.01; Tetracycline (0.5 μg/mL) inhibited catalase activity of P. aeruginosa by 21.51%* ± 0.02.