Evaluating the potential of Kalanchoe pinnata, Piper amalago amalago, and other botanicals as economical insecticidal synergists against Anopheles gambiae

Table 3 Inhibition strength of Jamaican plant extracts that demonstrated strong inhibition of Anopheline CYPs

Plant extracts and compounds IC₅₀	CYP6P9a	CYP6P3	CYP6M2
Kalanchoe (Bryophyllum) pinnata µg/ml	> 20	> 20	3.52 ± 0.68
Condea (Hyptis) verticillata µg/ml	6.95 ± 0.11	> 20	> 20
Piper amalago var. amalago µg/ml	2.61 ± 0.17	5.84 ± 0.42	4.30 ± 0.42
Piperine µg/ml	8.01 ± 0.67	3.18 ± 0.17	0.14 ± 0.08
Deltamethrin µg/ml	1.34 ± 0.21	10.96 ± 3.57	8.91 ± 3.40
PBO µg/ml	0.15 ± 0.03	0.30 ± 0.02	0.06 ± 0.00

The Table shows the concentrations of K. pinnata, C. verticillata, P. amalago amalago, piperine—the active metabolite of P. amalago amalago, the insecticide deltamethrin and synergist piperonyl butoxide (PBO) that reduced CYP6P9a, CYP6P3, and CYP6M2-catalyzed diethoxyfluorescein activity by 50% (IC₅₀). Test compound concentrations varied between 0 and 200 μg/ml, as described in the Methods. Control enzyme activity (mean ± SEM) for CYP6P3, CYP6P9a, and CYP6M2 was 0.39 ± 0.01, 0.03 ± 0.05, and 0.02 ± 0.00 µM/min/pmol of CYP, respectively. Data are expressed as the mean concentration (mean ± SEM) to inhibit 50% enzyme activity for three independent experiments

ISSN: 1475-2875