Table 3.
Tricyclic compounds that inhibit Plasmodium yoelii nigeriensis N67 oocyst formation in the mosquito midgut
| Compounda | Action | Dose (mg/kg) | No. of mosquitoes dissected | Mean (SD) no. of oocysts | % reduction | % mosquitoes with oocysts |
|---|---|---|---|---|---|---|
| No-drug control 1 | 14 | 457.5 (55.6) | 100 | |||
| No-drug control 2b | 22 | 101.2 (65.3) | 90.9 | |||
| Primaquineb | Antimalarial | 10 | 30 | 0*** | 100 | 0 |
| Ketotifen | Tricyclic antihistamine | 10 | 18 | 0*** | 100 | 0 |
| MLS000708402-02b | Tricyclic compound | 10 | 24 | 1.1 ( 2.6)*** | 98.9 | 33.3 |
| MLS000708402-02b | Tricyclic compound | 10 | 17 | 2.2 ( 4.2)*** | 99.5 | 23.5 |
| Cyproheptadineb | Psychiatric | 10 | 27 | 9.6 (33.7)*** | 90.5 | 55.6 |
| Protryptyline | Antidepressant | 10 | 16 | 20.9 (25.5)*** | 95.4 | 93.8 |
| Desloratadineb | Tricyclic antihistamine | 10 | 18 | 18.8 (33.7)*** | 81.4 | 70.6 |
| Chlorpromazine | Antipsychotic | 30 | 14 | 143.0 (48.7)*** | 68.7 | 100 |
| Imipramine | Antidepressant | 100 | 15 | 201.2 (86.5)*** | 56 | 100 |
| MLS000556884-02b | Tricyclic compound | 10 | 22 | 48.2 (41.6)** | 52.4 | 100 |
| Trimipramineb | Tricyclic antidepressant | 10 | 29 | 65.5 (46.0)* | 35.3 | 89.7 |
| Doxipin | Antidepressant | 30 | 13 | 420.6 (73.5) | 8.1 | 100 |
| Pizotifenb | Serotonin antagonist | 10 | 21 | 109.0 (65.8) | −1 | 95.2 |
| MLS000556883-02b | Tricyclic compound | 10 | 26 | 116.8 (78.4) | −1.15 | 96.2 |
a
Mice infected with the parasites were injected with the compounds 1 h before allowing mosquitoes to feed, and the mosquitoes were dissected 8 days after feeding. *, P < 0.5; **, P < 0.01; ***, P < 0.001 (unpaired t test).
b
Data from second feeding; note that the oocyst count of the control was different from that for the first feeding.