Table 1: Comparison of phytochemical resistance in Crithidia bombi, other trypanosomes and parasites, animal cells, and insects.

From: Bumble bee parasite strains vary in resistance to phytochemicals

PhytochemicalEC50 (ppm)Species or cell typeReference
Anabasine628–2160Crithidia bombiThis study
 >100Trypanosoma cruzi (epimastigote)81
 >100Spodoptera frugiperda (Sf9) cells81
 >100CHO cells (hamster ovary)81
 5–20Crithidia (reduced infection in Bombus impatiens)22
 20Crithidia (reduced infection in Bombus impatiens)82
 5Nectarinea osea (sunbird feeding deterrent)63
Nicotine>1000Crithidia bombiThis study
 >1000Trypanosoma brucei45
 2Crithidia (reduced infection in Bombus impatiens, B. terrestris)22,23
 2000Apis mellifera (2 d LD50)14
Amygdalin>10,000Crithidia bombiThis study
 >10,000Herpetomonas culicidarum carbon source83
 >2000Leishmania tropica84
 30Apis mellifera (2 d LD50)14
 2100Apis mellifera (6 d LD50)85
Caffeic acid>250Crithidia bombiThis study
 5.6Leishmania donovani (amastigote)24
 1.1Trypanosoma brucei rhodesiense (bloodstream form)24
 >30Trypanosoma cruzi (trypomastigote)24
 56Trypanosoma cruzi (trypomastigote)86
 53.3L6 rat muscle cells24
 109.1Human lymphocytes87
 >128Paenibacillus larvae (American foulbrood–MIC)88
 >300Culex quinquefasciatus Say (mosquito) larvae89
 >500 μg fly−1Musca domesticus (housefly) adults89
Chlorogenic acid#>2500Crithidia bombiThis study
 7Leishmania donovani (unknown strain)49
 >17.7Leishmania donovani MHOMET- 67/L8250
 18.9Trypanosoma brucei rhodesiense (STIB 900)49
 >10.6Trypanosoma brucei rhodesiense (STIB 900)50
 61Trypanosoma cruzi (trypomastigote)86
 >90Trypanosoma cruzi (amastigote)49
 >50Plasmodium falciparum49
 >3.5Plasmodium falciparum K1 resistant strain50
 >90L6 rat muscle cells49
 8149.13Rat hepatocytes90
 111.5Human lymphocytes87
 >12760Spodoptera eridania larvae91
Eugenol19.7–23.5Crithidia bombiThis study
 93.7Crithidia fasciculata27
 80Leishmania amazonensis92
 37.2Trypanosoma brucei brucei TC221 (bloodstream form)44
 246Trypanosoma cruzi27
 93HL-60 (human leukemia)44
 13Sarcoptes scabiei mites (permethrin-sensitive)93
 40Sarcoptes scabiei mites (permethrin-resistant)93
(clove oil*)7800Apis mellifera (8 d LD50)70
(clove oil*)240Apis mellifera (14 d LD50)70
Gallic acid>250Crithidia bombiThis study
 >30Leishmania donovani (extracellular)24
 >25.0Leishmania donovani (extracellular)26
 4.4Leishmania donovani (intracellular)26
 8.0Trypanosoma brucei brucei (bloodstream form)48
 5.1Trypanosoma brucei brucei (procyclic form)48
 1.6Trypanosoma brucei rhodesiense (bloodstream form)24
 67Trypanosoma cruzi24
 14.4L6 rat muscle cells24
 15.6Mouse macrophages26
 >300Culex quinquefasciatus Say (mosquito) larvae89
 >500 μg fly−1Musca domesticus (housefly) adults89
β-caryophyllene>0.050Crithidia bombiThis study
 13.78Trypanosoma brucei brucei TC221 (bloodstream form)44
 41.2Trypanosoma brucei brucei Lister 427 (bloodstream form)94
 >100Trypansoma brucei brucei Lister 427 (procyclic form)94
 0.002–0.004Pseudomonas syringae15
 221Heliothis virescens (cell cultures)95
 19.31HL-60 (human leukemia)44
 >300A. mellifera (<300 ppm attractive)14
Thymol4.53–22.2Crithidia bombiThis study
 32.5Crithidia fasciculata27
 22.9Trypanosoma brucei brucei44
 62Trypanosoma cruzi (epimastigote)25
 53Trypanosoma cruzi (trypomastigote)25
 64–128Paenibacillus larvae (MIC)88
 40.7HL-60 (human leukemia)44
 >1000Apis mellifera (8 d LD50)70
 30Culex quinquefasciatus Say (mosquito) larvae89
 53 μg fly−1Musca domesticus (housefly) adults89
(thyme oil)**>10,000Apis mellifera (2 d LD50)14
  1. Concentrations are from this study (bold) and the sources cited in the table. Values are in EC50 in ppm of pure compound unless otherwise noted. Within each compound, observations are arranged (if applicable) beginning with trypanosomes, then other pathogens, followed by animal cells and insects. Trypanosome EC50 values all refer to in vitro assays of cell cultures. See specific references for methodological details. #Refers to 3-O-caffeoylquinic acid. *Clove (Syzygium aromaticum) oil: 86.7% eugenol96. **Thyme (Thymus) oil: 65.3% thymol97.