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Jackass Bitters

Scientific Name(s): Neurolaena lobata (L.) R. Br.
Common Name(s): Capitana, Contragavilana, Cow-gall bitter, Gavilana, Herbe-a-pique, Inaciabi, Jackass bitters, Mano de lagarto, Tres puntas, Zeb-a-pique

Clinical Overview


The plant species has numerous ethnomedicinal uses. Medical literature documents in vitro and animal studies on the plant's antibacterial, antimalarial, antiplasmodial, anthelminthic, and hypoglycemic activity, but there are no clinical trials to support its use for any indication.


None validated by clinical data. Ethnomedicinal resources vary for dosage of an N. lobata leaf decoction in treating malaria, ranging from 3 glasses daily for 4 days to 1 glass daily before breakfast for 7 days.


Patients with known hypersensitivity reactions to any of the components of the plant species.


Information regarding safety and efficacy in pregnancy and lactation is lacking.


None well documented.

Adverse Reactions

None well documented.


Chemical analysis revealed the presence of pyrrolizidine alkaloids. No toxicity was observed with oral doses up to 5,000 mg/kg in mice.


The weedy herbaceous plant N. lobata grows in northwestern South America through Central America and into southern Mexico. The plant species also is found throughout the Caribbean islands. It grows 1 to 2 m tall and has alternate trilobed leaves. The yellow flowers grow in compact groups at the end of the branches. All portions of the plant have a bitter taste. When handled, the fresh leaves and stems stain the skin yellow.1, 2, 3, 4


The plant species has numerous ethnomedicinal uses. In Mesoamerica, the herb was used to treat several diseases, including cancer, diabetes, dysentery (amebiasis), and malaria. In Panama, an infusion of the leaves was used to treat diabetes, hypertension, and hepatic ailments. In the Panamanian province of Darian, it is used for malaria and as an insect repellent. In Caribbean folk medicine, the herb was used medicinally to treat skin diseases, gastric pain, ulcers, and as a general pain reliever. In Guatemala, the plant has been used to treat malaria, anemia, and nervous weakness. It also has been used as a tonic and an antipyretic.2, 4, 5, 6, 7, 8, 9


The primary medicinal components, the sesquiterpene lactones, are found in the leaf. The germacranolide sesquiterpene lactones include neurolenins A, B, C, D, E, and F and lobatin A. The neurolenins are found in the leaves in high concentrations and may be involved with the plant's medicinal use in treating dysentery. The neurolenins are extremely bitter substances. The germacranolide sesquiterpene lactones possess the structural requirements for cytotoxic and anticancer activities; however, neurolenins A and B were inactive in an animal model against sarcoma-180. Examples of isolated furanoheliangolides from N. lobata include lobatins B and C. The sesquiterpene content also is associated with the plant's antimalarial activity and activity against insects. N. lobata plants of different geographical origin show some qualitative and quantitative variations in their sesquiterpene lactone content. Flavonoids, coumarins, thymols, mellilotic acid, iridoids, and alkaloids also have been identified. More than 12 flavonoids have been isolated.2, 3, 4, 7, 10, 11, 12, 13, 14, 15, 16

Uses and Pharmacology

Clinical studies are lacking.

Anti-inflammatory effects

Animal data

Studies in rodents (induced paw edema) and in vitro suggest chemical constituents of N. lobata may have anti-inflammatory activity.8, 17, 18

Clinical data

Research reveals no clinical studies regarding the use of N. lobata for anti-inflammatory effect.

Antimicrobial activity

Animal data

Based on in vitro studies, some animal experiments have been conducted.5, 6, 19, 20 in vitro antibacterial activity has been reported.21 Antiplasmodial effects of chemical constituents neurolenins, and of ethanol and methanol extracts have been demonstrated in rodents.22, 23

Other uses

Hypoglycemic activity in mice was demonstrated in an older study; however this line of research does not appear to have been further pursued.24

Various fractions of a hydroalcoholic extract of N. lobata aerial parts reduced gastric lesion formation in rodent models. Researchers suggest the mechanism of action may be associated with mucus production and prostaglandin synthesis.25 Wound healing in a study in rats was improved with extracts of the leaves of the plant.26

Extracts of the branches, leaves, and stems of N. lobata had moderate neutralization activity at doses up to 4 mg per mouse against the hemorrhagic effect of Bothrops atrox snake venom of from Antioquia and Chocó, northwestern Colombia.27


None has been validated by clinical data. Ethnomedicinal resources vary for dosage of an N. lobata leaf decoction in treating malaria, ranging from 3 glasses daily for 4 days to 1 glass daily before breakfast for 7 days.9, 19

Pregnancy / Lactation

Avoid use during pregnancy and lactation because of lack of clinical studies.22


None validated by clinical data. The herb has the potential to produce additive effects in patients also taking analgesics, diuretics, or antimalarial medications.

Adverse Reactions

None well documented.


Chemical analysis revealed the presence of pyrrolizidine alkaloids; however, toxic necine pyrrolizidines were not present. No toxicity was observed with oral doses up to 5,000 mg/kg in mice. 8, 22


1. Neurolaena lobata. USDA, NRCS. 2016. The PLANTS Database (, April 2017). National Plant Data Team, Greensboro, NC 27401-4901 USA. Accessed April 2017.
2. Borges-del-Castillo J, Manresa-Ferrero MT, Rodríguez-Lius F, Vázquez-Bueno P, Gupta MP, Joseph-Nathan P. Panama flora. II. New sesquiterpene lactones From Neurolaena lobata. J Nat Prod. 1982;45:762-765.
3. Manchand PS, Blount JF. Chemical constituents of tropical plants. 11. Stereostructures of neurolenins A and B, novel germacranolide sesquiterpenes from Neurolaena lobata (L.) R. Br. J Org Chem. 1978;43:4352-4354.
4. Passreiter CM, Wendisch D, Gondol D. Sesquiterpene lactones from Neurolaena lobata. Phytochemistry. 1995;39:133-137.
5. Caceres A, Lopez B, Gonzalez S, Berger I, Tada I, Maki J. Plants used in Guatemala for the treatment of protozoal infections. I. Screening of activity to bacteria, fungi and American trypanosomes of 13 native plants. J Ethnopharmacol. 1998;62:195-202.9849628
6. Franssen FF, Smeijsters LJ, Berger I, Medinilla Aldana BE. In vivo and in vitro antiplasmodial activities of some plants traditionally used in Guatemala against malaria. Antimicrob Agents Chemother. 1997;41:1500-1503.9210673
7. Passreiter CM, Isman MB. Antifeedant bioactivity of sesquiterpene lactones from Neurolaena lobata and their antagonism by γ-aminobutyric acid. Biochem System Ecol. 1997;25:371-377.
8. Gracioso JS, Paulo MQ, Hiruma Lima CA, Souza Brito AR. Antinociceptive effect in mice of a hydroalcoholic extract of Neurolaena lobata (L.) R. Br. and its organic fractions. J Pharm Pharmacol. 1998;50:1425-1429.10052860
9. Giron LM, Freire V, Alonzo A, Caceres A. Ethnobotanical survey of the medicinal flora used by the Caribs of Guatemala. J Ethnopharmacol. 1991;34:173-187.1795521
10. Bohimann F, Natu AA, Kerr K. Naturally occurring terpene derivatives. Part 185. Thymol derivatives from Neurolaena species. Phytochemistry. 1979;18:489-490.
11. Kerr KM, Mabry TJ, Yoser S. 6-Hydroxy- and 6-methoxyflavonoids from Neurolaena lobata and N. macrocephala. Phytochemistry. 1981;20:791-794.
12. Castro O, Barrios M, Chinchilla M, Guerrero O. Chemical and biological evaluation of the effect of plant extracts against Plasmodium berghei [in Spanish]. Rev Biol Trop. 1996;44:361-367.9246360
13. Todorova MN, Ognyanov IV, Navas H. Sesquiterpene lactones in Neurolaena lobata from Costa Rica. Biochem Syst Ecol. 1997;25:267-268.
14. Passreiter CM, Medinilla A, Beatriz E. Variability of sesquiterpene lactones in Neurolaena lobata of different origin. Planta Medica. 1998;64:427-430.17253261
15. Passreiter CM, Sandoval-Ramirez J, Wright CW. Sesquiterpene lactones from Neurolaena oaxacana. J Nat Prod. 1999;62:1093-1095.10479310
16. Passreiter CM. Pyrrolizidine alkaloids from Neurolaena lobata. Biochem Syst Ecol. 1998;26:839-843.
17. McKinnon R, Binder M, Zupkó I, et al. Pharmacological insight into the anti-inflammatory activity of sesquiterpene lactones from Neurolaena lobata (L.) R.Br. ex Cass. Phytomedicine. 2014;21(12):1695-1701.25442279
18. Lajter I, Vasas A, Béni Z, et al. Sesquiterpenes from Neurolaena lobata and their antiproliferative and anti-inflammatory activities. J Nat Prod. 2014;77(3):576-582.24476550
19. Berger I, Barrientos AC, Caceres A, et al. Plants used in Guatemala for the treatment of protozoal infections: II. Activity of extracts and fractions of five Guatemalan plants against Trypanosoma cruzi. J Ethnopharmacol. 1998;62:107-115.9741882
20. Fujimaki Y, Kamachi T, Yanagi T, Caceres A, Maki J, Aoki Y. Macrofilaricidal and microfilaricidal effects of Neurolaena lobata, a Guatemalan medicinal plant, on Brugia pahangi. J Helminthol. 2005;79:23-28.15831109
21. Lentz DL, Clark AM, Hufford CD, et al. Antimicrobial properties of Honduran medicinal plants. J Ethnopharmacol. 1998;63:253-263.10030730
22. Francois G, Passreiter CM, Woerdenbag HJ, Van Looveren M. Antiplasmodial activities and cytotoxic effects of aqueous extracts and sesquiterpene lactones from Neurolaena lobata. Planta Med. 1996;62:126-129.8657743
23. Berger I, Passreiter CM, Caceres A, Kubelka W. Antiprotozoal activity of Neurolaena lobata. Phytother Res. 2001;15:327-330.11406857
24. Gupta MP, Solis NG, Avella ME, Sanchez C. Hypoglycemic activity of Neurolaena lobata (L.) R. Br. J Ethnopharmacol. 1984;10:323-327.6748709
25. Gracioso JS, Hiruma-Lima CA, Souza Brito AR. Antiulcerogenic effect of a hydroalcoholic extract and its organic fractions of Neurolaena lobata (L.) R.Br. Phytomedicine. 2000;7:283-289.10969721
26. Nayak BS, Ramlogan S, Chalapathi Rao A, Maharaj S. Neurolaena lobata L. promotes wound healing in Sprague Dawley rats. Int J Appl Basic Med Res. 2014;4(2):106-110.25143886
27. Otero R, Nunez V, Barona J, et al. Snakebites and ethnobotany in the northwest region of Colombia. Part III: neutralization of the haemorrhagic effect of Bothrops atrox venom. J Ethnopharmacol. 2000;73:233-241.11025161


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