Family • Asteraceae - Eupatorium japonicum Thunb. - JAPANESE THOROUGH-WORT - Chen gan cao

Scientific names

Eupatorium japonicum Thunb.
E. chinense simplicifolium (Makino) Kitm.Thunb.
Eupatorium fortunei Turcz.
Eupatorium stoecdosum Hance.

Common names

Apanang-gubat (Tag.)
Japanese bog orchid (Engl.)
Japanese boneset (Engl.)
Japanese thorough-wort (Engl.)
Chen gan cao (Chin.)
Bai tou po (Chin.)



Apanang-gubat is an erect, leafy branched, smooth herb, 60 to 90 meters high. Leaves are fragrant, up to 19 centimeters long, divided quite to the base into three segments – the upper leaves subtending the branches of the inflorescence being deeply divided. Segments are elliptic-lanceolate or elliptic-ovate, up to 13 centimeters long, pointed at both ends, and toothed at the margins. Inflorescence is terminal, measuring up to 14 centimeters across. Flowering heads are 3 to 4 millimeters across. Flowers are white and fragrant.

– In thickets at low altitudes in the Batan Islands.
– Occurs in Japan to China and Taiwan.

Parts used
– Yields essential oil thymol.

– Contains pyrrolizidine alkaloids—class of hepatotoxic and tumorigenic compounds that have been detected in herbal plants and dietary supplements.
– Study of flowers and leaves yielded volatile oils. Main constituents were germacrene D (27.3%, 37.1%), gemacrene B (12.4%, 11.7%) and β-caryophyllene (8.6%, 10.1%).

Additional Sources and Suggested Readings

(1) Pyrrolizidine alkaloid composition of three Chinese medicinal herbs, Eupatorium cannabinum, E. japonicum and Crotalaria assamica / Edgar JA, Lin HJ et al / Am J Chin Med. 1992;20(3-4):281-8.

(2) A comparative study on the hepatic toxicity and metabolism of Crotalaria assamica and Eupatorium species / Chan MY, Zhao XL, Ogle CW / Am J Chin Med. 1989;17(3-4):165-70.

(4) Coumarin and euponin, two inhibitors for insect development from leaves of Eupatorium japonicum. / Nakajima, S.; Kawazu, K. / Agricultural and Biological Chemistry 1980 Vol. 44 No. 12 pp. 2893-2899

(5) Extraction,GC-MS Analysis and Antibacterial Activities of Volatile Oils from Eupatorium fortune / LIU Jie,JIN Yan / Journal of Hebei Agricultural Sciences, 2011-03

(6) Reciprocal Regulation of Adipocyte and Osteoblast Differentiation of Mesenchymal Stem Cells by Eupatorium japonicum Prevents Bone Loss and Adiposity Increase in Osteoporotic Rats. / Kim MJ, Jang WS, Lee IK, Kim JK, Seong KS, Seo CR, Song NJ, Bang MH, Lee YM, Kim HR, Park KM, Park KW. / J Med Food. 2014 Jun 13.

(7) Japanese bog orchid (Eupatorium japonicum) extract suppresses expression of inducible nitric oxide synthase and cyclooxygenase-2 induced by toll-like receptor agonists / Gyo-Jeong Gu, Sang-Hoon Eom, Hwa-Jeong Shin, Ji Hun Paek, Songmun Kim, Soon Sung Lim, Hyung-Sun Youn / Food Science and Biotechnology, June 2013, Volume 22, Issue 3, pp 811-815

(8) Volatile constituents of essential oils isolated from flowers and leaves of Eupatorium cannabinum L. from Iran /
Mehdi Mirza*, Mehrdokht Najafpour Navaei and Mohammad Dini / Iranian Journal of Pharmaceutical Research (2006) 2: 149-152

(9) SAFETY ISSUES AFFECTING HERBS: PYRROLIZIDINE ALKALOIDS / Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon /

– Considered anodyne, antibacterial, antidandruff, antiviral.
– Carminative, diaphoretic, diuretic, nervine.
– Leaves and stems considered vermifuge.

Parts used
Leaves, roots.

– In Japan, leaves consumed as tea.
– Leaves used as diuretic and anthelmintic.
– Also used as tea for indigestion.
– In China, used for diseases of the women.
– Rukai tribe of Wutai, southern Taiwan, used for ulcer, fever, headaches, fractures.
– Root is beneficial to the circulation and restorative to women after parturition.
– Herb soaked in oil is applied to the hair as treatment for dandruff.

Study Findings
• Pyrrolizidine Alkaloids: Study on the pyrrolizidine alkaloid composition of three Chinese herbs (E. cannabinum, E. japonicum and Crotolaria assamica) yielded viridiflorine, cynaustraline, amabiline, supinine, echinatine, rinderine and isomers of these alkaloids were found in the Eupatorium species.
• Hepatotoxicity: Study concludes the alkaloid in Eupatorium species is metabolized to “pyrrole” and an N-oxide metabolite in the liver, but the hepatotoxicity is much lower when compared to that caused by Crotolaria.
• Pyrrolizidine Alkaloids / Hepatotoxic and Tumorigenic: Studies have indicated that pyrrolizidine alkaloids induce tumores via a genotoxic mechanism mediated by 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine(DHP)-derived DNA adduct formation.
• Ovicide and Larval Growth Inhibitor: In a study with test insects Drosophila melanogaster, an ovicide identified as coumarin and a larval growth inhibitor, a new sesquiterpene lactone called euponin, were isolated from leaf extracts.
• Antibacterial / Volatile Oils: Study of volatile oils showed significant antibacterial activities against Micrococcus tetragenus, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis.
• Osteoporosis Prevention: A previous study showed bioactive constituents can reciprocally regulate adipogenic and osteogenic fates of bone marrow cells. This study showed stems extracts suppressed lipid accumulation and inhibited the expression of adipocyte markers. Results showed bioactive anti-adipogenic and pro-osteogenic components in the stem extracts, suggesting a potential as a functional food and therapeutic alternative for preventing osteoporosis and bone fractures.
• Anti-Inflammatory / COX and iNOS Suppression / Flowers: Study investigated the ethanol extracts of flowers on nuclear factor (NF)-kB activation and expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) by TLR agonists in murine macrophages. Results showed EJE can regulate TLR signaling pathways and suggests a potential as anti-inflammatory drug.
• Safety Issues on Pyrrolizidine Alkaloids: PAs have been shown to cause toxic reactions in humans, particularly veno-occlusive disease, when ingested with food and herbal medicines (ex: comfrey). PAs are found primarily in three plant families: Asteraceae (Eupatorium and Ageratum), Boraginaceae, and Fabaceae. Peilan, a commonly used Chinese herb, contains Eupatorium fortunii and E. japonicum.

Extracts and supplements in the cybermarket.