Family • Betulaceae - Alnus japonica Steud. - JAPANESE ALNUS

Scientific names

Alnus japonica (Thunb.) Steud.
Alnus harinoki Siebold
Alnus reginosa Nakai
Betula japonica Thunb.

Common names

Arnus (If.)
Japanese alder (Engl.)
Japanese alnus (Engl.)

Other vernacular names

CHINESE: Ri ben qi mu.
JAPANESE: Han no ki.


Arnus is a small- to medium-sized deciduous tree growing to a height of 15 meters. Leaves are alternate, narrow-elliptic, acuminate, wedge-shaped at the base, up to 12 centimeters long, glossy and dark green above and pale underneath, the margins slightly toothed. Flowers are staminate, in long catkins; the pistillate flowers are in short catkins, becoming woody cones with 5-lobed scales.


– Indigenous to Korea.
– Grows in Baguio and other parts of the Mountain Province.
– Propagated by seed or grafting.

– Two diarylheptanoids, oregonin and hirsutanone were isolated by bioassay-guided fractionation of the methanol extracts of the leaves of Alnus japonica Steud and their structures were elucidated from their spectroscopic data. Compounds exhibited significant low-density lipoprotein (LDL)-antioxidant activities.

– Studies suggest hepatoprotective and antioxidant effects.

Parts used
Stem bark, leaves.

Additional Sources and Suggested Readings

(1) Cytotoxic activities of diarylheptanoids from Alnus japonica / Sun Eun Choi et al / Archives of Pharmacal Research • Volume 31, Number 10 / October, 2008 / DOI 10.1007/s12272-001-2108-z

(2) Alnus japonica / Plants For A Future

(3) Further investigation of the phenolic components

(4) Hepatoprotective and antioxidant effects of Alnus japonica extracts on acetaminophen-induced hepatotoxicity in rats / Sang Tae Kim et al / PTR. Phytotherapy research • 2004, vol. 18, no12, pp. 971-975

(5) Effects of Diarylheptanoids on the Tumor Necrosis Factor-α-Induced Expression of Adhesion Molecules in Human Umbilical Vein Endothelial Cells / Jong-Min Han et al / J. Agric. Food Chem., 2007, 55 (23), pp 9457–9464 / DOI: 10.1021/jf072157h

(6) Diarylheptanoid and Flavonoid with Antioxidant Activity from Alnus japonica Steud on DPPH Free Radical Scavenging Assay 

(7) Effect of 5- O-Methylhirsutanonol on Nuclear Factor-κB-Dependent Production of NO and Expression of iNOS in Lipopolysaccharide-Induced RAW264.7 Cells / Jon-Min Han et al / J. Agric. Food Chem., 2008, 56 (1), pp 92–98 / DOI: 10.1021/jf0721085

(8) Suppression of T cell activation by hirsutenone, isolated from the bark of Alnus japonica, and its therapeutic advantages for atopic dermatitis / Joo SS, Kim S G et al / Eur J Pharmacol. 2009 Jul 1;614(1-3):98-105. Epub 2009 May 3.

(9) An Anti-Influenza Component of the Bark of Alnus japonica / Nguyen Huu Tung, Hyuk-Joon Kwon, Jae-Hong Km, Jeong Chan Ra, Jeong Ah Kim, and Young Ho Kim / Archives of Pharmacal Research, March 2010, Volume 33, Issue 3, pp 363-367

(10) Oregonin from the bark of Alnus japonica restrained ischemia-reperfusion induced mesentery oxidative stress by inhibiting NADPH oxidase activation / Nguyen Huu Tung, Kai Sun, Jing-Yu Fan, Yukihiro Shoyama,* andJing-Yan Han* / DOI: 10.1111/micc.12147

(11) Diarylheptanoids from Alnus japonica Inhibit Papain-Like Protease of Severe Acute Respiratory Syndrome Coronavirus / Ji-Young Park, Hyung Jae Jeong, Jang Hoon Kim, Young Min Kim, Su-Jin Park, Doman Kim, Ki Hun Park, Woo Song Lee,* and Young Bae Ryu* / Biol. Pharm. Bull. 35(11) 2036–2042 (2012) Vol. 35, No. 11

(12) Effect of Alnus japonica extract on a model of atopic dermatitis in NC/Nga mice. / Journal of Ethnopharmacology, 2010

(13) Alnus japonica (Thunb.) Steud. / The Plant List

– No reported folkloric medicinal use in the Philippines.
– Popular folk medicine in Korea, used for cancer, gastric disorders, hepatitis and fatty liver.
– Various species of alder, including this species, seem to contain antitumor compounds.
Other uses
– Dye is obtained from the bark.
– Wood – close grained; used for turnery, charcoal.

Study Findings
• Hepatoprotective / Antioxidant: Alnus japonica showed antioxidant activity and hepatoprotective effects against acetaminophen-induced cytotoxicity in cultured hepatocytes in vitro.
• Cytotoxic / Diarylheptanoids: Study isolated 10 compounds from the bark of Alnus japonica. The diarylheptanoids showed potent cytotoxic activities against murine B16 melanoma cells and human SNU-C1 gastric cancer cell line.
• Anti-Influenza / Diarylheptanoids: Study isolated two rare acylated diarylheptanoids from the bark of A japonica – oregonoyl A and oregonoyl B, with nine known compounds. Platyphyllone, was strongly active, and platyphyllonol-5-xylopyranoside was moderately active on antiviral testing, compared with positive control, zanamivir.
• Anti-Atherosclerosis / Diarylheptanoids: Study isolated reported the inhibitory effects of two diarylheptanoids from the methanolic extracts of Alnus japonica leaves on the expression of adhesion molecules in human umbilical vein endothelial cells. Results suggest the compounds may be useful in prevention and treatment of atherosclerosis.
• Antioxidant: Study isolated naturally occurring bioactive compounds from AJ that showed significant radical-scavenging antioxidant activity in a concentration-dependent manner.
• Antioxidant / Anti-LDL Oxidation / Anti-Inflammatory: Study isolated 5-O-methylhirsutanonol (5-MH) from the leaves of A japonica which exhibited antioxidant activities on Cu2+ and AAPH-mediated LDL oxidation and well as macrophage-mediated LDL oxidation. 5-MH also suppressed the expression of inflammation-associated genes, such as tumor necrosis factor alpha, COX-2 and IL-1ß.
• Hirsutenone / Atopic Dermatitis: Study isolated hirsutenone from the bark of Alnus japonica. Results showed hirsutenone may specifically inhibit calcium-activated processes in both T cells and mast cells and presents a potential for a new topical drug for atopic dermatitis, probably through a calcineurin inhibitor-mimicking mechanism.
• Anti-Influenza Component / Bark: Study of bark isolated four lupane-type triterpenes (1-4) and one steroid. Compound 3, betulinic aldehyde, exhibited a particularly strong anti-influenza effect against KBNP-0028 relative to a positive control.
• Oregonin / I/R Induced Mesentery Oxidative Stress / Inhibition of NADPH Oxidase Activation/ Bark: Study suggests that ORG restrained I/R-induced ROS production might be correlated to its inhibitive effect on NADPH activation.
• Diarylheptanoids / Inhibition of Papain-Like Protease of SARS: The papain-like protease, which controls replication of the acute respiratory syndrome coronavirus is identified as the potential drug target for the treatment of SARS. Of the nine diarylheptanoids isolated from Alnus japonica, hirsutenone (compound 2) showed the most potent PL inhibitory effect.
• Atopic Dermatitis: Study evaluated the immunomodulatory effect of A. japonica in a model of atopic dermatitis in NC/Nga mice. Leaf and bark extract suppressed the development of AD-like skin lesions, with decrease in blood eosinophils and decrease in serum IgE and Th2-related cytokine levels. Results suggest the leaf and bark extract may prove useful in the treatment of atopic dermatitis and other allergic skin diseases.

Seeds in the cybemarket