IngredientsKadsura japonica Dunal (also written Kadsura japonica (L.) Dunal) is the accepted botanical name for the plant commonly known as Japanese kadsura, Japanese kadsura vine, or kadsura vine. The species was one of many first described by Linnaeus in the 10th edition of his Systema Naturae in 1759, originally as Uvaria japonica. Homotypic synonyms include Schisandra japonica (L.) Baill., published in 1868. In Japan it is known as Sanekazura (サネカズラ), a name reflecting the plant's prominent berries. The Japanese name Binankazura translates literally to "Handsome Man Vine," referring historically to its use as a hair preparation.
The genus Kadsura is one of the three genera of the family Schisandraceae and contains 22 species. The species is native to Japan — specifically Honshū, Kyūshū, and the Ryukyu Islands — found in woodlands; it is also a cultivated, dioecious, ornamental plant in gardens, with edible fruits that can be eaten raw or cooked. It is also found in southern China, southern Korea, and eastern Asia more broadly. It occurs at elevations of 500–2,000 m in provinces of China including Fujian and Taiwan.
Morphologically, Kadsura japonica is an evergreen, climbing shrub with twining stems; it can grow up to 3.5 metres tall. It grows from 8 feet (2.4 m) to 15 feet (4.6 m), is evergreen with deep green, glossy leaves that turn slightly red in autumn, has very bright scarlet fruits, and bears white, unisexual flowers. The red to purple aggregate fruit is composed of around 34–40 apocarps, each 5–8 mm long and 5–8 mm wide, containing 1–3 seeds. K. japonica is notable for its dioecious reproductive system, featuring unisexual flowers on separate male and female plants.
Numerous phytochemical and pharmacognostic studies of Kadsura and Schisandra plants have demonstrated similarity in chemical taxonomy; the constituents from Schisandraceae plants mainly are volatiles, lignans, and triterpenoids. The drug derived from K. japonica is often used as a substitute for Schisandra chinensis (Turcz.) Baill. — the well-known five-flavour berry — reflecting the close botanical and chemical relationship between the two genera. The fruits of K. japonica have historically been designated as Fructus Kadsurae in traditional materia medica.
Parts of the plant that have been used medicinally and commercially include the dried fruits (Fructus Kadsurae), stems, roots, and bark. The dried fruits are the source of "Fructus Kadsurae." In traditional Kampo practice, the berries are first dried, then simmered until gooey, strained, and taken as a tea. A viscid material extracted from the fruit has been used as a hair dressing, and a viscid derivative of the bark has been used as a pomade for hair-dressing. A mucilaginous extract from the leaves has been used in traditional Japanese washi paper manufacture. Preparations used in research include ethyl acetate (EtOAc) extracts, methanolic extracts, and petroleum ether extracts of various plant parts.
In Japanese, the plant is known as Sanekazura; it is used in Kampo, the Japanese adaptation of traditional Chinese medicine, as a tonic to boost the immune system. The berries are first dried, then simmered until gooey, strained, and taken as a tea — a decoction said to relieve coughs and reduce excessive mucus production. In East Asian herbal medicine, a decoction of the dried fruits of Kadsura japonica is used as a bechic, stomachic, and tonic remedy, particularly for kidney diseases, cough, and asthma.
The drug is used in traditional medicine as a tonic, stimulant, antitussive, beneficial to kidneys and lungs, and is prescribed in cough and asthma. In East Asian folk medicine, including practices in Japan and Korea, K. japonica is utilized to address respiratory issues, such as drawing phlegm from the lungs and relieving coughs. Plants of the genus have been widely used as folk medicine for a long time in history, with the functions of relieving pain, promoting "qi" circulation, activating blood to resolve stasis, and treating rheumatoid arthritis and gastroenteric disorders.
The stem of Kadsura plants is mainly used for promoting blood circulation, relieving pain, and removing wind and dehumidifying. The plant is harvested from the wild for local use as a food, medicine, and source of mucilage.
In Japan, a viscid material extracted from the fruits is applied as a natural hair dressing, valued for its adhesive and conditioning properties. Historically, Japanese men used the mucilaginous sap extracted from the inner bark as a natural hair gel and tonic to style their hair into traditional arrangements — which is the origin of the name "Handsome Man Vine" (Binankazura). A mucilaginous extract from the leaves also contributes to the production of traditional Japanese washi paper, where the plant material aids in fiber processing and strengthening during manufacturing. Other documented uses include making fruit liquor and jam.
A large number of compounds have been isolated from the genus Kadsura, including lignans, triterpenoids, flavonoids, and sesquiterpenoids, with lignans and triterpenoids as the main chemical constituents. Lignans are the primary characteristic constituents with various biological activities of plants from genus Kadsura. This phytochemical profile is shared across the genus, and published studies on K. japonica specifically have confirmed the presence of all major classes.
Research has summarized 81 lignans isolated from plants of genus Kadsura, which belong to five types: dibenzocyclooctadienes, spirobenzofuranoid dibenzocyclooctadienes, aryltetralins, diarylbutanes, and tetrahydrofurans. The dibenzocyclooctadiene class is the largest and most pharmacologically investigated group in the genus.
Phytochemical studies specific to K. japonica have yielded important lignan identifications. Three new dibenzocyclooctadiene lignans — acetyl-, angeloyl-, and caproylbinankadsurin A — were isolated from the fruits of Kadsura japonica in work published in 1981 by Ookawa, Ikeya, Taguchi, and Yosioka, representing some of the earliest systematic chemical characterisation of the species. Two new dibenzocyclooctadiene lignans, angeloylbinankadsurin B and acetylbinankadsurin B, along with a known lignan, deangeloylschisantherin F, were isolated from the fruits of Kadsura japonica, with their structures determined on the basis of chemical and spectral studies.
Bioassay-directed fractionation of the EtOAc extract of Kadsura japonica has led to the isolation of six new C18 dibenzocyclooctadiene lignans — schizanrins I, J, K, L, M, N — along with four known C19 homolignans, taiwanschirins A, B, C, and heteroclitin F. Additional lignans identified across the genus and found in or closely associated with K. japonica include kadsurarin, binankadsurin A, schizandrin, kadsuralignan I, kadsuralignan J, schisantherin F, acetylgomisin R, and various spirobenzofuranoid compounds.
Triterpenoids isolated from the stems of Kadsura japonica have been documented to exhibit potent antiviral activity; four undescribed schitriterpenoids named kadsujanonols J–M, along with five previously reported compounds — schincarin D, ananosin E, changnanic acid, longipedlactone A, and schiglansin S — were isolated and identified.
Twenty 3,4-seco-triterpenoids, including nine new ones, were isolated from the methanolic extract of Kadsura japonica L. vines and characterized by 1D- and 2D-NMR, HRESIMS, CD, single-crystal X-ray diffraction, and computational analysis. These belong to the schitriterpenoid skeletal class — a structurally distinctive group characteristic of the Schisandraceae family. Schitriterpenoids such as kadsujanonols A–I, schincarin D, changnanic acid, and longipedlactone A have been isolated specifically from K. japonica.
Beyond lignans and triterpenoids, Schisandraceae plants in general, including K. japonica, contain volatile components and sesquiterpenoids. The fruits are edible and can be consumed raw or cooked, offering a mild flavor, though they are small, typically measuring up to 6 mm in length. The mucilaginous polysaccharide-rich material in the bark and stems is another notable class of compounds, exploited in traditional topical and paper-making applications.
All isolates from K. japonica vines were evaluated for anti-neuroinflammatory activity on LPS-stimulated NO production in BV2 microglial cells; compounds 2, 4, 5, 7, 9, 11, 13–16, and 18 exposed better or comparable suppression abilities than the positive control PDTC, and kadlongilactone B showed the most significant inhibiting ability (IC50 = 0.87 μg/mL) through the attenuation of the inflammatory transcription factor p65NF-κB. The NF-κB pathway is a central mediator of inflammatory gene expression, and its inhibition represents a mechanistically plausible anti-inflammatory route for these triterpenoid constituents.
In the broader genus, the in vitro anti-inflammatory assay of lignans longipedunculatin A, longipedlignan M, and longipedlignan J showed significant inhibitory effects with inhibition rates of 55.1%, 74.9%, and 89.8%, respectively. Lignans and triterpenoids are the main bioactive constituents, exhibiting anti-HIV, anti-tumor, anti-hepatitis, anti-oxidant, and anti-platelet aggregation activities and neuroprotective effects.
The antihepatotoxic effects of twenty-three lignans — including one from the fruits of Kadsura japonica — were investigated using carbon tetrachloride (CCl4)- and galactosamine (GalN)-induced cytotoxicity in primary cultured rat hepatocytes as model systems; prominent protective actions were found with several compounds, and structure-activity relationship analysis suggests that the methylenedioxy group of the dibenzocyclooctane skeleton may play an important role in antihepatotoxic activity.
Acetylepigomisin R, isovaleroylbinankadsurin A, and binankadsurin A isolated from Kadsura coccinea have the effect of protecting rat liver injury caused by tert-butyl hydrogen peroxide, with ED50 values of 135.7, 26.1, and 79.3 mol/L, respectively. Because binankadsurin A is also a known constituent of K. japonica, this mechanistic finding has relevance to the species.
Among 982 extracts of a screening library, nine originated from three different Schisandraceae species — Kadsura longipedunculata, Kadsura japonica, and Schisandra chinensis — and petroleum ether extracts of K. longipedunculata and K. japonica showed promising GABAA receptor activity. The phytochemical profile of petroleum ether extracts of Kadsura japonica fruits showed 114.1 ± 2.6% potentiation of I(GABA) at 100 μg/mL (n=2), while Schisandra chinensis fruits were inactive at 100 μg/mL. GABAA receptor potentiation is the mechanism underlying sedative, anxiolytic, and anticonvulsant pharmacological effects in many botanical preparations. The specific constituents of K. japonica responsible for this activity were not fully isolated in the reported study.
The schitriterpenoids from K. japonica were subjected to antiviral examination against collected H1N1 influenza viruses; several showed antiviral activity, with changnanic acid in particular unveiling excellent anti-H1N1 activity compared to Tamiflu. The mechanism of anti-HBV activity of dibenzocyclooctadiene lignans involves inhibition of viral antigen secretion, as demonstrated in cell-based assays measuring HBsAg and HBeAg levels.
Evidence level: Preclinical (in vitro); no published human clinical trials.
The most directly species-specific pharmacological research on K. japonica concerns hepatitis B virus (HBV) antigen inhibition. Bioassay-directed fractionation of the EtOAc extract of Kadsura japonica led to the isolation of six new C18 dibenzocyclooctadiene lignans (schizanrins I–N) and four known C19 homolignans; bioassay evaluation against human type B hepatitis revealed that taiwanschirins A and B showed strong activity for anti-HBsAg and a medium effect for anti-HBeAg at 25 μg/mL (12.9 and 11.9 μM for taiwanschirins A and B, respectively). This in vitro study, published in Planta Medica in 2005, used cell-based assay systems and did not evaluate human subjects.
Separately, the antihepatotoxic effects of a lignan from the fruits of Kadsura japonica (together with 22 from Schizandra chinensis) were investigated utilizing CCl4- and galactosamine-induced cytotoxicity in primary cultured rat hepatocytes. This represents preclinical (in vitro) evidence. No clinical trials on K. japonica for liver protection have been identified in the peer-reviewed literature.
Evidence level: Preclinical in vitro; no human clinical trials.
Twenty 3,4-seco-triterpenoids, including nine new ones, were isolated from the methanolic extract of Kadsura japonica L. vines. All isolated triterpenoids were evaluated for anti-neuroinflammatory activity on LPS-stimulated iNOS-dependent NO production in BV2 microglial cells; kadlongilactone B exhibited the most significant inhibiting ability (IC50 = 0.87 μg/mL) through the attenuation of the inflammatory transcription factor p65NF-κB. This 2023 study, published in Bioorganic Chemistry, used BV2 murine microglial cell lines stimulated with bacterial lipopolysaccharide, a standard in vitro neuroinflammation model. It is not a human or animal study, and the findings do not confirm clinical efficacy for any neurological condition in humans.
Evidence level: Preclinical in vitro; no human clinical trials.
Triterpenoids isolated from the stems of Kadsura japonica L. exhibit potent antiviral activity against collected influenza viruses; four undescribed schitriterpenoids named kadsujanonols J–M along with five previously reported compounds were isolated and identified. Changnanic acid in particular unveiled excellent anti-H1N1 activity compared to Tamiflu in these in vitro assays. As with the hepatoprotective data, no clinical trials in humans have been published.
Evidence level: Preliminary in vitro screening; no human clinical trials.
It has been reported that K. japonica has anti-hepatitis activity and GABAA receptor modulatory activity. The phytochemical profiles of petroleum ether extracts of Kadsura japonica fruits showed 114.1 ± 2.6% potentiation of I(GABA) at 100 μg/mL in a Xenopus oocyte expression system. This finding is from a screening study and has not been followed by clinical investigations.
Evidence level: Traditional use only; no controlled clinical trials identified.
The drug is used in traditional medicine as a tonic, stimulant, antitussive, beneficial to kidneys and lungs, and is prescribed in cough and asthma. In East Asian folk medicine, including practices in Japan and Korea, K. japonica is utilized to address respiratory issues, such as drawing phlegm from the lungs and relieving coughs. No controlled clinical study has evaluated K. japonica preparations for respiratory indications in humans.
Evidence level: Genus-level in vitro data only; no K. japonica-specific or clinical data.
Previous pharmacological studies have shown that lignans of the genus Kadsura have antitumor, anti-inflammatory, antibacterial, anti-HIV, anti-platelet aggregation, immunomodulatory, and antioxidant effects. Anti-platelet aggregation activity has been attributed to dibenzocyclooctadiene lignans in the genus broadly, but no studies specifically examining K. japonica extracts for cardiovascular endpoints have been identified.
Evidence level: In vitro cell-line data at the genus level; no K. japonica-specific clinical evidence.
Heilaohulignan C from Kadsura coccinea showed good cytotoxicity in HepG-2 human liver cancer cells with IC50 values of 9.92 µM. Interiorin A and interiorin B isolated from Kadsura heteroclita showed anti-HIV activity with EC50 of 1.6 and 1.4 μg/mL respectively. These data, while pertaining to related species and shared compound classes, cannot be directly extrapolated to K. japonica or to clinical outcomes in humans.
No standardized dosage has been established for K. japonica preparations by any major regulatory authority or pharmacopoeia. The following reflect dosages reported in the scientific literature:
No human clinical trial has established a therapeutic dosage for any preparation of K. japonica. Traditional preparations such as decoctions do not have standardized concentrations in the published literature.
The overall evidence base for Kadsura japonica as a medicinal agent is preliminary and preclinical. The research to date consists exclusively of:
There is a lack of robust modern scientific research validating these traditional uses. While the chemical profile is rich and the in vitro findings are promising in several areas — particularly HBV antigen inhibition, NF-κB-mediated anti-neuroinflammation, and GABAA receptor modulation — none of these findings has advanced to human trials for K. japonica specifically.
Formal human safety or toxicology data specific to Kadsura japonica have not been published in the peer-reviewed scientific literature identified in this review. The following represents what can be ascertained from the available sources:
Health conditions that Japanese kadsura may help support.
Body systems that Japanese kadsura may help support.
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