IngredientsOxytropis falcata Bunge is a perennial herbaceous plant belonging to the family Leguminosae (Fabaceae), subfamily Papilionoideae. It is a perennial acaulescent herb of Oxytropis in the Leguminosae family. The genus Oxytropis encompasses over 300 species distributed throughout the temperate zones of Asia, Europe, and North America, with a particularly pronounced diversity noted in Central Asia.
The accepted scientific name is Oxytropis falcata Bunge, where the epithet "Bunge" denotes the botanist Alexander von Bunge, who first formally described the taxon. The Chinese name for O. falcata is Lian Xing Ji Dou, which refers to the whole grass of the leguminous plant Oxytropis falcata Bunge. Known as "Er-Da-Xia" in Tibetan medicines, it is a wild-growing plant mainly distributed in the Qinghai-Tibet Plateau at an altitude of 2,700–4,300 m in China. It is also referred to in Chinese literature as edaxia.
Morphological description: The plant is a 1–35 cm high perennial clustered herb, also known as edaxia, has viscosity and a special smell, and is mainly distributed in the western areas of China, such as Qinghai, Gansu, Tibet, and Sichuan. The root of O. falcata has a diameter of 6 mm, is straight and deep, dark red, and its stems are shortened, woody, and multibranched.
Geographical distribution: Oxytropis falcata Bunge, belonging to the Leguminosae family of perennial herbs, is widely distributed in the northwestern and southwestern regions of China, including Qinghai, Gansu, Tibet, Sichuan, and Xinjiang provinces.
Consistent with its status as a foundational herb in Tibetan formulary medicine, O. falcata is prepared in a variety of forms. The plant has been used as a folk remedy to treat inflammation, sores, and bleeding for thousands of years, and some traditional patented prescriptions containing this herb have also been launched into the market.
Modern pharmaceutical development has produced several dosage forms derived from the plant or its total flavonoid extracts:
O. falcata as a traditional Tibetan medicine has been used for approximately 2,000 years. It is recorded in Jingzhu Bencao and the Chinese Materia Medica, which describe its effects of clearing away heat and detoxification, healing sores, astringing the pulse to stop bleeding, and as a laxative. It is one of the three most commonly used anti-inflammatory drugs in Tibetan medicine.
Furthermore, O. falcata has excellent anti-inflammatory and analgesic effects, and it is one of the three major anti-inflammatory drugs in Tibetan medicine, known as "the king of herbs."
Traditionally used to clear heat, relieve toxicity, and reduce pain, it is mainly found in the northwestern region of Gansu. With a documented use spanning over 2,000 years, references to sickle-shaped Oxytropis appear in both the Jingzhu Bencao and the Chinese Materia Medica, where it is referred to as the "King of Herbs."
Within the framework of Tibetan and traditional Chinese medicine (TCM), O. falcata enters the lung and spleen meridian and has the function of clearing heat, detoxifying, and treating influenza, tonsillitis, carbuncle, gangrene, high fever, hematochezia, dysentery, and anthrax.
Topical application of the whole plant or its extracts to treat sores, wounds, and bleeding sites has been a core traditional practice. Oxytropis falcata has long been used to treat inflammation, sores, and bleeding in Tibet. Oxytropis falcata Bunge, designated as the "king of herbs," is a traditional Tibetan medicinal preparation employed for the purpose of wound hemostasis and anti-inflammation.
A total of 373 chemical constituents have been found from Oxytropis DC., including flavonoids, alkaloids, steroids, terpenoids, and others. Within O. falcata specifically, flavonoids represent the dominant and most pharmacologically investigated class of secondary metabolites.
O. falcata is rich in flavonoids, which are the main secondary metabolites and key bioactive components of this plant. Up to now, 91 flavonoids have been isolated from O. falcata, including isoflavones, flavones, flavanones, flavonols, homoisoflavonoids, chalcones, dihydrochalcones, chalcone dimers, and pterocarpans.
Subsequent analyses have extended this catalogue further. Notably, three new flavonoids, echinacoside A, echinacoside B, and (6aR,11aR)-3,8-dihydroxy-9,10-dimethoxypterocarpane, have been identified, and a total of 115 flavonoids have been isolated from both the aerial parts and roots, suggesting flavonoids are its dominant metabolites.
Key individual flavonoid constituents include:
Six new indole alkaloids, named oxytrofalcatins A–F, were isolated from Oxytropis falcata. These compounds did not show significant cytotoxic effects against certain tumor cell lines, marking the first identification of N-benzoylindole compounds in a natural source.
A critically important alkaloid present across many Oxytropis species is swainsonine. The genus Oxytropis is known as "locoweed" because of its toxic component swainsonine. Swainsonine inhibits lysosomal α-mannosidase and mannosidase II, resulting in altered oligosaccharide degradation and incomplete glycoprotein processing. The presence of swainsonine is central to safety considerations discussed below.
Previous phytochemical investigations on O. falcata have led to the isolation of a series of flavonoids, alkaloids, and triterpenoids, while flavonoids are the major class of chemical constituents. Polysaccharides have also been reported. A variety of chemical constituents were isolated and analysed from O. falcata, including flavonoids, alkaloids, polysaccharides, etc. References in the literature to 24-hydroxyoleanane-type triterpenes from the aerial parts and roots of O. falcata have also been reported.
The pharmacological actions of O. falcata are attributed primarily to its total flavonoid fraction (FOFB) and specific chalcone constituents. Multiple intracellular signalling pathways have been identified in preclinical studies.
The total flavonoids of O. falcata are proved to possess potent anti-inflammatory and analgesic activities in vivo, and 2′,4′-dihydroxychalcone, the main constituent of this plant, exhibits effective inhibitory activities against NO production in RAW 264.7 cells in vitro as well as anti-inflammatory activities in vivo.
In the context of metabolic inflammation, the flavonoids may reduce the production of inflammatory cytokines through downregulation of NF-κB expression in the inflammatory pathway and regulate the IRS-1-PI3-K-PKB/Akt insulin pathway, thereby increasing GLUT4 expression.
In models of atopic dermatitis, the action does not rely on broad immunosuppression or induce skin toxicity and may involve inhibition of proinflammatory cytokine release and downregulation of the HDAC3/NF-κB signalling pathway.
A total of 92 flavonoids reported in O. falcata targeted 213 potential MIRI-associated factors, including tumour necrosis factor (TNF), prostaglandin-endoperoxide synthase 2 (PTGS2), and the NF-κB signalling pathway. The in vitro assay on H9c2 cardiomyocytes subjected to hypoxia/reoxygenation injury confirmed that the flavonoids in OFF1 reduced myocardial marker levels, apoptotic rate, and the inflammatory response triggered by oxidative stress. Moreover, OFF1 attenuated MIRI by downregulating the ROS-mediated JNK/p38MAPK/NF-κB pathway.
Studies have shown that FOFB can reduce the expression of profibrosis factors such as type I and type III collagen, inhibit TGF-β1-induced human renal tubular epithelial cell proliferation, and slow down the progress of fibrosis. In the lung, the TGF-β1/Smad pathway has been identified as a key target, and the JAK/STAT axis has also been implicated.
The expressions of EGF and CD34 in OFG (25, 50 g/kg) treatment increased obviously from immunohistochemical assessment at 7 days. Serum EGF expression reached 321.27 ± 7.20 ng/mL by OFG treatment, while p38 and IL-1β levels were significantly lower than the model and vehicle groups from day 1 to day 7. The mechanism may be related to the increase in biosynthesis and the release of EGF and CD34 and the decrease in p38 and IL-1β levels.
Important caveat: The totality of published evidence for O. falcata consists almost entirely of in vitro cell-culture studies and in vivo animal studies (predominantly rodent models). As of the date of this article, no published randomised controlled human clinical trials specifically examining isolated O. falcata extract were identified in international peer-reviewed databases. The clinical evidence that does exist relates to multi-herb traditional formulas containing O. falcata as one ingredient. All evidence characterisations below reflect this limitation.
Evidence level: Preclinical (in vitro and in vivo animal data); very limited clinical evidence from multi-ingredient formulas.
The flavonoids in O. falcata have good anti-inflammatory and analgesic activities, which are comparable to those of a positive drug control (indomethacin). This comparison, however, is drawn from animal and in vitro models.
Studies have confirmed that FOFB has multiple pharmacologic actions, including antitumour activity, antioxidant effects, improvement of insulin resistance, protection against UV damage, enhancement of immune cofunction, anti-inflammatory effects, and analgesia. Among them, the anti-inflammatory effect is the most significant.
In terms of human clinical formula data, Ershiwuwei Ercha Gel was used to treat 32 cases of atopic dermatitis in young adults, with an effective rate of 96.9%. It could improve AD skin lesions, relieve itching, and other symptoms. Compared with hydrocortisone butyrate ointment, it had a low recurrence rate and fewer adverse reactions. This is an uncontrolled clinical observation involving a multi-ingredient formula, and results cannot be attributed solely to O. falcata.
Evidence level: Preclinical — in vitro cell models and rat models only.
Oxytropis falcata Bunge is a plant used in traditional Tibetan medicine, with reported anti-inflammatory and antioxidant effects and alleviation of myocardial ischaemia–reperfusion injury (MIRI). However, the underlying mechanism against MIRI and the phytochemical composition of O. falcata are vague.
A 2022 study published in Molecules (PMC8911915) used UHPLC-MS/MS profiling and network pharmacology to map flavonoid targets in MIRI. A total of 92 flavonoids reported in O. falcata targeted 213 potential MIRI-associated factors, including TNF, PTGS2, and the NF-κB signalling pathway. The in vitro assay on H9c2 cardiomyocytes subjected to hypoxia/reoxygenation injury confirmed that the flavonoids in OFF1 reduced myocardial marker levels, apoptotic rate, and the inflammatory response triggered by oxidative stress. Moreover, OFF1 attenuated MIRI by downregulating the ROS-mediated JNK/p38MAPK/NF-κB pathway. The study was conducted entirely in a cell model system; no animal or human data were presented for cardioprotection in this publication.
Oxytropis falcata is used as the main material to prepare various Tibetan traditional medicines whose activities were reported to include anti-inflammation and analgesia. Flavonoids are the chemical basis for the anti-inflammatory and anti-oxidant efficacy. The influence of total flavonoids of Tibetan herb O. falcata on myocardial ischaemic-reperfusion injury was investigated using ethanol, chloroform, and ethyl acetate extracts.
Evidence level: Preclinical — rodent bleomycin models only.
Two studies published in indexed journals (Journal of Ethnopharmacology 2022; Evidence-Based Complementary and Alternative Medicine 2020) investigated total flavonoids of O. falcata (FOFB) on bleomycin (BLM)-induced IPF in rats.
A study on the TGF-β1/Smad pathway (J Ethnopharmacol 2022, PMID 34826543) established an IPF model and administered FOFB. After successful modelling, FOFB or normal saline was administered once a day for 4 weeks. The results showed that a large number of blue collagen fibers were deposited in the lung interstitium, the alveolar wall was obviously thickened, and there was an alveolar fusion phenomenon in the model group. Treatment with FOFB at doses of 100, 200, and 400 mg/kg attenuated these changes.
A 2020 study on the JAK/STAT axis (PMC7474768) used the same bleomycin model. Rats model with IPF was established by one-off intratracheal injection of bleomycin (5 mg/kg). After 14 days, the same volume of low dose (100 mg/kg), medium dose (200 mg/kg), and high dose (400 mg/kg) of FOFB and prednisolone acetate (20 mg/kg) as positive control drugs, as well as normal saline, were orally administered to rats once a day for 28 consecutive days.
An earlier preclinical study assessed anti-fibrotic inflammatory markers. Middle or high dose of FOFB and the PAT (prednisone acetate) group could significantly decrease infiltration of inflammatory cells, degree of fibrosis, and expression of inflammatory cytokines levels. FOFB can attenuate BLM-induced IPF via inhibiting inflammatory response, reducing inflammatory infiltration, and improving the degree of fibrosis. These findings are restricted to animal models and have not been validated in human clinical trials.
Evidence level: Preclinical — streptozotocin-induced diabetic rat model only.
A 2017 study published in Evidence-Based Complementary and Alternative Medicine (PMC5385212) investigated the antihyperglycaemic mechanism of FOFB. STZ-induced T2DM rats (n = 35) were divided into 5 groups: model, low-, medium-, and high-dose total flavonoids, and pioglitazone groups. Ten healthy rats were used as controls. Serum insulin and inflammatory cytokines (MCP-1, TNF-α, and IL-6) levels were measured by ELISA.
The treatment of medium- and high-dose total flavonoids significantly reduced fasting plasma glucose (FPG) and two-hour postprandial plasma glucose (P2hPG) and enhanced insulin level in T2DM rats (P < 0.05). The proposed mechanism involved suppression of NF-κB-mediated inflammation and restoration of the IRS-1/PI3K/PKB (Akt)/GLUT4 insulin-signalling cascade. No human clinical data exist for this application.
Evidence level: Preclinical — rat model only.
A 2017 study published in Evidence-Based Complementary and Alternative Medicine (PMC5702923) evaluated OFG (an O. falcata gel preparation) on deep second-degree burn injury in Wistar rats. The study aimed at assessing the effect of Oxytropis falcata gel (OFG) on deep second-degree burn rats and exploring its mechanism. Wistar rats with second-degree burn were treated with OFG and silver sulfadiazine.
Rats treated with OFG (25, 50 g/kg) consisting of the major rhamnocitrin-3-O-β-neohesperidoside significantly accelerated incrustation (P < 0.001) and decrustation (P < 0.001). According to HE staining, edema and infiltration of inflammatory cells decreased apparently with good hyperplasia and incrustation in administration groups at day 7. The expressions of EGF and CD34 in OFG (25, 50 g/kg) treatment increased obviously from immunohistochemical assessment at 7 days. Serum EGF expression reached 321.27 ± 7.20 ng/mL by OFG treatment, while p38 (P < 0.05) and IL-1β (P < 0.05) levels were significantly lower than the model and vehicle groups from day 1 to day 7.
Evidence level: Preclinical — in vitro cytotoxicity data; some in vivo rodent tumour data; no human trials.
Oxytropis extracts have been reported to exhibit cytotoxic effects against a variety of human cancer cell lines. It is a kind of Chinese traditional herbal medicine with extensive pharmacological effects including anti-viral, anti-inflammatory, and anti-diarrhoeal as well as antitumour activities. In respect of the antitumour activity, Oxytropis extracts have been reported to exhibit cytotoxic effects against a variety of human cancer cell lines.
Oxyfadichalcone C is a novel chalcone dimer isolated from Oxytropis falcata and Oxytropis chiliophylla. Its anti-proliferative and anti-metastatic activity on human melanoma A375 cells in vitro has been investigated.
One compound showed potent cytotoxicity against human non-small cell lung cancer (A549), pancreatic cancer (Panc-28), and colon carcinoma (HCT-116) cells with GI50 values at 7.39, 25, and 19.17 µM, respectively; the other isolates showed no cytotoxicity against the above-tested cell lines with GI50 values > 50 µM. All antitumour data are in vitro or early-stage in vivo, and no clinical translation has been documented.
Evidence level: Preclinical in vitro studies only.
Experiments have shown the antibacterial activity of O. falcata on nine Gram-positive and Gram-negative bacteria. The flavonoids in O. falcata also exhibit antibacterial, antioxidant, antitumour, anti-cardiovascular disease, and haemostatic activities. Antibacterial testing in the cited literature is conducted in laboratory conditions and the clinical relevance remains unestablished.
Evidence level: Preclinical — rat model only.
A 2025 study (Frontiers in Microbiology, PMC12700028) investigated O. falcata Bunge in a rat HPH model. HPH was induced in male Sprague-Dawley rats exposed to chronic hypoxia. Animals were randomly assigned to normoxic control, hypoxic model, OFB-treated, or Rhodiola-treated groups. Serum metabolomics (LC-MS) and 16S rRNA sequencing of fecal microbiota were performed. Cardiopulmonary parameters including right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI) were assessed, and pulmonary arterial ultrastructure was examined.
OFB significantly attenuated HPH-induced elevations in RVSP and RVHI and mitigated pulmonary arterial remodelling. Metabolomic analysis identified 25 differentially regulated metabolites in HPH, primarily involved in pyrimidine metabolism, which were largely restored by OFB. OFB also reversed HPH-induced gut microbiota dysbiosis, restoring microbial diversity and composition toward normoxic levels. Given the ecological relevance of the Qinghai-Tibet Plateau altitude exposure to the traditional user population, this line of inquiry is noteworthy, though it remains entirely preclinical.
Evidence level: Preclinical (mouse model) for extract; very limited non-randomised clinical data for a multi-ingredient formula.
A 2025 study published in Frontiers in Pharmacology (PMC12222062) evaluated O. falcata extract combined with black soybean oil in a 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis mouse model. All treatments alleviated DNCB-induced atopic dermatitis symptoms, with the combination group showing the most significant improvement in epidermal thickness, mast cell infiltration, and dermatitis severity. The treatment groups also suppressed activation of the HDAC3/NF-κB signalling pathway.
Based on the available preclinical and limited clinical literature, O. falcata has been investigated in association with the following body systems:
Pharmacological actions of the genus Oxytropis DC. mainly include antitumour, antioxidation, anti-inflammatory, analgesic, antibacterial, antifibrosis, and other pharmacological actions; among them, the antitumour effect is particularly prominent.
All dosages below are exactly as reported in the cited preclinical studies in animals. No validated human dosing regimens have been established in published clinical trials for O. falcata extracts in isolation.
The most significant and well-documented safety concern with O. falcata and the broader Oxytropis genus is the presence of the indolizidine alkaloid swainsonine. Among the chemical components, swainsonine has antitumour activity. However, the genus Oxytropis DC. is known as "locoweed" because of its toxic component swainsonine.
The toxic component in locoweed has been identified as swainsonine, an indolizidine alkaloid. Swainsonine inhibits lysosomal α-mannosidase and mannosidase II, resulting in altered oligosaccharide degradation and incomplete glycoprotein processing.
Consumption of locoweeds by grazing animals can result in locoism, which is characterised by emaciation, staggering gait, lack of muscular coordination, reproductive disturbances, immune system impairment, and death.
Swainsonine toxicity caused by consumption of locoweed causes intention tremors, generalised depression, nervousness, proprioceptive deficits, aberrant behaviour, reproductive dysfunction, emaciation, and death. Additionally, locoweeds cause embryonic and fetal lethality, abortions, generalised reproductive dysfunction, and occasional birth defects.
Swainsonine, an indolizidine alkaloid, is the primary toxin in locoweeds. Swainsonine is an effective inhibitor of both lysosomal α-mannosidase and Golgi α-mannosidase II.
Research into the source of swainsonine has found a fungal endophyte origin. When these plants are infected by some fungi or endophytes, they will produce an alkaloid that is harmful to livestock. The indolizidine alkaloid swainsonine is the main toxic component of locoweeds, which specifically inhibits lysosomal α-mannosidase and Golgi mannosidase II in mammalian cells and disrupts the intracellular membrane system. There is sufficient evidence to show that endophytic fungi of locoweeds, Alternaria section Undifilum spp., including Alternaria oxytropis, are responsible for the biosynthesis of swainsonine.
Importantly, the toxicological dualism of Oxytropis species is well recognised. Swainsonine and dictamnine show antiproliferative, antimetastatic, and immunomodulatory actions in selected tumour models, but these same alkaloids also contribute to neurotoxicity and systemic toxicity at overlapping concentration ranges.
Extract of Oxytropis falcata treatment induced moderate liver damage and mild renal damage with maximum oral gavage dose for 15 days (subacute study). However, a separate study suggested that OFG (the gel formulation) had good absorption and no obvious skin toxicity. This finding indicates a route-of-administration-dependent safety profile, with oral intake at high doses carrying hepatic and renal risk, while topical application appears to have a more favourable local safety profile in rodent models.
Due to its outstanding therapeutic efficacy in anti-inflammatory and analgesic actions it is known as the "king of herbs." Some species of Oxytropis DC. can be used as animal feed and are rich in nutrients, but most species are toxic, causing cell vacuolar degeneration and damage to the nervous and reproductive systems of animals.
Although certain botanical specimens are classified as toxic to both animals and humans, their examination remains critical, as the phytochemical constituents responsible for their toxicity may also manifest considerable pharmacological activity when administered at regulated dosages.
The relationship between the therapeutic and toxic alkaloid load in processed medicinal preparations of O. falcata — particularly as used in traditional Tibetan formulas — has not been systematically characterised in accessible peer-reviewed literature in Western databases, and this represents a significant knowledge gap.
The scientific evidence base for Oxytropis falcata as a medicinal agent or dietary supplement rests almost exclusively on in vitro experiments and animal model studies. To date, O. falcata has not been reviewed comprehensively in terms of rigorous human clinical evidence. The anti-inflammatory and analgesic properties are the most robustly supported preclinically and are consistent with the herb's principal traditional applications. Emerging preclinical evidence in cardioprotection, anti-fibrosis, insulin sensitisation, wound healing, antitumour activity, and hypoxic pulmonary hypertension is promising but cannot be extrapolated to clinical practice in the absence of human pharmacokinetic data, dose-finding studies, and randomised controlled trials. The dual pharmacology of the genus — exhibiting both potent bioactivities and significant toxicity from swainsonine — makes careful standardisation of extracts and dose delimitation essential to any future translational development.
Health conditions that Oxytropis falcata may help support.
Body systems that Oxytropis falcata may help support.
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