Osha

Osha (Ligusticum porteri)

1. Identity and Botanical Description

Scientific name: Ligusticum porteri J.M. Coult. & Rose, a perennial herb belonging to the family Apiaceae (the carrot and parsley family). The species epithet porteri honors the botanist and Christian clergyman Thomas Conrad Porter (1822–1901).

Common names: Osha, Porter's lovage, Porter's licorice-root, Porter's wild lovage, loveroot, bear medicine, bear root, mountain lovage, Indian parsley, mountain ginseng, nipo, and chuchupate. It is also occasionally known as bear medicine, bear root, Colorado cough root, mountain lovage, wild parsley, and southern ligusticum. In New Mexico it is called chuchupate by Hispanic ranchers, a usage that extends as one of its Spanish names.

Morphology: Osha is an herbaceous perennial growing from 50 to 100 cm tall or more. In winter, the above-ground parts die back to a thick, woody, and very aromatic rootstock. The plant has deeply incised, elliptic or lance-shaped leaf segments that are 5 to 40 mm in width with larger basal leaves. The white flowers appear during late summer, are approximately 2 to 5 mm in diameter with five petals, and are grouped in flat-topped, compound umbels followed by reddish, oblong, ribbed fruits 5 to 8 mm in length.

Root characteristics: The root is dark brown and fibrous with a strong aromatic scent and a pungent, spicy flavor. Osha particularly resembles poison hemlock, but is easily distinguished from it by its "spicy celery" odor, hair-like material on root crowns, and dark chocolate-brown, wrinkled root skin.

Geographic range and habitat: Osha is a perennial herb found in parts of the Rocky Mountains and northern New Mexico, in the southwestern United States. It is strictly a mountain plant, most commonly found in deep, moist soils rich in organic material. The plant requires partial shade. Osha is widely distributed in the Rocky Mountains and the high mountains of northwestern New Mexico. It is most common in the upper limits of the subalpine zone — in the southern part of its range, it grows at elevations from 7,000 to 10,000 feet (2,100–3,000 m), while in Utah and Wyoming, it grows as low as 5,000 feet (1,500 m).

Relationship to other Ligusticum species: While 12 Ligusticum species exist, only Ligusticum porteri is deemed "true" osha. The related Ligusticum wallichii has been used for nearly 2,000 years in traditional Chinese medicine, and most of the scientific studies of osha were actually performed on the Asian species. Throughout the second part of the twentieth century, phthalides have been characterized from several plant families, mainly from the Umbelliferae (syn. Apiaceae) family, and major contributors include Ligusticum porteri (Hispanic name: Oshá).

2. Traditional and Historical Use

2.1 Indigenous North American Traditions

Oshá, bear root, or chuchupate was used by Native Americans to treat a variety of ailments, particularly those relating to the lungs and heart. Bear root has been a vital part of traditional practices among at least fifteen Native tribes, including the Apache, Pueblo, Navajo, Zuni, White Mountain Apache, Southern Ute, Lakota, and the Tarahumara in Mexico. These communities recognized bear root not only for its medicinal qualities but also as a sacred plant intertwined with their spiritual and cultural identities.

Apache, Navajo, and Zuni tribes prized osha root for respiratory support, using it to address coughs, colds, sore throats, and pneumonia. The root was chewed during healing ceremonies, made into teas for digestive complaints, or applied topically for wounds and snake bites.

The Zuni use an infusion of the root for body aches. The root is also chewed during curing ceremonies for various illnesses, and the crushed root and water used as a wash and taken for sore throat. The Rarámuri also use the root as herbal medicine.

Osha root plays a number of roles in traditional Western and Southwestern Indian cultures: it is used as a medicinal herb, as a ceremonial incense, and as an element in a medicine pouch or bundle. Many tribes associate osha plants with protection, healing, and good luck. The Yuki tribe and some Paiute bands believed that the osha plant repelled rattlesnakes and tucked pieces of osha root into their moccasins to guard against snakebite. To the Yuki, osha was known as "snake root" rather than "bear root."

In ceremony, pieces of the root are burned on the hot rocks during sweatlodge as part of Native American ceremonial smudging.

2.2 Hispanic New Mexican and Mexican Folk Traditions

Oshá also has a long history of use by Hispanics in New Mexico and the southwestern United States, and its significance in these cultures is highlighted by the fact that all locations containing the name "Oshá" are only found in New Mexico and in proximity to Hispanic communities.

Ligusticum porteri was occasionally used in very large amounts by Spanish New Mexicans as an abortifacient or emmenagogue. However, researchers George A. Conway and John C. Slocumb were unable to locate any person who reported successful use of this plant for this purpose.

2.3 Traditional Preparations

The root is traditionally harvested and prepared as a decoction, tincture, or infusion, and is administered orally or applied topically depending on the condition being treated. In many Native American traditions, osha was prepared as a decoction or chewed in small amounts within seasonal wellness practices and ceremony. When European colonists arrived in North America, osha was already being widely used by First Nations People in the American Southwest and Mexico to treat a variety of conditions, particularly those involving the upper respiratory and gastrointestinal tracts.

2.4 "Bear Root" Etymology and Zoopharmacognosy

Bear root and osha root are two common names for the same plant, Ligusticum porteri. The name "Bear Root" derives from traditional observations of bears digging and consuming the roots after hibernation. Ethnobotanical lore tells us that brown bears were observed digging up the roots after emerging from hibernation, eating the root to jumpstart their digestion and rubbing the chewed pulp over their fur to repel insects and parasites.

3. Key Phytochemical Constituents

3.1 Phthalides

The chemical constituents of the organic extracts from the rhizomes of Ligusticum porteri have been isolated, characterised, and identified as Z-ligustilide, Z-butylidenephthalide, diligustilide, tokinolide B, riligustilide, senkyunolides F and I, and ferulic acid, among other known compounds.

Thirty-one chemical constituents (more than 99.7% of the total content) have been identified in the essential oil, which is characterized by the presence of a high percentage of phthalides (44.61%) and sesquiterpenes (10.69%). Z-ligustilide and Z-6,6',7,3'-alpha-diligustilide are two of the major active phthalides of the medicinal plant Ligusticum porteri.

Quantitative analysis shows that the content of these two phthalides varies significantly among samples. All samples studied contained higher concentrations of Z-ligustilide (0.15–2.5%) than diligustilide (0.002–1.0%).

3.2 Additional Compound Classes

The constituents reported from the organic extract of L. porteri roots include phthalides, terpenoids, phenylpropanoids, and coumarins. These properties are mostly associated with the major compound of organic extracts, which is the (Z,Z')-diligustilide, a dimeric phthalide with high therapeutic potential.

Other isolated compounds include (Z)-6,6',7,3'α-diligustilide, (Z)-ligustilide, 3-(Z)-butylidenephthalide, myristicin, and ferulic acid.

4. Pharmacology and Proposed Mechanisms of Action

4.1 Sedative and Spasmolytic Activity

The sedative and spasmolytic activities of phthalides from L. porteri and their derivatives were evaluated using in vivo and in vitro models. Several of these dimeric phthalides displayed sedative and spasmolytic properties that may correlate with some popular uses of L. porteri.

4.2 Antimicrobial Activity

(Z)-ligustilide, a key constituent in Ligusticum species, has been shown to be antibacterial and antifungal in vitro. Test-tube studies show osha root extract to be particularly effective against numerous bacteria, including Staphylococcus aureus, E. coli, Enterococcus faecalis, and Bacillus cereus. Studies also tie the Z-ligustilide in osha root extract to potent antifungal properties, though human research is needed.

The essential oil (100 µg/mL) prepared from the roots increased the antimicrobial activity of antibiotic norfloxacin against the norfloxacin-resistant strain of Staphylococcus aureus.

4.3 Anti-inflammatory Activity

Z-ligustilide was reported to possess anti-inflammatory activity. Doses of 20 mg/kg/day of Z-ligustilide reduced pro-inflammatory cytokines.

4.4 Antinociceptive (Analgesic) Activity

The extracts, aqueous and organic, the essential oil, and major compounds (10–316 mg/kg) from L. porteri were evaluated as potential antinociceptive agents using the acetic acid-induced writhing and hot plate tests in ICR mice. All preparations tested exhibited significant antinociceptive effect in the two animal pain models selected. In vivo evidence supporting the use of L. porteri to treat painful conditions in folk medicine was thereby provided. These findings are limited to animal models; no human clinical trials on analgesic use have been published.

4.5 Gastroprotective Activity

The roots of Ligusticum porteri are used in Mexican traditional medicine for the treatment of gastrointestinal disorders. The dimeric phthalide (Z')-diligustilide found in their organic extracts is associated with the gastroprotective properties. The gastroprotective effect of a nanoemulsion of the volatile oil from the roots (at doses of 1, 3, 10, and 30 mg/kg) in an indomethacin-induced gastric damage model was tested, and nitric oxide (NO) and hydrogen sulfide (H₂S) gastric levels were also determined.

These results demonstrate that a nanoemulsion of the volatile oil from L. porteri (at 10 and 30 mg/kg) shows a significant gastroprotective effect (72% and 92%, respectively) against indomethacin-induced gastric damage. Again, these are animal (rat) studies; no human trials have replicated these findings.

4.6 Hypoglycemic Activity

An extract from the roots of Ligusticum porteri, orally administered to groups of normal and diabetic mice, showed significant hypoglycemic and antihyperglycemic effects. Experimental type-II diabetes mellitus was achieved by treating mice with streptozotocin. Compounds 1–3 showed antihyperglycemic activity, with 3-(Z)-butylidenephthalide being the most active. Compound 3 (56.2 mg/kg) decreased blood glucose levels in diabetic mice after an oral sucrose load, suggesting that its antihyperglycemic effect is due to inhibition of α-glucosidase at the intestinal level. The study provides scientific support for the use of L. porteri in Mexican folk medicine for the treatment of diabetes, though the evidence remains limited to animal models.

5. Scientific Evidence by Health Area

5.1 Respiratory Health

Osha root's most prominent traditional application is respiratory support. Its roots are currently wild-harvested by individuals and herbal product companies for sale and use in treating influenza, bronchitis, and sore throat. One of the key constituents, coumarin, is believed to exert bronchodilator and expectorant effects, making it particularly useful for respiratory conditions such as bronchitis, asthma, and congestion.

Evidence strength: Predominantly traditional and in vitro. Some people use osha for respiratory tract infections, skin infections, and viral infections such as herpes and HIV/AIDS, but there is no good scientific evidence to support these uses. No controlled human clinical trials specifically investigating osha root for respiratory outcomes have been published. Research on closely related Asian Ligusticum species suggests relevant mechanisms, but these findings cannot be directly extrapolated to L. porteri.

5.2 Antimicrobial and Antiviral Effects

Test-tube studies show osha root extract to be particularly effective against numerous bacteria, including Staphylococcus aureus, E. coli, Enterococcus faecalis, and Bacillus cereus. Studies also tie the Z-ligustilide in osha root extract to potent antifungal properties, though human research is needed.

Evidence strength: Preclinical (in vitro) only. Although osha has been used to treat some viral diseases such as hepatitis, no studies currently support the effectiveness of these applications. All antimicrobial data are from cell or test-tube assays.

5.3 Immunomodulation and Antioxidant Effects

Two closely related in vitro studies have examined osha's immune and antioxidant effects using human cells. The effects of the root extract at different doses on human peripheral blood lymphocytes (PBLs) were evaluated. The lymphocytes were incubated with different concentrations of the root extracts (0, 50, 100, 200, and 400 µg/mL) and harvested every 6 hours for 2 days. Treatments with L. porteri at 200 and 400 µg/mL increased the viability of PBLs. The deleterious effect of H₂O₂ was ameliorated by 400 µg/mL L. porteri treatment. The findings suggest that L. porteri might be a potential immune-modulating agent involving protective effects against oxidative damage.

A separate study published in Pharmacognosy Research (2017) examined osha root extract on human promyelocytic leukemia (HL-60) cells. The objective was to investigate the cytotoxicity, antioxidant, and immunomodulatory effects of L. porteri root extract on HL-60 cells and H₂O₂-induced oxidative damaged HL-60 cells. Cells were incubated with different concentrations of root extract, and cytokine levels (IFN-γ, IL-2, IL-10) and antioxidant indexes (MDA, GSH, SOD, CAT) were measured. The findings suggest that L. porteri root extract may be a potential antioxidant with protective effect against the oxidation of reduced glutathione (GSH), and treatment may be effective in preventing oxidative damage through increasing the activities of antioxidant enzymes (SOD and CAT) in acute promyelocytic leukemia cells. Notably, findings from that study may not support the use of L. porteri root extract as an antiproliferation and differentiation therapy for acute promyelocytic leukemia.

Evidence strength: These are in vitro studies using human cell lines, not controlled clinical trials. Results are preliminary and cannot be translated into clinical recommendations.

5.4 Gastrointestinal Effects

L. porteri enhances the immune system, stimulates appetite, and may improve gastrointestinal discomforts such as indigestion and stomach upset associated with vomiting, according to traditional accounts corroborated by initial laboratory work. As noted above, animal studies have demonstrated gastroprotective properties attributable to diligustilide. Evidence strength: Preclinical (animal) only; no human trial data exist.

5.5 Analgesic Effects

The roots and rhizomes of Ligusticum porteri are widely used in Mexican folk medicine for several purposes, including painful complaints. Animal studies using ICR mice demonstrated significant antinociceptive effects from aqueous extracts, organic extracts, essential oil, and major isolated compounds in the dose range 10–316 mg/kg. Evidence strength: Preclinical (animal) only.

5.6 Blood Glucose Regulation

In diabetic mouse models, L. porteri root extracts and isolated phthalides produced significant hypoglycemic and antihyperglycemic effects, with 3-(Z)-butylidenephthalide acting as an α-glucosidase inhibitor. Evidence strength: Preclinical (animal and in vitro) only; no human clinical evidence.

6. Body Systems Associated with Osha

• Respiratory system: Osha root is revered for its ability to support respiratory health, alleviate coughs and colds, relieve sore throats, and promote overall immune function.
• Immune system: Osha root exhibits antimicrobial properties, which may help combat bacterial and viral infections, further supporting immune health.
• Gastrointestinal system: The roots of Ligusticum porteri are used in Mexican traditional medicine for the treatment of gastrointestinal disorders, and the dimeric phthalide (Z')-diligustilide is associated with gastroprotective properties.
• Musculoskeletal / pain: Traditional use for body aches, corroborated by preclinical antinociceptive findings in animal models.
• Endocrine / metabolic: Preclinical evidence for blood-glucose-lowering effects via α-glucosidase inhibition by butylidenephthalide.
• Cardiovascular: Native American use included conditions relating to the heart; however, clinical evidence for cardiovascular applications is absent.

7. Dosage Forms

Osha root is sold in a variety of forms, including teas, tinctures, essential oils, and capsules. The root itself is available whole, either dried or fresh. Osha root may also be found as an ingredient in herbal tea blends.

Dosages reported in preclinical studies (not established for human use):

• Extracts and major compounds from L. porteri were evaluated at 10–316 mg/kg in mouse antinociceptive models.
• The gastroprotective effect of a nanoemulsion of volatile oil was tested in rats at doses of 1, 3, 10, and 30 mg/kg.
• In the α-glucosidase inhibition study, compound 3 (56.2 mg/kg) decreased blood glucose levels in diabetic mice after an oral sucrose load.
• In the human peripheral blood lymphocyte study, concentrations of 0, 50, 100, 200, and 400 µg/mL were tested in vitro.

Effective dosages in humans are unknown due to a lack of human research. There is not enough reliable information to know what an appropriate dose of osha might be for human use.

8. Safety Considerations

8.1 General Safety Profile

The Botanical Safety Handbook rates Ligusticum porteri as being in safety class 2B, meaning it should be avoided during pregnancy except under the supervision of a qualified healthcare practitioner. It has an interaction class of "A," suggesting that no clinically relevant adverse reactions are expected to occur under normal use. In general, this herb is considered well tolerated and safe for most individuals.

Although osha root is widely consumed as a decoction, there are reports that the chronic administration of hexane, ethyl acetate, and methanol extracts of osha root may produce toxicity. Slight effects of acute toxicity were observed in mice, whereas a weak LC₅₀ value (ranging from 436 to 778 µg/mL) was observed in the brine shrimp lethality assay. High doses of osha root taken over extended periods of time may cause kidney or liver toxicity.

8.2 Pregnancy and Lactation

It is considered unsafe to take osha when pregnant, as it might start menstruation and this might cause a miscarriage. Traditionally, osha root was used as an emmenagogue and abortifacient by communities from New Mexico. Osha has also been detected in the milk of lactating mothers, and should not be used by women who are pregnant or breastfeeding. There is no modern clinical research looking at the safety of osha root during pregnancy or lactation; based on traditional usage, this herb is not recommended during pregnancy.

8.3 Misidentification Risk

Few safety studies have been conducted on osha, and it is easily confused with poison hemlock and water hemlock. Because people typically harvest osha root from the wild, pickers may confuse the two plants. Accidental consumption of poisonous hemlock instead of osha root may cause hemlock poisoning, with symptoms including confusion, dilated pupils, rapid heartbeat, seizures, sweating, and vomiting.

8.4 Potential Drug Interactions

There is the theoretical danger that osha and related herbs may cause or worsen bleeding since they appear to be platelet aggregation inhibitors. No such cases involving oshá have been reported, but monitoring is warranted if these herbs are used in combination with vitamin K antagonist anticoagulant drugs.

8.5 Allergy and Family Cross-Reactivity

Individuals with known allergies to plants in the Apiaceae family (parsley, celery, carrots, fennel) should exercise extreme caution.

9. Conservation Status and Sustainability

Although osha is not yet classified as endangered, United Plant Savers (UpS) has placed it on the "At-Risk" list. It is doing well in some areas of its range and is alarmingly over-harvested in others.

Osha is not officially endangered nor threatened according to the USDA; therefore, there are no current state or federal laws in the United States regarding osha's conservation or plant population in the wild. This means osha is not tracked by any federal conservation agencies. Lack of regulation paired with osha's slow growth has led to over-harvesting, which has created a decline in osha's population.

There are no current state or federal laws in the U.S. regarding the conservation of Ligusticum porteri. This species has not yet been evaluated by the IUCN Red List, nor has it been listed in the CITES flora appendices for endangered species.

Osha is dependent on mycorrhizal fungi, and attempts to artificially cultivate the plant outside of its habitat have not been successful. Cultivation in areas where osha naturally grows has been more successful.

The entire plant is removed when the roots are harvested. Osha is considered to be slow-growing, and some estimates consider the plants to be over ten years old when harvested. The destructive collection of osha from slow-growing populations could lead to unsustainable harvesting.

Initial studies indicate that L. porteri may be able to withstand lower levels of root harvest by hand tools while maintaining stand integrity; however, further study is necessary to evaluate the long-term impacts of low-level root harvest.

The American Herbal Products Association (AHPA) reported increasing commercial demand and interest for osha root in their 2011–2017 Tonnage Survey, with a large contributor being commercial herbal supplement companies.

10. Summary of Evidence

The body of scientific literature specifically investigating Ligusticum porteri remains modest. The best-characterized pharmacological data come from in vitro cell studies and animal (mouse and rat) experiments conducted primarily by Mexican and U.S. research groups. These preclinical studies support plausible mechanisms for the plant's traditional uses — including antimicrobial, antinociceptive, spasmolytic, gastroprotective, antioxidative, and hypoglycemic activities — but no randomized controlled trials in humans have been published as of the time of writing. As summarized by WebMD's Natural Medicines database review, there is no good scientific evidence to support the specific clinical uses attributed to osha. Many pharmacological inferences are drawn from closely related Asian Ligusticum species, and these cannot be assumed equivalent. Modern evidence varies by preparation and study design, and more well-controlled human trials are needed.

References

• Wikipedia — Ligusticum porteri
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• Quantitative HPLC method for determining two of the major active phthalides from Ligusticum porteri roots. PubMed PMID 22468345
• Brindis F et al. (2011). (Z)-3-Butylidenephthalide from Ligusticum porteri, an α-glucosidase inhibitor. Journal of Natural Products. PubMed PMID 20879744
• Phthalides: Distribution in Nature, Chemical Reactivity, Synthesis, and Biological Activity. PubMed PMID 28160212
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• Gastroprotective Properties of Nanoemulsion of Ligusticum porteri Volatile Oil in Rats. Revista Brasileira de Farmacognosia. Springer
• Pharmacodynamic interaction of 3α-hydroxymasticadienonic acid and diligustilide against indomethacin-induced gastric damage in rats. PubMed PMID 30957263
• Nguyen K, Sparks J, Omoruyi F (2017). Effects of Ligusticum porteri (Osha) Root Extract on Human Promyelocytic Leukemia Cells. Pharmacognosy Research. PMC5424556
• Nguyen K, Sparks J, Omoruyi FO (2016). Investigation of the cytotoxicity, antioxidative and immune-modulatory effects of Ligusticum porteri (Osha) root extract on human peripheral blood lymphocytes. Journal of Integrative Medicine. ScienceDirect
• United Plant Savers — Osha (Ligusticum porteri) Species At-Risk Profile
• Medicinal Plant Fact Sheet: Ligusticum porteri / Osha — Pollinator.org / IUCN Medicinal Plant Specialist Group
• Oshá — Native Medicinal Plant Research Program, University of Kansas
• WebMD Natural Medicines — Osha monograph
• Healthline — Osha Root: Benefits, Uses, and Side Effects
• The Botanical Institute — Osha Root: 5 Key Benefits, Dosage, Safety
• Naturopathic Doctor News and Review — Ligusticum and Lomatium: Western Antivirals
• ResearchGate — Locally and traditionally used Ligusticum species: A review of their phytochemistry, pharmacology and pharmacokinetics
• Mountain Rose Herbs — Osha: A Supportive, but At-Risk Plant Ally