Pacific Yew ☠️

What Is Pacific Yew?

Pacific yew is a slow-growing evergreen tree of the Pacific Northwest understorey, with flat dark needles and, on female trees, single seeds held in bright red fleshy cups called arils ^{16,17Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

It grows in the shade of larger conifers from southeast Alaska to central California and inland to the northern Rocky Mountains ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}. Its hard, elastic wood was prized for bows and tools by the peoples of the Northwest Coast ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

Yews contain taxine alkaloids, which are cardiotoxic and give the genus its reputation as a poison ^{1Reference 1Wilson CR et al. · 2001ReviewTaxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids — reviewView study →}. Pacific yew bark is also where paclitaxel was first found, a molecule that stabilises microtubules and became a major chemotherapy drug ^{3,15Reference 3Wani MC et al. · 1971Plant antitumor agents VI: the isolation and structure of taxol, a novel antileukaemic and antitumour agent from Taxus brevifoliaView study →Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}. The poison and the drug are different molecules.

The yews most often behind human poisonings are the ornamental English and Japanese yews, which are planted widely in gardens and hedges ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

Identification & Lookalikes

Yew is not usually mistaken for an edible plant. The usual exposure is a child eating the conspicuous red arils.

In yews, the foliage, bark and seeds are toxic, but the fleshy red aril is not ^{8,16Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

Part	Status
Aril flesh (the red fleshy cup)	Non-toxic
Seed inside the aril	Toxic
Needles	Toxic — with bark and stems the main hazardous parts
Bark and stems	Toxic

A swallowed aril whose seed passes intact is therefore a very different event from a chewed seed.

Recognising the tree. Pacific yew has flat needles that usually look two-ranked along the twig. They are shiny yellow-green above and paler beneath, and soft-pointed rather than sharp to the touch ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}. The bark is thin and scaly, with purplish outer scales over reddish inner ones ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}. The tree bears no seed cones; each seed sits in a red aril instead ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

Botany

Pacific yew (Taxus brevifolia Nutt.) is a conifer in the Taxaceae. Male and female cones grow on separate plants ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

It is a shrub or small tree, commonly 6–12 m tall at maturity ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}. The Flora of North America gives a maximum of 15 m, occasionally 25 m, with a trunk up to 60 cm across, occasionally 120 cm ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}. The trunk may be straight or contorted, and is often fluted ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

The bark is scaly. Its outer scales are purplish to purplish brown, and the inner scales are reddish to reddish purple ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

The needles are 1–2.9 cm long and usually slightly curved. They are shiny yellow-green above and pale green beneath, with two broad pale bands of pores on the underside ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

The seed is ovoid, 5–6.5 mm long, and ripens from late summer into autumn ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}. It sits in a soft, scarlet, cup-shaped aril that is open at the tip and leaves the hard seed coat exposed ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

Pacific yew grows very slowly. It is the most shade-tolerant tree in the Pacific Northwest ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

Distribution

Pacific yew grows along the Pacific Coast from southeastern Alaska through western British Columbia to central California ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}. Inland, it grows from southeastern British Columbia through northwestern Montana and northern Idaho into eastern Washington and Oregon, and it reaches Alberta ^{16,17Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

It grows in cool, moist, shaded places: open to dense forest, streamsides, moist flats, slopes, deep ravines and coves, from sea level to 2,200 m ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}. It is commonly found beneath western hemlock, Douglas-fir and Pacific silver fir ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

It is usually a scattered understorey tree. In parts of northern Idaho it forms dense, shrubby stands, which dominate about 16,000 ha of the South Fork of the Clearwater drainage ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

The IUCN assesses Pacific yew as Near Threatened ^{18Reference 18Thomas P · 2013Taxus brevifoliaView study →}. Its population is estimated to have fallen by 10–30% over the last three generations, and a generation is likely to exceed 30 years ^{18Reference 18Thomas P · 2013Taxus brevifoliaView study →}. The decline came from logging and from bark harvesting for paclitaxel production in the 1980s and 1990s ^{18Reference 18Thomas P · 2013Taxus brevifoliaView study →}.

Pacific yew recovers slowly after disturbance. Broadcast burning after clearcutting has virtually eliminated it in some areas, and after one hot slash burn in northern Idaho, seedlings did not appear for at least six years ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}. Large trees are also poached for their wood, and in some areas the species has been nearly extirpated ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

Since the development of other sources of paclitaxel, the rate of decline has slowed ^{18Reference 18Thomas P · 2013Taxus brevifoliaView study →}. The drug is now made from needles of cultivated yews and from cell cultures, rather than from wild bark ^{15Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}. There is no herbal product to source.

Phytochemistry

Yews carry two separate groups of compounds.

The taxine alkaloids are the poison. They are diterpenoid pseudoalkaloids built on a 6/8/6 tricyclic taxane skeleton. The two principal members are taxine A and taxine B. In English yew, taxine B makes up about 30% of the alkaloid fraction and is the more cardiotoxic; taxine A makes up about 1.8% ^{14Reference 14Pinto A et al. · 2021Case reportTaxus baccata intoxication: the sun after the electrical storm — case reportView study →}.

An early analysis did not find taxine in Pacific yew, and poisoning by Pacific yew has not been conclusively recorded ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}. The English and Japanese yews are the best documented for toxicity ^{16Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}.

Paclitaxel is a taxane diterpenoid found in the bark in small amounts ^{15Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}. It works in an entirely different way, by stabilising microtubules and stopping cell division ^{4,5Reference 4Schiff PB et al. · 1979In vitroPromotion of microtubule assembly in vitro by taxol — in vitroView study →Reference 5Schiff PB · 1980In vitroTaxol stabilizes microtubules in mouse fibroblast cells — in vitroView study →}. 10-Deacetylbaccatin III is a related taxane obtained from yew needles, and is the starting material for making paclitaxel ^{10,15Reference 10Kou P et al. · 2024An integrated strategy based on 10-DAB extraction and in-situ whole-cell biotransformation of renewable Taxus needles to produce baccatin III — bioprocessView study →Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}.

Constituent Summary

Taxine figures are from English yew.

Toxicology

Class of poison. Diterpenoid pseudoalkaloid; a blocker of sodium and calcium channels in the heart.

Mechanism. Taxine blocks both the sodium current and the calcium current in heart muscle cells. In isolated guinea-pig heart cells, taxine from English yew reduced both currents in a dose-dependent way. At the highest concentration, the index of sodium current fell to about 9% of control ^{12Reference 12Tekol Y · 1987In vitroElectrophysiology of the mechanisms of action of the yew toxin, taxine, on the heart — in vitro electrophysiology (isolated guinea-pig ventricular myocytes)View study →}. Clinically this appears as widening QRS, bradycardia or wide-complex tachycardia, hypotension, cardiogenic shock and arrest.

Course. Early symptoms are nausea, vomiting, dizziness and abdominal pain, sometimes with seizure ^{1,8Reference 1Wilson CR et al. · 2001ReviewTaxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids — reviewView study →Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}. They usually begin 30 minutes to 1.5 hours after eating the plant, and death, when it occurs, usually follows between 1.5 and 24 hours ^{19Reference 19Nižnanský Ľ et al. · 2022ReviewNatural taxanes: from plant composition to human pharmacology and toxicity — reviewView study →}.

The early signs are mild and easily dismissed. Cardiac deterioration can then be abrupt and refractory ^{1Reference 1Wilson CR et al. · 2001ReviewTaxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids — reviewView study →}.

How often serious harm happens. US poison centres recorded 11,197 Taxus exposures between 1985 and 1994, and 96.4% involved children under 12 ^{2Reference 2Krenzelok EP et al. · 1998Case reportIs the yew really poisonous to you? — poison-centre case seriesView study →}. Of the 7,269 with a recorded outcome, 92.5% had no effect and 7.0% had minor effects. Thirty had moderate effects, four had major effects, and none died ^{2Reference 2Krenzelok EP et al. · 1998Case reportIs the yew really poisonous to you? — poison-centre case seriesView study →}.

Serious and fatal cases in the medical literature are mostly intentional ingestions of leaves and branches of ornamental yew ^{8,19Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →Reference 19Nižnanský Ľ et al. · 2022ReviewNatural taxanes: from plant composition to human pharmacology and toxicity — reviewView study →}.

Lethal dose. The lethal oral dose of yew leaves has been estimated at 0.6–1.3 g per kg of body weight ^{1,8Reference 1Wilson CR et al. · 2001ReviewTaxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids — reviewView study →Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}. For an adult, the lethal dose is reported as about 50 g of needles ^{14Reference 14Pinto A et al. · 2021Case reportTaxus baccata intoxication: the sun after the electrical storm — case reportView study →}. Both are estimates; no human lethal dose has been measured experimentally.

Antidote — none proven. There is no validated antidote, and supportive care is the mainstay ^{8Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}. Case reports describe sodium bicarbonate, digoxin-specific antibody fragments, lipid emulsion and albumin dialysis ^{8Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}. Atropine works poorly against the bradycardia ^{19Reference 19Nižnanský Ľ et al. · 2022ReviewNatural taxanes: from plant composition to human pharmacology and toxicity — reviewView study →}. Defibrillation and overdrive pacing have repeatedly failed against taxine arrhythmias ^{8Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}. Haemodialysis is unlikely to remove the taxines, because they are large, widely distributed and bound to protein ^{19Reference 19Nižnanský Ľ et al. · 2022ReviewNatural taxanes: from plant composition to human pharmacology and toxicity — reviewView study →}.

Circulatory support. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has rescued patients in yew-induced cardiogenic shock. It supports the circulation until the toxin clears. A 39-year-old man made a full neurological recovery this way, and the authors counted several similar published cases ^{8Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}.

Traditional & Historical Use

Native American Medicine and Technology

Pacific yew wood is fine-grained, heavy, hard and very strong ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}. Native Americans made harpoons, spear handles, eating utensils, wedges, paddles, and clubs used in battle and for hunting seals from it ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

It was renowned for bows. The Salish called it “bow plant”, and its bows tended to be broad, short and flat ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

Tonics made from Pacific yew were used medicinally by many peoples of the Pacific Northwest ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}. The fleshy arils were sometimes eaten, although the seeds are poisonous ^{17Reference 17Tirmenstein DA · 1990Taxus brevifolia, Pacific yewView study →}.

European History: English Yew

English yew (Taxus baccata) has been known as a poison since antiquity ^{8Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}. Julius Caesar records that Catuvolcus, king of half of the Eburones, too old to endure war or flight, killed himself with the juice of the yew tree, “of which there is a great abundance in Gaul and Germany” ^{20Reference 20Caesar GJ et al. · 1869Perseus Digital Library. https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0001:book=6:chapter=31View study →}.

The Drugs Derived From It

⚠⚠ Everything in this section is about intravenous cytotoxic chemotherapy, and none of it transfers to the plant. No preparation of yew delivers paclitaxel without taxine.

The discovery. Paclitaxel was found during a National Cancer Institute screening programme in the 1960s ^{15Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}. Wani, Taylor, Wall, Coggon and McPhail reported the isolation and structure of taxol from Pacific yew in 1971 ^{3Reference 3Wani MC et al. · 1971Plant antitumor agents VI: the isolation and structure of taxol, a novel antileukaemic and antitumour agent from Taxus brevifoliaView study →}.

The mechanism. Earlier antimitotics, such as the vinca alkaloids and colchicine, work by blocking microtubule assembly. Paclitaxel does the opposite: it promotes microtubule assembly and stabilises microtubules against breakdown, which stops cell division. This was first shown in a cell-free assembly assay in 1979 ^{4Reference 4Schiff PB et al. · 1979In vitroPromotion of microtubule assembly in vitro by taxol — in vitroView study →}, and then in intact mouse fibroblasts in 1980 ^{5Reference 5Schiff PB · 1980In vitroTaxol stabilizes microtubules in mouse fibroblast cells — in vitroView study →}.

The clinical record belongs to the molecule. In the Gynecologic Oncology Group’s GOG-111 randomised trial (n = 410), cisplatin plus paclitaxel was compared with cisplatin plus cyclophosphamide in advanced ovarian cancer. Response was 73% against 60%, median progression-free survival 18 months against 13, and median overall survival 38 months against 24 (P<0.001) ^{6Reference 6McGuire WP et al. · 1996RCTCyclophosphamide and cisplatin compared with paclitaxel and cisplatin in patients with stage III and stage IV ovarian cancer (GOG-111) — randomised controlled trialView study →}.

The larger ICON3 trial (n = 2,074) compared paclitaxel plus carboplatin with carboplatin alone or a cyclophosphamide–doxorubicin–cisplatin regimen. It found no difference in overall survival: hazard ratio 0.98 (95% CI 0.87–1.10), P = 0.74 ^{7Reference 7International Collaborative Ovarian Neop · 2002RCTPaclitaxel plus carboplatin versus standard chemotherapy in women with ovarian cancer — randomised controlled trialView study →}. The two trials used different comparators.

Paclitaxel and its semisynthetic relative docetaxel are now used against several cancers ^{15Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}.

Immune activity. In mouse macrophages, paclitaxel mimics bacterial lipopolysaccharide, activating TLR4 and MyD88 signalling and the release of inflammatory signals ^{9Reference 9Byrd-Leifer CA et al. · 2001In vitroThe role of MyD88 and TLR4 in the LPS-mimetic activity of Taxol — in vitro and mouse macrophageView study →}. This effect is unrelated to its action on cell division.

The supply problem. Paclitaxel occurs only in small amounts in the bark, and about 1 g could be isolated from the bark of three trees ^{15Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}. Harvesting the bark kills the tree. Supply was secured by semisynthesis from 10-deacetylbaccatin III, which is extracted from yew needles that the tree regrows ^{10,15Reference 10Kou P et al. · 2024An integrated strategy based on 10-DAB extraction and in-situ whole-cell biotransformation of renewable Taxus needles to produce baccatin III — bioprocessView study →Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}, and by plant cell culture ^{15Reference 15Christensen SB · 2022ReviewDrugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — reviewView study →}. The story is told in our piece on medicinal plant conservation.

An endophytic fungus. Taxomyces andreanae, a fungus isolated from the inner bark of Pacific yew, produced taxol and related compounds in culture ^{11Reference 11Stierle A et al. · 1993In vitroTaxol and taxane production by Taxomyces andreanae, an endophytic fungus of Pacific yew — in vitroView study →}. It did not become a production route.

Safety & Pregnancy

Full Safety Detail

Why most exposures are harmless. Almost all exposures involve young children ^{2Reference 2Krenzelok EP et al. · 1998Case reportIs the yew really poisonous to you? — poison-centre case seriesView study →}. The aril flesh is not toxic ^{8,16Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →Reference 16Hils MH · 1993Taxus brevifolia Nuttall, and genus TaxusView study →}, and a seed swallowed whole is a very different event from a chewed one. Severe cases mostly come from leaves and branches eaten deliberately ^{8Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →}.

A child who has swallowed an aril. Whether the seed was chewed is the detail that matters. In the US series, gut decontamination made no difference to the outcome ^{2Reference 2Krenzelok EP et al. · 1998Case reportIs the yew really poisonous to you? — poison-centre case seriesView study →}.

Why treatment fails. Blocking both sodium and calcium channels leaves the heart slow to conduct and weak to contract. The usual rescue drugs act on one problem or the other, not both ^{8,19Reference 8Schreiber N et al. · 2022Case reportCardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/View study →Reference 19Nižnanský Ľ et al. · 2022ReviewNatural taxanes: from plant composition to human pharmacology and toxicity — reviewView study →}.

References

1. Wilson CR, Sauer J, Hooser SB. (2001). Taxines: a review of the mechanism and toxicity of yew (Taxus spp.) alkaloids — review. Toxicon. https://pubmed.ncbi.nlm.nih.gov/10978734/
2. Krenzelok EP, Jacobsen TD, Aronis J. (1998). Is the yew really poisonous to you? — poison-centre case series. Journal of Toxicology: Clinical Toxicology. https://pubmed.ncbi.nlm.nih.gov/9656977/
3. Wani MC, Taylor HL, Wall ME, Coggon P, McPhail AT. (1971). Plant antitumor agents VI: the isolation and structure of taxol, a novel antileukaemic and antitumour agent from Taxus brevifolia. Journal of the American Chemical Society. https://pubmed.ncbi.nlm.nih.gov/5553076/
4. Schiff PB, Fant J, Horwitz SB. (1979). Promotion of microtubule assembly in vitro by taxol — in vitro. Nature. https://pubmed.ncbi.nlm.nih.gov/423966/
5. Schiff PB, Horwitz SB. (1980). Taxol stabilizes microtubules in mouse fibroblast cells — in vitro. Proceedings of the National Academy of Sciences USA. https://doi.org/10.1073/pnas.77.3.1561
6. McGuire WP, Hoskins WJ, Brady MF, et al. (1996). Cyclophosphamide and cisplatin compared with paclitaxel and cisplatin in patients with stage III and stage IV ovarian cancer (GOG-111) — randomised controlled trial. New England Journal of Medicine. https://pubmed.ncbi.nlm.nih.gov/7494563/
7. International Collaborative Ovarian Neoplasm (ICON3) Group. (2002). Paclitaxel plus carboplatin versus standard chemotherapy in women with ovarian cancer — randomised controlled trial. The Lancet. https://pubmed.ncbi.nlm.nih.gov/12241653/
8. Schreiber N, Manninger M, Pätzold S, et al. (2022). Cardiogenic shock due to yew poisoning rescued by VA-ECMO — case report and literature review. https://pubmed.ncbi.nlm.nih.gov/35942511/
9. Byrd-Leifer CA, Block EF, Takeda K, Akira S, Ding A. (2001). The role of MyD88 and TLR4 in the LPS-mimetic activity of Taxol — in vitro and mouse macrophage. European Journal of Immunology. https://pubmed.ncbi.nlm.nih.gov/11500829/
10. Kou P, Yu Y, Wang H, Zhang Y, Jin Z, Yu F. (2024). An integrated strategy based on 10-DAB extraction and in-situ whole-cell biotransformation of renewable Taxus needles to produce baccatin III — bioprocess. Molecules. https://doi.org/10.3390/molecules29112586
11. Stierle A, Strobel G, Stierle D. (1993). Taxol and taxane production by Taxomyces andreanae, an endophytic fungus of Pacific yew — in vitro. Science. https://pubmed.ncbi.nlm.nih.gov/8097061/
12. Tekol Y, Kameyama M. (1987). Electrophysiology of the mechanisms of action of the yew toxin, taxine, on the heart — in vitro electrophysiology (isolated guinea-pig ventricular myocytes). Arzneimittelforschung. https://pubmed.ncbi.nlm.nih.gov/2440454/
13. Turner NJ. (1998). Plant Technology of First Peoples in British Columbia. UBC Press — ethnobotanical reference.
14. Pinto A, Lemos T, Silveira I, Aragão I. (2021). Taxus baccata intoxication: the sun after the electrical storm — case report. Revista Brasileira de Terapia Intensiva. https://pubmed.ncbi.nlm.nih.gov/33886867/
15. Christensen SB. (2022). Drugs that changed society: microtubule-targeting agents belonging to taxanoids, macrolides and non-ribosomal peptides — review. Molecules. https://doi.org/10.3390/molecules27175648
16. Hils MH. (1993). Taxus brevifolia Nuttall, and genus Taxus. In: Flora of North America Editorial Committee, eds. Flora of North America North of Mexico, Vol. 2. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501253 and http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=132355
17. Tirmenstein DA. (1990). Taxus brevifolia, Pacific yew. In: Fire Effects Information System. USDA Forest Service, Rocky Mountain Research Station. https://research.fs.usda.gov/feis/species-reviews/taxbre
18. Thomas P. Taxus brevifolia. Threatened Conifers of the World. Royal Botanic Garden Edinburgh (summarising the IUCN Red List assessment, 2013: e.T34041A2841142). https://threatenedconifers.rbge.org.uk/conifers/taxus-brevifolia
19. Nižnanský Ľ, Osinová D, Kuruc R, et al. (2022). Natural taxanes: from plant composition to human pharmacology and toxicity — review. International Journal of Molecular Sciences. https://pubmed.ncbi.nlm.nih.gov/36555256/
20. Caesar GJ. Commentarii de Bello Gallico, Book 6, chapter 31. Trans. McDevitte WA, Bohn WS (1869). Perseus Digital Library. https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0001:book=6:chapter=31

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