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The Americas
Published in Michael J. O’Dowd, The History of Medications for Women, 2020
The biggest success story in plant medications of recent times concerns the Pacific yew, Taxus brevifolia. This evergreen coniferous tree is found in groves along the Pacific coast of North America and inland from British Columbia to Idaho. The Pacific yew has provided one of our latest wonder drugs, paclitaxel, or Taxol as we know it. It was described by Wani et al. (1971) and introduced much later to clinical practice. The bark of six trees is required to treat one patient with ovarian or breast cancer. Exploitation of T. brevifolia led to the Pacific Yew Act of 1992 which sought to conserve this wonderful medicinal asset. The closely related T. baccata, the common yew, provided the wood to make bows for archery many centuries ago. It was sacred to the ancient druids, and is to be found in churchyards, but unfortunately T. baccata contains only small amounts of active anti-cancer chemicals and, until recendy, was only useful for research. The common yew is now used to produce paclitaxel.
An Overview of Important Endemic Plants and Their Products in Iran
Published in Raymond Cooper, Jeffrey John Deakin, Natural Products of Silk Road Plants, 2020
Taxus baccata (Figure 7.42) is an evergreen tree growing up to 15 m by 10 m at a slow rate. The species is dioecious. The plant is not self-fertile. It is suitable to grow in light (sandy), medium (loamy), and heavy (clay) soils, prefers well-drained soil, and can grow in heavy clay soil. It is suitable to grow in the soil with acid, neutral, and basic (alkaline) pH and can grow in very acid and very alkaline soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers dry or moist soil and can tolerate drought. It can tolerate atmospheric pollution. The yew tree is a highly toxic plant that has occasionally been used medicinally, mainly in the treatment of chest complaints. Modern research has shown that the plants contain the substance “taxol” in their shoots. Taxol has shown exciting potential as an anticancer drug, particularly in the treatment of ovarian cancers. All parts of the plant, except the fleshy fruit, are anti-spasmodic, cardiotonic, diaphoretic, emmenagogue, expectorant, narcotic, and purgative. The leaves have been used internally in the treatment of asthma, bronchitis, hiccup, indigestion, rheumatism, and epilepsy. Externally, the leaves have been used in a steam bath as a treatment for rheumatism. A homeopathic remedy is made from the young shoots and the berries. It is used in the treatment of many diseases including cystitis, eruptions, headaches, heart and kidney problems, rheumatism, etc. (Zargari, 2014; Mozaffarian, 2011; Plant for a Future; Thomas & Polwart, 2003).
Catalog of Herbs
Published in James A. Duke, Handbook of Medicinal Herbs, 2018
Toxicity — After yew (Maryland’s number-one poisonous plant), it is considered the “most poisonous tree in Britain”. Loss of human life is reported. Cytisine is excreted in the milk.14 Cytisine causes excitement, stomach and intestinal irritation with nausea, severe vomiting, and diarrhea, irregular pulse, convulsions, coma, and death in overdoses.
Characteristics of emergency department presentations following ingestion of Taxus baccata (yew)
Published in Clinical Toxicology, 2023
Vanessa Alexandra Buetler, Alexandra Maria Braunshausen, Stefan Weiler, Jolanta Klukowska-Rötzler, Aristomenis K. Exadaktylos, Evangelia Liakoni
Gastroscopy occurred in 52 presentations (95%), with a median interval of 4.1 h (range 1.7 − 7.5 h) post-ingestion. Yew leaves were found in the gastrointestinal tract in 37 of 52 cases, with a median of 23 leaves and of range 0 (fifteen presentations) to 300 leaves (one presentation). A not strong positive correlation (correlation coefficient 0.41, p < 0.05) was found between the estimated number of leaves ingested and number recovered by gastroscopy (Figure 2). Table 3 includes details of the six presentations with ≥100 leaves found on gastroscopy (amount reported as potentially lethal [6]). Activated charcoal administration occurred in 24 presentations following gastroscopy and in one without gastroscopy (45% of total cases). Sodium bicarbonate was administered in two presentations. The patient with cardiac arrest received lipid emulsion, extracorporeal membrane oxygenation (ECMO), installation of a ventricular support device (Impella CP SmartAssist®, ABIOMED) and a temporary pacemaker.
Strategies for the drug discovery and development of taxane anticancer therapeutics
Published in Expert Opinion on Drug Discovery, 2022
Changwei Wang, Angelo Aguilar, Iwao Ojima
It is expected that the three FDA-approved taxane drugs, paclitaxel, docetaxel, and cabazitaxel will continue to be used as first-line chemotherapies in the foreseen future. The heavily invested cultivation of yew trees in China will keep supplying substantial amounts of API intermediates for the global market. The extraordinary efficacy of Abraxane, specifically its combination therapy with gemcitabine for pancreatic cancer patients indicates that one future for taxane drugs will be in combination therapies. Additionally, there is continuous exploration and development of tumor targeting drug delivery systems, especially highly efficacious formulations that spare normal cells and are superior to Abraxane. These show promise to produce single agent taxane drugs with less toxic side effects.
Quantitative proteomic analysis to the first commercialized liposomal paclitaxel nano-platform Lipusu revealed the molecular mechanism of the enhanced anti-tumor effect
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Minzhi Zhao, Haiyun Li, Linyang Fan, Yan Ma, He Gong, Wenjia Lai, Qiaojun Fang, Zhiyuan Hu
In recent years, the nanotechnology has offered researchers the opportunity to solve these problem, while maximizing the proven antineoplastic activity. Development of nanoparticle formulations for tumor treatment has been a field of intense scientific efforts for over two decades. To date, PTX has been marketed in three different nano-platforms for its parenteral delivery: liposomes (Lipusu®, liposomal PTX approved by State FDA of China), polymeric nanoparticles (Abraxane®, albumin nanoparticle-based PTX preparation), and polymeric micelles (Genexol®, Nanoxel® and Paclical®). A fourth nanocarrier might be available soon, as phase III studies of OpaxioTM, a polymeric-conjugated, are near completion. Furthermore, other several nano-formulations are currently in various stages of clinical trials [7]. Liposome-encapsulated PTX (LEP) exhibited lower toxicity and enhanced drug efficacy compared with Cr-P formulation [8–10]. By the encapsulation of PTX in liposomes, the acute toxicity associated with Cremophor EL® was eliminated [11]. The growth-inhibitory activity of LEP was retained in vitro against a variety of tumor cell lines. And in vivo, LEP was found to be well-tolerated in mice model [12]. Lipusu® (lip) is the first commercially available PTX formulation. It represents a natural extract from Yew which was used in the treatment of NSCLC, breast, ovarian, gastric and head and neck cancer. The application of a liposome technology resolved the issues of PTX insolubility and eliminated the use of solvents causing toxic side-effects. The drug delivery by liposomes reduced the side-effects to the medulla, blood pressure, peripheral blood and the liver after injection. These improvements enabled to use higher drug doses leading to an enhanced drug efficacy. The advanced drug distribution had led to an increased tolerance of PTX. Moreover, the lyophilized preparation provides flexible storage conditions for LEP [13]. A clinical study had been performed to obtain an optimal premedication protocol for lip. Lip as a component of combined chemotherapy was administered to patients including advanced NSCLC (30%). The intra-pleural administration of LEP could maximize the treatment effect of local disease while minimizing a systemic toxicity [14]. To confirm this finding, a phase II study of a large number of patients was recommended [15,16].