Tetrandrine

Tetrandrine is a bisbenzylisoquinoline alkaloid extracted from Stephania tetrandra that demonstrates calcium channel blocking activity. This compound modulates cellular signaling pathways including JNK1/2 activation and reactive oxygen species generation.

Origin & History

Tetrandrine is a bis-benzylisoquinoline alkaloid isolated primarily from the root of the plant *Stephania tetrandra* S Moore and other related species. It is a naturally derived compound formed through the oxidative coupling of phenylpropanoid units. Its chemical formula is C₃₈H₄₂N₂O₆.

Historical & Cultural Context

Tetrandrine has been documented for centuries in the Chinese Pharmacopoeia and is a cornerstone of traditional Chinese medicine. Historically, its source plant, *Stephania tetrandra*, was used as an analgesic and diuretic, and to treat conditions like hypertension, asthma, cancer, and fever. It continues to be used in traditional clinical practice for silicosis, autoimmune disorders, and cardiovascular diseases.

Health Benefits

[{"benefit": "May induce cancer cell death (apoptosis) by generating reactive oxygen species (ROS) and activating JNK1/2 pathways.", "evidence_quality": "Evidence is preliminary and based on *in vitro* studies on multiple cancer cell lines (e.g., MCF-7, HeLa, PC3)."}, {"benefit": "Acts as a potent inducer of autophagy (the body's cellular cleanup process), demonstrating stronger activity than rapamycin in some cell models.", "evidence_quality": "Evidence is from preliminary *in vitro* studies across multiple cell lines."}, {"benefit": "Exhibits potential antiviral activity by inhibiting endosomal calcium channels, which has been shown to block Ebola virus infection.", "evidence_quality": "Evidence is from preliminary *in vitro* and *in vivo* animal studies."}, {"benefit": "Functions as a calcium channel blocker, a mechanism relevant to its traditional use in managing hypertension and cardiovascular diseases.", "evidence_quality": "Evidence is based on its known pharmacological mechanism and a history of traditional use; specific human clinical trials were not found in the research."}, {"benefit": "May possess anti-inflammatory properties, as indicated by its long-standing use in traditional Chinese medicine for inflammatory pulmonary diseases and autoimmune disorders.", "evidence_quality": "Evidence is based on traditional use; specific clinical trials confirming this effect were not present in the research dossier."}]

How It Works

Tetrandrine functions as a potent calcium channel blocker, inhibiting L-type voltage-gated calcium channels and reducing intracellular calcium influx. The compound activates JNK1/2 signaling pathways while generating reactive oxygen species (ROS) in cancer cells, leading to apoptosis. Additionally, tetrandrine modulates inflammatory responses by inhibiting NF-κB activation and reducing pro-inflammatory cytokine production.

Scientific Research

The provided research dossier does not contain any specific human clinical trials, randomized controlled trials (RCTs), or meta-analyses with PubMed PMIDs for tetrandrine. The available evidence is primarily from *in vitro* cell culture and *in vivo* animal models, alongside references to its use in traditional Chinese clinical practice.

Clinical Summary

Current evidence for tetrandrine is primarily based on in vitro studies using cancer cell lines including MCF-7 breast cancer, HeLa cervical cancer, and PC3 prostate cancer cells. Laboratory studies demonstrate IC50 values ranging from 10-50 μM for cytotoxic effects across various cancer types. Animal studies suggest anti-inflammatory effects at doses of 20-40 mg/kg body weight. However, human clinical trials are extremely limited, with most research confined to traditional medicine observational studies rather than controlled interventions.

Nutritional Profile

Tetrandrine (C₃₈H₄₂N₂O₆, MW ~622.75 g/mol) is a bisbenzylisoquinoline alkaloid, not a nutritional substance. It is a bioactive phytochemical isolated primarily from the root of Stephania tetrandra (Han Fang Ji) in traditional Chinese medicine, and also found in minor amounts in other Menispermaceae family plants such as Cyclea peltata and Cissampelos pareira. It is not consumed as a food or dietary supplement in conventional nutrition and therefore has no meaningful macronutrient (protein, fat, carbohydrate, fiber) or micronutrient (vitamin, mineral) profile. Key pharmacological/biochemical characteristics include: (1) Chemical class: Bisbenzylisoquinoline alkaloid featuring two tetrahydroisoquinoline units linked by two ether bridges; (2) Typical concentration in dried Stephania tetrandra root: approximately 1.0–2.8% w/w of total alkaloid content, with tetrandrine often comprising 30–60% of the total alkaloid fraction alongside fangchinoline (~0.5–1.5% w/w); (3) Solubility: Poorly water-soluble (lipophilic, logP ~4.2), freely soluble in chloroform, ethanol, and acidified aqueous solutions; (4) Oral bioavailability: Estimated at approximately 5–20% in animal models (rats), limited by poor aqueous solubility, significant first-pass hepatic metabolism (primarily CYP3A4/CYP2C-mediated oxidation and N-demethylation), and P-glycoprotein (P-gp) efflux; notably, tetrandrine itself is a calcium channel blocker and a known inhibitor of P-glycoprotein (MDR1/ABCB1), which may modulate absorption of co-administered compounds; (5) Primary bioactive mechanisms: Dual calcium channel blockade (L-type and T-type voltage-gated Ca²⁺ channels, IC₅₀ in the low micromolar range ~1–10 µM), inhibition of NF-κB signaling, ROS generation, activation of JNK and caspase-mediated apoptotic pathways, and potent autophagy induction (reported more potent than rapamycin in certain in vitro models); (6) Plasma protein binding: >90%; (7) Half-life: Approximately 10–16 hours in animal pharmacokinetic studies; (8) Typical investigational doses in preclinical/clinical contexts: 40–200 mg/day orally in limited human studies (e.g., silicosis treatment trials in China), though no standardized therapeutic dose is internationally recognized. Tetrandrine contains no vitamins, minerals, dietary fiber, or caloric value in pharmacologically relevant doses. Caution: Hepatotoxicity has been reported at higher doses, and the compound has a narrow therapeutic window.

Preparation & Dosage

The research dossier does not provide any clinically studied dosage ranges for tetrandrine in any form, nor does it specify standardization protocols. Information on effective or safe human dosages is not available in the provided sources. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Information not available in the provided research dossier.

Safety & Interactions

Tetrandrine may cause hypotension due to its calcium channel blocking properties and should be used cautiously with antihypertensive medications. The compound can potentially interact with other calcium channel blockers like nifedipine or diltiazem, amplifying cardiovascular effects. Hepatotoxicity has been reported in some traditional medicine preparations containing Stephania species. Pregnant and breastfeeding women should avoid tetrandrine due to insufficient safety data and potential teratogenic effects.