Endogenous Metabolite
Isotetrandrine primarily targets cytoplasmic phospholipase A2 (PLA2) and the α1 adrenoceptor. PLA2 is a key enzyme in the inflammatory response that catalyzes the release of arachidonic acid, the precursor for pro-inflammatory eicosanoids. By inhibiting PLA2, Isotetrandrine reduces the production of these inflammatory mediators. It has also been shown to inactivate MAPK and NF-κB signaling pathways, which are central to the inflammatory response.

Fangji is derived from the root and rhizome of Schisandra chinensis, and it is frequently used to treat rheumatoid arthritis [1].
Fangchi, one of the most commonly used traditional herbal medicines, is derived from the rhizoma of S. acutum and the radix of S. tetrandra. S. acutum, and S. tetrandra have been widely used for the treatment of rheumatic arthritis.1,2 The main bioactive components in S. acutum are alkaloids and lignan such as sinomenine, isosinomenine, magnoflorine, and syringaresinol;3 whereas in S. tetrandra, tetrandrine and fangchinoline, respectively. Additionally, C. trilobus and A. fangchi have been also called “Mu fangchi” and “Guang fangchi”, respectively. C. trilobus has been used in folk medicine as a diuretic, analgesic and an anti-inflammatory. The chemical compositions of Fangchi species are slightly different according to their different origins. Thus, the development of a practical method for simultaneous determination of structural-diverse markers is essential for quality control of Fangchi species with different origins. Fangchi has been studied using several analytical methods, including HPLC-DAD, LC-DAD-mass spectrometry (MS), LC-DAD-MS/MS, gas chromatography-MS (GC-MS), capillary electrophoresis (CE). Among them, HPLC methods have been popularly applied as an incisive tool for the quality control of herbal medicines. Recently, HPLC assay has been replaced with UHPLC method due to its rapid analysis and high peak capacity. The UHPLC-DAD methods have been used for chemical fingerprinting analysis of specific components in Salviae Miltiorrhizae Radix12 and Coptidis Rhizoma. In this study, isolation of marker compounds in Fangchi was performed as described in a previous report. The purity of the isolated compounds was greater than 90% as evaluated by HPLC with UV detection. Protonated, sodiumadducted or intact molecules, [M+H]+ , [M+Na]+ , or [M]+ , of these compounds were detected by FAB-MS in positive ion mode. To elucidate the elemental composition of alkaloids and syringaresinol isolated from S. Acutum, exact mass measurements were performed using HRMS at a mass resolution of 10,000. The measured masses of [M+H]+ ions were within 2.6 mmu of the calculated masses, showing excellent agreement. For simultaneous determination of various markers (alkaloids, nitrophenanthrene carboxylic acid, and lignan) in Fangchi species, the optimization of UHPLC separation conditions was a prerequisite. To optimize separation of these marker compounds, the pH variation, chemical composition, and the ammonium acetate (AmAc) concentration of the mobile phase were investigated. Retention of ionizable compounds with RP-UHPLC is strongly dependent on the pH of the eluent, in addition to the percentage and strength of the organic solvent in the mobile phase [1].

---

In vitro, Isotetrandrine is a small molecule inhibitor that modulates various aspects of LPS-induced inflammation. It dose-dependently suppresses the severity of inflammatory responses. It has been shown to block NMO-IgG binding to AQP4, indicating a potential role in neuromyelitis optica. Its ability to inactivate MAPK and NF-κB pathways explains its broad anti-inflammatory effects.

In vivo, Isotetrandrine has been shown to suppress the severity of LPS-induced acute lung injury (ALI) by inactivating MAPK and NF-κB pathways. This suggests it can reduce tissue oxidative injury and the pulmonary inflammatory process. These in vivo studies confirm its anti-inflammatory activity and suggest its therapeutic potential for inflammatory lung diseases.

The in vitro activity of Isotetrandrine is typically assessed in cell culture models of inflammation, such as LPS-stimulated macrophages. In a standard protocol, macrophages (e.g., RAW 264.7 cells) are stimulated with LPS to induce an inflammatory response. The cells are then treated with various concentrations of Isotetrandrine. The levels of pro-inflammatory cytokines (e.g., TNF-α, IL-1β, IL-6) and nitric oxide (NO) are measured in the supernatant. The inhibition of MAPK and NF-κB activation is confirmed by Western blot.

In cellular assays, Isotetrandrine is typically dissolved in DMSO and then diluted in cell culture medium. Cells are pre-treated with the compound for a period before LPS stimulation. After incubation, cell viability is assessed to ensure the compound is not cytotoxic. The effect on inflammatory mediator production is quantified using ELISA or similar assays. The effect on signaling pathways is assessed by Western blot analysis of phosphorylated MAPKs and NF-κB.

The in vivo efficacy of Isotetrandrine is evaluated in animal models of inflammation, such as the LPS-induced acute lung injury (ALI) model in mice. In these studies, mice are administered LPS to induce ALI. Isotetrandrine is administered before or after LPS challenge. The severity of lung injury is assessed by measuring lung wet/dry weight ratio, inflammatory cell infiltration, and levels of inflammatory mediators in bronchoalveolar lavage fluid (BALF).

Dosing in animal models would typically involve intraperitoneal or oral administration of Isotetrandrine. The compound would be formulated in a suitable vehicle. Pharmacokinetic studies would be conducted to determine its absorption, distribution, metabolism, and excretion, though detailed data is not provided in the search results. Its molecular weight and formula are typical for a bisbenzylisoquinoline alkaloid.

The oral LD50 in mice was 6400 mg/kg, Japanese Journal of Pharmacology, 65(5)(176S), 1969; the intraperitoneal LD50 in mice was 160 mg/kg, Acta Chemica Sinica, 24(2413), 1976 [PMID:1017086]

---

The safety and toxicity of Isotetrandrine are not extensively documented. As a natural product with a history of use in traditional medicine, it is generally considered to have a favorable safety profile. However, like any bioactive compound, it would require thorough toxicological evaluation for development as a therapeutic agent. Its ability to inhibit PLA2 suggests potential for effects on arachidonic acid metabolism.

[1]. UHPLC Separation of Structurally Diverse Markers in Fangchi Species. (2013).

Isotetrandrine has been reported in Atherosperma moschatum, Berberis stolonifera and other organisms with relevant data. In summary, ultra-high performance liquid chromatography (UHPLC) has advantages over high performance liquid chromatography (HPLC) in terms of time saving, solvent saving, performance and efficiency. In addition, this method has good resolution, high sensitivity and short analysis time, thus achieving higher sample throughput, lower solvent consumption and smaller injection volume than HPLC. In this study, a rapid and simple UHPLC-DAD method was established for the simultaneous analysis of five alkaloids, aristolochic acid I and eugenol in different Stephania species. UHPLC-DAD can be used as a practical and effective tool for the quality control of Stephania species from different origins. [1]

---

Isotetrandrine is a bisbenzylisoquinoline alkaloid isolated from Stephania tetrandra. It is a potent inhibitor of cytoplasmic phospholipase A2 (PLA2) and an α1 adrenoceptor blocker. It has demonstrated anti-inflammatory effects in vitro and in vivo by inactivating MAPK and NF-κB pathways. It is a research compound of interest for studying inflammation and related diseases, but it is not an approved drug.

C38H42N2O6

622.7499

622.304

C, 73.29; H, 6.80; N, 4.50; O, 15.41

477-57-6

457825

White to light yellow solid powder

1.2±0.1 g/cm3

710.5±60.0 °C at 760 mmHg

180-182ºC

175.8±30.1 °C

0.0±2.3 mmHg at 25°C

1.586

3.55

0

8

4

46

979

2

CN1CCC2=CC(=C3C=C2[C@@H]1CC4=CC=C(C=C4)OC5=C(C=CC(=C5)C[C@@H]6C7=C(O3)C(=C(C=C7CCN6C)OC)OC)OC)OC

WVTKBKWTSCPRNU-XZWHSSHBSA-N

InChI=1S/C38H42N2O6/c1-39-15-13-25-20-32(42-4)34-22-28(25)29(39)17-23-7-10-27(11-8-23)45-33-19-24(9-12-31(33)41-3)18-30-36-26(14-16-40(30)2)21-35(43-5)37(44-6)38(36)46-34/h7-12,19-22,29-30H,13-18H2,1-6H3/t29-,30+/m0/s1

(11S,31R)-16,36,37,54-tetramethoxy-12,32-dimethyl-11,12,13,14,31,32,33,34-octahydro-2,6-dioxa-1(7,1),3(8,1)-diisoquinolina-5(1,3),7(1,4)-dibenzenacyclooctaphane

Isotetrandrine; (R,S)-Tetrandrine; Isosinomenin A; Isotetrandrine; 477-57-6; (+)-Isotetrandrine; O-Methylberbamine; O,O'-Dimethylobamegine; Isosinomenine A

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

---

Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

View More

Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

---

Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

View More

Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

---

Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

---

 (Please use freshly prepared in vivo formulations for optimal results.)