2,3-oxidosqualene

Cyclosporin A is a natural product and an active fungal metabolite, classified as a cyclic polypeptide immunosuppressant. It binds to cyclophilin and inhibits the activity of calcineurin (IC₅₀ = 7 nM) as well as CD11a CD18 adhesion molecules. It is commonly used to induce uremia models.

Trimethylamine N-oxide (TMAO) is a gut microbiota-dependent metabolite derived from dietary choline, betaine, and carnitine. It induces inflammation by activating the ROS NLRP3 inflammasome and promotes fibroblast differentiation through the activation of the TGF-β Smad2 signaling pathway. TMAO is commonly used to induce cardiac fibrosis models.

Prostaglandin E2 (PGE2) is a natural hormone-like substance involved in various physiological functions, including the contraction and relaxation of smooth muscles, dilation and constriction of blood vessels, regulation of blood pressure, and modulation of inflammation. It can be used to induce neuropathic pain models.

Phorbol 12-myristate 13-acetate (PMA) is a natural phorbol ester that acts as an activator of PKC, SphK, and NF-κB, and is commonly used to induce differentiation of THP-1 cells and establish dermatitis models.

Adenine is a purine-derived nucleobase and one of the four bases of DNA. It is an important chemical component of both DNA and RNA, involved in cellular respiration, the formation of ATP and coenzymes NAD and FAD, as well as protein synthesis. Adenine is commonly used to induce chronic kidney injury models.

D-Galactose is a naturally occurring hexose and a C-4 epimer of glucose. It can combine with glucose to form lactose and is commonly used to establish animal models of aging.

Cholesterol is the primary sterol in mammals, accounting for approximately 20–25% of the plasma membrane structure. It plays a key role in regulating membrane fluidity, permeability, and protein function. As an endogenous agonist of estrogen-related receptor α (ERRα), cholesterol is widely involved in metabolic regulation and serves as a precursor for the synthesis of hormones and bile acids. It is commonly used in experimental models of hyperlipidemia.

L-DOPA (Levodopa) is an orally active metabolic precursor of the neurotransmitter dopamine. It can cross the blood-brain barrier and be converted into dopamine in the brain. L-DOPA exhibits anti-hyperalgesic effects and holds potential in Parkinson’s disease research, and it can also be used to induce Parkinson’s disease models.

Fructose is a simple ketose monosaccharide widely found in many plants and commonly combines with glucose to form the disaccharide sucrose. It can be used to induce hyperuricemia and diabetes models.

5-Hydroxytryptophan (NSC-92523) is a metabolite of tryptophan and a direct precursor of serotonin. It is a substrate of aromatic amino acid decarboxylase and can be used to induce depression models.

L-Arginine (L-Arg) is a substrate of endothelial nitric oxide synthase (eNOS). It is transported into vascular smooth muscle cells via the cationic amino acid transporter family, where it is metabolized into nitric oxide (NO), polyamines, or L-proline. L-Arginine is an effective vasodilator and is commonly used to induce experimental acute pancreatitis.

Norepinephrine is an alkaloid neurotransmitter and an effective adrenergic receptor (AR) agonist that activates α1, α2, and β1 receptors. It is commonly used as a vasoactive agent for the treatment of shock and can also be used to induce cardiomyopathy models.

Bicuculline is an alkaloid extracted from Corydalis decumbens, acting as a competitive antagonist of the neurotransmitter GABAA receptor (IC50 = 2 μM). It also blocks Ca2+-activated potassium (SK) channels and inhibits slow afterhyperpolarization (slow AHP). Bicuculline has anticonvulsant effects and is commonly used to establish mouse seizure models.

Colchicine is an orally active natural alkaloid that acts by inhibiting microtubule polymerization (IC50 = 3 nM) and as a competitive antagonist of the α3 glycine receptor. It possesses broad anti-inflammatory, immunosuppressive, and antifibrotic activities, can inhibit NLRP3 inflammasome activation to prevent NSAID-induced small intestine injury, holds potential for gouty arthritis and rheumatoid arthritis research, and is commonly used to establish Alzheimer’s disease models.

Capsaicin is an active natural component found in chili peppers and acts as a TRPV1 agonist (EC50 = 0.29 μM). It possesses multiple activities, including pain relief, antitumor, anti-inflammatory, antioxidant, and neuroprotective effects, as well as some neurotoxicity. Capsaicin can be used to establish itch models.

Amiodarone is an antiarrhythmic compound that inhibits ATP-sensitive potassium channels (IC₅₀ = 19.1 μM) and can induce pulmonary toxicity. It has shown some antiviral activity in diseases caused by SARS-CoV-2 and is commonly used to establish animal models of pulmonary fibrosis.

Scopolamine is a high-affinity (nanomolar level) muscarinic receptor antagonist that can reversibly inhibit 5-HT₃ receptor responses (IC₅₀ = 2.09 μM). It is commonly used to induce animal models of Alzheimer's disease or memory impairment.

Glycerol is an important component of triglycerides (fats and oils) and phospholipids. It is widely used in the food industry as a sweetener, humectant, and in pharmaceutical formulations. Additionally, glycerol is used in sample preparation and gel formation for polyacrylamide gel electrophoresis and can be employed to induce acute kidney injury models.

Indomethacin sodium is a potent and orally active COX-1 2 inhibitor with IC50 values of 18 nM and 26 nM, respectively. It possesses anti-inflammatory, anticancer, and anti-infective activities and is widely used in research on cancer, inflammation, and viral infections. Additionally, it can be used to establish gastric ulcer animal models.

Bicuculline methochloride is a convulsant alkaloid and a selective GABAA receptor antagonist (IC50 = 3 μM) that can block Ca²⁺-activated potassium channels. It induces clonic-tonic seizures in mammals and is commonly used to establish animal models of epilepsy.

Angiotensin II human TFA is a potent vasoconstrictor in the renin-angiotensin system that regulates blood pressure through interactions with AT1R and AT2R receptors. It activates sympathetic nerve activity, promotes aldosterone synthesis and renal function, induces proliferation of vascular smooth muscle cells, and enhances type I and III collagen production in fibroblasts, leading to vascular and myocardial thickening and fibrosis. It also triggers apoptosis and promotes capillary formation, making it suitable for establishing models of cardiac hypertrophy, hypertension, and abdominal aortic aneurysm.

Doxycycline calcium is an orally active tetracycline antibiotic that also functions as a broad-spectrum matrix metalloproteinase (MMP) inhibitor, exhibiting antibacterial and anti-tumor cell proliferation activities, and is commonly used to induce gene expression in ON-OFF systems.