Gastrodia is a dry tuber of the orchid plant Gastrodia elata. It is a traditional and precious Chinese medicine for calming the liver, relieving wind and relieving spasm. Gastrodin is the main active ingredient of Gastrodia. Pharmacological studies have shown that Gastrodia has sedative, anti-convulsant, anti-epileptic properties, and increases cerebral blood flow. Protect nerve cells and promote energy metabolism of cardiomyocytes. A study on the dmpk of gastrodin in rats can provide a theoretical basis for the reasonable clinical application of the drug.
Pharmacokinetics is a discipline that explores how drugs in the body work. It combines mathematical principles and methods to make quantitative analysis of the drug dynamics in the body. It has great significance and effect on drug research and development. Medicilon’s pharmacokinetic laboratory has passed CFDA’s GLP certification. The experimental research follows the guidelines of ICH, CFDA and FDA. It can design and carry out in vivo and in vitro pharmacokinetic tests according to customer needs, and provide customers with a complete set of pharmacokinetics. Dynamic evaluation and optimization services.
Study on the pharmacokinetics of gastrodin in mice
After the mice were administrated gastrodin, the drug disappeared from the gastrointestinal tract very quickly. After 2 hours, only 5.2% of the remaining dose, the blood rose rapidly, t1/2α was only 6 minutes, and maintained a high level around 1 hour. The time of sedation is consistent with that of mice. The elimination half-life is 4.44 hours for intravenous injection and 7.47 hours for oral administration. The distribution in the body is highest in kidney, followed by liver, lung, heart, spleen and brain. It is mainly excreted in urine. The total amount of urine, feces and bile excreted in 24 hours after gavage is 76.8% of the administered dose, of which 97% is excreted in urine. Mainly in the first 2 hours, bile and feces are excreted very little.
Under different administration methods, there are differences in the distribution of drug concentration in rats; there are also differences in drug concentration distribution at different times under the same administration method; brain drug metabolism is faster, so gastrodin will be distributed in organs and tissues in a short time , Where the concentration in brain tissue is low and the metabolism is relatively fast.
The pharmacokinetics of gastrodin in different animals have obvious species differences
Reversed-phase high performance liquid chromatography was used to separate and determine gastrodin (glycoside) and its metabolite p-hydroxybenzyl alcohol (glycogen) in rabbit, rat, and dog plasma. This method is simple, rapid, sensitive and highly precise . The one-time curves of the three animals after iv gastrodin belong to the two-compartment open model, and their t_(1/2β) were 8.41 min for rats, 38.4 min for rabbits, and 105 min for dogs. The pharmacokinetic behaviors of gastrodin iv in rat and rabbit plasma at 100mg/kg and 200mg/kg are in the linear range.
Studies have found that the distribution and elimination of gastrodin in the above three kinds of animals is relatively rapid. The bioavailability of rat ig is 81%. When the same dose is given to rabbit ig, no prototype drug is detected in plasma, but gastrodin can be measured in plasma after duodenal administration, and its bioavailability is 2.8%. A small amount of aglycone can be detected in the plasma of rabbit iv gastrodin, but not in the plasma of rat or dog. Therefore, the pharmacokinetics of the three animals have obvious species differences.
The pharmacological effects of gastrodin
(1) Sedative and hypnotic effect
The experimental monkeys received intravenous injection of gastrodin 50mg/kg, and after 20 minutes, they appeared quiet and no tension, and lasted for 2 hours. The results of subcutaneous injection of gastrodin in experimental mice showed that gastrodin had obvious synergistic effects with pentobarbital sodium, chloral hydrate and thiopental sodium.
(2) Anticonvulsant effect
Mice were intraperitoneally injected with gastrodin 30mg/kg, and 30 minutes later by intravenous infusion of 0.5% pentylenetetrazol solution 30mg/kg, the results showed that gastrodin can prolong the incubation period of pentylenetetrazol-clonic convulsions and has obvious anti-pentylenetetrazol-clonic properties The effect of convulsions.
(3) Analgesic effect
Gastrodia administering continuously, using electric shock to the tail and writhing method, it is observed that gastrodin has a significant analgesic effect, and the analgesic effect is related to the dose.
(4) Protective effect on brain cell damage
The neonatal rat cerebral cortex was cultured in vitro and neuronal damage models were established in vitro with glutamate. The effect of gastrodin on the neurotoxicity of excitatory amino acids was observed. It was found that adding gastrodin in the culture solution can significantly reduce the death of nerve cells. Therefore, gastrodin can antagonize the toxic effects of excitatory amino acids on nerve cells. In addition, studies have also found that gastrodin can inhibit nerve cell damage induced by oxygen free radicals.
(5) Effect on the circulatory system
Gastrodin also has a certain effect on the circulatory system. It can not only reduce peripheral vascular resistance, lower blood pressure and increase arterial vascular compliance, but also increase cardiovascular and cerebrovascular blood flow and protect myocardial cells. Gastrodin injection can enhance immunity, anti-amnesia and anti-aging. It also has the vasoconstrictive effect of anti-adrenaline (AD) in rats, and has a preventive effect on microcirculation disorders to prevent thrombosis.
The researchers conducted an experimental study on noise-induced cochlear damage in guinea pigs, measured the ABR threshold, cochlear basement membrane spread and electron microscopy and observed that gastrodin can reduce the auditory brainstem response (ABR) threshold after noise exposure in guinea pigs and reduce hair cell damage , It has a protective effect on noise-induced cochlear damage.
At present, the development and utilization of Gastrodia is not only in medicinal use, but also in food and health products. Research on the pharmacokinetics and pharmacological effects of Gastrodia can provide a basis for the rational use of Gastrodia.