Gentianine was shown to mitigate formaldehyde-induced paw swelling in rats and accelerate its subsidence. Swelling was basically relieved by injection of 90 mg/kg IP daily for 10 days; the anti-inflammatory efficacy was equivalent to that of sodium salicylate 200 mg/kg. Likewise, pretreatment with gentianine injection 90 mg/kg also reduced egg white-induced paw swelling in rats and accelerated its subsidence. However, gentianine was ineffective in bilaterally adrenalectomized rats and in normal rats anesthetized with pentobarbital sodium.

Another experiment proved that gentianine markedly and dose-dependently decreased the vitamin C content in the rat adrenal glands. No such action, however, was achieved in hypophysectomized animals and in animals under pentobarbital sodium anesthesia. Hence, it is postulated that the anti-inflammatory effect of Gentiana macrophylla was realized through activation of the pituitary-adrenocortical function via the nervous system. The dye diffusion method, moreover, showed that injection of gentianine 90 mg/kg IP to rats markedly decreased capillary permeability boosted by injection of egg white.

Gentiana macrophylla was shown to have sedative, analgesic, and antipyretic actions, and an inhibitory effect on the reflex intestinal secretion. Intragastric or intraperitoneal administration of gentianine to mice produced sedation; it also potentiated the hypnotic action of pentobarbital sodium in mice and rats.

Gentianine at 20-40 mg/kg SC, IP or IV dose-dependently inhibited the reflex intestinal secretion in dogs due to perfusion of mercurous chloride into the intestinal fistulae.

Injection of gentianine 90 mg/kg IP to rabbits markedly decreased the symptoms of egg white-induced anaphylactic shock. The same dosage administered intraperitoneally to guinea pigs also markedly abated asthma and convulsion induced by histamine aerosol.

Injection of gentianine 180-250 mg/kg IP to rats elevated the blood glucose level 30 minutes after medication; the duration of action was approximately 3 hours. The dosages of 150-250 mg/kg IP also produced hyperglycemia in mice; the higher the dosage, the stronger the action. The hyperglycemic effect of gentianine injection did not appear in adrenalectomized animals however. Also, a significant reduction of liver glycogen was observed concurrent with hyperglycemia. Adrenergic blocking agents partially or completely blocked the hyperglycemic action of gentianine, indicating that it was mediated primarily by the release of epinephrine.

Gentianine had prominent but brief hypotensive and bradycardic effects on anesthetized dogs and rabbits. Blood pressure was lowered promptly and dose-dependently after injection of 5-20 mg/kg IV. However, the original blood pressure was usually recovered in 2-10 minutes and no tachyphylaxis developed. Neither intravenous injection of atropine nor bilateral vagotomy blocked the hypotensive effect, indicating that it was not related to the vagus nerve. Gentianine also depressed the isolated frog heart: At the concentration of 1:2,000 the gentianine infusion progressively reduced the heart rate, while increasing the concentration to S1:1000 caused insufficient diastole and decreased cardiac output apart from bradycardia. The hypotensive effect is probably secondary to direct cardiac depression.

Injection of gentianine 5-20 mg/kg IV to anesthetized dogs did not modify the ileal movement. Likewise, concentrations of 1:10,000-1:2500 had no effect on the movement of the isolated guinea pig ileum, but antagonized histamine- and acetylcholine-induced intestinal contractions. The 1:5000 concentration virtually antagonized the action of histamine but not quite that of acetylcholine.

In vitro, the ethanol extract of Gentiana macrophylla inhibited Shigella dysenteriae, Salmonella typhi, Vibrio cholerae, and Staphylococcus aureus. The aqueous extract (1:3) also exhibited various degrees of inhibitory effect on some common skin fungi in vitro.

The LD50 of gentianine in mice were determined to be 486 mg/kg P0 and 300 mg/kg IP. No significant ill effects were observed after a single dose of 420-520 mg/kg P0 in rats, a single dose of 240 mg/kg P0 or 80 mg/kg IV in dogs, or 100 mg/kg PO once daily for 3 days in monkeys and cats.

Gentiana macrophylla is one of the important ingredients in many antirheumatic compound prescriptions. The herb is mainly used in rheumatic arthritis. G. macrophylla injection, 2 ml/ampoule, is a sterilized solution of the total alkaloids of Gentiana macrophylla; each ampoule contains total alkaloids equivalent to 10 mg of gentianine. It is administered intramuscularly to treat rheumatic and rheumatoid arthritis. Excellent analgesic, detumescent, and antipyretic effects, as well as a restorative effect on articular function were achieved with this agent.

In twenty-one cases cured in 3-7 days by injection of G. macrophylla Injection, 0.625 g(crude drug)/ml, 2-5 ml IM every 6 hours, not a single case developed sequelae or side effects during treatment.

Except those noted, all references come from Weng Weiliang, et al., Clinical Chinese materia medica, Henan Science & Technology Press, 1998