Effects of vietnamese ginseng on opioid agonist — and conditioned fear stress-induced antinociception
We investigated the effects of Vietnamese ginseng (VG) extract, VG saponin and the VG major saponin constituent majonoside-R2 on opioid receptor agonist-induced antinociception using the tail-pinch and hot-plate tests in mice and on conditioned fear stress-induced antinociception using the tail-flick test in rats. VG extract (50–100 mg/kg, p.o.), VG saponin (12.5–25 mg/kg, p.o.) and majonoside-R2 (6.2–12.5 mg/kg, p.o.), as well as Panax ginseng extract (PG extract, 50–100 mg/kg, p.o.), dose-dependently attenuated the μ-opioid agonist morphine-induced antinociception in the tail-pinch and hot-plate tests. Moreover, repeated administration of VG saponin and majonoside-R2 suppressed the development of morphine tolerance in the tail-pinch test. VG extract (100–200 mg/kg, p.o.) also dose-dependently blocked the antinociceptive effects of the selective κ-opioid agonist U-50, 488H in the tail-pinch and hot-plate tests, while PG extract (100–200 mg/kg, p.o.) dose-dependently attenuated the U-50,488H-induced antinociception in the hot-plate test but not in the tail-pinch test. VG saponin (6.2–25 mg/kg, p.o.) blocked the U-50,488H-induced antinociception in the tail-pinch test but not in the hot-plate test. Furthermore, VG saponin (25 mg/kg, i.p.) and majonoside-R2 (6.2 mg/kg, i.p.), as well as naloxone (2 mg/kg, i.p.), reversed the tail-flick latency increased by conditioned fear stress in rats. These results indicate that VG and its major saponin constituent, majonoside-R2, attenuate the antinociception caused by opioid agonists and conditioned fear stress.
http://www.sciencedi...944711396800079
Ethnobotanically it is a secret medicine of the Sedang ethnic group as a miraculous, life-saving plant drug used for the treatment of many serious diseases and for enhancing body strength in long journeys in high mountains.[citation needed]
In tests, Vietnamese ginseng extract attenuated psychological stress-induced antinociception, produced the protective effect against psychological stress-induced gastric lesions, and restored the stress-induced decrease in pentobarbital sleep to the normal level.[citation needed] This action was not observed on Panax ginseng extract. Vietnamese ginseng extract showed inhibitory activity on Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA. This activity was concentrated to the saponin fraction and especially, major saponin, majonoside R2 exhibited the strongest activity.[5]
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Recently there has been some attention brought towards the opioid kappa-receptor as a fundamental operator of fear, depression, anxiety and anhedonia. It appears that Vietnamese Ginseng blocks k-opioid agonist effects, while Panax Ginseng only has partial effect.
I've always liked the idea of using adaptogens to "teach" the nervous system a better way to function and respond to stress. Panax Ginseng has been very useful and never fails to at least make things more bearable, but it's not fully effective for fear extinction. Vietnamese Ginseng may have greater potential for attenuating conditioned fear stress, but it seems rather rare herb and difficult to find a place to buy it. Anyone know a reliable source to buy it in bulk?
