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ACTIVITY OF CANNABIS IN RELATION TO ITS Δ‘‐ trans ‐TETRAHYDROCANNABINOL CONTENT
Author(s) -
FAIRBAIRN J.W.,
PICKENS JOAN T.
Publication year - 1981
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1981.tb10990.x
Subject(s) - chemistry , tetrahydrocannabinol , cannabis , ethanol , cannabinoid , herb , cannabinol , pharmacology , petroleum ether , delta 9 tetrahydrocannabinol , dronabinol , chromatography , traditional medicine , biochemistry , medicine , extraction (chemistry) , receptor , psychiatry , medicinal herbs
1 Conditions have been worked out for a reliable estimation of the cataleptic activity of Δ′‐ trans ‐tetrahydrocannabinol (THC) after oral administration to mice, using the ring test over a period of 6 h. 2 By this method, the activity of cannabis herb and 5 crude fractions were measured against THC; at the same time the THC contents were determined chemically. 3 The B/C ratio (biological activity divided by chemical assay) was calculated for each. With cannabis herb the value was 3.3 and with extracts prepared with ethanol or 70% ethanol the values ranged from 3.2 to 7.1, indicating that in all samples the activity was much higher than would be expected from their THC content. 4 The cannabinoids were completely extracted from a sample of herb using petroleum spirit and the marc examined for a possible synergist. Surprisingly, it contained a powerful inhibitor of the action of THC, which could be restored by intraperitoneal prostaglandin E 2 (3 μg/kg). Some crude fractions had inhibitory activities about 10 times that of aspirin. 5 In contrast, the petroleum spirit extract (referred to in 4 ) had a surprisingly high B/C ratio of 23, indicating that a powerful synergist of THC activity is present. 6 The net effect of the herb and ethanol extracts is probably due to a balance of synergist and inhibitor.