Comparison of the inhibitory action of delta-9-tetrahydrocannabinol and petroleum spirit extract of herbal cannabis on human sperm motility.

1 Using the trans-membrane migration method to measure drug effects on human sperm motility, it is found that delta-9-tetrahydrocannabinol is the major constituent of cannabis which inhibits sperm motility and unlike the cataleptic effect, other constituents in the petroleum spirit extract do not potentiate this effect significantly. 2 It is suggested that the mechanisms for sperm immobilization and cataleptic effects are different.

Activity of cannabis in relation to its delta'-trans-tetrahydro-cannabinol content.

1 Conditions have been worked out for a reliable estimation of the cataleptic activity of delta'-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 E2 (3 microgram/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.

Meconic acid and alkaloids in Papaver somniferum and P. bracteatum.

Meconic acid (C (7)H (4) O (7)) has an unusually low H content in relation to C and O; it seems also to be restricted to Papaver species which characteristically produce morphinanes. The suggestion that it is an energy exhausted product of the citric acid cycle whose formation controls alkaloid production has been investigated. Using HPLC methods the concentrations of meconic acid and of alkaloids in the latex have been shown to vary significantly during the day suggesting active metabolism but little firm evidence of formation of meconic acid from fumarate or pyruvate was obtained.

The effect of conditions influencing endogenous prostaglandins on the activity of delta'-tetrahydrocannabinol in mice.

1 The cataleptic effect of delta'-tetrahydrocannabinol (THC) depends upon the availability of the precursors of prostaglandins and the response is reduced in mice maintained on a diet deficient in arachidonic acid (AA) and restored by exogenous AA given intraperitoneally, or by feeding a normal diet. 2 In yeast-induced fever, which is accompanied by an increase in the synthesis of prostaglandins, THC shows an enhanced cataleptic effect. 3 Exposure to cold which results in depletion of prostaglandins reduces the effect of THC.

The oral activity of delta'-tetrahydrocannabinol and its dependence on prostaglandin E2.

1 delta'-trans-Tetrahydrocannabinol (THC) is more active orally in mice than previously thought, as cataleptic responses occur at doses from 0.06 mg/kg upwards, with peak activity at 2 to 4 h after dosing. These doses and peaks correspond well with the effects in man. 2 Comparison with chlorpromazine in mice shows that chlorpromazine and THC are equipotent as cataleptics during the first 2 h after dosing; thereafter the THC activity increases to a peak when it is 5.67 times as active as chlorpromazine. 3 The cataleptic effect of THC is abolished by aspirin, indomethacine, diffunisal and phenylbutazone which inhibit the biosynthesis of prostaglandins and is restored by exogenous prostaglandin E2 (PGE2) but not PGE1 and PGF2 alpha. This suggests that the effect of THC depends upon the presence of PGE2. 4 In contrast, the cataleptic effect of chlorpromazine is not affected by pretreatment with aspirin. 5 THC is very much less active intraperitoneally than orally; our results suggest this is not due to poor absorption or extraction into fat depots. 6 Cannabidiol has no cataleptic effect.

Cascarosides A and B.

Electron-impact and field desorption mass spectrometry, together with NMR and circular dichroism spectroscopy, were used to confirm that cascarosides A and B are C-10 isomers of 8-O-(beta-D-glucopyranosyl)barbaloin. Several batches of cascarosides A and B were prepared and oxidatively hydrolyzed to aloe-emodin. The results are discussed in relation to the assay for cascara given in the European Pharmacopoeia, 1971.

Cannabinoid patterns in seedlings of Cannabis sativa L. and their use in the determination of chemical race.

We have examined the cannabinoid contents of seedlings from twelve strains of Cannabis of known chemical race. Fourteen days after emergence of the shoot those of the tetrahydrocannabinol (THC) type could be distinguished from those of the cannabidiol (CBD) type. The true leaves of the THC type contained a relatively high content of THC and also contained cannabichromene (CBC), sometimes as the major cannabinoid, whereas the CBD type had much lower amounts of THC and no CBC; CBD being the major component. A strain from China corresponded to the THC type but showed some unusual features. Seeds purchased at seven outlets in Britain were also examined. Only two batches germinated by these proved to be of a THC type and resembled the Chinese strain.

Papaver bracteatum Lindley: thebaine content in relation to plant development.

Four thebaine-rich varieties of P. bracteatum have been grown in the open over two seasons and the thebaine distribution in aerial parts examined to determine the most suitable source material for commercial production. The leaves contained only 0-1 to 0-15%; the capsules 0-5 to 3-0% and the bled latex 28 to 53%. The maximum for the latter occurred about 3-4 weeks after petal opening and during the day, at about 15,00 h. A product 'bractium' prepared exactly as opium from P. somniferum contained up to 55% thebaine and calculations from the 1974 results gave theoretical yields up to 58 k of thebaine per hectare. However this is a very labour intensive method; furthermore bled latex only represents about 46% of the total thebaine of the capsule. In addition the pedicels contain significant amounts of thebaine, so that fruiting tops may be recommended as source material. In the capsule the thebaine content reaches a peak 3 to 4 weeks after petal opening and again two weeks later. At this fully ripe stage there is a theoretical yield of 50 kg per hectare. Two further advantages accrue from collection at this time: the ripe seeds can probably be used for similar purposes as poppy seed; and the pericarps at this stage contain no 'bound thebaine' (i;e., thebaine insoluble in MeOH; NH4OH but soluble in acetic acid--in unripe capsules bound thebaine represents 18 to 36% of the total thebaine). There is some evidence that, as this perennial plant increases in age, the capacity for thebaine production seems to continue increasing. Storage of raw material, even in ideal conditions, led to a loss of thebaine of 12 to 20% in one year.

The stability of cannabis and its preparations on storage.

Solutions of pure cannabinoids, nine samples of herbal and two of resin cannabis (one freshly prepared) were stored in varying conditions for up to 2 years. Exposure to light (not direct sunlight) was shown to be the greatest single factos in loss of cannabinoids especially in solutions, which should therefore be protected from light during analytical and phytochemical operations. Previous claims that solutions in ethanol were stable have not been substantiated. The effect of temperature, up to 20 degrees, was insignificant but air oxidation did lead to significant losses. These could be reduced if care was taken to minimize damage to the glands which act as "well filled, well closed containers". Loss of tetrahydrocannabinol after exposure to light does not lead to an increase in cannabinol, but air oxidation in the dark does. It is concluded that carefully prepared herbal or resin cannabis or extracts are reasonably stable for 1 to 2 years if stored in the dark at room temperature.

The determination of thebaine in Papaver bracteatum Lindl by gas-liquid chromatography.

Several solvents have been examined in the process of developing a convenient method for extracting powdered material and removing interfering pigments to produce an extract of Papaver bracteatum suitable for g.l.c. assay. The most suitable extracting solvent was aqueous acetic acid (5%); the assay method gave satisfactory reproducibility with a wide range of plant materials (coefficient of variation 0.63 to 3.33%). The accuracy was checked by recovery experiments with pure thebaine and by examination of exhausted marcs. The presence of other alkaloids did not interfer with the assay. There were substantial differences in the amounts of thebaine extracted from capsule and root samples by ammoniacal methanol and by aqueous acetic acid, indicating the presence of thebaine in a "bound" form. The minimum amount of thebaine that could readily be determined by the g.l.c. method was 0.3 mg in the sample of powder used for the assay.