Page 133 - Pharmacognosy 2 PG303

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

Powder

It is dark green in color with heavy characteristic narcotic odor and no taste. It is
characterized microscopically by the presence of the following:

1- Fragments of the upper epidermis of the leaves, bracts and bracteols showing polygonal
straight- walled cells with no stomata, short non- glandular trichomes with enlarged base
containing cystoliths of calcium carbonate and glandular trichomes.

2- Fragments of the lower epidermis of the leaves, bracts and bracteols showing sinuous-
walled cells, numerous anomocytic stomata and trichomes.

3- Fragments of vein islet and the lower hypodermal layer of leaves with numerous clusters
of calcium oxalate.

4- Abundant glandular and non- glandular trichomes.
5- Fragments of papillosed stigma.
6- Fragments of unbranched brown laticiferous tubes associated with xylem vessels.
7- Thin- walled parenchyma containing clusters of calcium oxalate.
8- A few fragments of thickened cells of pericarp.

Constituents

The drug produces 15- 20% soft brown resin, which contains:
1- Oily cannabinoid tetrahydrocannabinol (THC), the main psychotropic principle, which

varies from 0- 8 % according to the origin and storage time. Pure THC is unstable unless
is kept in dark and under nitrogen but is better preserved in the undamaged plant.
2- Cannabinol (CBN), cannabinal, cannabindiol (CBD) and cannabivarin which have varying
euphoric activity.
3- Other constituents include nitrogenous bases such as choline and cannabinine, traces of
volatile oil, sterols, amino acids and trigonelline.

Uses

Drug act upon C.N.S. produces first excitement accompanied by hallucination and then
followed by lethargy and sleep. (C.N.S. depression).
1- In the past it was used as sedative in mania and hysteria and spasmodic cough but now because
of its narcotic properties, importation to many countries has become illegal.
2- THC is used as an antiemetic for patients receiving cancer chemotherapy as it inhibits intestinal
motility.

Toxicity

It alters perception by acting on CNS producing mental excitement and euphoria. Large
dose produces delirium with enjoyable hallucination followed by sleep interrupted by dreams,
marked weakness and mental depression. The relationship between objects becomes altered, time
seems much longer than clock or absence and impaired recent memory and selective attention.

Chemical tests

1- Add 15% gaseous HCl in dehydrated alcohol to light petroleum extract of the drug give red
color at the junction of the liquids, shake the upper layer becomes colorless while the lower layer
acquires an orange-pink color which disappear on addition of water.

2- Beam’s test

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