Phytotherapy & Central Nervous System PDF

Phytotherapy & Central Nervous System  CNS stimulant plants CNS stimulant plants are classified into the following: 1- Medullary or brain stem stimulants (analeptics): picrotoxin. 2- Spinal cord stimulants: strychnine. 3- Cerebral cortex stimulants: Caffeine, Atropine (large dose) and Coccaine...

Phytotherapy & Central Nervous System  CNS stimulant plants CNS stimulant plants are classified into the following: 1- Medullary or brain stem stimulants (analeptics): picrotoxin. 2- Spinal cord stimulants: strychnine. 3- Cerebral cortex stimulants: Caffeine, Atropine (large dose) and Coccaine. 4- Hallucinating drugs: cannabinoids and lysergic acid.  Cocculus (Fishberries)  Picrotoxin is very toxic substance used in stupefying fish.  Intravenously, it was used as antidote for barbiturates and narcotics because of its CNS stimulant effect (GABA inhibitor).  Picrotoxin is an analeptic drug having a very narrow margin of safety.  P.S. GABA= γ-aminobutyric acid.  Nux vomica seeds  Strychnine is used as: 1- Circulatory stimulant in cases of surgical shocks. 2- Respiratory stimulant. 3- Improves appetite and digestion. 3- Sexual tonic. 4- Rodenticide because of its high toxicity.  Nux vomica seeds Pharmcological effects of strychnine:  Strychnine is CNS stimulant and its site of action is spinal cord.  In large dose this stimulation extends upward to the brain stem (ascending CNS stimulation).  In its site of action, strychnine is antagonist to an inhibitory neurotransmitter called glycine.  Nux vomica seeds In toxic doses strychnine results in tetanic convulsions characterized by the following: 1- Reflex in Origin. 2- Symmetric in both sides of the body. 3- Attacks lasting from 1-2 min followed by exhaustion and a new attack and so on. 4- Death occurs after 2-5 attacks.  Cocaine  Once inhaled, it is readily absorbed into the bloodstream. Once cocaine reaches the brain, dopamine gets released, stimulating pleasurable feelings.  The physical signs of cocaine abuse can vary, depending on the person. For one, cocaine acts as an appetite suppressant so cocaine abusers often aren't hungry and end up losing considerable amounts of weight.  Also, after intense happiness, paranoid feeling, anger, irritability, over sensitivity to the surrounding sound, sight or touch  Cocaine How cocaine affects the brain  Once cocaine reaches the brain, dopamine is released by a neuron into the synapse, where it can bind with dopamine receptors on neighboring neurons. Normally, dopamine is then recycled back into the transmitting neuron by a specialized protein called the dopamine transporter. If cocaine is present, it attaches to the dopamine transporter and blocks the normal recycling process, resulting in a buildup of dopamine in the synapse, which contributes to the pleasurable effects of cocaine.  Cannabis (Indian Hemp)  Cannabinoids has the following effects: Positive effects 1- Mood lift 2- Relaxation, stress reduction 3- Creative, deep thinking: ideas flow more easily 4- Increased appreciation of music. More aware of (deeper) connection to music. 5- Increased awareness of senses. (eating, drinking, smell) 6- Change in experience of muscle fatigue. Pleasant body feel. 7- Pain relief (headaches, cramps) 8- Reduced nausea, increased appetite (used medically for this, with chemotherapy)  Cannabis (Indian Hemp)  Negative effects 1- Nausea, especially in combination with alcohol, some pharmaceuticals, or other psychoactive drugs 2- Coughing, asthma, upper respiratory problems 3- Difficulty with short term memory during effects and during periods of frequent use 4- Mild to severe anxiety 5- Headaches 6- Dizziness, confusion CNS depressant plants 1- Conium (Hemlock)  This is said to be the plant that Socrates took in 399 BC  It contains liquid volatile piperidine alkaloids (coniine, g-coniceine, conhydrine, pseudoconhydrine, N-methylconiine).  It is very toxic, medullary depressant in treatment of convulsive diseases as epilepsy, tetanus, whooping cough  CNS depressant plants 2- Hyoscine  A major tropane alkaloid of solanceous plants.  It is CNS depressant and sedative and antiemetic in motion sickness.  It decreases the REM stage (rapid eye movement) and prolongs the non- REM stage of sleeping leading to very deep sleeping.  Antispasmodic to relief cramps in smooth muscles of colon and stomach