**4.7. Ma huang**

**4.3. Ginkgo**

218 Herbal Medicine

**4.4. Ginseng**

**4.5. Kava**

**4.6. St John's wort**

have been detected at acclaimed doses [8].

sants and kava may lead to a comatose state [8, 28].

mouth, headaches, dizziness and photosensitivity [8].

Ginkgo (*Ginkgo biloba*) and its leaf extracts contain active compounds which have been found to improve circulation and cognition. The extracts are sold in both solid and liquid forms and appear to be relatively safe [28]. Medicinal use of ginkgo dates back 2800 BC, the seeds are used as an expectorant, antitussive and anti-asthmatic, and the leaves aid in asthma and cardiovascular disorders [26]. The most common side effects are dizziness, headache, restlessness, vomiting, nausea, diarrhea and dermal sensitivity. Cross-allergenicity with poison ivy has been reported. Ginkgo as an inhibitor of platelet-activating factor may alter bleeding times, therefore it may cause an upsurge of the anticoagulant effect of aspirin and warfarin [28].

Ginseng (*Eleutherococcus senticosus*) is the fourth most extensively used Chinese medicinal herb, treating a variety of conditions. It is used as a general tonic and is claimed to increase the body's resistance against stress and builds up general vitality besides treating diabetes, depression and hypertension [29]. Products are made from dehydrated roots, such as extracts, elixirs and tea, also tablets and capsules. Numerous active constituents, ginsenosides, respectively have specific pharmacologic effects that sometimes compete with each other, thus the whole root is used in preparations [28]. Excessive doses of ginseng have been reported to cause insomnia, agitation and elevation of blood pressure, mastalgia and vaginal bleeding

Kava (*Piper methysticum*) is believed to be beneficial for health by soothing nervous illnesses, inducing sleep and relaxation, reducing weight and counteracting fatigue. It is often used to treat asthma, urinary infections, fever, headaches, syphilis, rheumatism and gonorrhea, it is also used as a stomachic and diuretic [26]. Kava is commonly known as an anxiolytic agent. Reported side effects include dizziness, gastrointestinal discomfort, headaches and localized numbness after oral ingestion. Long term use at high doses may cause scaly, dry skin and discoloration of nails and the skin, eye redness and photosensitivity. Diplopia and photophobia may also occur after excessive consumption. Interaction of central nervous system depres-

St John's wort (*Hypericum perforation*) is specified to possess astringent and sedative properties. It has been used for neuralgia, excitability, fibrositis, menopausal neurosis, sciatica, wounds, depression and anxiety. Modern interest is focused on its antidepressant use [26]. St John's wort possesses active compounds such as hyperforin, hypericin and melatonin. It is reported to have side effects which include fatigue, constipation, nausea, vomiting, dry Ma huang (*Ephedra sinica*) is a medicinal plant traditionally used to treat hay fever, bronchial asthma, colds, coughs, enuresis, myasthenia gravis, narcolepsy, rheumatism and chronic postural hypotension. It contains a number of alkaloids including ephedrine and pseudoephedrine [26]. Ma huang is not considered as a safe herb, with adverse effects including insomnia, dizziness, headaches, nervousness, stroke, seizures, hypertension, psychosis, irritability, myocardial infarction, premature ventricular contraction and death [28].
