With increasing use of herbal medicine for treating various diseases in recent years, their safety, efficacy and quality aspects are becoming a matter a serious concern, according to Dr Prakash V Diwan, deputy director and head of Pharmacology Division of Indian Institute of Chemical Technology, Hyderabad.

Talking to Pharmabiz, he said that there is a general belief that herbs are safe, effective and have fewer side effects and are accepted by all. According to WHO, 80 per cent of the world population uses the herbal medicine, which warrants critical evaluation for their safety and efficacy. The herbal market is about US $ 20 billion in European countries and about US $ 8 billion in the US.

"For many years, herbal medicine has been used without prescription of the doctor. The data available with respect to its toxicity is very scanty. The published data shows that the risk of plants used for treating various diseases are mainly due to poor quality control, contamination and adding allopathic drugs for effectiveness. The belief and the concept that herbal drugs are safe and free from toxic effects are false. Plants do contain hundreds of compounds and constituents and some of them can be very toxic. But, the nature of toxicity is less serious than that of allopathic drugs," Dr Prakash said.

The plant identification plays an important role. There are two categories of plants, harvested and wildly grown plants. Herbal medicine is finding place in the dermatology segment, but dermatologists are not aware that these herbs can also lead to side effects and cause allergic reactions. The plant products from Eucalyptus, Camphor, Kava, Henna is found to cause serious skin allergic reactions. And thus it is very essential that ayurvedic medicines undergo systematic investigation in terms of safety and efficacy as these products are used for a longer duration, he added.

It is prudent to say that the consumer is not fully aware of herbal toxicity and safety. Post marketing surveillance in herbal market reveals the influence of these herbs on the consumers. Some of the herbal medicines used for the cardiovascular disease have been found to have serious side effects. Inhalation of some essential oils including lavender, jasmine and rosewood used in perfumes or as an ingredient in aromatherapy can elicit similar allergic reactions related to respiratory systems.

He explained, Neem, which is used in the preparation of dental products and is valued for its anti-microbial and anti-inflammatory effects, may cause some problems. If the ideal Neem dentifrice is to be formulated, then the compounds that promote dental health should be retained and other components that can cause adverse effects need to be eliminated. Neem oil, bark and leaf extracts are particularly bio-reactive and are currently being evaluated for a wide range of medicinal uses including hypoglycemic action and as contraceptive due to immuno-modulatory effects.

Detoxification and clearance of poisonous substances from the body are primarily a function of liver and kidneys and they are often the first to be affected by toxic herbs. One should be aware of the fact that herbal medicines are usually formulated from various raw materials and contain wide range of compounds and substances that can vary in pharmacokinetic and pharmacodynamic properties, Dr Diwan added.

He recommended certain guidelines for effective use of herbal medicine:

a. Do not depend upon the product claim by manufacturer
b. Always inform your physician about your herbal medicine
c. Do not exceed the recommended dosage
d. Know the potential drug interactions
e. Never use herbal drugs during pregnancy or nursing the child
f. Take care when given to children or elderly
g. Do not use for serious illness
h. Do not use for prolonged periods
i. Select the standardised formulations from standardized pharma companies
j. Do not venture to collect the plant by yourself as it may prove dangerous
k. Store them appropriately as prescribed, consult herbal physician before consuming, report immediately to your doctor if there are adverse effects, make sure that the herbs are scientifically proven for disease treatment.