TOXICITY OF HEAVY METALS IN SOME MEDICINAL PLANTS

The heavy metals are elements which occur naturally and occur into the water and soil mostly. In the biological process the metals are important but it is also toxic for the human when occur in more amount. In the metals trace level of copper, iron, manganese, zinc and nickel are important for the plant for their different activity. The some metals are non essential for the human activity but it causes toxicity in human like lead, mercury, aluminum and arsenic. The World Health Organization has mention that in the world herbal medicine share is reach about 60%. The plant which used in therapeutic remedy they accumulate the heavy metal from the soil and produce toxicity in human. This accumulation of heavy metals shows its effect when that herbal plant consumed as remedies or dietary supplement. The long term accumulation of heavy metals like arsenic, cadmium, leads and mercury it causes serious health problems like cancer, kidney damage, neurological damage and developmental disorders. In the modern period the plants grows under technogenic pressure for medicinal purpose, the material harvested such condition sources of different toxicant enter human body. In the toxicant primarily heavy metals, nitrates, pesticides and some other xenobiotics which affect human health. In the environment common heavy metals are mercury, lead and cadmium, the vehicles, agriculture production, industry, thermal power plants and waste incinerates are main sources. The Russian Federation Pharmacopoeia state that the medicinal plants not contain exceed than 1.0 mg per kilogram arsenic, 6.0 mg cadmium to per kilogram and mercury about 1.0 mg per kilogram. In the Indian medicinal plants like Terminilia chebula, Terminilia belerica, Adhatoda vascia, Acorus calamus, Phyllanthus emblica, Ocimum sanctum, Asparagus, Piper longum, Withania sominifera, Tinospora cardfolia and Tribulus terrestris. The heavy metals like mercury, nickel, zinc, chromium, iron, copper and lead like heavy metals are presents in these medicinal plants. These plants used as medicinal purposes Terminilia chebula plants seed is used as laxative, Terminilia belerica plants seed is used as laxative and anti-pyretic, Phyllanthus emblica plants fruit is used as digestive and revitalize, Piper longum plants fruit is use as digestive and bronchitis, Adhatoda vascia plants leaves are used expectorant and asthmatic, Withania sominifera plants roots are used as nerve tonic and Ocimum sanctum plant used in cough and fever.