Medicinal Herbs and Pharmaceutical Drugs :: Health, Medication

A herb-drug interaction is defined as any pharmacological modification caused by a herbal substance(s) to another exogenous-chemical (e.g. a prescription medication) in the diagnostic, therapeutic or other action of a drug in or on the body (Brazier and Levine, 2003). This relates to drug-drug interactions, herb-herb interaction or drug-food interaction. A herb can potentially mimic, magnify or reduce the effects of co-administered drugs and the consequences of these interactions can be beneficial, undesirable or harmful effects (Fugh and Ernst, 2001). It should be pointed out that both the putative active ingredient(s) and other constituents present in that herbal mixture have the potential to interact with various classes of drugs (Miller, 1998). Many medicinal herbs and pharmaceutical drugs are therapeutically active at one dose and toxic at another. Interaction between herbs and drugs may increase or decrease the pharmacological or toxicological effects of either component. Synergistic and therapeutic effects may complicate the dosing of long-term medication. e.g. herbs traditionally used to decrease glucose concentrations in diabetes could therapeutically precipitate hypoglycemia if taken in combination with conventional drugs (Fugh, 2000). Plausible cases of herb-drug interactions include: bleeding when warfarin is combined with ginkgo (Ginkgo biloba), garlic (Allium sativum), danshen (Salvia miltiorrhiza) and decreased bioavailability of digoxin, theophylline, and cyclosporine when they are combined with St. John’s wort (Hypericum perforatum) etc.,(Shu-feng et al., 2007). Health–care practitioners should caution patients against mixing herbs and pharmaceutical drugs (Fugh, 2000). Cardiovascular diseases particularly myocardial toxicity is one of the leading causes of mortality. Risk factors for cardiovascular diseases are many, like hypertension, atherosclerosis, drugs like doxorubicin & catecholamines like isoproterenol, isoprenaline etc (Gupta et al., 2004). Doxorubicin/Adriamycin (Dox) is a powerful, well established and highly efficacious drug in the fight against many kinds of cancers like solid tumors, leukemia’s, soft tissue sarcoma, breast cancer, small cell carcinoma of the lung and esophageal carcinomas. But its clinical usefulness is still restricted due to its specific toxicities to cardiac tissues (Zhon et al., 2001). Congestive heart failure, cardiomyopathy, and electrocardiographic changes were demonstrated after cumulative Dox administration (Lenaz and Page, 1976). The possible mechanisms proposed for myocardial toxic effects of Dox include free radical induced myocardial injury, lipid peroxidation (Myers et al.