Antibiotics have an important place in modern drug medicine and prevention of various aliments. The philosophy behind their use in the treatment of infections is simple; they kill the invading organism without harming the host tissue. The development of antiviral drugs along similar lines has not lived up to early expectations. This is largely because a virus does not show all the qualities of a living organism until it invades the host cell . This means that:
- Viruses are difficult to inactivate chemically and usually require highly toxic agents to do so.
- Once a cell is infected it is difficult selectively to inhibit the virus without harming the cell.
Also viruses can exhibit rapid rates of mutation which make immunity difficult to sustain. It is even possible that viruses, through natural selection, are becoming better equipped at infecting host cells and evading immune destruction.
The world least developing Countries are currently facing the prospects of two major chronic viral epidemics among other prevailing infectious diseases, those are AIDS and Hepatitis B, and due to the poverty and lack of health care facilities, uses of medicinal herbs has consequently intensified , and have much to offer in this area. Plants are subject to viral infections too and it is possible that they have evolved effective and nontoxic antiviral metabolites. Even if this is not the case, the diversity of chemical compounds found in plants far exceeds the human imagination, and it is likely that potent non-toxic antiviral agents already exist, however it is unfortunate that medicinal plants which can contribute to the prevention of so many infectious diseases are underscored only by the traditional healers, waiting recognition and new developments in research to take place by professional investigators from and outside of this least developed world. We will now proceed to review some commonly used herbs (Materia Medica).