An in vitro evaluation of extracts from some medicinal plants in Kenya against herpes simplex virus.

The extracts from 21 medicinal plants commonly used in traditional remedies in Kenya were screened for antiviral activity against wild type 7401H strain herpes simplex virus type 1. The plant extracts exhibited antiviral activity against the virus in the plaque and yield reduction assays. The results reveal that twelve plants may contain constituents that could be exploited for the management of HSV infections. Although the extracts used in these experiments contain a complex matrix of a large number of compounds the results indicate that useful compounds can be isolated for further exploitation.

Effect of an aqueous extract of Azadirachta indica on the immune response in mice.

Because of the very wide spectrum of infectious and non-infectious diseases for which preparations from Azadirachta indica are said to be efficacious, it was suspected that a general immunopotentiating ability could be part of the mechanisms by which it ameliorates so many disease conditions. Using the haemolytic plaque technique, an aqueous extract of Azadirachta indica stem bark was shown to enhance the immune response of BALB/C mice to sheep red blood cells in vivo.

Newer directions for plant drug research: The need to examine and investigate traditional remedies for pharmacotherapy of animal and zoonotic diseases.

Traditional remedies for animal diseases have not been investigated as much as those for human diseases. Yet, there is a wealth of knowledge available to be tapped from the remedies used in the treatment of animal and zoonotic diseases. The indigenous knowledge available could be rationalized in the modern pharmaceutical context and applied directly to field use where appropriate. Furthermore, it is well known that many drugs have been developed initially through their use in animals because the ethical issues are easier to handle. It is worth examining some the indigenous medicinal plants that are used for both human and animal disease treatment, and determine the practical and cost-effective ways of exploiting the values of these plants.

Anti-trypanosomal effects of some compounds isolated from the extracts of Warburgia ugandensis.

The plant kingdom has been used as a source of compounds employed in the treatment of many disease conditions for many years. Even with the new technology in synthetic chemistry, plants are still being used as a source of lead compounds in drug development. In the treatment of trypanosomiasis, the drugs that are currently in the market were developed between 1950-1960's. These drugs are expensive and associated with a number of toxic effects, therefore there is still need to develop newer drugs in the management of trypanosomiasis. The plant Warburgia ugandansis is a common plant that has been used traditionally to treat many disease conditions. The crude and pure compounds from this plant were tested against trypanosomes: T. congolense, T. evansi and T. bruceL In vitro tests using tissue culture method and in vivo tests using mice were carried out The results of the in vitro method indicated that the pure compound was more active than the crude extract The in vivo method indicated that the total extract was not effective, while one of the pure compounds was too toxic, and the other one showed activity. The two compounds investigated were basically of the same structure type with a slight difference on the functional groups. These preliminary results indicate that there is a possibility of finding active compounds against Trypanosomes in plants.

Optimization of pharmaceutical formulations for therapy

A pharmaceutical formulation is aimed at ensuring drug delivery at the site of action in order to produce the desired therapeutic effect. The design of a pharmaceutical formulation must reflect the chemical reactivity of the drug substance as well as those of any other substances that are used in the formulation. Standardized manufacturing procedures which conform to accepted codes of Good Manufacturing Practices are prerequisites for the preparation of pharmaceutical formulations for optimal drug delivery. Drug formulations produced by such methods are expected to have the desired bioavailability characteristics for pharmacotherapy. The different types of pharmaceutical formulations usually prepared for administration by various routes are aimed at achieving the most appropriate drug delivery system for each drug. When necessary; special drug delivery systems are designed to achieve this objective. Advances in biotechnology has led to production of labile substances for use as drugs in therapy and this has created new challenges in the development of novel drug delivery systems. [abstract terminated]