HOW STANDARDIZED ARE OUR HERBAL MEDICINES IN GHANA?
Herbal medicines are prepared from a variety of plant materials such as leaves, stems, stem bark, roots, root bark, fruits and flowers. These are harvested mainly from the wild and at various stages of development. Plant raw materials harvested at various stages of development contain active constituents that may also be at different stages of biosynthesis. While young plants may contain only precursors, over-aged plants may contain degradation products of the active ingredients. For instance, monkshood is harmless when young but when mature, it contains highly toxic alkaloids.
Active ingredients are usually unequally distributed among the different parts of the plants, active constituents are concentrated in a single part of the plant. For instance, the invigorating constituents of ginseng are concentrated in only the roots. In some other plants, different types of active ingredients are found in different parts of the plant. For instance, the fruits of the orange tree contain invigorating substances while sedative substances are located in the flowers.
Due to inherent variations in the concentrations of active constituents, which sometimes make it difficult to establish how effective herbal medicines are, a lot of skeptisms have been associated with the use of herbal medicine
These observations, and others, bring to the fore the need for standardization of herbal medicines. Without standardization, herbal medicines, as they are now prepared in Ghana, are likely to contain varying levels of active constituents. Some medicines may have high levels of active constituents and thus lead to over-dose while others may have little or no active constituents at all, and may at best be described as placebos.
Standardization should begin with cultivation of medicinal plants, and herbal medicine manufacturers should be encouraged to use cultivated medicinal plant raw materials in the production of their medicines. Cultivated plants offer several advantages in terms of standardization. The plants can be cultivated in homogeneous climatic and soil conditions and can be harvested at the right time (i.e age and time of collection).
Plant material processing should also be standardized.
Harvested raw materials need to be dried at controlled time and temperature to ensure stability of the active constituents. Processed raw materials could then be stored under appropriate conditions.
The manufacturer of the final product should also set and follow standard operating procedures and also be guided by Good Manufacturing Practice to ensure production of quality herbal medicines and make herbal medicines more acceptable both locally and internationally.
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