Research has shown that chances of identifiying a lead compound from an ethnopharmacological/ethnobotanical survey are much higher than those from a random survey. Ethnopharmacological surveys tend to consume less time and are less costly. They also give a justification for the selection of a particular plant species for particular tests.

For example Svetaz et al., (2010), found a significantly higher probability (p < 0.01) of detecting plants with antifungal activity (MIC≤1000μg/mL) against at least one fungus when plants possess reported ethnopharmacological uses related to fungal infections. 

The Random approach is known to be costly and time consuming. Imagine doing a random screening for plants for a particular disease target in the tropics where the plant diversity is very high! You may take ages, or use expensive high throughput screeing targets to achieve your targets.

The National Cancer Institute (NCI) in the USA had such an approach while screening plants for anticancer properties in the 70's. They were not very successful.

See

Svetaz, L., Zuljan, F., Derita, M., Petenatti, E., Tamayo, G., Cáceres, A., . Gupta, M. (2010). Value of the ethnomedical information for the discovery of plants with antifungal properties. A survey among seven Latin American countries. Journal of Ethnopharmacology, 127(1), 137-158. doi: http://dx.doi.org/10.1016/j.jep.2009.09.034

to start research on medicinal plants for its therapeutic value evidence of ethnopharmacology is necessary. Further to get any lead for the phytoconstiutents etc also ethno use is also helpful. Generally it is told that for any research history is important so all so the medicinal plants.

Selection of a plant for research in the area of medicinal plants on the basis of  ethnopharmacology may have certain advantages  like reduction in time and cost involved. Ethnopharmacology has given many lead in medicinal plants research. On the other-hand random selection of plants may explore new pharmacological uses. 

Research has shown that chances of identifiying a lead compound from an ethnopharmacological/ethnobotanical survey are much higher than those from a random survey. Ethnopharmacological surveys tend to consume less time and are less costly. They also give a justification for the selection of a particular plant species for particular tests.

For example Svetaz et al., (2010), found a significantly higher probability (p < 0.01) of detecting plants with antifungal activity (MIC≤1000μg/mL) against at least one fungus when plants possess reported ethnopharmacological uses related to fungal infections. 

The Random approach is known to be costly and time consuming. Imagine doing a random screening for plants for a particular disease target in the tropics where the plant diversity is very high! You may take ages, or use expensive high throughput screeing targets to achieve your targets.

The National Cancer Institute (NCI) in the USA had such an approach while screening plants for anticancer properties in the 70's. They were not very successful.

See

Svetaz, L., Zuljan, F., Derita, M., Petenatti, E., Tamayo, G., Cáceres, A., . Gupta, M. (2010). Value of the ethnomedical information for the discovery of plants with antifungal properties. A survey among seven Latin American countries. Journal of Ethnopharmacology, 127(1), 137-158. doi: http://dx.doi.org/10.1016/j.jep.2009.09.034

I agree with Dr. Anywar, research to  identify  compound from an ethnopharmacological/ethnobotanical survey are much higher than those from a random survey. Ethnobotanical surveys provide  a rich source of information regarding plants and their uses, and several studies have confirmed the biological activities in some plants and related them to their traditional uses.

I fully agree with the explanation given by Dr Godwin Anywar from Makerere University. I will simply attach my notes on few slides where I also indicate the sources in the books by Martin, and Balick and Cox, both 1996 editions but you can even get later editions.

Thank you all for the suggestions.

I agree with Godwin and Rana.  Ethnopharmacological approach and bioassay guided isolation have for example, provided a lead in identifying potential AChE inhibitors from plant sources, including those for memory disorders (e.g., galanthamine).

Ethnobotanical and ethnopharmacological surveys give us idea in advance whether a plant has medicinal property or not. Informant consensus factor, fidelity level, use mentions, etc. tools under ethnopharmacological survey guides us and facilitates us to select the medicinal plant for bioassay. 

Dear all,

Thank you so much for your valuable thoughts.

Dear All,

I would be grateful to you all if you ponder your thoughts over this question which i just asked on Research gate.

Which part of a medicinal plant should be selected for research?

It depends on your medicinal plant. All plant parts are equally important for pharmacological screening. Alkaloids, phenolic glycosides, and cyanogenic glycosides are expected to be higher in annual medicinal herbs whereas phenolics are higher in forest tree species. In general, roots and rhizomes are best at commencement.  

Ethno- Pharmacological bases will be more suitable to start research on medicinal plant rather than random selection. Becz. plants reported in ethnopharmacological studies are the medicinal species which are already in use by traditional practitioners for a reported disease or symptoms.

Justification for selection of the plant will also be easy if the plant is selected based on ethnopharma.. report. There are successful studies or outputs were obtained when the research is started based on ethnopharma reports. Examples can be seen in J of Ethnopharmacology, and Phytotherapiea. These journal accept the plant research carried out based on ethnopharma reports.

As given by Anywar random selection tedious job.

no. It must me cogent.

The first research is always best fit with the ethnopharmacological basis. It helps you approach the medicinal plants and even encourage to appraise and rectify the use that has long been adopted. Ethnopharmacological basis also helps you build strategy for sampling poisonous plants for research. This generates the idea of which plant parts are pharmacologically enriched and good to sample.