I talk with many traditional healers, who said that the conservation of decoctions, infusions of plant material decrease their pharmacological activity. This is verified scientifically? If so, how would it can be explained?
Dear Dr Nyemb
I don't have any experience in this field and i think that you can test the amount of chemical composition of these preparations during conservation.After this experiment, you can decide scientifically.
Herbal medicines just like their commercial counterparts can degrade over time, especially under varying humidity, heat or dryness. It is well known that powders degrade faster than whole roots - because of the increased surface area. Much depends on the type of active phytochemical. For an example, please read Syamaladevi, R., Andrews, P, davies, N, Walters, T & Sablani, S. (2011) "Storage effects on anthocyanins, phenolics and antioxidant activity of thermally processed conventional and organic blueberries" J. Sci. Food Agr.
I think that refrigeration will reduce the enzyme activity in plant material and then the pharmacological activity when we compared with metabolic activity in live plant
Refrigeration may not reduce the biological activity of plant material if it is maintained at a very low temperature (not freezing).
Heat, light and oxygen would seem to be a greater risk in lowering medicinal properties.
Volatile oils are lost, as well vitamins when subject to these.
According to some scientific reserch I have read recently regarding antioxidant values of medicinal mushrooms, the results found that canned mushrooms had lost significant amounts of antioxidant values, where as freeze dried had lost but a few values. Polysacharide values , mostly responsible for immune defenses, were unaffected by freezing compared to fresh.
I believe there is no blanket answer to this question for all medicinal plants. This depends on the physico -chemical charectereristic of the active ingredient in the medicinal plant. Some times freeze drying needs to be used for heat sensitive substances to ensure we do not loose it all.
Plant drugs contain chemicals and many of them are subject to decay/loss over time.In Ayurvedic literature there is expiry time for all the drugs ,though it varies with forms such as powders, fermented potions,ghrits(Fatty mixtures),pills etc.As a chemist I would say that liquid formulations other than tinctures are sure to decay and lose their potency.
I agree with aSo far my experience goes: 1.There is a gradual loss of bio-activity while plant material is stored in refrigerator. You know that at 0- -80 degree Centigrade the water contents in the plant materials freeze as hexagonal structures, thus killing the plant cells/tissue/structure, and disrupting all the physio-chemical process in the cell. There is no immediate freezing in refrigerator. However if we store plant material instantly at > -85 deg cent, the water freezes as amorphous structures keeping the physio-chemo-morphology status, preserving the plant material in as-is status. Plant extracts showed some what similar activity. However all depends on the type and nature of the bio-active molecules in the plant.
Even, I followed drying plant material at 25-35 deg Cent in a place with constant stabilized, controlled and regulated air flow for perfect dried plant material, I feel if we incorporate freezing and thawing also in this process to make the plant drying process perfect and standardized.
Further I used cold grinding -temperature controlled 15 to 20 deg cent-for preparing powder for extraction purposes.
Even in extract preparation we used graded solvents for differential extraction depending upon the chemical constituents to be extracted.
In all the processes we avoided temperature beyond 35 deg Cent
About the expiry issues, I know that there are some plant derived remedies where it is said that older is better. There fore we can not generalised that medicinal values are lost in all the Natural drugs.
Yes, definitely by refrigeration the biological activity of plant extracts would be lost, since volatile compounds may loss their activity with in less time.
Dear,
Hope u will ge fi9. the medicinal and terresterial plants does not reduces their activity untill they are contaminated with fungus and any other organism. You cam confirm these findings winth a simple activity, that perform activity before and agter freezing. Contamination can destruct chemical constituents in plants.
Regards
M. Asif bhatti
Yes it is the fungal/bacterial contamination which creeps in while drying and storing at room temperature. Therefore, I find. Freeze drying/lypholisation is the best answer for preserving biological activity in plant samples, and storing the samples at -85 d cent
Plants vary in their responses once picked. For example there is a great deal of difference between lavender flowers which dry quickly and retain much of their essential oils and dandelion flowers which continue to age and mature after picking so that within a few days there are puffballs with seeds. What I would like to impress is that there is no one method that will be true for all plants. For some plants cold may trigger enzymatic changes and for others slow change down. What is needed is more experimentation, research and publications in this area.
It is really difficult to give a definite answer to such a question. Because plant material is a set of various compounds, with physico-chemical porperties. The use of refrigerator depends on the temperature at which it is set. Some plant chemicals can be more potent at a cold temperature than at hot temperature , while others are keeping the same efficiency. Morealso, the effect can rather be reduced after refrigeration for some chemicals. Thus, until you study a specific case, you can not conclude for its temperature-depending efficiency.
Hello! Any supporting papers on the effect of cold-grinding and freeze drying?
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