Plants as sources of biomolecules for pharmaceutical drugs

Jiten Sharma
Contd from previous issue
ometimes, after identification of the chemical structures, molecules are synthesized, thus contributing to precise experiments for evaluating the biological activities. By in vitro tests carried out on specific cell lines which mimic human pathologies, it is possible to evaluate whether plant molecules have biological activities.
The data obtained can then beassessedfor potential perspectives of pharmaceuticals used against cancer or degenerative pathologies, anti-microbial activities and anti-viral pharmaceuticals, stimulation in human immune system, efficiency of  vascular system and sperm movement contributing to contraceptive pharmaceuticals. Common plants such as ginger (containing 6-gingerol, 6-shogaol and zingerone), garlic (allicin, alliin and 6-allylcysteine), turmeric (curcumin and related curcuminoids), bean (phaseolin), ginseng (ginsenosides and saponins), peppermint (menthol and rosmarinic acid), fennel (trans-anethole), rosemary (oleanolic acid), sage (safficinolide), etc. are widely used in Indian system of traditional medicine. Plants like betel nut (containing arecoline and guvacine), tea (catechin, caffeine, and epicatechin gallate), bittergourd (momordicine and charantin),tulsi (eugenol, vicenin and orientin),amla (phyllantin and phyllantidine), etc. are used to treat human immunodeficiency virus. Even to cure the dreaded covid-19, several plants possessing anti-viral properties such as licorice (containing glycyrrhizin, liquiritigenin and glabridin), bayberry (myricetin and linolenic acid) and sweet sagewort (artemisinin) have been used.
The results of such in vitro investigations are dependent on the accuracies of the screening methods. In recent times, well-established screening methods and accurate protocols for biological tests are available.It is also possible to use virtual screening software to test libraries of compounds on panel of targets characterizing different pathologies. Molecules showing biological activities are further experimented in pre-clinical phases using laboratory animals, and if such tests confirm the results without toxic effects, further human experimentation can start. The human experimental protocol(s) must be carried out and evaluated following precise guidelines established at the international level. It consists of different steps of investigation during which accurate biochemical studies are carried out to establish the drug, human target(s) and molecular mechanism(s) of action.