Biological Evaluation Strategy: From In-Vitro to In-Vivo

Biological activity evaluation is the process by which the phytochemical composition data generated in Phase 3 is translated into functional pharmacological evidence of therapeutic potential, and follows a deliberately hierarchical, resource-efficient strategy. In-vitro screening — using isolated enzymes, cultured cells, or microbial cultures — establishes whether a candidate extract or compound possesses measurable activity and quantifies its potency, typically expressed as an IC50 or MIC value, using assay platforms that are rapid, inexpensive, and amenable to testing many samples in parallel. Compounds or extracts demonstrating consistent, mechanistically plausible in-vitro activity then proceed to in-vivo animal studies, which confirm efficacy within the full physiological complexity of a living organism and additionally generate preliminary safety data. Finally, mechanistic studies — spanning enzyme kinetics, receptor binding, gene and protein expression analysis — elucidate the specific molecular mode of action underlying the observed activity, completing the pharmacological characterisation of the candidate herbal drug.