Use of Human Primary Stem Cell Cultures for Screening Cell Proliferation Stimulatory and Inhibitory Effects of Botanical Preparations: an Alternative to Animal Models

Animals are widely used in scientific research as highly specific ‘models’ of humans. Primary cell culture is a widely used model to reduce and replace the use of animal models, as per the 3R concept. We investigated cell stimulatory effects of selected botanical preparations on primary human stem cell cultures, in place of animal models. Primary human fibroblast stem cell (hFSC), human mesenchymal stem cell (hMSC), and human haematopoietic stem cell (hHSC) cultures, were established in-house, and characterized by immunophenotyping. Varying concentrations of selected botanical preparations (mature leaf concentrate of Carica papaya Sri Lankan wild type cultivar [MLCC], distillates of Vernoina/ Mallotus [VMD], and Ficus benghalensis [FBD]) were tested ex vivo for cell proliferation stimulation on these cell platforms, using the MTT assay. Compared with untreated controls, significant proliferative effects were demonstrated by MLCC on female (at 0.2% concentration) and male (0.6%) hMSCs, and on male and female hHSCs (0.6-0.2%) (P<0.05). FBD (0.05-1.2%) stimulated significant proliferation of both male hMSCs, and male hHSCs, but inhibited proliferation of female hMSCs (P<0.05), with no significant effects on female hHSCs. Conversely, VMD (0.2-1%) showed significant inhibitory effects on both male and female hMSCs, yet at 0.6% showed significant proliferative effects on female hHSCs (P<0.05). Selected VMD concentration exhibited approximately 1.5-folds higher % cell stimulation than the positive control (p < 0.01). Thus, eff ective cell proliferative concentrations of botanical preparations were identified using primary stem cell lines, aligning with “replacement” as per the 3R concept. Keywords: Human stem cells; botanical preparations; cell proliferation stimulants; 3R concept; Animal models