Evaluation of Therapeutic Potential of Selected Plant-Derived Homeopathic Medicines for their Action Against Cervical Cancer

Background: Plant-derived homeopathic medicines (HMs) are cheap and commercially available but are mechanistically less explored entities than conventional medicines. Aim: To evaluate the impact of selected plant-derived HMs from Berberis aquifolium (BA), Berberis vulgaris (BV), Mentha piperita (MP), Curcuma longa (CL), Cinchona officinalis (CO), Thuja occidentalis (TO), and Hydrastis canadensis (HC) on cervical cancer (CaCx) cells in vitro . Methods: Mother tincture (MT) and 30C potencies of the selected HMs were screened for anti-proliferative and cytotoxic activity on human papillomavirus (HPV)-negative (C33a) and HPV-positive CaCx cells (SiHa and HeLa) by MTT assay. Total phenolic content (TPC) and the free-radical scavenging activity of each homeopathic medicine were determined using standard assays. Phytochemicals reportedly available in these HMs were examined for their potential inhibitory action on HPV16 E6 by in silico molecular docking. Results: All tested MTs induced a differential dose-dependent cytotoxic response that varied with cell line. For C33a cells, the order of response was TO > CL > BA > BV > HC > MP > CO, whereas for SiHa and HeLa cells, the order was HC > MP > TO > CO > BA > B V > CL and CL > BA> CO, respectively. Analysis revealed anti-oxidant content of BA, BV, and HC had the lowest contribution to their anti-CaCx activity. Using in silico modelling of molecular docking between the HPV16 E6 protein crystallographic structures and main phytochemical components of BV, BA, HC, CL, and TO, their potential to inhibit the HPV16 E6 protein carcinogenic interactions was identified. Conclusion: The study showed a comparative evaluation of the potential of several plant-derived HMs to affect CaCx cell line survival in vitro and their theoretical molecular targets in silico for the first time. Data demonstrated that MTs of BA and BV are likely to be the most potent HMs that strongly inhibited CaCx growth and have a strong anti-HPV phytochemical constitution.