Biology subjects

Samarakoon, S. R.

Publications and source records attributed to Samarakoon, S. R..

5 recordsLinked to original sources

bioRxiv2026

In vivo pharmacokinetics and tissue distribution profile of a Wnt/β-catenin pathway-targeting anticancer cassane diterpene isolated from Caesalpinia pulcherrima

A cassane diterpene, 6{beta}-cinnamoyl-7-hydroxyvouacapen-5-ol (6{beta}CHV), isolated from Caesalpinia pulcherrima, has emerged as a promising anticancer drug lead with reported Wnt/{beta}-catenin pathway inhibitory activity and in vivo safety. The present study reports the in vivo pharmacokinetics and tissue distribution of 6{beta}CHV in Wistar rats following a single oral dose of 200 mg/kg. A reproducible RP-HPLC-UV method was developed and validated for quantifying 6{beta}CHV in rat plasma and tissues. Chromatographic separation was achieved using a gradient elution of methanol and water. The method was subsequently applied to investigate the pharmacokinetics and tissue distribution of 6{beta}CHV. Plasma pharmacokinetic analysis revealed delayed and moderate absorption, with a Tmax of 4 h and a Cmax of 1314.12 ng/mL. Following absorption, 6{beta}CHV is distributed widely across peripheral tissues, including the liver, heart, lungs, spleen, and kidneys, as well as pharmacological sanctuary sites such as the brain and testes. The highest concentrations were observed in the stomach, small intestine, and liver, with detectable levels persisting up to 24 h, reflecting extensive tissue partitioning and retention. Overall, these findings demonstrate that oral administration of 6{beta}CHV is feasible. However, the delayed absorption suggests that further optimization of formulation or alternative administration routes may enhance systemic exposure. This study provides the first comprehensive pharmacokinetic and tissue distribution profile of 6{beta}CHV, supporting its continued preclinical development as a potential anticancer therapeutic. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/715187v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@1621f86org.highwire.dtl.DTLVardef@1039b3aorg.highwire.dtl.DTLVardef@1c40175org.highwire.dtl.DTLVardef@13bcf2f_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2025

Preclinical Safety Evaluation of Vernolac, a Commercially Available Polyherbal Nutraceutical Comprising Vernonia zeylanica, Nigella sativa, Hemidesmus indica, Smilax glabra, and Leucas zeylanica, in Wistar Rats

Vernolac is a commercially available polyherbal formulation comprising Vernonia zeylanica aerial parts, Nigella sativa seeds, Hemidesmus indica roots, Smilax glabra rhizome, and Leucas zeylanica aerial parts. Although previous in vitro studies have demonstrated anticancer potential of Vernolac and its active ingredients, safety data are available only for some of the plant ingredients of Vernolac. In the present study, acute and 28-day repeat-dose toxicity of Vernolac were evaluated in Wistar rats following OECD guidelines 420 and 407, respectively. Acute toxic effect was investigated during 14 days after administering a single oral dose of 2000 mg/kg to 10 animals (5 males, 5 female) which was followed by repeat-dose study where a human equivalent therapeutic dose HED (165 mg/kg/day), a mid-dose (2x HED, 330mg/kg/day) and a high dose (4x HED, 660 mg/kg/day) were administered separately to a group of 10 fresh animals (5 male, 5 female) for 28 days. In both acute and repeat-dose studies, no morbidity, mortality, changes in food and water intake, relative organ weights, microscopic changes in organs, hematological changes, or clinical signs of toxicity were observed. In the acute study, significant differences appeared only in AST and ALT levels in males, indicating the liver may be a target organ of toxicity at extremely high doses. In 28-days repeated dose study, a significant reduction in ALT was observed only in females receiving high doses, with no changes in males. In summary, a dose up to four times the therapeutic daily dose is non-toxic in Wistar rats over a 28-day period.

pharmacology and toxicology↗

bioRxiv2025

Anti-proliferative and Apoptosis Inducing Effect of Thymoquinone in Human Teratocarcinomal (NTERA-2) Cancer Stem-Like Cells

Cancer stem cells (CSCs) are key drivers of tumor progression, therapeutic resistance and recurrence. Nigella sativa, a medicinal plant widely used in traditional medicine, has gained significant importance due to its diverse pharmacological properties. Thymoquinone (TQ), a biologically known active compound isolated from N.sativa, has demonstrated anticancer properties in various cancers. However, its effect on CSC-like cells has not been fully elucidated. In the present study, the anti-proliferative and apoptosis inducing properties of TQ was evaluated on human embryonal carcinoma cells (NTERA-2, cancer stem cell like model) and human peripheral blood mononuclear cells (PBMCs) in vitro. Antiproliferative effects of TQ on NTERA-2 cells and PBMCs were evaluated using the Sulforhodamine B (SRB) and WST-1 assays, respectively. The effect of TQ was further evaluated using colony formation assay, cell migration assay, fluorescence microscopy and quantification of caspase 3/7 activities. Oxidative stress markers (reactive oxygen species [ROS]) were also determined in NTERA-2 cells treated with TQ. Thymoquinone revealed promising dose- and time-dependent antiproliferative effects (half-maximal inhibitory concentration [IC50] 1.282, 1.167, and 0.984 g/mL at 24, 48, and 72 h post-treatment) in NTERA-2 cells while exerting a minimal cytotoxic effect in PBMCs. Apoptosis related morphological changes, and increased Caspase 3/7 activities confirmed the pro-apoptotic effects of TQ. Further, NTERA-2 cells treated with TQ expressed a significant increase (P < 0.001) in intracellular ROS activity. Overall results confirm that TQ exerts anti-proliferative and apoptotic effects in a dose- and time-dependent manner. Therefore, TQ can be considered as a potent drug lead for chemotherapy and radiotherapy resistant cancer stem cells.

pharmacology and toxicology↗

bioRxiv2025

A network pharmacology-based approach and molecular docking study to explore the therapeutic potential of a nutraceutical formula (Vernolac) in the treatment of cancer

Vernolac is a commercially available polyherbal nutraceutical capsule comprised of Vernonia zeylanica aerial parts, Nigella sativa seeds, Hemidesmus indicus roots, Leucas zeylanica aerial parts, and Smilax glabra rhizome. Different herbal formulations, organic extracts, and many isolated phytochemicals of the above plants have been reported to exhibit anticancer properties. However, the anticancer mechanisms of action of Vernolac, as a polyherbal formulation, remain unexplored. This study employed an integrative network pharmacology-based approach, complemented by in vitro experiments, to investigate the anticancer potential of Vernolac. Phytochemicals in Vernolac were retrieved from databases, screened for drug-likeness and oral bioavailability using SwissADME, yielding 155 drug-like phytochemicals, and their protein targets were predicted via SwissTargetPrediction. The intersection of targets of phytochemicals and cancer-related targets from GeneCards yielded 137 common targets. Protein-protein interaction analysis in STRING and Cytoscape identified key hub nodes, including AKT1, BCL2, CASP3, CTNNB1, EGFR, ESR1, GAPDH, HSP90AA1, HSP90AB1, IL6, JUN, SRC, STAT3, and TNF. Clustering, topology, and formula-herb-compound-target-disease and target-pathway networks highlighted key phytochemicals, including vernolactone, thymoquinone, quercetin, nigellidine, -hederin, and carvacrol. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed that the identified targets are significantly enriched in multiple cancer pathways. Molecular docking and dynamics simulations identified novel target-ligand interactions. Overall, network analysis suggests that Vernolac may exert anticancer effects through apoptosis induction, immune modulation, antioxidant, anti-inflammation, antiproliferative, and chemoradiosensitizing mechanisms. Moreover, Vernolac may exhibit chemoradioprotective potential by alleviating therapy-induced toxicity, supporting its promise as a potential adjunct to conventional cancer treatments. The Sulforhodamine B assay demonstrated selective antiproliferative activity of Vernolac against cancerous cells MCF-7 (IC50 = 54.01 {+/-} 0.02 g/mL), Caco-2 (IC50 = 85.52 {+/-} 0.13 g/mL), NTERA-2 cl.D1 (IC50 = 42.41 {+/-} 0.06 g/mL), and non-cancerous MCF-10A (IC50 = 803.5 {+/-} 0.03 g/mL). Novel target-ligand interactions identified via molecular docking and dynamics simulations, and the underlying mechanisms of Vernolac predicted in this study, require further validation through in vitro and in vivo experiments.

bioinformatics↗

bioRxiv2025

In vitro anti-cancer properties of a commercially available polyherbal nutraceutical (Vernolac) capsule on cancer stem cell-like (NTERA-2 cl.D1) cells.

Vernolac is a commercially available polyherbal nutraceutical formulation comprising Vernonia zeylanica aerial parts, Nigella sativa seeds, Hemidesmus indica roots, Smilax glabra rhizome, and Leucas zeylanica aerial parts. Previous studies have demonstrated anti-cancer activities of phytochemicals derived from these individual plant components. However, the anti-cancer properties of the supercritical CO2 extract of Vernolac remain unexplored against cancer stem-like cell populations. The current study is focused on the anti-cancer potential of Vernolac extract on NTERA-2 cl.D1 cancer stem-like model, a human embryonal carcinoma-derived pluripotent cell line. Gas Chromatography-Mass Spectrometry (GC-MS) was performed for phytochemical analysis. Several in vitro assays evaluated the anti-cancer properties of the Vernolac extract. Cytotoxicity was assessed using the Sulforhodamine B assay, and apoptosis induction was determined by Acridine Orange/Ethidium Bromide staining and the caspase 3/7 activity assay. Scratch assay was used to evaluate cell migration, and Reverse Transcriptase quantitative Polymerase Chain Reaction (RT-qPCR) was performed to analyze the expression levels of apoptosis-related genes (TP53, BIRC5) and the autophagy-related gene mTOR. Further, the free-radical scavenging activity of Vernolac extract was assessed using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay. The reactive oxygen species levels in NTERA-2 cl.D1 cells were quantified using the nitroblue tetrazolium assay. GC-MS analysis revealed 20 phytochemical constituents in the supercritical CO2 extract. In vitro assay results demonstrated that Vernolac extract exhibits significant anti-proliferative activity in NTERA-2 cl.D1 cells, with an IC50 of 41.12 {micro}g/mL at 48 h, while exerting minimal effects on non-cancerous MCF-10A cells (IC50 > 1000 g/mL). Fluorescence microscopy and caspase 3/7 assay showed that Vernolac extract leads to early apoptosis in NTERA-2 cl.D1 cells. RT-qPCR revealed the upregulation of tumor suppressor protein P53 while downregulating BIRC5 and mTOR. Additionally, Vernolac extract inhibited the migration rate of NTERA-2 cl.D1 cells and elevated intracellular reactive oxygen species levels. These findings suggest that the supercritical CO2 extract of Vernolac exerts potent anticancer properties against NTERA-2 cl.D1 cancer stem-like model, highlighting its therapeutic potential for targeting cancer stem cells.

pharmacology and toxicology↗