β-Sitosterol from Ipomoea carnea Jacq. As a promising anti-inflammatory agent: Evidence from in silico modeling and in vitro validation

A sterol molecule extracted from the shrub Ipomoea carnea Jacq. has emerged as the leading anti-inflammatory candidate from a new study that combined network pharmacology, molecular docking, molecular dynamics simulation, quantum chemical calculations, and laboratory assays. In research published in Results in Chemistry, a team led by Sourabh Malabade and colleagues including Kiran Gaikwad, Tejas Nirwave, Sukanya Pote, Shailendra Gurav, and Parixit Bhandurge examined five phytoconstituents of the plant—ferulic acid, vanillic acid, β-sitosterol, 1-triacontanol, and 2,5-dihydroxybenzoic acid—and found that β-sitosterol showed the strongest predicted interaction with a key inflammatory receptor along with demonstrable membrane-protective activity in vitro. The work, carrying the DOI 10.1016/j.rechem.2026.103750, offers computational and preliminary experimental evidence that this common plant sterol may underlie part of the anti-inflammatory reputation of I. carnea, a species long used in traditional medicine although also known to contain toxic constituents.

The rationale for the study rests on the biology of inflammation itself. Rather than being governed by a single molecular switch, inflammatory responses arise from interlocking signaling networks involving cytokines, kinases, and transcription factors that amplify and modulate one another. Drugs aimed at a single target often deliver incomplete benefit, prompting researchers to look for multi-target agents, particularly among natural products that contain mixtures of structurally diverse compounds. The authors framed their investigation around this premise, asking whether the constituents of I. carnea could plausibly act on several nodes of the inflammatory circuitry simultaneously and whether the most promising candidate could withstand computational and biochemical scrutiny.

The first stage of the analysis was network pharmacology, an approach that maps the relationships between candidate compounds, their protein targets, and the disease-relevant pathways those targets populate. From the five phytoconstituents studied, the team identified a set of key inflammatory targets that included TNF, IL6, IL1B, MAPK1, MAPK14, STAT3, and NFKB1. These targets are central players in inflammatory signaling: TNF, IL6, and IL1B are potent pro-inflammatory cytokines; MAPK1 and MAPK14 are mitogen-activated protein kinases that relay stress and cytokine signals; STAT3 is a transcription factor activated by many cytokine receptors; and NFKB1 is a core component of the NF-κB pathway, one of the most important regulators of inflammatory gene expression. Pathway enrichment analysis placed these targets within the NF-κB, TNF, IL-17, JAK-STAT, NOD-like receptor, and FoxO signaling pathways, all of which are well-documented contributors to inflammatory disease processes. The network picture suggested that the I. carnea constituents, if active, would not act at a single point but across a web of interconnected inflammatory mechanisms.

To narrow the field, the researchers turned to molecular docking, a computational technique that predicts how well a small molecule fits into the binding site of a protein and estimates the strength of that interaction through a docking score. The protein chosen for this exercise was the receptor represented by the Protein Data Bank entry 3HA8, a structure commonly used in inflammation-related docking studies. When all five phytoconstituents were docked against this receptor, β-sitosterol ranked first with a docking score of −7.0, indicating the most favorable predicted binding among the candidates. β-Sitosterol is a plant sterol structurally related to cholesterol, abundant in many seeds, nuts, and plant oils, and previously studied for cholesterol-lowering and other effects. Its top ranking here positioned it as the primary candidate for the deeper computational analyses that followed.

Before committing to expensive simulation work, the team assessed the drug-like properties of β-sitosterol using QuickProp analysis, a rapid computational method for estimating absorption, distribution, metabolism, and excretion parameters. The results were mixed and, importantly, the authors were candid about the limitations. On the positive side, QuickProp predicted high membrane permeability, which is often desirable for oral absorption. However, the analysis also revealed high lipophilicity, extremely poor aqueous solubility, and multiple property alerts. These characteristics point to a practical problem: molecules that dissolve poorly in water may fail to reach meaningful concentrations in the bloodstream after oral administration, regardless of how well they permeate membranes once dissolved. The authors explicitly noted that dissolution and formulation limitations may restrict the compound’s actual oral exposure, a caution that tempers any simple translation of the docking results into expectations about therapeutic efficacy in patients or animals.

The centerpiece of the computational work was a 500-nanosecond molecular dynamics simulation of the β-sitosterol–3HA8 complex. Docking provides a static snapshot of a predicted binding mode, but proteins and ligands in solution are constantly in motion, and a docking pose that looks good on paper may fall apart within nanoseconds of realistic simulation. Molecular dynamics addresses this by simulating the physical movements of every atom in the system over time. The team subjected the complex to a half-microsecond simulation and then analyzed the trajectory with a battery of complementary metrics. Root mean square deviation (RMSD) tracks how far the protein and ligand drift from their starting positions; root mean square fluctuation (RMSF) measures flexibility residue by residue; protein–ligand contact analysis catalogues the specific interactions—hydrogen bonds, hydrophobic contacts, and others—that persist over the simulation; principal component analysis (PCA) identifies the dominant collective motions of the protein; the free energy landscape (FEL) maps the conformational states the complex explores; and the dynamic cross-correlation matrix (DCCM) reveals how motions in different parts of the protein are coordinated. According to the study, all of these analyses indicated stable binding and favorable conformational behavior for the β-sitosterol–3HA8 complex across the full simulation, lending credibility to the docking result.

In parallel, the researchers performed density functional theory (DFT) calculations, a quantum chemical method that describes the electronic structure of molecules. From these calculations they obtained a HOMO-LUMO energy gap of 6.90 electron volts for β-sitosterol. The HOMO-LUMO gap is the energy difference between the highest occupied and lowest unoccupied molecular orbitals, and a large gap generally signifies a chemically “hard” molecule—one that is less prone to donate or accept electrons readily and therefore less reactive in charge-transfer or redox chemistry. The authors interpreted the 6.90 eV gap as consistent with a chemically hard electronic structure and a comparatively low propensity for frontier-orbital excitation within the applied computational model. For a sterol that acts largely through hydrophobic and steric interactions with a protein binding site, such electronic inertness is not surprising, though the authors appropriately scoped the interpretation to the model they used.

Computational predictions, however encouraging, do not by themselves establish biological activity. The team therefore carried out two classical in vitro assays of anti-inflammatory potential. The first measured the inhibition of protein denaturation, a widely used surrogate assay based on the observation that many anti-inflammatory agents protect proteins from heat-induced or chemically induced denaturation, a process thought to contribute to inflammation by exposing new antigenic epitopes. The second was the human red blood cell (HRBC) membrane stabilization assay, which exploits the similarity between red blood cell membranes and lysosomal membranes; compounds that stabilize red blood cells against hemolysis under stress are presumed to have the capacity to stabilize lysosomal membranes and thereby limit the release of inflammatory mediators. In both assays, β-sitosterol-containing preparations from the study showed concentration-dependent effects. At the highest tested concentration of 300 micrograms per milliliter, inhibition of protein denaturation reached 76.32 ± 1.35 percent, and HRBC membrane stabilization reached 82.47 ± 1.42 percent. These are substantial effects in the context of such assays, and the concentration dependence supports a direct relationship between the amount of compound present and the protective effect observed.

Taken together, the study builds a layered argument for β-sitosterol as a contributor to the anti-inflammatory potential of I. carnea. The network pharmacology places it among compounds whose targets span the major inflammatory pathways; docking ranks it first against the chosen receptor; a long molecular dynamics simulation supports the physical stability of that interaction; DFT characterizes its electronic behavior; and the in vitro assays demonstrate genuine, dose-dependent biochemical effects on protein denaturation and membrane stability. The authors summarized the case as one of multi-target pathway modulation, stable receptor interaction, and membrane-protective effects, while explicitly stating that further experimental validation is required—a necessary caveat given the nature of the evidence.

That caveat deserves emphasis. The in vitro assays used here are screening-level tools: they measure general biophysical effects rather than the modulation of specific inflammatory signaling events in living cells or organisms. The study did not report enzyme inhibition assays against the identified targets such as TNF, IL6, or the MAP kinases, nor did it include cell-based assays of cytokine production or animal models of inflammation. The docking and simulation results are predictions about one receptor structure, and real biological activity would require confirming that β-sitosterol binds and modulates this and the other network targets in experimental systems. Moreover, the pharmacokinetic concerns raised by QuickProp—extremely poor aqueous solubility in particular—mean that even a genuinely active compound may struggle to achieve effective concentrations in vivo without advanced formulation strategies such as lipid-based delivery systems, which are already used for other lipophilic nutraceuticals.

There is also broader context worth noting. Ipomoea carnea Jacq., commonly known as bush morning glory, is a flowering shrub widespread in tropical and subtropical regions and used in folk medicine across its range, but it is also documented to contain toxic compounds such as swainsonine, and its safety profile is a matter of ongoing study. The present work examined individual phytoconstituents rather than the plant itself, which is the appropriate strategy for separating beneficial molecules from harmful ones. β-Sitosterol itself has an established safety record in the nutritional literature, where it is consumed as a cholesterol-lowering supplement, which may ease the path toward further development, although doses and contexts differ substantially between supplements and potential anti-inflammatory therapeutics.

The study’s chief contribution is methodological as much as substantive: it illustrates how a tiered pipeline—network pharmacology to define plausible targets, docking to prioritize candidates, property prediction to flag liabilities, molecular dynamics and quantum chemistry to stress-test the leading hit, and in vitro assays to confirm biochemical activity—can efficiently triage natural product constituents before more costly biological experimentation. For β-sitosterol from I. carnea, the next steps suggested by the evidence would include target-specific biochemical assays, cell-based models of inflammatory signaling, and pharmacokinetic studies addressing solubility and bioavailability. Until such work is done, the finding stands as a promising but preliminary indication that a familiar plant sterol may help explain the anti-inflammatory potential of a widely used medicinal shrub.