Clinacanthus nutans (Burm. f.) Lindau ameliorates type 2 diabetes mellitus by suppressing chemokine-mediated inflammation and apoptosis in pancreatic β-cells: An integrated multi-omics study.

ETHNOPHARMACOLOGICAL RELEVANCE: Type 2 diabetes mellitus (T2DM) is characterized by chronic hyperglycemia and metabolic dysregulation, in which pancreatic β-cell dysfunction and local chronic inflammation are key drivers of disease progression. Clinacanthus nutans (Burm. f.) Lindau (CN) is a traditional medicinal plant with anti-inflammatory and antioxidant activities; however, the mechanism underlying its protective effects on pancreatic β-cells in T2DM remains unclear.

AIM OF THE STUDY: This study aimed to systematically identify the blood-absorbed constituents of CN and, by integrating multi-omics analyses and in vivo and in vitro experiments, to investigate its pharmacological effects against T2DM and the underlying mechanism by which CN ameliorates islet inflammation and apoptosis via regulation of the chemokine signaling pathways in β-cells.

MATERIALS AND METHODS: UHPLC-QTOF-MS was employed to identify the chemical constituents of CN extracts and their prototypes absorbed into the bloodstream. Network pharmacology analysis was performed based on the identified compounds to construct the protein-protein interaction and compound-target networks. Representative binding conformations were subjected to molecular docking and 100-ns molecular dynamics simulations to evaluate binding stability. Transcriptomic sequencing of cellular samples, combined with enrichment analysis, was conducted to elucidate key signaling pathways. The effects of CN were further evaluated in a high-fat diet and streptozotocin-induced T2DM mouse model by assessing glucose metabolism, pancreatic morphology, and markers of inflammation and apoptosis. In MIN6 cells exposed to high-glucose (HG) and palmitic acid (PA) conditions, CN-containing serum (CN-CS) was used to validate its effects on cell viability, insulin secretion, chemokine expression, inflammation, and apoptosis.

RESULTS: UHPLC-QTOF-MS identified 45 prototype compounds derived from CN in the serum. Both network pharmacology and transcriptomic enrichment analyses consistently indicated that the chemokine signaling pathway, along with inflammation- and apoptosis-related pathways, played dominant roles in the pharmacological actions of CN. Molecular docking and dynamics simulations demonstrated that several major constituents formed stable interactions with key inflammatory proteins such as TNF-α and IL-1β. In vivo experiments showed that CN dose-dependently improved fasting blood glucose levels, OGTT/ITT indices, and partially restored islet morphology in diabetic mice. Moreover, CN significantly reduced the expression of inflammatory cytokines (TNF-α, IL-1β, IL-18) and chemokines (CCL2, CXCL12) in tissues and serum, while suppressing the abnormal expression of apoptosis-related proteins. In vitro experiments showed that 15% CN-CS significantly restored the viability of MIN6 cells exposed to HG/PA conditions, promoted insulin secretion, modulated CCL2 and CXCL12 expression, thereby reducing inflammatory cytokine expression, attenuated apoptosis, and restored pancreatic β-cell function.

CONCLUSIONS: This study is the first to demonstrate that flavonoids, phenols, terpenoids, phenylpropanoids, and alkaloids are the key active constituents of CN. This traditional herbal medicine exerts its pharmacological effects by modulating the chemokine signaling pathway in β-cells, thereby suppressing inflammatory responses and apoptosis, significantly improving pancreatic β-cell function, and restoring metabolic homeostasis. This study provides a systematic basis for elucidating the mechanisms of CN as a natural multi-target candidate agent and offers new theoretical insights into the development of chemokine pathway-targeted strategies for the prevention and treatment of T2DM.