Elucidating the Anti-Senescence Effects of Calophyllum Species and its Underlying Mechanism in Hydrogen Peroxide Induced Premature Senescence in Endothelial Cells

Nurul Amilin, Che Kamarudin and Nor Hisam, Zamakshshari and Ker, Woon Choy and Edmund Sim, Ui Hang and Suhaila, Abd Muid (2026) Elucidating the Anti-Senescence Effects of Calophyllum Species and its Underlying Mechanism in Hydrogen Peroxide Induced Premature Senescence in Endothelial Cells. Masters thesis, Universiti Malaysia Sarawak (UNIMAS).

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Abstract

Ageing, marked by cell cycle arrest and changes in metabolic pathways, is recognised as a crucial element in the onset and advancement of cardiovascular diseases (CVDs). Senescent cells have a role in oxidative stress, and decreased nitric oxide (NO) availability, all of which when accumulated are linked to endothelial dysfunctions that ultimately lead to cardiovascular diseases. Xanthone is a part of large group of phenolic compounds, active ingredients that can be found in Calophyllum spp. proven to have valuable properties such as antioxidants, inhibit the enzymes that lead to Reactive Oxygen Properties (ROS) formation which is one of the many factors leading to cellular senescence. However, the study on the anti-senescence effects of Calophyllum spp. extracts on stress-induced premature senescence (SIPS) remains underexplored. Thus, this research aims to explore the anti-senescence effects of Calophyllum spp. extracts on SIPS HUVECs. HUVECs were incubated with H2O2 (20 µM) to establish SIPS model and treated with various concentration of ethyl acetate (EA, 5 and 20 µg/ml), Apocynin (20 µM) to evaluate the cell viability using phase contrast microscopy and MTT Assay. The senescence markers, senescence associated-β-galactosidase (SA-β-gal) was measured by SA-β-gal assay. Additionally, the involvement of NADPH and COX-2 pathways was analysed using Colorimetric Assay and ELISA Assay. Results demonstrated that H2O2 (20 µM) induced senescence in HUVECs and then reversed by the EA extract from C. gracilentum and C. soulattri and Apocynin (20 µM). Treatment with EA also upregulated the NADPH levels, indicating the involvement of EA in inhibiting oxidative stress effects in SIPS HUVECs. In contrast, a significant decrease in expression of COX-2 as an inflammatory response, after treatment with EA extract was not portrayed. Taken together, the findings underscore that Calophyllum spp. extracts prevent CVDs by alleviating endothelial senescence and reducing endothelial dysfunctions of SIPS in HUVECs through the inhibition of SA-β-gal and regulation of NADPH but not COX-2.

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