Photoprotection of Chlorella sp. and Tetradesmus dimorphus Extracts on Ultraviolet-Irradiated Human Retinal Pigment Epithelial Cells

Tang, Yi Teng; Chin, Yun Zhi; Lew, Chun Yik; Mes Ewan, Farhan Aisar; Chia, Kiat Fatt; Koh, Rhun Yian; Wong, Chiew Yen; Mai, Chun-Wai; Lim, Chooi Ling

doi:10.30491/jabr.2025.495987.1824

Photoprotection of Chlorella sp. and Tetradesmus dimorphus Extracts on Ultraviolet-Irradiated Human Retinal Pigment Epithelial Cells

Document Type : Original Article

Authors

Yi Teng Tang ¹

Yun Zhi Chin ¹

Chun Yik Lew ¹

Farhan Aisar Mes Ewan ¹

Kiat Fatt Chia ²

Rhun Yian Koh ¹

Chiew Yen Wong ¹^{, 3}

Chun-Wai Mai ⁴

Chooi Ling Lim ¹

¹ Division of Applied Biomedical Science and Biotechnology, School of Health Sciences, IMU University, 57000 Kuala Lumpur, Malaysia

² Centre for Postgraduate Studies by Research, IMU University, 57000 Kuala Lumpur, Malaysia

³ Centre for Environmental and Population Health, Institute for Research, Development and Innovation (IRDI), IMU University, 57000 Kuala Lumpur, Malaysia

⁴ Centre for Cancer and Stem Cell Research, Institute for Research, Development and Innovation (IRDI), IMU University, 57000 Kuala Lumpur, Malaysia

10.30491/jabr.2025.495987.1824

Abstract

Introduction: Ultraviolet radiation induces retinal cell injury associated with age-related macular degeneration (AMD). Bioactive compounds from microalgae have demonstrated photoprotective properties against ultraviolet B (UVB)-induced injury, however, their protective activity on the retinal pigment epithelium (RPE) remains unexplored. In this study, the photoprotective effects of Chlorella sp. and Tetradesmus dimorphus extracts on UVB-irradiated ARPE-19 cells were investigated.
Materials and Methods: ARPE-19 cells were irradiated with UVB, followed by treatment with Chlorella sp. and T. dimorphus extracts from distilled water, absolute methanol, 20% aqueous methanol (v/v), or 95% ethanol. Viability of ARPE-19 cells was assessed using 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), while oxidative stress was evaluated with diacetyldichlorofluorescein (DCFHDA). The presence of acidic vesicular organelles (AVOs) and apoptotic cells was detected through acridine orange and Hoechst 33258 staining.
Results: Aqueous-methanol (20%) extracts of Chlorella sp. (1 μg/ml) improved ARPE-19 cell viability by 23.26%, while other solvent extracts of T. dimorphus did not show significant improvement compared to the control group. Besides, aqueous extracts of Chlorella sp. (1 μg/ml) showed the greatest reduction in reactive oxygen species (ROS) level by 0.46-fold, while aqueous-methanol (20%) extracts of T. dimorphus (10 μg/ml) decreased the ROS level by 0.33-fold. Moreover, treatment with aqueous-methanol (20%) extracts of Chlorella sp. and T. dimorphus reduced autophagy by 38.52% and 36.26%, respectively. Apoptotic activity was attenuated by aqueous extracts of Chlorella sp. (37.33%) and T. dimorphus (46%).
Conclusions: Chlorella sp. and T. dimorphus extracts exert photoprotective effects on UVB-irradiated ARPE-19 cells, highlighting their potential as a novel approach for AMD treatment.

Keywords

Ultraviolet B

Chlorella sp

Tetradesmus dimorphus

Microalgae

Human Retinal Pigment Epithelial Cells

Photoprotection