Mulberry Leaf Polysaccharides Attenuate Oxidative Stress Injury in Peripheral Blood Leukocytes by Regulating Endoplasmic Reticulum Stress

Wenqiang Jiang; Yan Lin; Linjie Qian; Siyue Lu; Huaishun Shen; Xianping Ge; Linghong Miao

doi:10.3390/antiox13020136

Mulberry Leaf Polysaccharides Attenuate Oxidative Stress Injury in Peripheral Blood Leukocytes by Regulating Endoplasmic Reticulum Stress

Antioxidants (Basel). 2024 Jan 23;13(2):136. doi: 10.3390/antiox13020136.

Authors

Wenqiang Jiang¹, Yan Lin², Linjie Qian¹, Siyue Lu², Huaishun Shen^{1

2}, Xianping Ge^{1

2}, Linghong Miao^{1

2}

Affiliations

¹ Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
² Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.

Abstract

The present study assessed the protective effects and underlying mechanisms of mulberry leaf polysaccharides (MLPs) against hydrogen peroxide (H₂O₂)-induced oxidative stress injury in the peripheral blood leukocytes (PBLs) of Megalobrama amblycephala. Five treatment groups were established in vitro: the NC group (PBLs incubated in an RPMI-1640 complete medium for 4 h), the HP group (PBLs incubated in an RPMI-1640 complete medium for 3 h, and then stimulated with 100 μM of H₂O₂ for 1 h), and the 50/100/200-MLP pre-treatment groups (PBLs were pre-treated with MLPs (50, 100, and 200 μg/mL) for 3 h, and then stimulated with 100 μM of H₂O₂ for 1 h). The results showed that MLP pre-treatment dose-dependently enhanced PBLs' antioxidant capacities. The 200 μg/mL MLP pre-treatment effectively protected the antioxidant system of PBLs from H₂O₂-induced oxidative damage by reducing the malondialdehyde content and lactic dehydrogenase cytotoxicity, and increasing catalase and superoxide dismutase activities (p < 0.05). The over-production of reactive oxygen species, depletion of nicotinamide adenine dinucleotide phosphate, and collapse of the mitochondrial membrane potential were significantly inhibited in the 200-MLP pre-treatment group (p < 0.05). The expressions of endoplasmic reticulum stress-related genes (forkhead box O1α (foxO1α), binding immunoglobulin protein (bip), activating transcription factor 6 (atf6), and C/EBP-homologous protein (chop)), Ca²⁺ transport-related genes (voltage-dependent anion-selective channel 1 (vdac1), mitofusin 2 (mfn2), and mitochondrial Ca²⁺ uniporter (mcu)), and interleukin 6 (il-6) and bcl2-associated x (bax) were significantly lower in the 200-MLP pre-treatment group than in the HP group (p < 0.05), which rebounded to normal levels in the NC group (p > 0.05). These results indicated that MLP pre-treatment attenuated H₂O₂-induced PBL oxidative damage in the M. amblycephala by inhibiting endoplasmic reticulum stress and maintaining mitochondrial function. These findings also support the possibility that MLPs can be exploited as a natural dietary supplement for M. amblycephala, as they protect against oxidative damage.

Keywords: Megalobrama amblycephala; endoplasmic reticulum stress; mulberry leaf polysaccharides; oxidative damage; peripheral blood leukocytes.

Abstract

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