Protective Effects of Lycium barbarum Polysaccharides, Mulberry Leaf Flavonoids, and Ginkgo Leaf Flavonoids on HBZY-1 Cell Injury: An Investigation of Lactate Dehydrogenase and Total Nitric Oxide Synthase

Abstract

The impacts of natural plant extracts, including Lycium barbarum polysaccharides (LBP), mulberry leaf flavonoids (MLF), and ginkgo leaf flavonoids (GLF), on high glucose (HG)-induced injury in HBZY-1 mesangial cells were analyzed. LBP, MLF, and GLF were individually extracted, and their purities were determined. HBZY-1 cells cultured in low glucose (LG) served as the Normal group (NG), while HG culture represented the HG group. Subsequently, HBZY-1 cells in the HG group were treated with 300 μg/mL of LBP, MLF, and GLF, resulting in the HG+LBP, HG+MLF, and HG+GLF groups, respectively. Cell viability (CV) was assessed using the MTT assay, and cellular morphological changes were observed through HE staining. Meanwhile, lactate dehydrogenase (LDH) and nitric oxide (NO) levels were examined using the microplate method. Furthermore, malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels were detected by ELISA. mRNA levels in IL-6, IL-1β, and TNF-α were assessed using real-time quantitative polymerase chain reaction (rt-qPCR), and Collagen IV was examined using immunofluorescence. The results revealed that the polysaccharide content in the LBP extract was 63.57%, the flavonoid contents in the MLF and GLF extracts were 55.40% and 48.62%, respectively. Based on the NG group, HG group exhibited decreased CV, increased LDH and MDA, decreased NO, SOD, and GSH-Px, elevated mRNA levels in IL-6, IL-1β, and TNF-α, and reduced Collagen IV, showing great differences (P < 0.05). Based on the HG group, the HG+LBP, HG+MLF, and HG+GLF groups demonstrated increased CV, decreased LDH and MDA levels, increased NO, SOD, and GSH-Px levels, decreased mRNA levels in IL-6, IL-1β, and TNF-α, and increased Collagen IV, presenting obvious differences (P < 0.05). Comparing to the HG+LBP group, the HG+MLF and HG+GLF groups exhibited enhanced CV, downshifted LDH and MDA, elevated NO, SOD, and GSH-Px, downregulated mRNA in IL-6, IL-1β, and TNF-α, and increased Collagen IV (P < 0.05). No significant changes in CV, LDH, MDA, NO, SOD, GSH-Px, IL-6, IL-1β, TNF-α, or Collagen IV were observed in the HG+MLF and HG+GLF groups to the NG group (P >0.05). In conclusion, natural plant extracts such as LBP, MLF, and GLF exerted protective effects against injury in HBZY-1 mesangial cells caused by HG and possessed significant anti-inflammatory, antioxidant stress, and antifibrotic damage properties.