Protective Effects of Total Flavonoids from Lysimachia christinae on Calcium Oxalate-Induced Oxidative Stress in a Renal Cell Line and Renal Tissue

Abstract

Oxidative stress (OS) in renal tubular epithelial cells (RTECs) is induced by calcium oxalate (CaOx) stones and plays an important role in the pathology of CaOx nephrolithiasis. The nuclear factor-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway is an important endogenous antioxidant pathway. Flavonoids are compounds with 2-phenylchromone as the basic mother nucleus and are natural antioxidant components of Lysimachia christinae. Our previous studies demonstrated that the total flavonoids from L. christinae (TFL) reduced calcium and oxalic acid concentrations in urine, thus inhibiting CaOx stone formation. We also showed that TFL can reduce OS in renal tissue. However, whether TFL inhibit the formation of CaOx stones through the Nrf2/ARE pathway requires further investigation. Here, we found that TFL protected against injury to a renal cell line and renal tissue, reduced CaOx-induced OS in renal tissue, and reduced CaOx crystal formation. In addition, TFL significantly increased nuclear Nrf2 and the expression of the downstream antioxidant genes heme oxygenase 1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO-1). Furthermore, TFL increased superoxide dismutase (SOD) activity and decreased the malondialdehyde (MDA) content, thereby alleviating OS in RTECs. Silencing Nrf2 expression blocked the protective effect of TFL on CaOx-induced OS. Taken together, our findings indicate that TFL reduce CaOx-induced OS in renal tissue by activating the Nrf2/ARE pathway.

Structural Characterization and Anticomplement Activity of an Acidic Heteropolysaccharide from Lysimachia christinae Hance

“…So GlcA was 1,4-linked with a relative molar ratio of about 11.88 (GlcA = 13. The chemical shifts of sugar residues in LCP-90-1 were assigned by the analysis of 1 H, 13 C, HSQC, 1 H-1 H COSY, and HMBC NMR spectra (▶ Fig. 4), combined with the results of glycosyl composition, methylation analysis, and literature data [16][17][18][19] ▶ Table 1 Monosaccharides compositions of LCP-90-1 and its degradation products.…”

“…Signals at δ 99.88 and 97.63 ppm were assigned to C-1 of 1,4-α-D-GlcpA (F) and T-α-D-Manp (G), correlating to H-1 of them (δ 5.35 and 5.01 ppm), respectively [17,27]. The 1 H and 13 C chemical shift assignments of LCP-90-1 were defined and are summarized in ▶ Table 3.…”

“…Similarly, the cross-peaks at δ 5.35/82.54 ppm (FH1/AC3) indicated that the linkage of residue F with residue A through (1 → 3); the cross-peaks at δ 5.35/78.77 ppm (FH1/FC4) and 99.88/4.49 ppm (FC1/FH4) indicated that the linkage of residue F with residue F through (1 → 4); the cross-peaks at δ 5.42/ 78.77 ppm (EH1/FC4) and 100. 13 Degraded LCP-90-1 products were mainly divided into LCP-90-1-A (40.8 mg) and LCP-90-1-B (4.3 mg) (▶ Fig. 3 g), with relative molecular weight decreasing significantly (LCP-90-1-A: 5.18 kDa; LCP-90-1-B: 0.29 kDa).…”

“…As a traditional "heat-clearing" Chinese medicine, Lysimachia christinae Hance (Primulaceae) is commonly used in water decoctions to treat urinary calculi diseases and liver inflammation [10]. It has been reported that the flavonoids, phenolic acids, and crude polysaccharides from the plant exhibited antioxidant and anti-inflammatory activities [11][12][13][14][15], but no studies have focused on the anticomplement activity of the plant. Our preliminary studies showed that the water extract of L. christinae had much more potent anticomplement activity than the alcohol extract, indicating that the polysaccharides might be the major anticomplement components of L. christinae.…”

Isolation and Characterization of Flavonoids from Fermented Dandelion (Taraxacum mongolicum Hand.-Mazz.), and Assessment of Its Antioxidant Actions In Vitro and In Vivo

“…Flavonoids generally refer to a class of compounds formed by the connection of two benzene rings and with 2-phenylchromone as the basic nucleus [21]. Flavonoid glycosides with different structures are classified according to the type, number, and location of sugars.…”