Kukoamine B from Lycii Radicis Cortex Protects Human Keratinocyte HaCaT Cells through Covalent Modification by Trans-2-Nonenal

Abstract

The unsaturated aldehyde trans-2-nonenal is known to be generated by lipid peroxidation at the surface of the skin in an aging-related manner and has harmful effects on keratinocytes in the skin. In this study, the protective effect of a Lycii Radicis Cortex (LRC) extract against trans-2-nonenal-induced cell damage on human keratinocyte cell lines (HaCaT) was investigated. Notably, treatment with the LRC extract resulted in an increase in cell survival, while trans-2-nonenal decreased the viability of HaCaT cells. For identification of interaction between the LRC extract and trans-2-nonenal, this mixture was incubated in simulated physiological conditions, showing a strong decrease in the amount of trans-2-nonenal by the LRC extract. Subsequent LC-ESI-MS analysis revealed that kukoamine B (KB) formed Schiff base-derived pyridinium adducts with trans-2-nonenal. Thus, these results suggest that KB could be a potential agent that may protect HaCaT cells by forming new products with trans-2-nonenal.

Potential of Lycii Radicis Cortex as an Ameliorative Agent for Skeletal Muscle Atrophy

“…Through comparison with the literature [ 27 ] and HPLC analysis, the main peak in Figure 1 A has been identified as kukoamines A and B, the primary component of the LRC extract (LRCE), which demonstrates the suitability of the utilized LRCE in the experiment. To assess the cytotoxicity of LRCE, fully differentiated C2C12 cells were treated with LRCE in various concentrations (5, 25, 50, and 100 µg/mL) for 24 h at 37 °C.…”

“…Through comparison with the literature [27] and HPLC analysis, the main peak in Figure 1A has been identified as kukoamines A and B, the primary component of the LRC extract (LRCE), which demonstrates the suitability of the utilized LRCE in the experiment.…”

“…However, treatment with both 50 and 100 µg/mL of LRCE markedly prevented the DEX-induced reductions in MHC-positive area, diameter, and fusion index capacity in C2C12 myotubes (Figure 1D-G), respectively. Through comparison with the literature [27] and HPLC analysis, the main peak in Figure 1A has been identified as kukoamines A and B, the primary component of the LRC extract (LRCE), which demonstrates the suitability of the utilized LRCE in the experiment. To assess the cytotoxicity of LRCE, fully differentiated C2C12 cells were treated with LRCE in various concentrations (5,25,50, and 100 µg/mL) for 24 h at 37 °C.…”

“…Kukoamine B (KB), the main constituent of LRC ( Figure 1 A), is a member of the spermine alkaloid (SA) family and has two dihydrocaffeoyl moieties and one spermine unit [ 33 ]. KB has been found to possess the antioxidant and anti-inflammatory properties of common SAs [ 34 , 35 ], and recent studies have demonstrated its ability to protect human keratinocyte HaCaT cells by inhibiting covalent modification by trans-2-nonenal [ 27 ]. However, despite these diverse activities, there has been no prior report on the effects of LRC on DEX-induced muscle atrophy.…”