β-Sitosterol 3-O-D-glucoside increases ceramide levels in the stratum corneum via the up-regulated expression of ceramide synthase-3 and glucosylceramide synthase in a reconstructed human epidermal keratinization model

Abstract

β-Sitosterol 3-O-d-glucoside (BSG) is known to act as an agonist by binding to estrogen receptors, and estrogen has been reported to enhance the activity of β-glucocerebrosidase, an epidermal ceramide metabolizing enzyme. In this study, we determined whether BSG up-regulates ceramide levels in the stratum corneum (SC) of a reconstructed human epidermal keratinization (RHEK) model. Treatment with BSG significantly increased the total ceramide content by 1.2-fold compared to that in the control in the SC of the RHEK model, accompanied by a significant increase of the ceramide species, Cer[EOS] by 2.1-fold compared to that in the control. RT-PCR analysis demonstrated that BSG significantly up-regulated the mRNA expression levels of serine palmitoyltransferase (SPT)2, ceramide synthase (CerS)3, glucosylceramide synthase (GCS) and acid sphingomyelinase by 1.41–1.89, 1.35–1.44, 1.19 and 2.06-fold, respectively, compared to that in the control in the RHEK model. Meanwhile, BSG significantly down-regulated the mRNA expression levels of sphingomyelin synthase (SMS)2 by 0.87–0.89-fold. RT-PCR analysis also demonstrated that BSG significantly up-regulated the mRNA expression levels of CerS3 and GCS by 1.19–1.55 and 1.20-fold, respectively, but not of SPT2 and significantly down-regulated that of SMS2 by 0.74-fold in HaCaT keratinocytes. Western blotting analysis revealed that BSG significantly increased the protein expression levels of CerS3 and GCS by 1.78 and 1.28–1.32-fold, respectively, compared to that in the control in HaCaT cells. These findings indicate that BSG stimulates ceramide synthesis via the up-regulated expression levels of CerS3 and GCS in the glucosylceramide pathway, which results in a significantly increased level of total ceramides in the SC accompanied by significantly increased levels of acylceramide species such as Cer[EOS].

Oryza Ceramide®, a rice-derived extract consisting of glucosylceramides and β-sitosterol glucoside, improves facial skin dehydration in Japanese subjects

“…On the other hand, only a single clinical study has reported the beneficial effects of rice GlcCer [16]. The ingestion of rice-derived GlcCer has been shown to enhance skin ceramide production [22], particularly ceramide [EOS], which exerts stronger hydrating effects among ceramide species [42]. As the underlying mechanism, we confirmed that BSG enhanced the production of ceramide synthase-3 and glucosylceramide synthase [22].…”

“…Therefore, BSG may be digested and absorbed from the gut and alter epidermal hydration similar to cholesterol and ceramides. Secondly, we recently demonstrated that BSG increased ceramides in the s. corneum of a human epidermal equivalent by enhancing the de novo ceramide synthesis pathway [22]. Based on these findings about dietary supplemented GlcCer and an in vitro study of BSG, we hypothesized that the combination of GlcCer and BSG is an appropriate composition for effectively improving epidermal dehydration.…”

Lycoperoside H, a Tomato Seed Saponin, Improves Epidermal Dehydration by Increasing Ceramide in the Stratum Corneum and Steroidal Anti-Inflammatory Effect

“…Lycoperoside H ( 3 ) is the most abundant saponin in TSE, and its concentration-dependent effect (1 and 10 µM) was observed in ceramide production. Our previous studies demonstrated that tiliroside isolated from strawberry seeds increases the ceramide (NS, NDS) contents [ 32 ], and β-sitosterol 3- O -glucoside isolated from rice bran increased ceramide (EOS) [ 44 ]. On the other hand, the present study demonstrated that lycoperoside H ( 3 ) increased ceramide (NP), which was not observed in tiliroside and β-sitosterol 3- O -glucoside.…”

“…The separated SC samples were washed with PBS and stored at −80 °C until the determination of ceramides. The extraction method described in previous studies [ 32 , 44 ] was used for lipid extraction. Namely, the SC samples were homogenized with an ultrasonic homogenizer (AGC Techno Glass Co., Ltd. Shizuoka, Japan) in a 4 mL mixture of chloroform, methanol, and PBS (1:2:0.8).…”

“…The ceramide contents in SC were measured by HPTLC. The quantification method as described by previous studies [ 32 , 44 ] was carried out for TLC analysis. The dried lipid samples were dissolved in a mixture of chloroform and methanol (2:1) and were developed on a TLC plate (10 × 10 cm).…”