Dae Bang Seo

AMP-activated protein kinase (AMPK) activators from Myristica fragrans (nutmeg) and their anti-obesity effect

AMP-activated protein kinase (AMPK) is a potential therapeutic target for the treatment of metabolic syndrome including obesity and type-2 diabetes. As part of an ongoing search for new AMPK activators from plants, this study found that the total extract of Myristica fragrans (nutmeg) activated the AMPK enzyme in differentiated C2C12 cells. As active constituents, seven 2,5-bis-aryl-3,4-dimethyltetrahydrofuran lignans, tetrahydrofuroguaiacin B (1), saucernetindiol (2), verrucosin (3), nectandrin B (4), nectandrin A (5), fragransin C(1) (6), and galbacin (7) were isolated from this extract. Among the isolates, compounds 1, 4, and 5 at 5 microM produced strong AMPK stimulation in differentiated C2C12 cells. In addition, the preventive effect of a tetrahydrofuran mixture (THF) on weight gain in a diet-induced animal model was further examined. These results suggest that nutmeg and its active constituents can be used not only for the development of agents to treat obesity and possibly type-2 diabetes but may also be beneficial for other metabolic disorders.

Lithospermic acid derivatives from Lithospermum erythrorhizon increased expression of serine palmitoyltransferase in human HaCaT cells

A MeOH extract of the dry root of Lithospermum erythrorhizon showed strong increasing effect on serine palmitoyltransferase (SPT) in normal human keratinocyte cells (HaCaT cells). Bioassay-guided separation on this extract using repeated chromatography resulted in the isolation of lithospermic acid (1) and two derivative esters, 9-methyl lithospermate (2) and 9-methyl lithospermate (3). Compounds 1-3 significantly increased SPT expressions in the relative quantity (%) of SPT1 mRNA as well as SPT2 mRNA. These constituents also raised the level of SPT protein in HaCaT cells in a dose-dependent manner, with the increased level of SPT protein in HaCaT cells of 55%, 23%, and 81% at the concentration of 100 microg/ml, respectively. This finding suggests that lithospermic acid and its derivatives from L. erythrorhizon might improve the permeability barrier by stimulating the protein level of SPT.

Beneficial Effect of a Collagen Peptide Supplement on the Epidermal Skin Barrier

Recent research has revealed that hydrolyzed collagen peptides have beneficial effects in various diseases such as osteoarthritis and human rheumatoid arthritis and also play a protective role in skin by improving the activity of antioxidants. In this study, we investigated the effects of a novel mixture (AP-CPM01) containing collagen peptides and elastin peptides on photoaged hairless mice skin both in vivo and in vitro. To evaluate the effects of AP-CPM01 on UVBinduced skin wrinkle formation in vivo, the hairless mice were exposed to UVB irradiation and orally administered the AP-CPM01 at 333 mg/kg per day for 10 weeks. The effects on skin appearance and epidermal thickness were measured using bioengineering and histochemical methods. In addition, the influence of AP-CPM01 on collagen metabolism in human skin fibroblasts was also investigated. The skin of mice in the AP-CPM01 treated group had better appearance and less wrinkling than that of mice in the control group. In the human fibroblast cells, the amount of de novo procollagen synthesis was increased after AP-CPM01 treatment, reflecting that AP-CPM01 can induce de novo procollagen synthesis and reduce UVB-induced skin wrinkle formation. These results suggest that AP-CPM01 is a potent candidate for antiphotoaging functions.

The Effect of Gromwell (Lithospermum erythrorhizon) Extract on the Stratum Corneum Hydration and Ceramides Content in Atopic Dermatitis Patients

BACKGROUNDnA disruption of the balance between the water content of the stratum corneum (SC) and skin surface lipids may lead to the clinical manifestation of dryness of skin in patients with atopic dermatitis (AD).nnnOBJECTIVEnTo determine whether supplementation of gromwell (Lithospermum erythrorhizon), one of herbs used in East Asia in remedies for various abnormal skin conditions, may improve the SC level of hydration and ceramides, major lipid in SC in patients with AD.nnnMETHODSnA total of 28 subjects with AD were randomly assigned into two groups: either gromwell group received dextrose contained capsules with 1.5 g of gromwell extracts or placebo group received only dextrose contained capsules for 10 weeks.nnnRESULTSnIn contrast to no alteration of SC hydration and ceramides in placebo group, the SC hydration in gromwell group was significantly increased in parallel with an increase of SC ceramides. Furthermore, % increase of SC hydration in gromwell group bore a positive correlation with the clinical severity, which suggests that the increase of SC hydration in gromwell group was more effective as AD was more severe.nnnCONCLUSIONnSupplementation of gromwell improves SC hydration in parallel with an increase of ceramides in part.