In vitro and in vivo effects of protein phosphatase inhibitors, microcystins and nodularin, on mouse skin and fibroblasts

Three microcystins, YR, LR and RR and nodularin, all of which are hepatotoxic compounds, inhibited dose-dependently the activity of protein phosphatase 2A in and the specific [3H]okadaic acid binding to a cytosolic fraction of mouse skin, as strongly as okadaic acid. However, microcytins and nodularin did not induce any effects on mouse skin or primary human fibroblasts. Microinjection of microcystin YR into primary human fibroblasts induced morphological changes which were induced by incubation with okadaic acid. Microcystins and nodularin penetrate into the epithelial cells of mouse skin and human fibroblasts with difficulty, which reflects tissue specificity of the compounds.     

Steroidal glycosides from the aerial part of Asclepias incarnata

The aerial part of Asclepias incarnata afforded 34 pregnane glycosides. These were confirmed to have lineolon, isolineolon, ikemagenin, 12-O-nicotinoyllineolon, deacylmetaplexigenin, metaplexigenin, rostratamine, 12-O-acetyllineolon, 15beta-hydroxylineolon and 15beta-hydroxyisolineolon moieties as their aglycones, and 2.6-dideoxyhexopyranose, glucopyranose and allopyranose as the corresponding sugar constituents. Their structures were determined using both spectroscopic and chemical methods.     

The Structures of Two Flavonoid Glycoside from Oxytropis ochrocephala

Two flavonoid glycosides separated from water soluble fraction of Oxytropis ochrocephala Bge. were identified by using IR, NMR, and MS spectroscopic methods. The aglycones and sugars of the two compounds were determined directly from the hydrolytic solutions by using a sugar column and a bonded phase column. The results showed that compound 1 contained two kinds of sugars which have the same retention times as galactose and glucose, compound 2 only contained galactose. The aglycones of the two compounds have the same retention times and UV-spectra of rhamnocitrin. Finally, the structures of the two compounds were elucidated as rhamnocitrin-3-galactoside-4’-glucoside and rhamnocitrin-3-galactoside. The first one is a new flavonoid glycoside and the second one is, for the first time, found in the Oxytropis species.     

The effect of erythrodiol-3-acetate on the expressions of matrix metalloproteinase-1 and type-1 procollagen caused by ultraviolet irradiated cultured primary old aged human skin fibroblasts

Methanol and aqueous extracts of Styrax japonica used traditionally for the treatments of skin elastic materials were screened in vitro for the matrix metalloproteinase (MMP)-1 inhibitor actions. The methylene chloride soluble fraction of methanol extract from the stems of S. japonica showed significant MMP-1 inhibition in primary old aged human skin fibroblasts caused by ultraviolet (UV) irradiation. Main triterpenoids were isolated by repeated column chromatography. Among them, the triterpenoid erythrodiol-3-acetate reduced the expression of MMP-1 and induced the expression of type-1 procollagen at the protein levels in a dose-dependent manner caused by UV irradiated cultured old aged human skin fibroblasts. Taken together, our results suggest that erythrodiol-3-acetate plays an important role in the skin aging process caused by UV irradiation.     

Accumulation of phosphorus compounds in tissues and cultured skin fibroblasts in patients with hypophosphatasia

Patients with hypophosphatasia caused by a deficiency of alkaline phosphatase first showed marked accumulation of phosphoethanolamine and other phosphorus compounds in kidney and liver, while in placenta and intestine contents of these compounds were within a normal range. Furthermore, 32P-incorporation in cultured skin fibroblasts of patients with hypophosphatasia was increased about two to three times of control. FPLC chromatographic analysis also indicates that the accumulated phosphorus compounds in hypophosphatasia was smaller molecular phosphorus containing compounds. These data provide new pathophysiological aspect of hypophosphatasia.     

Kiwi fruit (Actinidia chinensis L.) polysaccharides exert stimulating effects on cell proliferation via enhanced growth factor receptors, energy production, and collagen synthesis of human keratinocytes, fibroblasts, and skin equivalents

Within physiological engineering exogenous carbohydrates were recently confirmed as pharmacologically active compounds. To investigate potential dermatological activity purified polysaccharides from kiwi fruits (Actinidia chinensis L., Actinidiaceae) were characterized concerning monomer composition, linkage types and molecular weights and were tested under in vitro conditions for regulating activities on cell physiology of human keratinocytes, fibroblasts, and skin equivalents. Ten micrograms per milliliter of raw polysaccharide, neutral type-II-arabinogalactans, and acidic arabinorhamnogalacturonans of kiwi fruits stimulated cell proliferation of human keratinocytes (NHK, HaCaT) up to 30% significantly while mitochondrial activity was stimulated for nearly 25% in regard to control cells. Fibroblasts were not as sensitive as keratinocytes but >130 microg/ml kiwi fruit polysaccharides increased proliferation and ATP-synthesis significantly, too. Proliferation-stimulating activity was dependent on terminal 1-alpha-l-arabinose residues since enzymatic release of these sugar moieties caused significantly decreased proliferation of HaCaT and fibroblasts of about 10% in regard to untreated cells. In three dimensional skin equivalents, it was shown that the polysaccharides led to a doubled collagen synthesis of fibroblasts compared to the normally strongly reduced biosynthetic activity.     

Localization of phospholipids in the membrane of Bacillus megaterium.

The intracellular localization of exogenously supplied human platelet beta-glucuronidase in cultured skin fibroblasts derived from a beta-glucuronidase-deficient patient was studied. Four cellular fractions were obtained by differential speed centrifugation. Following two days of incubation, the exogenously supplied enzyme exhibited a distribution pattern identical to that of endogenous beta-hexosaminidase. Disruption of membranes by freezing and thawing caused a 35% increase of the enzyme activity, thus indicating a latent activity following the internalization. This indicated localization in the lysosomal fractions. Longer incubation periods led to an intracellular shift of the engulfed enzyme from the lighter lysosomal fraction to heavier particles. Once located in the heavier fraction, the enzyme was relatively stable, and participated in the catabolism of 35S-labeled mucopolysaccharides which had accumulated in the lysosomes of these fibroblasts. A marked reduction in the accumulated mucopolysaccharides of the lysosomal fraction was observed following addition of the enzyme. This was accompanied by the formation of smaller sized molecules.     

Isolation of fat cell precursors from adult rat adipose tissue

Summary The possible existence of adipocyte precursors in adult rat adipose tissue was investigated. Cells were isolated from the stromal fraction of adipose tissue and were grown in culture. Skin fibroblasts were used as controls. The stromal fraction cells were initially fusiform and proliferated; in culture, they accumulated lipid inclusions, became rounder and acquired an eccentric nucleus. In contrast, the skin fibroblasts from the same rat and grown under identical culture conditions, did not exhibit any appreciable lipid accumulation. The doubling time for both the stromal fraction cells and skin fibroblasts was 40–60 h. At confluency, the stromal fraction cells contained 5–7 times more glyceride-glycerol than skin fibroblasts.Thus, adipose tissue of adult rats contains cells with the potential to proliferate and acquire morphological characteristics similar to those of adipocytes.This work was supported by The Medical Research Council of Canada Grant MA-5827, The Ontario Heart Foundation, The Atkinson Charitable Foundation, The Banting Research Foundation and The J.P. Bickell Foundation     

Norrish-Prins reaction as a key step in the synthesis of 14β-hydroxy-5α (or 5β or Δ(5,6))-pregnane derivatives

Numerous bioactive glycosteroids are characterized by aglycones bearing a 14β-hydroxy pregnane skeleton like boucerin and isoramanone. In general, the syntheses of the latter are achieved by acidic hydrolysis of the corresponding glycosteroids. These aglycones were also obtained by a combined Norrish type I-Prins reaction starting from the corresponding 12-keto-pregnane derivatives. However, for the Norrish-Prins reaction, no reports describe the influence of the A/B ring junction (cis or trans or Δ(5,6) double bond) or the influence of the substitution pattern at position 20. Herein, we describe the use of Norrish type I-Prins reactions to synthesize isoramanone and boucerin derivatives and their A/B cis and trans analogs. The influence of the parameters mentioned above is also presented. These studies showed that the A/B ring junction has little influence on the Norrish type I-Prins reaction but that the substitution pattern at position 20 is important. The presence of a dioxolane group induced not only the formation of the desired 14β-hydroxy pregnane derivatives in the highest yields but also the formation of new spiro derivatives.     

Abnormalities of lysosomes in human diploid fibroblasts from patients with Farber's disease

An accumulation of ceramide associated with the deficiency of acid ceramidase has been demonstrated in cultured diploid skin fibroblasts from a patient with Farber's disease. We extend this observation to investigate the lysosomal localization of accumulated ceramide and the abnormalities of lysosomes caused by this ceramide accumulation in Farber's diseased fibroblasts. We have found that the lysosomal fraction isolated from Farber's diseased fibroblasts by a subcellular fractionation procedure is markedly low in density compared with that of normal fibroblasts and is separated from other subcellular organellers. Ultrastructural studies of the isolated lysosomal fraction from Farber's diseased fibroblasts showed in mixed population of intact and swollen vesicles with a lysosomal appearance. Examination under high magnification clearly demonstrated lysosomal inclusions which contain lamellar and curvilinear membranes and resembled those seen in the intact fibroblasts. Subcellular localization of Farber's fibroblasts showed that the accumulated [³H]ceramide from the culture medium was predominantly localized in the lysosomal fraction with a markedly low density and very little was found to be associated with other cellular membranes. Our finding that ceramide is accumulated in the lysosomal fraction of Farber's fibroblasts and that these cells also show membranous inclusions strongly suggests that the accumulation of ceramide is directly involved in the formation of lysosomal inclusions.     

Resin glycosides from the aerial parts of Operculina turpethum

Three glycosidic acids, turpethic acids A−C, and two intact resin glycosides, turpethosides A and B, all having a common pentasaccharide moiety and 12-hydroxy fatty acid aglycones of different chain lengths, were obtained from the aerial parts of Operculina turpethum. Their structures were elucidated by spectroscopic analyses and chemical correlations. The aglycones were characterized as 12-hydroxypentadecanoic acid in two compounds, 12-hydroxyhexadecanoic acid in two other components, and 12-hydroxyheptadecanoic acid in the fifth compound, which were all confirmed by synthesis. The absolute configurations of these aglycones were all established as S by Mosher’s method. These compounds represent the first examples of resin glycosides with a monohydroxylated 12-hydroxy fatty acid as an aglycone, and one compound is the first described resin glycoside having a hydroxylated C₁₇ fatty acid as its aglycone.     

Enhancement of polyphenol bio-activities by enzyme reaction

Using β-glucosidase to hydrolyze glycosides into aglycones, the present study attempted to improve the bio-activity of the extract from mulberry leaves. When varying the ethanol fraction, pH, and temperature of the extract, the optimum conditions for the enzyme reaction were identified as a 10% ethanol fraction in the extract, pH 5.0, and 40 °C temperature. Under these optimum conditions, the enzyme reaction produced a remarkable increase in the anti-oxidation and tyrosinase inhibition activities of the extract by as much as 219.5% and 230.9%, respectively. This improved bio-activity of the extract was due to the hydrolysis of the glycoside polyphenols rutin, isoquercitrin, and astragalin into the aglycone polyphenols quercetin and kaempferol. Furthermore, the enzymatic hydrolysis of the extract by β-glucosidase also produced some additional benefits that are critical factors for the skin absorption of bio-active ingredients, including an improved hydrophobicity (239.41%) and reduced mean molecular weight (from 387.3 to 291.4), resulting in a significantly enhanced skin permeability (513%).     

Identification of new qingyangshengenin and caudatin glycosides from the roots of Cynanchum otophyllum

HPLC analysis of the roots of Cynanchum otophyllum Scheind (Asclepiadaceae) led to the isolation of six new pregnane glycosides, specifically otophyllosides N-P (2-4) and otophyllosides Q-S (7-9), in addition to the identification of three known C-21 steroidal glycosides, otophylloside A (1), otophylloside B (5) and caudatin 3-O-β-D-glucopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside (6). The structure of each glycoside was determined by detailed spectroscopic analysis and chemical methods. All compounds contain qingyangshengenin or caudatin aglycones and a straight sugar chain consisting of 4-7 hexosyl moieties with the mode of 1→4 linkage. The optically isomeric monosaccharides, D- and L-cymarose, coexisted in both otophyllosides R (8) and S (9).     

Cancer preventive agents. Part 8: Chemopreventive effects of stevioside and related compounds

In a search for potential cancer chemopreventive agents from natural resources, stevioside (1), a sweetener, and six related compounds, including two aglycones steviol (6) and isosteviol (7), were screened in an in vitro assay for inhibitory effects on Epstein–Barr virus early antigen activation. Compounds 1, 6 and 7 showed significant activity in this assay and also exhibited strong inhibitory effects in a two-stage carcinogenesis test using mouse skin induced by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). The inhibitory effects of these three compounds were greater than that of glycyrrhizin. Furthermore, these three compounds significantly inhibited mouse skin carcinogenesis initiated by peroxynitrite and promoted by TPA. Their activities were comparable to that of curcumin. These results suggested that 1, as well as 6 and 7, could be valuable as chemopreventive agents for chemical carcinogenesis.     

Formation of cholic acid from 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid in human skin fibroblasts.

Whether 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) was converted into cholic acid in human skin fibroblasts was examined. THCA was incubated with subcellular fractions of cultured skin fibroblasts in the presence of NAD+, ATP, CoA, and Mg2+. The reaction products were analyzed by thin-layer chromatography and high-performance liquid chromatography after p-bromophenacyl ester derivatization. The highest specific activity was found in the light mitochondrial fraction (2.71 nmol/mg protein/h). The specific activity was about 9-fold higher than that in heavy mitochondrial fraction. The peroxisomal fraction prepared from the light mitochondrial fraction by sucrose gradient centrifugation was also able to catalyze the conversion of THCA into cholic acid. The specific activity in this fraction was a further 2.2-fold higher than that in the light mitochondrial fraction. These results suggest that cultured human skin fibroblasts are able to convert THCA into cholic acid, and that the activity exists in peroxisomes.     

Zinc and Propolis Reduces Cytotoxicity and Proliferation in Skin Fibroblast Cell Culture: Total Polyphenol Content and Antioxidant Capacity of Propolis

It has been demonstrated that zinc exerts its beneficial influence on skin fibroblasts. Propolis, a complex mixture of plant-derived and bees’ products, was reported to stimulate cicatrization processes in skin and prevent infections. The aim of this study was to find out how zinc and propolis influence human skin fibroblasts in cell culture and to compare the effect of individual compounds to the effect of a mixture of zinc and propolis. In this study, zinc, as zinc aspartate, at a concentration of 16 μM, increased human fibroblasts proliferation in cell culture, whereas propolis at a concentration of 0.01 % (w/v) revealed antiproliferative and cytotoxic action followed by mild cell necrosis. In culture, zinc was effectively transported into fibroblasts, and propolis inhibited the amount of zinc incorporated into the cells. An addition of propolis to the medium caused a decrease in the Zn(II) amount incorporated into fibroblasts. The obtained results also indicate an appreciable antioxidant property of propolis and revealed its potential as a supplement when applied at doses lower than 0.01 % (w/v). In conclusion, the present study showed that zinc had a protective effect on human cultured fibroblasts’ viability, although propolis revealed its antiproliferative action and caused mild necrosis.     

Epicatechin and its methylated metabolite attenuate UVA-induced oxidative damage to human skin fibroblasts

The ultraviolet A component of sunlight causes both acute and chronic damage to human skin. In this study the potential of epicatechin, an abundant dietary flavanol, and 3'-O-methyl epicatechin, one of its major in vivo metabolites, to protect against UVA-induced damage was examined using cultured human skin fibroblasts as an in vitro model. The results obtained clearly show that both epicatechin and its metabolite protect these fibroblasts against UVA damage and cell death. The hydrogen-donating antioxidant properties of these compounds are probably not the mediators of this protective response. The protection is a consequence of induction of resistance to UVA mediated by the compounds and involves newly synthesized proteins. The study provides clear evidence that this dietary flavanol has the potential to protect human skin against the deleterious effects of sunlight.     

Biflavonoids isolated from Selaginella tamariscina regulate the expression of matrix metalloproteinase in human skin fibroblasts

The methanol extract from Selaginella tamariscina significantly inhibited UV irradiation induced activity of matrix metalloproteinase-1 (MMP-1) in primary fibroblasts from human skin. Using the technique of bioassay-directed chromatographic separation, five biflavonoids were isolated from the ethyl acetate soluble fraction of S. tamariscina. Here, we investigated the effect of these five biflavonoids on the regulation of MMP-1 and -2 in UV irradiated cultured dermal fibroblasts from human neonatal foreskins. Among these biflavonoids, sumaflavone and amentoflavone showed significant MMP-1 inhibitory activity in primary human dermal fibroblasts after UV irradiation. The IC(50) values of sumaflavone, amentoflavone and retinoic acid, which was used as a positive control, were 0.78, 1.8, and 10microM, respectively.     

Possible therapeutic effects of myxobacterial metabolites on type I Gaucher disease

Gaucher disease (GD) is the most prevalent lysosomal storage disorder caused by an inherited deficiency of glucocerebrosidase. In the present study, we aimed to determine whether myxobacterial metabolites exhibit a potential therapeutic effect in the cells from a patient with type I GD. We screened 288 bioactive compounds of myxobacteria in the skin fibroblasts from a patient with type I GD. MTT assays were performed to determine their effects on cell viability. The expression levels of Bcl-2-associated X protein (Bax), ATP-citrate synthase (ATP-CS), E3-binding protein (E3BP), and acetyl-coenzyme A acetyltransferase 1 (ACAT1) were determined by western blotting to understand the molecular mechanisms of myxobacterial metabolites in cells. Thin-layer chromatography (TLC) was carried out to measure changes in glucosylceramide levels in the cultured fibroblasts. This screening process identified 4 compounds that increased cell viability more than 1.45 times. After exposure to these compounds, the expression level of Bax decreased, whereas those of ATP-CS, E3BP, and ACAT1 increased. TLC revealed reduced amounts of intracellular glucosylceramides in patient cells. Here we suggest that myxobacterial metabolites can relieve the stress due to glucosylceramide accumulation, and that it may be utilized as a new therapeutic approach.     

New pregnane glycosides from Caralluma dalzielii

Twenty-seven new pregnane glycosides were isolated from the whole plant of Caralluma dalzielii, and their structures elucidated from extensive 2D NMR analysis as well as ESI-MS experiments. All isolated compounds were tested for their antiproliferative activity on J774.A1, HEK-293, and WEHI-164 cell lines. Moderate to high potency of cytotoxicities were found in almost all tested compounds, confirming the significant cytotoxic activity of pregnane glycosides.