Proteomics reveals that quinoa bioester promotes replenishing effects in epidermal tissue.

The continuous search for natural products that attenuate age-related losses has increasingly gained notice; among them, those applicable for skin care have drawn significant attention. The bioester generated from the Chenopodium quinoa's oil is a natural-origin ingredient described to produce replenishing skin effects. With this as motivation, we used shotgun proteomics to study the effects of quinoa bioester on human reconstructed epidermis tridimensional cell cultures after 0, 3, 6, 12, 24, and 48 h of exposure. Our experimental setup employed reversed-phase nano-chromatography coupled online with an Orbitrap-XL and PatternLab for proteomics as the data analysis tool. Extracted ion chromatograms were obtained as surrogates for relative peptide quantitation. Our findings spotlight proteins with increased abundance, as compared to the untreated cell culture counterparts at the same timepoints, that were related to preventing premature aging, homeostasis, tissue regeneration, protection against ultraviolet radiation and oxidative damage.

The Plasmodium falciparum eIK1 kinase (PfeIK1) is central for melatonin synchronization in the human malaria parasite. Melatotosil blocks melatonin action on parasite cell cycle.

Melatonin and its indoles derivatives are central in the synchronization of malaria parasites. In this research, we discovered that melatonin is unable to increase the parasitemia in the human malaria Plasmodium falciparum that lacks the kinase PfeIK1. The PfeIK1 knockout strain is a valuable tool in the screening of indol-related compound that blocks the melatonin effect in wild-type (WT) parasite development. The assays were performed by using flow cytometry with simultaneous labeling for mitochondria viability with MitoTracker Deep Red and nucleus staining with SYBR Green. We found that Melatotosil leads to an increase in parasitemia in P. falciparum and blocks melatonin effect in the WT parasite. Using microscopy imaging system, we found that Melatotosil at 500 nM is able to induce cytosolic calcium rise in transgenic PfGCaMP3 parasites. On the contrary, the compound Triptiofen blocks P. falciparum cell cycle with IC50 9.76 µM ± 0.6, inhibits melatonin action, and does not lead to a cytosolic calcium rise in PfGCaMP3 parasites. We also found that the synthetic indol-related compounds arrested parasite cycle for PfeIK1 knockout and (WT) P. falciparum (3D7) in 72 hours culture assays with the IC50 values slighting lower for the WT strain. We concluded that the kinase PfeIK1 is central for melatonin downstream signaling pathways involved in parasite cell cycle progression. More importantly, the indol-related compounds block its cycle as an upstream essential mechanism for parasite survival. Our data clearly show that this class of compounds emerge as an alternative for the problem of resistance with the classical antimalarials.

Unraveling the molecular and cellular mechanisms of stretch marks.

BACKGROUND: Striae distensae, commonly known as stretch marks, are cutaneous lesions that accompany the hormonal upheavals of the major stages of life: puberty and pregnancy. Stretch marks occur in 90% of women, and they appear as red or purple lines that slowly fade to pale lines on the skin. There have been few studies regarding stretch mark origins, and new preventive and corrective treatments are needed. AIMS: The aim of this work was to understand the primary genes and proteins involved in the regulation of striae compared to normal skin and to identify the differentially expressed genes and biochemical aspects of SA and SR Importantly, this is the first published study to use a molecular high-throughput approach combined with in vivo evaluation. METHODS: In this study, we analyzed the molecular differences between skin with and without stretch marks (rubra [SR] and alba [SA]) of female volunteers using DNA microarray (Whole Human Genome Microarray Kit, 4×44 K, Agilent Technologies) analyses of cutaneous biopsies (2 mm) and in vivo confocal Raman spectroscopy of selected buttock regions, a technique recently introduced as a noninvasive skin evaluation method. RESULTS: We identified gene expression alterations related to ECM, cellular homeostasis, and hormones such as secretoglobulins. Spectral analyses of collagen, fibrillin, and glycosaminoglycans were conducted by Raman spectroscopy at different skin depths. The main differences observed when comparing skin with and without stretch marks were at depths between 75 and 95 µm, corresponding to the dermal-epidermal junction and dermis regions and showing differences between normal skin and stretched skin regarding collagen, collagen hydration, and elastin fibers. CONCLUSION: The results obtained by RNA and protein analyses are complementary and show that significant changes occur in the skin affected by stretch marks. These results suggest new strategies and opportunities to treat this skin disorder and for the development of new and eficiente cosmetic products.

Investigation of antimalarial activity, cytotoxicity and action mechanism of piperazine derivatives of betulinic acid.

OBJECTIVES: To semisynthesise piperazine derivatives of betulinic acid to evaluate antimalarial activity, cytotoxicity and action mechanism. METHODS: The new derivatives were evaluated against the CQ-sensitive Plasmodium falciparum 3D7 strain by flow cytometry (FC) using YOYO-1 as stain. Cytotoxicity of 4a and 4b was performed with HEK293T cells for 24 and 48 h by MTT assay. The capability of compound 4a to modulate Ca(2+) in the trophozoite stage was investigated. The trophozoites were stained with Fluo4-AM and analysed by spectrofluorimetry. Effect on mitochondrial membrane potential (ΔΨm) was tested for 4a by FC with DiOC6 (3) as stain. For ß-haematin assay, 4a was incubated for 24 h with reagents such as haemin, and the fluorescence was measured by FlexStation at an absorbance of 405 nm. RESULTS: Antimalarial activity of 4a and 4b was IC50 = 1 and 4 µm, respectively. Compound 4a displayed cytotoxicity with IC50 = 69 and 29 µm for 24 and 48 h, respectively, and 4b was not cytotoxic at the tested concentrations. Addition of 4a leads to an increase in cytosolic Ca(2+) . We have measured ΔΨm after treating parasites with the compound. Data on Figure 4a show that mitochondria were not affected. The action mechanism for 4a, inhibition of ß-haematin formation (17%), was lower than CQ treatment (83%; IC50 = 3 mm). CONCLUSION: Compound 4a showed excellent antimalarial activity, and its action mechanism is involved in Ca(2+) pathway(s).

Synthetic indole and melatonin derivatives exhibit antimalarial activity on the cell cycle of the human malaria parasite Plasmodium falciparum.

Discovering the mechanisms by which cell signaling controls the cell cycle of the human malaria parasite Plasmodium falciparum is fundamental to designing more effective antimalarials. To better understand the impacts of melatonin structure and function on the cell cycle of P. falciparum, we have synthesized two families of structurally-related melatonin compounds (7-11 and 12-16). All synthesized melatonin analogs were assayed in P. falciparum culture and their antimalarial activities were measured by flow cytometry. We have found that the chemical modification of the carboxamide group attached at C-3 position of the indole ring of melatonin (6) was crucial for the action of the indole-related compounds on the P. falciparum cell cycle. Among the melatonin derivatives, only the compounds 12, 13 and 14 were capable of inhibiting the P. falciparum growth in low micromolar IC50. These results open good perspectives for the development of new drugs with novel mechanisms of action.

Biological evaluation of hydroxynaphthoquinones as anti-malarials.

BACKGROUND: The hydroxynaphthoquinones have been extensively investigated over the past 50 years for their anti-malarial activity. One member of this class, atovaquone, is combined with proguanil in Malarone®, an important drug for the treatment and prevention of malaria. METHODS: Anti-malarial activity was assessed in vitro for a series of 3-alkyl-2-hydroxy-1,4-naphthoquinones (N1-N5) evaluating the parasitaemia after 48 hours of incubation. Potential cytotoxicity in HEK293T cells was assessed using the MTT assay. Changes in mitochondrial membrane potential of Plasmodium were measured using the fluorescent dye Mitrotracker Red CMXROS. RESULTS: Four compounds demonstrated IC50s in the mid-micromolar range, and the most active compound, N3, had an IC50 of 443 nM. N3 disrupted mitochondrial membrane potential, and after 1 hour presented an IC50ΔΨmit of 16 µM. In an in vitro cytotoxicity assay using HEK 293T cells N3 demonstrated no cytotoxicity at concentrations up to 16 µM. CONCLUSIONS: N3 was a potent inhibitor of mitochondrial electron transport, had nanomolar activity against cultured Plasmodium falciparum and showed minimal cytotoxicity. N3 may serve as a starting point for the design of new hydroxynaphthoquinone anti-malarials.

Two series of new semisynthetic triterpene derivatives: differences in anti-malarial activity, cytotoxicity and mechanism of action.

BACKGROUND: The discovery and development of anti-malarial compounds of plant origin and semisynthetic derivatives thereof, such as quinine (QN) and chloroquine (CQ), has highlighted the importance of these compounds in the treatment of malaria. Ursolic acid analogues bearing an acetyl group at C-3 have demonstrated significant anti-malarial activity. With this in mind, two new series of betulinic acid (BA) and ursolic acid (UA) derivatives with ester groups at C-3 were synthesized in an attempt to improve anti-malarial activity, reduce cytotoxicity, and search for new targets. In vitro activity against CQ-sensitive Plasmodium falciparum 3D7 and an evaluation of cytotoxicity in a mammalian cell line (HEK293T) are reported. Furthermore, two possible mechanisms of action of anti-malarial compounds have been evaluated: effects on mitochondrial membrane potential (ΔΨm) and inhibition of ß-haematin formation. RESULTS: Among the 18 derivatives synthesized, those having shorter side chains were most effective against CQ-sensitive P. falciparum 3D7, and were non-cytotoxic. These derivatives were three to five times more active than BA and UA. A DiOC(6)(3) ΔΨm assay showed that mitochondria are not involved in their mechanism of action. Inhibition of ß-haematin formation by the active derivatives was weaker than with CQ. Compounds of the BA series were generally more active against P. falciparum 3D7 than those of the UA series. CONCLUSIONS: Three new anti-malarial prototypes were obtained from natural sources through an easy and relatively inexpensive synthesis. They represent an alternative for new lead compounds for anti-malarial chemotherapy.

Hybrid scaffolds built from PET and collagen as a model for vascular graft architecture.

A hybrid material with excellent mechanical and biological properties is produced by electrospinning a co-solution of PET and collagen. The fibers are mapped using SEM, confocal Raman microscopy and collagenase digestion assays. Fibers of different compositions and morphologies are intermingled within the same membrane, resulting in a heterogeneous scaffold. The collagen distribution and exposure are found to depend on the PET/collagen ratio. The materials are chemically and mechanically characterized and biologically tested with fibroblasts (3T3-L1) and a HUVEC culture in vitro. All of the hybrid scaffolds show better cell attachment and proliferation than PET. These materials are potential candidates to be used as vascular grafts.