Stability Study of Alpinia galanga Constituents and Investigation of Their Membrane Permeability by ChemGPS-NP and the Parallel Artificial Membrane Permeability Assay.

Alpinia galanga Willd., greater galangal, has been used for thousands of years as a spice as well as in traditional medicine. Its central nervous system (CNS) stimulant activity and neuroprotective effects have been proved both in animal models and human trials. However, the compounds responsible for these effects have not been identified yet. Therefore, the main constituents (p-OH-benzaldehyde (1), trans-p-coumaryl-alcohol (2), p-coumaryl-aldehyde (4), galanganol A (5), galanganol B (6), trans-p-acetoxycinnamyl alcohol (7), 1'S-1'-acetoxychavicol acetate (ACA, 9), and 1'S-1'-acetoxyeugenol acetate (AEA, 10)) were isolated to investigate their aqueous stability and passive diffusion across the gastro-intestinal tract (GIT) membrane and the blood-brain barrier (BBB) by the parallel artificial membrane permeability assay (PAMPA). Our positive results for compounds 1, 2, 4, 7, 9, and 10 suggest good permeability, thus potential contribution to the effects of greater galangal in the CNS. The results of the PAMPA-BBB were corroborated by in silico chemography-based ChemGPS-NP framework experiments. In addition, examination of the chemical space position of galangal compounds in relation to known psychostimulants revealed that all the molecules in proximity are NET/SERT inhibitors. As ACA and AEA did not show much proximity to either compound, the importance of further investigation of their degradation products becomes more pronounced.

Hyperthermia-induced doxorubicin delivery from thermosensitive liposomes via MR-HIFU in a pig model.

PURPOSE: Encapsulation of cytotoxic drugs for a localized release is an effective way to increase the therapeutic window of such agents. In this article we present the localized release of doxorubicin (DOX) from phosphatidyldiglycerol (DPPG2) based thermosensitive liposomes using MR-HIFU mediated hyperthermia in a swine model. MATERIALS AND METHODS: German landrace pigs of weights between 37.5 and 53.5 kg received a 30-min infusion of DOX containing thermosensitive liposomes (50 mg DOX/m2). The pigs' biceps femoris was treated locally in two separate target areas with mild hyperthermia using magnetic resonance guided high intensity focused ultrasound, starting 10 min and 60 min after initiation of the infusion, respectively. The pharmacokinetics and biodistribution of DOX were determined and an analysis of the treatment parameters' influence was performed. RESULTS: Compared to untreated tissue, we found a 15-fold and a 7-fold increase in DOX concentration in the muscle volumes that had undergone hyperthermia starting 10 min and 60 min after the beginning of the infusion, respectively. The pharmacokinetic analysis showed a prolonged circulation time of DOX and a correlation between the AUC of extra-liposomal DOX in the bloodstream and the amount of DOX accumulated in the target tissue. CONCLUSIONS: We have demonstrated a workflow for MR-HIFU hyperthermia drug delivery that can be adapted to a clinical setting, showing that HIFU-hyperthermia is a suitable method for local drug release of DOX using DPPG2 based thermosensitive liposomes in stationary targets. Using the developed pharmacokinetic model, an optimization of the drug quantity deposited in the target via the timing of infusion and hyperthermia should be possible.

UHPLC-DPPH method reveals antioxidant tyramine and octopamine derivatives in Celtis occidentalis.

Celtis occidentalis L. (common Hackberry, Cannabaceae) has been applied in the traditional medicine for a long time as a remedy for sore throat, aid during menstruation and for treating jaundice. Nevertheless, the phytochemical exploration of the plant is still incomplete, literature data is limited to flavonoid derivatives isolated from the leaves. The present study reports screening approaches for bioactive compounds in C. occidentalis by fast and simple UHPLC-coupled assays. The UHPLC-DPPH method revealed six constituents in the methanolic extract of the twigs that had not been reported in C. occidentalis before. The antioxidant compounds were isolated by the means of flash chromatography and semi-preparative HPLC and identified by Orbitrap® MS and NMR spectroscopy as N-trans-p-coumaroyloctopamine (1), N-trans-feruloyloctopamine (2), N-trans-caffeoyltyramine (3), 2-trans-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl)-2-oxoethyl] prop-2-enamide (4), N-trans-p-coumaroyltryramine (5) and N-trans-feruloyltyramine (6). Despite the high antioxidant activity measured in the present study and literature data suggesting potential positive effects of the compounds in the central nervous system, the PAMPA-BBB assay performed with the Celtis extract revealed that none of the aforementioned compounds are able to penetrate across the blood-brain barrier via transcellular passive diffusion.

Blood-brain barrier permeability study of ginger constituents.

Ginger, the rhizome of Zingiber officinale Roscoe is of great importance in the traditional medicine for the treatment of various diseases. More than 400 constituents have been reported in the plant, the most important ones being the gingerol and shogaol derivatives. Positive effects of ginger extracts and isolated [6]-gingerol have been proved in animal models of anxiety, Alzheimer's disease, Parkinson's disease and epilepsy. Taken in consideration these promising positive effects of ginger and its constituents in the central nervous system, the isolation of gingerol and shogaol derivatives ([6]-gingerol (1), [8]-gingerol (2), [10]-gingerol (3), [6]-shogaol (4), [10]-shogaol (5), 1-dehydro-[6]-gingerdione (6), 1-dehydro-[10]-gingerdione (7)) and investigation of their transcellular passive diffusion across the blood-brain barrier (BBB) were carried out. For this purpose, a Parallel Artificial Membrane Permeability Assay for the Blood-Brain Barrier (PAMPA-BBB) was chosen that had previously been validated for natural compounds. Based on our results, [6]-gingerol, [8]-gingerol and [6]-shogaol were found to be able to penetrate the BBB via passive diffusion, suggesting them to contribute to the positive effects of ginger extracts in the central nervous system.

Relative contribution of different l-arginine sources to the substrate supply of endothelial nitric oxide synthase.

In certain cases of endothelial dysfunction l-arginine becomes rate-limiting for NO synthesis in spite of sufficiently high plasma concentrations of the amino acid. To better understand this phenomenon, we investigated routes of substrate supply to endothelial nitric oxide synthase (eNOS). Our previous data with human umbilical vein (HUVEC) and EA.hy.926 endothelial cells demonstrated that eNOS can obtain its substrate from the conversion of l-citrulline to l-arginine and from protein breakdown. In the present study, we determined the quantitative contribution of proteasomal and lysosomal protein degradation and investigated to what extent extracellular peptides and l-citrulline can provide substrate to eNOS. The RFL-6 reporter cell assay was used to measure eNOS activity in human EA.hy926 endothelial cells. Individual proteasome and lysosome inhibition reduced eNOS activity in EA.hy926 cells only slightly. However, the combined inhibition had a pronounced reducing effect. eNOS activity was fully restored by supplementing either l-citrulline or l-arginine-containing dipeptides. Histidine prevented the restoration of eNOS activity by the dipeptide, suggesting that a transporter accepting both, peptides and histidine, mediates the uptake of the extracellular peptide. In fact, the peptide and histidine transporter PHT1 was expressed in EA.hy926 cells and HUVECs (qRT/PCR). Our study thus demonstrates that l-citrulline and l-arginine-containing peptides derived from either intracellular protein breakdown or from the extracellular space seem to be good substrate sources for eNOS.

A behavioral-medicine program in HIV. Implications for quality of life.

The purpose of this descriptive study is to examine quality of life issues in participants in a behavioral-medicine group (N = 24). Of the sample, 60% indicated current use of complementary therapies. Sexual functioning, a subscale of the quality-of-life measure, was positively correlated with length of time with HIV. CD4+ lymphocyte counts were not significantly correlated with quality of life (QOL). Viral load (VL) was positively correlated with the social-support subscale of the QOL scale. Use of body therapies (massage, acupuncture) was associated with social functioning and use of nutritional therapies was associated with mental health. Results of the study indicate that clinical interventions, including behavioral-medicine interventions and complementary therapies for persons with HIV/AIDS, can result in greater QOL.