The Oestrogenis and Cytotoxic Effects of the Extracts of Labisia pumila var. alata and Labisia pumila var. pumila In Vitro

Aqueous, acid hydrolysed and ethanolic extracts of the roots and leaves of Labisia pumila var. alata and Labisia pumila var. alata and Labisia pumila var. pumila were investigated for their oestrogenic and cytotoxic effects using Ishikawa cell line by performing an in vitro Ishikawa alkaline phosphatase assay and an in vitro protein assay, respectively. Among them, only the ethanol extract of the root of L. pumila var. alata exhibited a weak oestrogenic activity at 10-50 mg/ml. The samples that exhibited significant cytotoxic effect were the ethanol extract of the roots of L. pumila var. alata (IC50 433 mg/ml), and the aqueous extracts of the roots of L. pumila var. alata (IC50 433 mg/ml) and the leaves of L. pumila var. pumila (IC50 458 mg/ml)

Isolation of an anthelmintic compound from Leucosidea sericea

The leaves of Leucosidea sericea (Rosaceae) are used medicinally by some indigenous South African people as a vermifuge and astringent. No information on the biological activity and phytochemistry of the plant could be found in the literature. Bioassay-guided fractionation was used to identify the active compound. Partial purification of the petroleum ether extract of the leaves and flowers was followed by fractionation using chromatographic methods. This process yielded the Phloroglucinol derivatives, aspidinol and desaspidinol, which were previously reported to be present in a Dryopteris species. Aspidinol was further isolated and structurally elucidated. This is the first report of the presence of these compounds in Leucosidea sericea. The disk diffusion method used in our study, indicated that the plant has antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Candida albicans

Antidiabetic activity of Terminalia sericea Burch. Ex DC constituents

Diabetes mellitus is an endocrine disorder that affects more than 100 million people worldwide. South African plants namely Terminalia sericea, Euclea natalensis, Warbugia salutaris, Aloe ferox Artemisia afra, Sclerocarya birrea, Spirostachys africana and Psidium guajava were investigated for their in vitro antidiabetic and antioxidant activities. Terminalia sericea stem bark extract showed the best results against α-glucosidase and α-amylase enzymes. Bioassay-guided fractionation of an acetone extract of T. sericea stem bark led to the isolation of four known compounds namely β-sitosterol (1), β-sitosterol-3-acetate (2), lupeol (3), and stigma-4-ene-3-one (4), in addition to two inseparable sets of mixtures of isomers [epicatechin-catechin; (M1) and gallocatechin-epigallocatechin; (M2). 1 and 3 showed best inhibitory activity on α-glucosidase (IC50:54.5 μM and 66.48). The bio-evaluation of purified compound’s inhibitory activity on α-amylase, showed that lupeol and β-sitosterol exhibited IC50 values of 140.72 and 216.02 μM respectively against α-amylase. 2, M1, 3 and M2 were found to be non-toxic to Vero cells. This study is the first to report a-glucosidase, a-amylase of M1, M2, 2 and 4 isolated from T. sericea which validated the traditional use of the bark of T. sericea for diabetes in South Africa.http://www.naturalproduct.us/nf201

Unitary limit and quantum interference effect in disordered two-dimensional crystals with nearly half-filled bands

Based on the self-consistent $T$-matrix approximation, the quantum interference (QI) effect is studied with the diagrammatic technique in weakly-disordered two-dimensional crystals with nearly half-filled bands. In addition to the usual 0-mode cooperon and diffuson, there exist $\pi$-mode cooperon and diffuson in the unitary limit due to the particle-hole symmetry. The diffusive $\pi$-modes are gapped by the deviation from the exactly-nested Fermi surface. The conductivity diagrams with the gapped $\pi$-mode cooperon or diffuson are found to give rise to unconventional features of the QI effect. Besides the inelastic scattering, the thermal fluctuation is shown to be also an important dephasing mechanism in the QI processes related with the diffusive $\pi$-modes. In the proximity of the nesting case, a power-law anti-localization effect appears due to the $\pi$-mode diffuson. For large deviation from the nested Fermi surface, this anti-localization effect is suppressed, and the conductivity remains to have the usual logarithmic weak-localization correction contributed by the 0-mode cooperon. As a result, the dc conductivity in the unitary limit becomes a non-monotonic function of the temperature or the sample size, which is quite different from the prediction of the usual weak-localization theory.Comment: 21 pages, 4 figure

The serum metabolome mediates the concert of diet, exercise, and neurogenesis, determining the risk for cognitive decline and dementia

Introduction: Diet and exercise influence the risk of cognitive decline (CD) and dementia through the food metabolome and exercise-triggered endogenous factors, which use the blood as a vehicle to communicate with the brain. These factors might act in concert with hippocampal neurogenesis (HN) to shape CD and dementia. Methods: Using an in vitro neurogenesis assay, we examined the effects of serum samples from a longitudinal cohort (n = 418) on proxy HN readouts and their association with future CD and dementia across a 12-year period. Results: Altered apoptosis and reduced hippocampal progenitor cell integrity were associated with exercise and diet and predicted subsequent CD and dementia. The effects of exercise and diet on CD specifically were mediated by apoptosis. Discussion: Diet and exercise might influence neurogenesis long before the onset of CD and dementia. Alterations in HN could signify the start of the pathological process and potentially represent biomarkers for CD and dementia

The mammalian gene function resource: The International Knockout Mouse Consortium

In 2007, the International Knockout Mouse Consortium (IKMC) made the ambitious promise to generate mutations in virtually every protein-coding gene of the mouse genome in a concerted worldwide action. Now, 5 years later, the IKMC members have developed highthroughput gene trapping and, in particular, gene-targeting pipelines and generated more than 17,400 mutant murine embryonic stem (ES) cell clones and more than 1,700 mutant mouse strains, most of them conditional. A common IKMC web portal (www.knockoutmouse.org) has been established, allowing easy access to this unparalleled biological resource. The IKMC materials considerably enhance functional gene annotation of the mammalian genome and will have a major impact on future biomedical research