Inhibition of HIV-1 entry by extracts derived from traditional Chinese medicinal herbal plants

<p>Abstract</p> <p>Background</p> <p>Highly active anti-retroviral therapy (HAART) is the current HIV/AIDS treatment modality. Despite the fact that HAART is very effective in suppressing HIV-1 replication and reducing the mortality of HIV/AIDS patients, it has become increasingly clear that HAART does not offer an ultimate cure to HIV/AIDS. The high cost of the HAART regimen has impeded its delivery to over 90% of the HIV/AIDS population in the world. This reality has urgently called for the need to develop inexpensive alternative anti-HIV/AIDS therapy. This need has further manifested by recent clinical trial failures in anti-HIV-1 vaccines and microbicides. In the current study, we characterized a panel of extracts of traditional Chinese medicinal herbal plants for their activities against HIV-1 replication.</p> <p>Methods</p> <p>Crude and fractionated extracts were prepared from various parts of nine traditional Chinese medicinal herbal plants in Hainan Island, China. These extracts were first screened for their anti-HIV activity and cytotoxicity in human CD4+ Jurkat cells. Then, a single-round pseudotyped HIV-luciferase reporter virus system (HIV-Luc) was used to identify potential anti-HIV mechanisms of these extracts.</p> <p>Results</p> <p>Two extracts, one from <it>Euphorbiaceae</it>, <it>Trigonostema xyphophylloides </it>(TXE) and one from <it>Dipterocarpaceae</it>, <it>Vatica astrotricha </it>(VAD) inhibited HIV-1 replication and syncytia formation in CD4+ Jurkat cells, and had little adverse effects on host cell proliferation and survival. TXE and VAD did not show any direct inhibitory effects on the HIV-1 RT enzymatic activity. Treatment of these two extracts during the infection significantly blocked infection of the reporter virus. However, pre-treatment of the reporter virus with the extracts and treatment of the extracts post-infection had little effects on the infectivity or gene expression of the reporter virus.</p> <p>Conclusion</p> <p>These results demonstrate that TXE and VAD inhibit HIV-1 replication likely by blocking HIV-1 interaction with target cells, i.e., the interaction between gp120 and CD4/CCR5 or gp120 and CD4/CXCR4 and point to the potential of developing these two extracts to be HIV-1 entry inhibitors.</p

Antioxidant potential of natural and synthesised polyprenylated hydroquinones

The metabolites 2-octaprenyl-1,4-hydroquinone (1) and 2-(24-hydroxy)-octaprenyl-1,4-hydroquinone (2), isolated from the sponge Ircinia spinosula. along with a series of synthetic derivatives, were evaluated for their antioxidant capacity, in order to establish a potential relationship between structural characteristics and antioxidant activity. The antioxidant potential of both natural and synthesised compounds was evaluated in vitro by their ability: (1) to interact with the stable free 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and (2) to inhibit the peroxidation, induced by the Fe++/ascorbate system, of heat inactivated hepatic microsomal membrane lipids. Metabolite 1 presented a strong interaction with DPPH and had a moderate effect on lipid peroxidation. while metabolite 2 interacted extensively with DPPH and exhibited a significant effect against lipid peroxidation. All derivatives retaining the free 1,4-hydroquinone system maintained fully or partly the free radical scavenging capacity. (C) 2002 Elsevier Science Ltd. All rights reserved

Protein Hydrolysis and Nitrogen Remobilisation in Plant Life and Senescence

In plant cells, as in all other cells, proteins are submitted to permanent turnover, and the intracellular content of a given protein depends on its rate of both synthesis and degradation. The life time of most proteins is shorter than that of the cell. Thus, in young leaves of Lemna minor, the average half-life of protein was estimated to be 7 days, and it was shorter under stress conditions (Davies 1982). Such observations mean that nitrogen and amino acid fluxes are both cylic and permanent. Although protein turnover may appear wasteful, in terms of energy, numerous studies have shown that proteolysis provides multiple functions in cell physiology, and is an essential regulatory mechanism of cell metabolism and development

Remarkable body architecture of marine sponges as biomimetic structure for application in tissue engineering

Recent advances in the study of marine environment, particularly of marine organismsâ architecture and composition, have isolated interesting compounds as proteins, GAG-like polysaccharides and bioactive compounds. These compounds have allowed the development of panoply of biomaterials inspired by morphological characteristics and anatomical structures of the marine species. Besides, the scientific community acknowledges the enormous biotechnological potential in the marine resources that can be a promising effective and efficient alternative to be used in Human health, namely tissue engineering and regenerative medicine, as well as to support the progress in pharmacological, cosmetic, nutraceutical and biomedical fields. Additionally, sustainable ways are being applied to explore these marine resources and address biomimetic approaches, aiming to take the most out of the astonishing marine environment in ecologically compatible ways. Marine sponges are a particular group of organisms feeding these biotechnological developments for human health, both as source of new drugs or inspiration for the development of marine biomaterials. This chapter aims to demonstrate, in a concise and clear way, the biotechnological potential of marine sponges used as susceptive bioscaffolds for regenerative medicine and biomedical applications in general.Horizon 2020 European Union Framework Programme for Research and Innovation under project SponGES (H2020-BG-01-2015-679849) and from the European Research Council Advanced Grant ComplexiTE (grant agreement ERC-2012-ADG 20120216-321266