[Study on neoflavonoids from heartwood of Dalbergia latifolia].

Dalbergiae Odoriferae Lignum is derived from heartwood of Dalbergia odorifera,which is national Ⅱ level of rare and endangered protective plants in China. Its resources are scarce and its price is high. In order to find substitutes of D. odorifera,the chemical constituents of 70% ethanol extract of heartwood of D. catifolia were systematically studied by using silica gel,Sephadex LH-20 column chromatography,and semi-preparative HPLC. Sixteen neoflavanoids were isolated and identified as eight dalbergiphenols( 1-8),three dalbergiones( 9-11),two dalbergins( 12,13),two benzophenones( 14,15) and one other type neoflavanoids( 16) based on spectroscopic data analyses and/or comparing the spectroscopic data with those in literature. Among them,compounds 3,7 and 11 were isolated from the genus Dalbergia for the first time,and compounds 2,4-6,8,14 and 15 were isolated from the D. latifolia for the first time. Ten neoflavonoids were both discovered from D. latifolia and D. odorifera.

Roles of aging in sleep.

With aging, various factors deteriorate the normal sleep process that is essential for the restoration of functional and physical performance. Due to aging-related diseases, life changes, or aging itself, disturbances in normal sleep cycles can profoundly affect healthy aging. To understand the interconnections between aging and the factors influencing sleep, with emerging evidence accumulated in recent years, this study elaborates on the roles of aging in sleep from four perspectives: cortical thinning, white matter degeneration, neurotransmitter dysregulation, and circadian disorganization. In brief, with aging, cortical thinning can be induced by the deposition of neurotoxic substances, and white matter degeneration can be induced by vascular abnormalities. These alterations emerging in the brain jointly disrupt sleep spindles and slow waves, leading to sleep disturbances. Age-related dysregulation in neurotransmitters (including galanin, orexin, serotonin, and adenosine) directly impairs the sleep modulation system. Disorganization in the circadian system consisting of suprachiasmatic nucleus dysfunction, reduced light transmission, and local circadian clock disruption collectively interrupts circadian rhythms, also causing sleep disturbances in the older. Of note is the bidirectional relationship between aging and sleep, which required us to examine this issue from different perspectives.

Effects of apoptosis on liver aging.

As an irreversible and perennial process, aging is accompanied by functional and morphological declines in organs. Generally, aging liver exhibits a decline in volume and hepatic blood flow. Even with a preeminent regenerative capacity to restore its functions after liver cell loss, its biosynthesis and metabolism abilities decline, and these are difficult to restore to previous standards. Apoptosis is a programmed death process via intrinsic and extrinsic pathways, in which Bcl-2 family proteins and apoptosis-related genes, such as p21 and p53, are involved. Apoptosis inflicts both favorable and adverse influences on liver aging. Apoptosis eliminates transformed abnormal cells but promotes age-related liver diseases, such as nonalcoholic fatty liver disease, liver fibrosis, cirrhosis, and liver cancer. We summarize the roles of apoptosis in liver aging and age-related liver diseases.

Apoptosis in the aging liver.

Various changes in the liver during aging can reduce hepatic function and promote liver injury. Aging is associated with high morbidity and a poor prognosis in patients with various liver diseases, including nonalcoholic fatty liver disease, hepatitis C and liver cancer, as well as with surgeries such as partial hepatectomy and liver transplantation. In addition, apoptosis increases with liver aging. Because apoptosis is involved in regeneration, fibrosis and cancer prevention during liver aging, and restoration of the appropriate level of apoptosis can alleviate the adverse effects of liver aging, it is important to understand the mechanisms underlying this process. Herein, we elaborate on the causes of apoptosis during liver aging, with a focus on oxidative stress, genomic instability, lipotoxicity, endoplasmic reticulum stress, dysregulation of nutrient sensing, and liver stem/progenitor cell activity.

[Generation and release of Microcystin-lR by Microcystis aeruginosa under hydroquinone inhibition].

The generation and release of algal toxin Microcystin-LR (MCLR), as well as the intracellular organic chemicals were studied during the inhibition processes of Microcystis aeruginosa using hydroquinone as the inhibitor. According to the dose-effect relationship, the corresponding dosages of EC20, EC50, EC70, EC90, EC99 were added to the algae suspension. The TOC was determined by the total organic carbon analyzer, and the three-dimensional fluorescence spectrum was obtained by the fluorescence spectrophotometer. The results showed that the generation of MCLR was inhibited at EC20 and the total MCLR was 72.4%-83.0% of the control samples. Whereas the cells were stimulated to produce higher amount of MCLR, and the total MCLR was 1.77-3.13 times as high as that of the control samples at EC50-EC99. The intracellular MCLR was largely released to the water at EC70-EC99. The release of other intracellular organic chemicals mainly referred to humic-like and fulvic-like substances, which were unstable and had an obvious degradation and transformation after 6 days of cultivation.