No abstract

According to the prediction of the 2008 World Health Organization (WHO) report, depression will be the highest burden disease by the year 2030. Daylily flower (金針花 Jīn Zhēn Huā ; the flower of Hemerocallis fulva) is traditionally used for soothing in Chinese dietary therapy. The major flavonoid of daylily flowers, rutin, is also characterized to be an antidepressant. In this study, we investigated the antidepressant effects of ethanol extract of daylily flowers (DFEtoH) and rutin by forced swimming test (FST) and neurotransmitter metabolism of brain regions (frontal cortex, hippocampus, striatum, and amygdala). Results show that either short- or long-term tests, the extract and rutin significantly reduce the immobility time and increased swimming time of FST, which are compared with the vehicle (P < 0.05). The extract and rutin also increase the serotonin, norepinephrine, and dopamine concentration of these brain regions (P < 0.05). In long-term tests, the daylily flowers extract markedly increased serotonin concentration and reduced serotonin turnover rate in these brain regions but not frontal cortex. In conclusion, present data illustrated that DFEtoH does have antidepressant-like effects possibly via the regulation of serotonergic system. Moreover, rutin might be playing a very important role in the antidepressant-like effects of DFEtoH.

Depression is one of the most common psychiatric disorders that affects over 10% of individuals. However there is no desirable therapeutic approach nowadays. Thus, looking for an alternative treatment is important. The objectives of this study are to investigate the antidepressant effects of the rhizomes of Gastradia elata B(L), a traditional Chinese medicine, in the animal model forced-swimming test (FST), and to analyze the monoamine content in the rats' brain regions in order to better understand the possible mechanisms of the water extract of the rhizomes of Gastrodia elata B(L) (WGE). Subchronic administration of 0.5 or 1.0 mg/kg bw WGE by gavage for 21 consecutive days significantly reduced the immobility duration of rats in the test session of FST as compared to the control group (p < 0.05), with the equivalent effects as the antidepressant drug fluoxetine. The concentration of serotonin (5-HT) in the frontal cortex and dopamine (DA) in striatum were significantly increased after WGE administration (p < 0.05). The ratio of 5-HIAA/5-HT and (DOPAC + HVA)/DA, i.e. the turnover of 5-HT and DA respectively, were also significantly lowered in WGE groups (p < 0.05). In summary, the present study showed that the WGE possesses antidepressant-like effect on rats in the animal model FST, and the possible mechanism may be via regulating both the serotonergic and dopaminergic systems.

Iridoplasts (modified plastids in adaxial epidermal cells) reported from Begonia were originally hypothesized to cause iridescence, which was broadly accepted for decades. However, several species of Begonia with iridoplasts are not iridescent causing confusion. Here chloroplast ultrastructure was observed in 40 taxa of Begoniaceae to explore the phenomenon of iridescence. However, 22 Begonias and Hillebrandia were found to have iridoplasts, but only nine display visually iridescent blue to blue-green leaves. Unexpectedly, a new type of plastid, a 'minichloroplast,' was found in the abaxial epidermal cells of all taxa, but was present in adaxial epidermal cells only if iridoplasts were absent. Comparative ultrastructural study of iridoplasts and a shading experiment of selected taxa show that a taxon with iridoplasts does not inevitably have visual iridescence, but iridescence is greatly affected by the spacing between thylakoid lamellae (stoma spacing). Thus, we propose instead the name 'lamelloplast' for plastids filled entirely with regular lamellae to avoid prejudging their function. To evaluate photosynthetic performance, chlorophyll fluorescence (F /F ) was measured separately from the chloroplasts in the adaxial epidermis and lower leaf tissues by using leaf dermal peels. Lamelloplasts and minichloroplasts have much lower photosynthetic efficiency than mesophyll chloroplasts. Nevertheless, photosynthetic proteins (psbA protein of PSII, RuBisCo and ATPase) were detected in both plastids as well as mesophyll chloroplasts in an immunogold labeling. Spectrometry revealed additional blue to blue-green peaks in visually iridescent leaves. Micro-spectrometry detected a blue peak from single blue spots in adaxial epidermal cells confirming that the color is derived from lamelloplasts. Presence of lamelloplasts or minichloroplasts is species specific and exclusive. High prevalence of lamelloplasts in Begoniaceae, including the basal clade Hillebrandia, highlights a unique evolutionary development. These new findings clarify the association between iridescence and lamelloplasts, and with implications for new directions in the study of plastid morphogenesis.