Juglanin ameliorates UVB­induced skin carcinogenesis via anti­inflammatory and proapoptotic effects in vivo and in vitro.

Ultraviolet (UV) radiation induces skin injury, and is associated with the development and formation of melanoma, which is a highly lethal form of skin cancer. Juglanin is a natural product, which is predominantly extracted from Polygonum aviculare, and is considered a functional component among its various compounds. Juglanin has been reported to exert marked protective effects in various diseases via the inhibition of inflammation and tumor cell growth. The present study aimed to explore the effects of juglanin on human skin cancer induced by UV and to reveal the underlying molecular mechanism. In the present study, immunohistochemical analysis, western blot analysis, RT-qPCR analysis and flow cytometry assays were mainly used in vivo and/or in vitro. The results indicated that in mice, UVB exposure increased susceptibility to carcinogens, and accelerated disease pathogenesis. Conversely, juglanin was able to ameliorate this condition via inhibition of inflammation, suppression of cell proliferation and induction of apoptosis via p38/c­Jun N­terminal kinase (JNK) blockage, nuclear factor (NF)­κB inactivation and caspase stimulation in vivo. In addition, in vitro, the present study demonstrated that treatment of UVB­stimulated B16F10 melanoma cells with juglanin resulted in a dose­dependent decrease in cell viability, as well as increased apoptosis via the upregulation of caspase expression and poly (ADP­ribose) polymerase cleavage. In addition, juglanin markedly attenuated p38/JNK signaling, inactivated the phosphoinositide 3­kinase/protein kinase B pathway and suppressed UVB­induced NF­κB activation. Taken together, these results indicated the possibility of applying juglanin in combination with UVB as a potential therapeutic strategy for preventing skin cancer.

[Characteristics of canopy stomatal conductance of Platycladus orientalis and its responses to environmental factors in the mountainous area of North China]. / åŽåŒ—å±±åŒºä¾§æŸå† å±‚æ°”å­”å¯¼åº¦ç‰¹å¾åŠå ¶å¯¹çŽ¯å¢ƒå› å­çš„å“åº”.

Canopy stomatal conductance (gs) is an important biological parameter to measure water vapor flux in canopy atmosphere interface. Exploring characteristics of canopy stomatal conductance and its responses to environmental factors can offer theoretical evidence for conducting mechanism based study of vapor exchange process in forest canopy. SF-L thermal dissipation probe was adopted to measure sap flow density (Js) of Platycladus orientalis in 2014. The environmental factors including photosynthetically active radiation (PAR), vapor pressure deficit (VPD) and air temperature (T) were simultaneously observed. The canopy stomatal conductance was calculated, and the responses of gs to environmental factors were analyzed. The results showed that the daily variation of sap flow density was of two peak pattern curve, and the Js in growing season was higher than in non-growing season. And the bigger DBH was, the higher Js would be. The daily variation of canopy stomatal conductance was similar to the canopy transpiration of per leaf area (EL), which was of two peak pattern curve. The gs and EL in growing season were higher than those in non growing season. The canopy stomatal conductance and air temperature presented parabolic relation, and gs reached peak valley at around 10 ℃. Taking the value of 400 µmol·m-2·s-1 as the PAR thre shold, when PAR was under this threshold, gs was positively correlated with PAR. When PAR was beyond this threshold, the correlation between gs and PAR would be small. The relationship between canopy stomatal conductance and vapor pressure deficit was negative logarithmic function. As VPD increasing, gs decreased gradually. Higher air temperature and photosynthetically active radiation, and lower vapor pressure deficit contributed to higher canopy stomatal conductance of P. orientalis and could promote greater canopy transpiration.

[Foliar water use efficiency of Platycladus orientalis of different canopy heights in Beijing western mountains area, China]. / åŒ—äº¬è¥¿å±±ä¾§æŸæž—å† å±‚ä¸åŒé«˜åº¦å¤„å¶ç‰‡æ°´åˆ†åˆ©ç”¨æ•ˆçŽ‡.

In this study, we focused on Platycladus orientalis, a widely distributed tree species in Beijing western mountains area, and precisely determined its foliar water use efficiency (including instantaneous water use efficiency derived from gas exchange and short-term water use efficiency obtained on carbon isotope model) by carefully considering the discrepancies of meteorological factors and atmosphere CO2 concentration and δ13C among different canopy heights, hoping to provide theoretical basis for carbon sequestration and water loss in regional forest ecosystem, and offer technical support for regional forest management and maintenance. The results showed that the foliar instan-taneous water use efficiency tended to increase with the increasing canopy height, following the order of the upper canopy > the middle canopy > the lower canopy. A variety of meteorological factors synergistically influenced stomatal movement, and stomatal conductance would in turn have an effect on foliar instantaneous water use efficiency. Foliar short-term water use efficiency also increased with increasing canopy height, following the order of the upper canopy > the middle canopy > the lower canopy. The differences of foliar short-term water use efficiency among different heights could be explained by discrepancies of environmental drivers and atmosphere CO2 concentration and δ13C. Platycladus orientalis leaves in upper canopy adapted to ambient condition by improving water use efficiency.

Preparation and comparative analysis of two podophyllotoxin liposomes.

OBJECTIVE: To prepare two different liposome gels containing podophyllotoxin (PPT) and compare their pharmaceutical properties. METHODS: PPT-Dipalmitoylphosphatidylcholine (DPPC) liposome and PPT-soya lecithin liposome were prepared by reverse phase evaporation technique, and optical and electron microscopy were performed respectively for examining the appearances of the 2 liposomes and the diameter of the particles. Gel filtration was employed to assess the embedding ratio of the liposomes. RESULTS: Under optical microscope, PPT-DPPC liposome was observed to be composed of spherical particles with diameter range of 2.05 to 0.825 microm (average 1.45 microm). The diameter range of the particles of PPT-soya lecithin liposome is 7.59 to 1.445 microm (average 3.78 microm). PPT-DPPC liposome appeared multivesicular under electron microscope, with the embedding ratio of 73.8%, and 79.1% for PPT-soya lecithin liposome (n=3). PPT-DPPC liposome had a embedding ratio of 65.2%, 58.8% and 56.4% after preserved 1, 3, 6 months respectively. As for PPT-soya lecithin liposome, the embedding ratios were 70.3%, 60.4%, and 51.3% respectively. CONCLUSION: The PPT in the liposomes prepared by reverse phase evaporation technique is evenly distributed throughout the gel. The preparation is relatively simple with high embedding ratio.

[Effect of liposome on permeability and drug retention of sodium fluorescein in rat skin: an experimental study].

OBJECTIVE: To investigate the effect of liposome on the permeability and drug retention of sodium fluorescein(NaFl) in rat skin. METHODS: With an improved Franz diffusion cell and 0.125% NaFl liposome suspension as the model drug, in vitro measurement of percutaneous absorption and skin reservoir capacity for NaF1 was conducted using a fluorescence spectrophotometry at 4 and 12 h respectively after the diffusion experiment had started, and distribution of the fluorescence in rat skin was observed under fluorescence microscope at 4 h penetration experiment. NaFl solution of the same concentration as the model drugs served as the control for this experiment. RESULTS: In comparison with NaFl solution, liposomal NaFl suspension resulted in larger amount of NaFl retention in rat skin but smaller amount in the receiver cell in a four-hour Franz diffusion test, with also higher fluorescence intensity in the skin, especially the skin around the hair follicles. CONCLUSION: Local high drug concentrations can be achieved in the skin by liposomal suspension of water soluble drug for more effective treatment of skin diseases.

[Effect of modified Yupingfeng granule on nuclear factor-kappaB expression in mice with allergic contact dermatitis].

OBJECTIVE: To investigate the effect of modified Yupingfeng granule on nuclear factor-kappaB (NF-kappaB)expression in mice with allergic contact dermatitis (ACD). METHODS: Mouse models of ACD were treated with the granules at low, medium and high doses, with normal saline and hydrocortisone as the negative and positive controls, respectively. The expressions of NF-kappaB and its distribution in the lesions were detected using immunohistochemistry. RESULTS: The staining intensity, area and positive expression rates of NF-kappaB p50 were significantly different between the treatment group and the normal saline group (P<0.05). CONCLUSION: Modified Yupingfeng granule can effectively inhibit the expression of NF-kappaB in ACD, which might be a possible mechanism for its therapeutic effect on ACD.