The inhibitory effects of 150 medicinal plants on elastase activity were investigated. Among the 150 plants, six plant extracts (final concentration 1 mg/ml in methanol) exhibited more than 65% of inhibition of elastase activity. The inhibitory effects of six active plants, including Areca catechu (IC50, 42.4 mug/ml), Cinnamonum cassia (IC50, 208.7 mug/ml), Myristica fragrans (IC50, 284.1 mug/ml), Curcuma longa (IC50, 398.4 mug/ml), Alpinia katsumadai (IC50, 465.7 mug/ml) and Dryopteris cassirrhizoma (IC50, 714.4 mug/ml) on the activity of human leukocyte elastase, hyaluronidase and lipid peroxidation were examined. In the lipid peroxidation assay, using the TBA method, three of the six plants, including Curcuma longa (IC50, 45.5 mug/ml), Areca catechu (IC50, 51.0 mug/ml) and Alpinia katsumadai (IC50, 116.3 mug/ml) exhibited more than 70% inhibition at the concentration of 1 mug/ml, but only one plant, Areca catechu (IC50, 563 mug/ml) showed high inhibitory effect on hyaluronidase activity. The results suggest that medicinal plants showing several biological activities may be potent inhibitors of the anti-ageing process in skin. This property might be useful for application in cosmetics.

[1] The Earth's outer radiation belt is known to vary often and significantly on various time scales. In this study, we have used the data of various instruments onboard the THEMIS spacecraft to study long-term changes of the outer radiation belt electrons around the year 2009. We find that the entire outer belt became extremely weak for nearly a year and was practically lost a few times, each time lasting~20 days up to~2 months, before eventually re-forming. This was revealed at a wide energy range from several tens of keV to up to 719 keV, which was covered by the THEMIS spacecraft measurements. The loss of the outer belt was associated with extremely weak solar wind conditions, i.e., low interplanetary magnetic field magnitude and slow solar wind speed. In particular, this set greatly reduced magnetospheric convection and/or injections for a prolonged time interval, which led to a large expansion of the plasmasphere, even beyond geosynchronous altitude and thus invading the majority of the typical outer belt territory for the same prolonged time interval. Consequently, preexisting electrons inside the plasmasphere had enough time to be lost into the atmosphere gradually over a time scale of several days without being supplied with fresh electrons from the plasma sheet under the same reduced convection and/or injections. Plasmaspheric hiss waves with an amplitude of up to a few tens of pT persisted to exist during the gradual decay periods, implying that they are likely responsible for the continual loss of the electrons inside the plasmasphere. A complete re-formation of the outer belt to full intensity was then realized over an interval of a few months. During the re-formation process, the magnetospheric convection and/or injections increased, which led to a gradual increase of whistler chorus wave activity, contraction of the plasmasphere, and supply of the plasma sheet electrons at high L shells. This set first an outward increasing profile of the phase space density, which eventually developed into a profile with a peak at low L of~5 over a time scale of 1-2 days. In this latter stage, a local acceleration at low L shells is found to be clearly needed although the radial diffusion process can contribute to some extent, in particular, for particles with a low first adiabatic invariant value.

[1] For various reasons, the Earth's outer radiation belt often exhibits dramatic and sudden increases or decreases in the observed particle flux. In this paper, we report three dropout events of energetic electrons observed by multiple spacecraft while traveling across the outer radiation belt. The three events were first identified based on observations of a significant dropout in the >2 MeV electron flux at geosynchronous orbit. Subsequently, for each event, we analyzed the energetic electron data obtained near the magnetic equator by THEMIS spacecraft to determine the responses of the entire outer radiation belt. Our analysis is mainly based on the electron fluxes measured at energies of 52 keV, 203 keV, and 719 keV, and on the phase space densities estimated for the first adiabatic invariant μ values of 100 MeV/G, 200 MeV/G, and 300 MeV/G. The main shared feature among the three events is that while, for the lowest energy, sources from the convection and/or particle injections of plasma sheet electrons dominate over losses, the higher energies exhibit a dramatic dropout effect that penetrates deeply into L~4.5 -5. In terms of the phase space density, a similar dropout effect is clearly seen for the μ values of 200 MeV/G and 300 MeV/ G, while the convection effect and/or injections dominates for μ = 100 MeV/G. What is astonishing about this dropout phenomenon is that the three events are all associated with only very weak magnetic storms with a SYM-H minimum of -40 nT or larger. This implies that a significant loss of electrons deep inside the outer radiation belt can occur even during a very weak magnetic storm. Low-altitude observations of electrons by NOAA POES satellites indicate no significant atmospheric precipitation due to strong diffusion. Our simulations with various conditions suggest that radial diffusion effect in combination with the magnetopause shadowing are responsible for the observed dropouts to a large extent for all of the three events, although the contribution by the weak atmospheric precipitation that might have been missed by the NOAA POES observations can be non-negligible.

Calcium-related proteins include transient receptor potential vanilloid (TRPV) 5 and 6, plasma membrane calcium-ATPase 1b (PMCA1b), and calbindin-D9k and -D28k. The TRPV6 is a major calcium channel located in the apical and basolateral membranes of cell and distributed widely in many other organs, especially in the exocrine tissues such as intestine and uterus. TRPV6s are generally regulated by vitamin D, a dietary calcium ion and hormone. In particular, uterine TRPV6 appears to be affected by sex steroid hormones, which are altered according to estrous cycle and pregnancy. In order to discover the effect of sex steroid hormones on the regulation of TRPV6, we examined the expression of TRPV6 mRNA by using RT-PCR and real-time PCR, and protein expression of TRPV6 by immunohistochemistry (IHC) in the uterus, duodenum, and kidney. To evaluate the effect(s) of sex steroid hormones on its uterine, duodenal, and renal regulation, 17β-estradiol [E2; 40 μg kg–1 of body weight (bw)] and/or progesterone (P4; 4 mg kg–1 of bw) or vehicle (n = 6/each group) were subcutaneously injected into Sprague-Dawley immature female rats (14 days old, n = 24 in total) for 3 days. As a result, the treatments of immature rats with E2 or P4 increased TRPV6 mRNA for calcium function or regulation in the uterus of immature rats. To confirm the specificity of E2 or P4 through their receptors, we treated the immature rats (extra n = 24 in total) with an estrogen receptor-antagonist, ICI 182,780 (ICI; 30 μg kg–1 of bw), and/or progesterone receptor antagonist, RU 486 (10 mg kg–1 of bw), at 3 days prior to E2 or P4 injection. Consequently, an increase in TRPV6 mRNA was observed in the following 2 treatments; ICI plus E2/P4 and E2/P4 alone. In IHC, we further observed that the expression of duodenal TRPV6 was increased by E2 or P4 and E2 or P4 plus ICI, while no difference was observed in renal TRPV6 by the treatments of sex steroid hormones. In conclusion, these results indicate that the expressions of uterine and duodenal TRPV6 may be induced by E2 and P4, but its renal expression may not be controlled by these steroids.