Bioactive extracts and association with C and N in Eleutherococcus senticosus subjected to chitosan nanoparticles in contrasting light spectra.

Bioactive compounds are major reasons for the value of Eleutherococcus senticosus, which can be modified by different lighting spectra. Light-emitting diode (LED) provides lights with specific spectra which can interact with other treatments to impact plant bioactive production. Chitosan nanoparticle (CN) is a biopolymer derived from marine creatures. It's usage may be a practical approach to cope with uncertainties in secondary metabolites induced by illumination. Carbon (C) and nitrogen (N) cyclings link plant eco-physiological performance and bioactive substance; hence their associations may reveal the mechanism of joint light-CN interaction. In this study, E. senticosus seedlings were raised under artificial lighting spectra from high-pressure sodium (HPS) lamps (44% red, 55% green, 1% blue) and white (44% red, 47% green, 8% blue) and red colored (73% red, 13% green, 14% blue) LED panels. Half of the seedlings received CN and the other half received distilled water as the control. Compared to the HPS spectrum, the red-light induced stronger shoot growth with greater biomass accumulation and higher water uptake but resulted in lower N concentration and biomass ratio in the root. The white light caused more biomass allocated to the root and strengthened stem C concentration. Stem eleutheroside B increased with shoot growth, while root eleutheroside B had a positive association with leaf C and stem protocatechuic acid had a negative association with leaf N. Having the CN treatment in white and red LED lights is recommended for increasing accumulation of bioactive compounds in the shoots and roots of E. senticosus seedlings, respectively.

Root foraging of birch and larch in heterogeneous soil nutrient patches under water deficit.

Water and nutrient are two critical factors that limit plant growth to spatial-temporal extents. Tree root foraging behavior has not received adequate attention in heterogeneous soil environments in temperate forest under drought pressure. In this study, birch (Betula platyphylla) and larch (Larix olgensis) seedlings were raised in pots in a split-root system with artificially heterogeneous soil environments to study the root foraging response to drought. Potted space was split into two halves where substrates were mixed with fertilizers in 67.5 mg nitrogen (N) plant-1 (N-P2O5-K2O, 14-13-13) to both halves as to create a homogeneous condition. Otherwise, a rate of 135 mg N plant-1 of fertilizers was delivered to a random half to create a heterogeneous condition. Half of seedlings were fully sub-irrigated every three days with the other half received the drought treatment by being watered every six days. Both birch and larch seedlings showed greater net shoot growth and biomass increment in well-watered condition, while root morphology was promoted by drought. Both species placed more fine roots with higher root N concentration in nutrient-enriched patches. In the heterogeneous pattern, birch showed a higher foraging precision assessed by biomass and greater foraging plasticity assessed in morphology and physiology. In contrast, larch seedlings had higher root N concentration in the well-watered condition. Neither species showed a significant response of N utilization to the heterogeneous pattern, but both used more N when water supply was improved. Overall, birch is better at acclimating to heterogeneous soil conditions, but its ability to seize N was lower than larch when drought was alleviated.

[Effects of fungi fraction on growth and anti-oxidative activity of Eleutherococcus senticosus].

The present study was conducted to explore the effect of endophytic fungi fraction on growth and anti-oxidative activity of Eleutherococcus senticosus. The growth,yield,contents of MDA,and antioxidant activities were assessed in E. senticosus under five fungi fractions,namely BZ,MH,DT,JS,and XFZ. The results showed that fungi fractions and component significantly affected the growth,low concentration of DT fungi fraction significantly increased the biomass of E. senticosus,reduced the MDA content in cells,and the antioxidant activities of the aqueous extracts were superior to the others. The results indicated that low concentration of DT fungi fraction was the optimum fraction to achieve high yield and quality of E. senticosus.

Optimal construction and pharmacokinetic study of CZ48-loaded poly (lactic acid) microbubbles for controlled drug delivery.

CZ48, a prodrug of camptothecin (CPT) with derivative resistant to lactone hydrolysis, suffers from limited application for cancer treatment due to poor water-solubility, thus causing its low bioavailability and absorption in vivo. To echo this problem, CZ48 was incorporated into poly (lactic acid) (PLA) microbubbles via a double emulsion technique (W/O/W), and the successful loading was confirmed by X-ray diffraction (XRD) patterns and confocal laser scanning microscope (CLSM). The obtained CZ48-loaded microbubbles had a diameter ranging from 0.5 to 6.7 µm, and the encapsulation efficiency and drug-loading content were as high as 85.73 ± 2.41% and 26.07 ± 0.76%, respectively. The in vitro drug release demonstrated that only about 55% of CZ48 was released for CZ48-loaded PLA microbubbles in 48 h. In contrast, over 90% of CZ48 was released for free CZ48 crystals sample in only 5 h. Besides, in vivo pharmacokinetic studies further revealed that the availability of both CZ48 and its metabolite CPT were obviously enhanced after the incorporation of CZ48 into PLA microbubbles. To be noted, the value of AUC0-∞ of the CZ48-loaded microbubbles was about 5-fold higher than that of free CZ48 suspension, implying a much higher anticancer effect of the CZ48-loaded microbubbles. The half-life time (T1/2) of both CZ48 and CPT of the CZ48-loaded microbubbles were also significantly longer than that of the free CZ48, indicating a delayed release time for the microbubbles. Hence, this work promotes a promising drug carrier system for the controlled release of CZ48 as well as other drugs with poor water-solubility.

The improvement of bioactive secondary metabolites accumulation in Rumex gmelini Turcz through co-culture with endophytic fungi

Abstract Aspergillus sp., Fusarium sp., and Ramularia sp. were endophytic fungi isolated from Rumex gmelini Turcz (RGT), all of these three strains could produce some similar bioactive secondary metabolites of their host. However the ability to produce active components degraded significantly after cultured these fungi alone for a long time, and were difficult to recover. In order to obtain more bioactive secondary metabolites, the co-culture of tissue culture seedlings of RGT and its endophytic fungi were established respectively, and RGT seedling was selected as producer. Among these fungi, Aspergillus sp. showed the most significant enhancement on bioactive components accumulation in RGT seedlings. When inoculated Aspergillus sp. spores into media of RGT seedlings that had taken root for 20 d, and made spore concentration in co-culture medium was 1 × 104 mL-1, after co-cultured for 12 d, the yield of chrysophaein, resveratrol, chrysophanol, emodin and physcion were 3.52-, 3.70-, 3.60-, 4.25-, 3.85-fold of the control group. The extreme value of musizin yield was 0.289 mg, which was not detected in the control groups. The results indicated that co-culture with endophytic fungi could significantly enhance bioactive secondary metabolites production of RGT seedlings.

The improvement of bioactive secondary metabolites accumulation in Rumex gmelini Turcz through co-culture with endophytic fungi.

Aspergillus sp., Fusarium sp., and Ramularia sp. were endophytic fungi isolated from Rumex gmelini Turcz (RGT), all of these three strains could produce some similar bioactive secondary metabolites of their host. However the ability to produce active components degraded significantly after cultured these fungi alone for a long time, and were difficult to recover. In order to obtain more bioactive secondary metabolites, the co-culture of tissue culture seedlings of RGT and its endophytic fungi were established respectively, and RGT seedling was selected as producer. Among these fungi, Aspergillus sp. showed the most significant enhancement on bioactive components accumulation in RGT seedlings. When inoculated Aspergillus sp. spores into media of RGT seedlings that had taken root for 20d, and made spore concentration in co-culture medium was 1×104mL-1, after co-cultured for 12d, the yield of chrysophaein, resveratrol, chrysophanol, emodin and physcion were 3.52-, 3.70-, 3.60-, 4.25-, 3.85-fold of the control group. The extreme value of musizin yield was 0.289mg, which was not detected in the control groups. The results indicated that co-culture with endophytic fungi could significantly enhance bioactive secondary metabolites production of RGT seedlings.

Iron/dextran sulfate multilayered microcapsules for controlled release of 10-hydroxycamptothecin.

Stable 10-hydroxycamptothecin (HCPT) microcrystals with a length of about 5-10µm and a ζ-potential of -38.5mV were produced by pH-induced reprecipitation in presence of a stabilizer hydroxypropylmethylcellulose. Sequential layer growth was achieved by the layer-by-layer (LbL) assembly of Fe(3+) and dextran sulfate (DS) on the surface of HCPT microcrystals via both electrostatic interaction and chemical complexation process. The satisfactory drug loading content (67.2±0.82%) as well as high encapsulation efficiency (60.56±0.82%) for four bilayers of Fe(3+)/DS coating was achieved. Both in vitro and in vivo release study revealed that the release time increased as the number of deposited Fe(3+)/DS bilayers increased. These results indicated that such iron-polysaccharide multilayered microcapsules can be a promising approach for the construction of an effective controlled release delivery system of HCPT as well as other drugs with potential cytotoxicity or short half-life time.

[Responses of larch seedling' s photosynthetic characteristics to nitrogen and phosphorus deficiency].

In this paper, the responses of larch seedling's photosynthetic characteristics to N and P deficiency were studied in greenhouse from April to September, 2002. On April 10, one-year-old larch seedlings, after their roots washed and sterilized, were transplanted into a plastic pot (diameter 30 cm, height 27 cm) containing sterilized and washed quartz sand, and supplied with complete nutrient solution (4 mmol NH4NO3 x L(-1), 1 mmol KH2PO4 x L(-1), 1 mmol KCl x L(-1), 1 mmol CaCl2 x L(-1), 0.6 mmol MgS4 x L(-1), 0.02 mmol FeCl3 x L(-1), 6 micromol MnC2 x L(-1), 0.016 mmol H3BO3 x L(-1), 0.3 micromol ZnCl2 x L(-1), 0.3 micromol CuCl2 x L(-1), and 0.3 micromol NaMoO4 x L(-1)). On May 20, the seedlings were treated with four different combinations of N and P supply, i.e., control (CK, 8 mmol N x L(-1) and 1 mmol P x L(-1)), low nitrogen supply (LN, 1 mmol N x L(-1) and 1 mmol P x L(-1)), low phosphorus supply (LP, 8 mmol N x L(-1) and 1/8 mmol P x L(-1)), and low nitrogen with low phosphorus supply (LN-LP, 1 mmol N x L(-1) and 1/8 mmol P x L(-1)). In treatment LN, the other nutrients were given as CK, while in treatment LP, the K level was adjusted by KCl, with the other nutrients kept as CK. On September 4, the net photosynthetic rate, chlorophyll fluorescence parameters, chlorophyll content, total soluble protein content, and N and P contents of the needle were determined. The results showed that in treatment LN, the N content, chlorophyll content, net photosynthetic rate (Pn), maximal PSII efficiency (Fv/Fm) and potential PSII activity (Fv/Fo) of the needle declined significantly by 37%, 31%, 58%, 22% and 57%, respectively, while in treatment LP, the N and P contents, chlorophyll content, total soluble protein content and Fv/Fm had no significant differences with CK, but the Pn and Fv/Fo was 13% lower than CK. The variation tendency and extent of Pn, chlorophyll fluorescence parameters, and other physiological indices in treatment LN-LP were similar to those in treatment LN.

[Seasonal variations in biomass and salidroside content in roots of Rhodiola sachalinensis as affected by gauze and red film shading].

Rhodiola sachalinensis A. Bor, a perennial herb, belonging to the family Crassulaceae, is mainly distributed in mountains at the altitudes of 1,700-2,500 m. It is a typical alpine plant and a very important medicinal plant with high activities of anti-fatigue, anti-senescence, and anti-radiation, due to the secondary metabolite salidroside in its root. Our previous findings have proven that red light promotes salidroside synthesis remarkably but decreases biomass insignificantly, resulting in a higher yield of salidroside in roots of Rh. sachalinensis in a greenhouse. In order to investigate the influences of shading and red light on seasonal variations in biomass and salidroside content in Rh. sachalinensis roots, the effects on 3 or 4 years old Rh. sachalinensis plants in a nursery in Daxinganling Mountain (124 degrees 02' E, 50 degrees 30' N) were studied in 2001. Compared to the control (CK) of full sunlight, 6 treatments with neutral transparent film and gauze, or red film alone had been conducted for 131 days. In treatment I, Rh. sachalinensis was shaded with neutral transparent film and gauze to achieve an irradiance 51.8% of full sunlight. In treatment II, the plants were shaded by red film alone, but the irradiance was as that in treatment I. In treatments III, IV, V and VI, neutral transparent film and gauze were originally used on May 8, then shifted to red film on Jun 3, July 4, August 4 and September 2, respectively and all experiments stopped on September 16, 2001. Rh. sachalinensis roots were harvested on 2-4th from June to September and finally on September 16, and root-biomass and salidroside content were measured. Root-biomass in plants decreased significantly under shading with neutral transparent film and gauze compared to the control with full sunlight, but little variations in salidroside content and yield. In comparison with shading by neutral transparent film and gauze, root-biomass reduced lightly and salidroside content and yield in roots were increased remarkably under red-film shading. At the end of the season, salidroside content under red light was 163% in 3-year-old and 155% in 4-year-old Rh. sachalinensis roots; whereas salidroside yields were 144% in 3-year-old and 145% in 4-year-old Rh. sachalinensis roots to those in plants under shading. The results also showed that the enhancement in the salidroside content and yield were little related to the duration of red film shading, which implied that in order to increase salidroside content and get higher salidroside yield, but less affect root-biomass, Rh. sachalinensis may be shaded with red film just several days before harvest.