Fermentation of Ganoderma lucidum and Raphani Semen with a probiotic mixture attenuates cyclophosphamide-induced immunosuppression through microbiota-dependent or -independent regulation of intestinal mucosal barrier and immune responses.

BACKGROUND: Probiotic fermentation is a promising strategy for improving the nutritional and functional properties of traditional Chinese medicines (TCMs). Ganoderma lucidum and Raphani Semen are famous TCMs that have been shown to help alleviate immune system disorders. However, few studies have experimentally investigated the effects of probiotic-fermented G.lucidum and Raphani Semen on the immune system. PURPOSE: We established the in vitro fermentation of G. lucidum and Raphani Semen with a probiotic mixture (Bifidobacterium longum, Lactobacillus acidophilus, and l. fermentum) (GRFB), investigated its ameliorating effect against cyclophosphamide (CTX)-induced immunosuppression, and explored its possible mechanisms. METHODS: First, the different components in GRFB were identified by high-performance liquid chromatography. Second, its immune-stimulatory activities were evaluated in CTX-treated mice. Lastly, its possible in vitro and in vivo mechanisms were studied. RESULTS: Probiotic fermentation of G. lucidum and Raphani Semen altered some of its chemical constituents, potentially helping improve the ability of GRFB to alleviate immunosuppression. As expected, GRFB effectively ameliorated CTX-induced immunosuppression by increasing the number of splenic lymphocytes and regulating the secretion of serum and ileum cytokines. GRFB supplementation also effectively improved intestinal integrity in CTX-treated mice by upregulating tight junction proteins. It also protects against CTX-induced intestinal dysbiosis by increasing the abundance of beneficial bacteria and reducing the abundance of harmful bacteria. GRFB could directly promote intestinal immunity but not systemic immunity in vitro, suggesting a microbiota-dependent regulation of GRFB. Interestingly, cohousing CTX-induced immunosuppressed mice with GRFB-treated mice promoted their symptoms recovery. Enhanced CTX-induced immunosuppression by GRFB in vitro depended on the gut microbiota. Remarkably, a Kyoto Encyclopedia of Genes and Genomes analysis showed that the GRFB-reprogrammed microbiota was significantly enriched in DNA damage repair pathways, which contribute to repairing the intestinal mucosal barrier. CONCLUSION: This is the first study to suggest that compare with unfermented G. lucidum and Raphani Semen, GRFB can more effectively promote intestinal immunity and manipulate the gut microbiota to promote immunostimulatory activity and repair immunosuppression-induced intestinal barrier damage by biotransforming G.lucidum and Raphani Semen components.

Influence path identification of topography, soil, hydrology and landscape on phosphorus buffering capacity in typical agricultural catchments in central subtropical China.

The catchment phosphorus buffering capacity (PBF) determines the pressure-state-response relationship between anthropogenic P inputs and aquatic ecosystems at a catchment scale, and is affected by biogeochemical, hydrological, and ecological catchment characteristics. However, the complex relationship between these catchment characteristic factors and their impact pathways on PBF remains ambiguous, leading to large uncertainty in balancing agricultural productivity and water conservation via improving BF through management practices. In this study, the short-term buffering index, calculated from net anthropogenic P input and riverine P exports, was used to quantify the spatiotemporal variations in PBF in source agricultural catchments in the Dongting Lake basin. Partial least squares structural equation modeling was used to investigate the relationship between the PBF and the catchment characteristics. The results indicate that catchment PBF was directly determined by soil properties and hydrological conditions, while landscape patterns significantly mediated the effects of topography on soil and hydrology. Considering the pathway preferences of the model, landscape patterns could be the priority for characterizing and regulating PBF. According to a change-point analysis, the probability of PBF weakening increases dramatically when the proportion of farmland (Farm%) > 24.6%, degree of patch interspersion (Contagion index) < 64.5%, and Perimeter-Area Ratio Distribution (PARA) > 348.7. These findings provide new insights into catchment buffering mechanisms and can be used to promote the simultaneous achievement of agricultural production and environmental conservation goals.

Landscape patterns of catchment and land-use regulate legacy phosphorus releases in subtropical mixed agricultural and woodland catchments.

Landscape composition and configuration determine the exchange of matter and energy among different landscape patches and may affect riverine phosphorus (P) exports derived from watershed legacy sources. However, a lack of understanding of landscape pattern effects on legacy P releases has yielded large uncertainties in mitigating watershed water quality using management practices or landscape planning. This study revealed the significance of legacy effect in the headwater catchments through the time-lag response of the long-term trend of river P exports to the change of net anthropogenic P input (NAPI). By constructing empirical statistical models that incorporated NAPI, hydroclimatic, terrain factors, soil chemical properties, and land use variables, the sources of annual riverine total phosphorus (TP) and dissolved inorganic phosphorus (DIP) exports were divided into current annual NAPI input and legacy sources inputs. The model estimations indicated that the contribution of legacy sources to riverine TP exports was 0.33-1.12 kg ha-1 yr-1 (50.7-82.8%), which was significantly higher than the contribution to DIP exports (0.18-0.49 kg ha-1 yr-1, 42.4-81.4%) in 2012-2017. Redundancy analysis (RDA) and variance partitioning analysis (VPA) methods were used to quantify the relative contribution of landscape patterns, soil P content, and terrain factors to legacy P releases. Results revealed that the relative contribution of the landscape composition and configuration to the total variations of legacy P releases was greater than that of the soil P and terrain factors. For different land use patches, a large area of woodland with a high aggregation degree and a large area of ponds with multiple net structures may significantly alleviate legacy P releases. In contrast, the legacy P releases were significantly positively associated with highly aggregated agricultural, tea plantation, and residential patches. This study provides theoretical support for strategies aiming to control legacy P from the perspective of landscape planning.

QKI-Regulated Alternative Splicing Events in Cervical Cancer: Pivotal Mechanism and Potential Therapeutic Strategy.

QKI is a vital regulator in RNA splicing and maturation, but its role in cervical cancer (CC) is little known. In this study, we found that QKI is decreased in human CC, and overexpression of QKI inhibits HeLa cell proliferation and promotes the apoptosis of cancer cells. We identified hundreds of endogenous QKI-regulated alternative splicing events (ASEs) and differentially expressed genes (DEGs) in QKI-overexpressed HeLa cells by RNA-seq and selectively validated their expression by quantitative reverse-transcription polymerase chain reaction. The gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that QKI-regulated ASEs and DEGs were closely related to cancer, apoptosis, and transcriptional regulatory functions. In short, QKI may affect the occurrence and development of CC by regulating gene expression through AS.

Probiotic fermentation of Ganoderma lucidum fruiting body extracts promoted its immunostimulatory activity in mice with dexamethasone-induced immunosuppression.

Ganoderma lucidum is a legendary traditional Chinese medicine with various bioactivities. This study was conducted (a) to explore the in vitro fermentation of the water extracts of G. lucidum fruiting body with Lactobacillus acidophilus and Bifidobacterium breve and (b) to investigate the effect of fermentation broth (GLFB) on dexamethasone (DEX)-induced immunosuppressed mice. Our results demonstrated that probiotic fermentation of G. lucidum fruiting body extracts underwent structural changing of major ganoderic acid components, such as ganoderic acid A (GA) into GC2, and this fermentation process involves changing of several metabolic pathways in the probiotic strains. GLFB could significantly improve the immunity, intestinal integrity, and gut microbiota dysbiosis in DEX-treated mice, and the immunostimulatory activity of GLFB was found closely related to its direct regulation on the expansion of CD4+ T cells in Peyer's patches of mice. These data implied that probiotic fermentation of G. lucidum fruiting body extracts promoted its immunostimulatory activity via biotransformation of components such as GA. This research provides a theoretical support for the development and application of G. lucidum fermentation by probiotics.

[Nitrogen and Phosphorus Removal in Surface Flow Constructed Wetland Planted with Myriophyllum elatinoides Treating Swine Wastewater in Subtropical Central China].

The loss of nitrogen (N) and phosphorus (P) from aquaculture has caused eutrophication of freshwater systems. Here, surface flow constructed wetland (SFCW) planted with Myriophyllum elatinoides were used to treat swine wastewater from a medium-sized hoggery in subtropical Central China. Inflow concentrations of NH4+-N, TN, TP, and COD ranged from 535.4 to 591.09, 682.09 to 766.96, 57.73 to 82.29, and 918.4 to 1940.43 mg·L-1, respectively. The mean removal efficiencies of NH4+-N, TN, TP, and COD were 97.4%, 97.1%, 91.0%, and 90.2%, respectively, and CW1 had the largest contributions of 37.3%, 38.4%, 43.3%, and 27.4%, respectively. Plant N and P uptake ranged 23.87-79.96 g·m-2 and 5.34-18.98 g·m-2, accounting for 19.1% and 20.2% of removal, respectively. Sediment N and P accumulation ranged 19.17-56.62 g·m-2 and 10.59-26.62 g·m-2, accounting for 19.8% and 61.7% of removal, respectively. Multiple linear regression showed that environmental factors explained 79.9% of the N removal and 70.1% of the P removal; DO was the main factor affecting N removal, and sediment adsorption was the key process in P removal. These results show that M. elatinoides constructed wetland can efficiently treat swine wastewater, thereby reduce the discharge of pollutants downstream.

Oral Supplements of Combined Bacillus licheniformis Zhengchangsheng® and Xylooligosaccharides Improve High-Fat Diet-Induced Obesity and Modulate the Gut Microbiota in Rats.

Gut dysbiosis induced by high-fat diet (HFD) may result in low-grade inflammation leading to diverse inflammatory diseases. The beneficial effects of probiotics and prebiotics on obesity have been reported previously. However, their benefits in promoting human health and the underlying mechanisms still need to be further characterized. This study is aimed at understanding how probiotic Bacillus licheniformis Zhengchangsheng® (BL) and prebiotic xylooligosaccharides (XOS) influence the health of a rat model with HF (60 kcal %) diet-induced obesity. Five groups of male Sprague Dawley (SD) rats were fed a normal fat diet (CON) or an HFD with or without BL and XOS supplementation for 3 weeks. Lipid profiles, inflammatory biomarkers, and microbiota composition were analyzed at the end of the experiment. Rats fed an HFD exhibited increased body weight and disordered lipid metabolism. In contrast, combined BL and XOS supplementation inhibited body weight gain and returned lipid metabolism to normal. Furthermore, BL and XOS administration changed the gut microbiota composition and modulated specific bacteria such as Prevotellaceae, Desulfovibrionaceae, and Ruminococcaceae. In addition, supplements of combined BL and XOS obviously reduced the serum LPS level, which was significantly related to microbial variations. Our findings suggest that modulation of the gut microbiota as a result of probiotic BL and prebiotic XOS supplementation has a positive effect on HFD-induced obesity in rats.

Nitrogen and phosphorus removal performance and bacterial communities in a multi-stage surface flow constructed wetland treating rural domestic sewage.

A multi-stage surface flow constructed wetland (SFCW) is used to treat decentralized rural domestic sewage. The performance of a multi-stage SFCW located in Hunan, China, and the associated microbial community structures were investigated. The average removal rates of the multi-stage SFCW planted with Myriophyllum elatinoides were 1.0 g m-2 d-1, 0.84 g m-2 d-1, 61.3 mg m-2 d-1, and 85.3 mg m-2 d-1 for total nitrogen (TN), ammonia (NH4+), nitrate (NO3-), and total phosphorus (TP), respectively. Furthermore, the sediment and presence of plants were found to be important for the removal N and P. The average removal rates by sediment and plants were 196.6 mg N m-2 d-1 and 49.9 mg P m-2 d-1, 17.6 mg N m-2 d-1 and 8.1 mg P m-2 d-1, respectively. The microbial community profiles demonstrated that Proteobacteria, Chloroflexi, Bacteroidetes, Firmicutes and Euryarchaeota were the predominant phyla in each stage and at different sampling times. The concentrations of NO3-, TP, TN, and NH4+, and the pH of the sediment and water had a significant effect on the presence of denitrifying bacteria in the anaerobic environment. Whereas, dissolved oxygen (DO) and redox potential (Eh) had a significant effect on the presence of nitrifying bacteria in the aerobic environment. This research strongly supports that the use of the multi-stage SFCW promotes bacterial diversity and changes bacterial community in the sediment.

Diversity and distribution of bacteria in a multistage surface flow constructed wetland to treat swine wastewater in sediments.

Managing waste produced from swine farming operations is a significant agricultural and environmental challenge. Confined animal feeding operations continually generate large amounts of animal waste, which necessitates adequate waste management systems. This study examines the use of multistage surface flow constructed wetlands (SFCWs) to treat pig farm sewage. The wastewater removal rate, sediment deposits, physicochemical properties, and microbial community compositions of each segment of a SFCW were examined. The results indicated that removal rates of chemical oxygen demand (COD), total nitrogen (TN), NH4+, NO3-, and total phosphorus (TP) were 89.8%, 97.9%, 98.2%, 87.6%, and 96.4%, respectively, in the multistage SFCW. The general trend showed increase in the dissolved oxygen (DO) concentrations and oxidation reduction potential (Eh) from the beginning of the SFCW to its end. Sediment concentrations of N and P in each segment of the SFCW generally decreased, suggesting their accumulation in each segment. High-throughput sequencing indicated that the bacterial diversity increased over time. Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes were dominant in multistage SFCW bacterial communities at the phylum level. Results further indicate that DO and Eh are major environmental factors that influence the bacterial community distribution. Overall, our findings suggest that multistage SFCWs not only improve contaminant removal but also change the bacterial community composition and promote bacterial community diversity.

Response of regional agricultural soil phosphorus status to net anthropogenic phosphorus input (NAPI) determined by soil pH value and organic matter content in subtropical China.

Exploring the relationship between net anthropogenic phosphorus input (NAPI) and soil available P (SAP) content could inform applied issues related to environmental quality and agronomic productivity and increase our knowledge of element biogeochemical cycles. Here, the NAPI was estimated and the SAP content determined in eight counties in subtropical China from 1980 to 2010. It is suggested that the NAPI ranging 318-924 km-2 yr-1 in 1980 had increased substantially to 865-3601 km-2 yr-1 in 2010 across the eight counties, in which the P fertilizer application was estimated to represent the largest individual source of NAPI, accounting for an average of 36.1-74.6% of the NAPI. The NAPI in agricultural land (NAPIa) was the largest component of the NAPI, and 60.7-77.1% of the NAPIa accumulated in the upper 20 cm layer of agricultural soils, which significantly increased soil total-P (TP) and SAP contents. The increases in SAP, resulting from 10,000 kg P km-2 of the NAPIa (IOPNAPI), were estimated to be 1.61-4.36 mg P kg-1 in the counties. Both the correlation and variation partitioning analyses (VPAs) suggested that the soil pH and organic matter content (SOM) were the most important factors influencing the variations of IOPNAPI (determination coefficient: 72.5%). Therefore, the contribution of soil pH and SOM should be considered in enriching soil SAP levels and implementing optimal P management strategies to improving the agronomic effectiveness of P fertilization and further reduce the environmental risk of P loss in subtropical region.

TMDL for phosphorus and contributing factors in subtropical watersheds of southern China.

Water eutrophication, particularly that caused by phosphorus runoff, is of major concern in China due to the serious threats it poses to watershed environments. We investigated one forested and nine agricultural watersheds with areas of 9-5212 ha in a hilly region of Hunan Province in a subtropical region of southern China from 2010 to 2012 to study total phosphorus (TP) loads and contributing factors. The annual TP loads varied from 35.7 to 222.1 kg P km(-2) year(-1) among the different watersheds, with the rainy season of spring and summer accounting for 56.3-82.0% of TP loss. The highest total maximum daily load (TMDL, 0.5 kg P km(-2) day(-1)) and existing exported daily TP loads (DTPL, 1.8 kg P km(-2) day(-1)) were observed under high flow and moist flow conditions in the ten watersheds. However, the target daily reduction ratios for the DTPLs to reach the water quality standard of 0.05 mg P L(-1) varied little with flow condition in the stream but depended on the type of watershed, i.e., <50, <80, and 80-90% for forested, agricultural, and livestock-dominated watersheds, respectively. Gray relational analysis (GRA) suggested that livestock density was the most important factor for watershed TP load under various hydrologic conditions, while livestock density (LD), soil available phosphorous (SAP), cropland percentage, and mean shape index (SHMN) were notable factors for daily reduction rate (DRR) under high and moist flow conditions. Therefore, to protect the local watershed environments, watershed management approaches that include the regulation of livestock production are recommended as the most effective means of reducing P loads at the watershed scale in subtropical areas of southern China.

Relating land use patterns to stream nutrient levels in red soil agricultural catchments in subtropical central China.

Land use has obvious influence on surface water quality; thus, it is important to understand the effects of land use patterns on surface water quality. This study explored the relationships between land use patterns and stream nutrient levels, including ammonium-N (NH4 (+)-N), nitrate-N (NO3 (-)-N), total N (TN), dissolved P (DP), and total P (TP) concentrations, in one forest and 12 agricultural catchments in subtropical central China. The results indicated that the TN concentrations ranged between 0.90 and 6.50 mg L(-1) and the TP concentrations ranged between 0.08 and 0.53 mg L(-1), showing that moderate nutrient pollution occurred in the catchments. The proportional areal coverages of forests, paddy fields, tea fields, residential areas, and water had distinct effects on stream nutrient levels. Except for the forest, all studied land use types had a potential to increase stream nutrient levels in the catchments. The land use pattern indices at the landscape level were significantly correlated to N nutrients but rarely correlated to P nutrients in stream water, whereas the influence of the land use pattern indices at the class level on stream water quality differentiated among the land use types and nutrient species. Multiple regression analysis suggested that land use pattern indices at the class level, including patch density (PD), largest patch index (LPI), mean shape index (SHMN), and mean Euclidian nearest neighbor distance (ENNMN), played an intrinsic role in influencing stream nutrient quality, and these four indices explained 35.08 % of the variability of stream nutrient levels in the catchments (p<0.001). Therefore, this research provides useful ideas and insights for land use planners and managers interested in controlling stream nutrient pollution in subtropical central China.

[Impact of rice agriculture on nitrogen and phosphorus exports in streams in hilly red soil earth region of central subtropics].

The research selected the Tuojia catchment and Jianshan catchment in Changsha County, Hunan Province, to comparatively study the effects of rice agriculture on the nitrogen and phosphorus concentrations and exports in streams in the typical agricultural catchments of the hilly red soil earth region. The monitoring of 16 months suggested that, there was a moderate stream nutrient pollution in both Tuojia and Jianshan catchments, especially for nitrogen pollution. Comparing the two catchments, the nitrogen and phosphorus concentrations were higher and the water quality was worse in the Tuojia catchment than that in the Jianshan catchment. From the nutrient composition of view, ammonia nitrogen was the main species of total nitrogen in the Tuojia catchment (accounting for 58.5% of total nitrogen), while it was nitrate nitrogen in the Jianshan catchment (accounting for 76. 1% of total nitrogen). The proportion of dissolved phosphorus in total phosphorus was 47. 1% in the Tuojia catchment, higher than the proportion of 37.5% in the Jianshan catchment. From temporal variations of nutrient dynamics of view, concentrations of all forms of nitrogen were higher during January to February and in July, respectively, and total phosphorus and dissolved phosphorus were higher during May to June and during October to December. Since the stream discharge in the catchments concentrated during the rice growing period from April to October, the higher nutrient concentrations during the period suggested potential risks of nitrogen and phosphorus losses. The total nitrogen mass flux was 1.67 kg x (hm2 x month)(-1) and TP was 0.06 kg x (hm2 x month)(-1) in the Tuojia catchment, which were greater than the 0.44 kg x (hm2 x month)(-1) and 0.02 kg x (hm2 x month)(-1) in the Jianshan catchment. Given the similar climate, geomorphology, soil type and cultivation patterns but the different area proportion of rice agriculture between two catchments, results suggested that, under the traditional crop management in hilly red soil earth region of central subtropics, the higher area proportion of rice agriculture has the potential to degrade stream aquatic environment.

Study on phosphorus loadings in ten natural and agricultural watersheds in subtropical region of China.

Water eutrophication in subtropical regions of southern China threatens watershed health and is of major concern. However, annual phosphorus (P) loading and its dominant causes are still unclear, especially at the watershed scale. In this study, we investigated dynamic P loadings and associated factors (e.g., land use, livestock production, and runoff depth) in ten watersheds that varied in area from 9 to 5,212 ha in a hilly area of Hunan Province, China. A flowmeter was installed at the outlet of each watershed, and total P (TP) and soluble P (SP) concentrations were monitored periodically from June 2010 to October 2012. The results showed that annual P loadings (APLs) in the ten watersheds ranged from 22.8 to 247.8 kg P/km(2) and that P loss primarily occurred from April to June of each year during the main rainfall season in the study area. In addition, the average eutrophication (>0.05 mg P/L) ratio for stream waters was 86.7 % during the study period, which was indicative of a potentially serious condition for the local water environments. Annual P loadings were linearly related to livestock density (LD; R = 0.92, p < 0.01), whereas the eutrophication ratio of stream water was significantly (p < 0.05) correlated with LD (R = 0.61), percentage cropland (R = 0.71), and percentage forest cover (R = -0.68). Thus, it is concluded that the control of livestock production has the greatest potential for reducing P loadings in watersheds in this subtropical area. This will be beneficial to the amelioration and protection of local environment.

[Effects of soil factors on vegetation community structure in an abandoned subtropical paddy wetland].

Based on the investigation data from a subtropical wetland having been abandoned from paddy agriculture for one year, a redundancy analysis was conducted on the relationships between vegetation community and soil factors in the wetland. It was found that soil moisture regime, available K and P, and pH were the main factors affecting the distribution of plant species. The common plant species could be classified into three groups, i. e., Ludwigia prostrata - Murdannia triquetra group (G1), Hemarthria altissima - Rotala rotundifolia - Lapsana apogonoides group (G2), and Conyza canadensis - Polygonum hydropiper - Paspalum pasaloides group (G3). G1 mainly distributed on the soils with higher available K, G2 mainly distributed in periodically flooded area, while G3 mainly distributed in drainage area and was positively correlated to soil available P and pH. Species diversity and above-ground biomass had significant positive correlations with soil pH and total K, respectively, while evenness index was significantly negatively correlated with soil available N. No significant correlations were observed among other indices.

[Variances of leptin mRNA in the adipose tissue of NAFLD rats intervened with the extracts of Polygonum cuspidatum compound].

The NAFLD rats were intervened with the extracts of Polygonum cuspidatum compound for 4 weeks. The reverse transcription and real-time quantitative polymerase chain reaction (RT-qPCR) methods were used to detecte the relative level of leptin mRNA in the adipose tissue of intervenient and control groups. Their variances of fat and glucose in serum were detected with the biochemical methods. The results showed that the level of leptin mRNA of intervenient group was significantly increased (P <0.05) and the triglycered and total cholesterol were significantly decreased (P <0.05). The extracts of Polygonum cuspidatum compound could increase leptin mRNA level in adipose tissue and improve the fat metablolism in serum. However, the serum glucose of the intervenient group was a little raised (P>0.05).

[TNF-alpha gene expression of NAFLD rat intervened by the extracts of Rizoma Polygoni Cuspidati].

The real-time qPCR method had been used to detect and analyze the non-alcohol fatty liver disease (NEFLD) model in medical intervention in this research. The relative level of TNF-alpha mRNA in adipose tissue of intervention group was lower than that of control group. Their difference was significant (t = 2.452, P = 0.22). Compared with the control group, it decreased that the contents of liver trilyceride, total cholesterol, and glucose in intervention group. The difference of total cholesterol between two groups was significant (t = 2.555, P = 0.019). The extracts of Rizoma Polygoni Cuspidati could significantly decrease TNF-alpha mRNA level in adipose tissue, and it could decrease the contents of triglyceride, total cholesterol, and glucose in liver tissue. This Chinese traditional medicine can adjust the metabolism of liver adipose and glucose,and improve steatosis in liver cell.

[Effect of soil tillage on phosphorus loss from slope land: an experimental study].

Intensive soil erosion and nutrient loss from slope land not only resulted in the serious degradation of soil quality, but also threatened the water environment of the lower area. In this paper, a simulated rainfall experiment with loessial soil was conducted to study the characteristics of the loss of different phosphorus forms under the conditions of tillage and compaction (no-tillage). The results showed that in comparing with compaction, tillage increased the loss of dissolved P(DP), sediment extractable P(SEP) and sediment total P(STP) by 10 times due to the increase of runoff and sediment amount. The forms of the lost P were mainly sediment-combined P, and the ratios of DP/BAP and BAP/TP in the lost runoff were 12% and 2.6% under compaction, and 15% and 2.4% under tillage, respectively. The application of no-tillage or mulch-keeping fallow in Summer was effective to decrease soil and nutrient loss from slope land, which would be effective and significant both to soil degradation prevention and water environment protection in the lower area of Loess Plateau.

Steroidal saponins from Myriopteron extensum and their cytotoxic activity.

Two new steroidal saponins, extensumsides A ( 1) and B ( 2), were isolated from the whole plants of Myriopteron extensum (Wight) K. Schum. Their structures were elucidated as 17 beta-uzarigenin-3- O- beta-glucopyranosyl-(1-->6)- beta-glucopyranosyl-(1-->4)- beta-thevetopyranosyl-(1-->4)- beta-cymaropyranoside ( 1) and 12-(3-methylbut-2-enoyloxy)pregn-5-en-20-one 3- O-[beta-cymaropyranosyl-(1-->4)-beta-cymaropyranosyl-(1-->4)-beta-thevetopyranosyl-(1-->4)-(6- O-sulfo-beta-glucopyranoside)] ( 2) on the basis of chemical and spectral evidence. Extensumside A exhibited significant cytotoxicity against eight cancer cell lines with a mean GI (50) value of 0.346 microg/mL.

[Effects of phosphorus application methods on phosphorus loss on sloping land under simulated rainfall].

A simulated rainfall experiment was conducted to study the effects of three phosphorus application methods on phosphorus loss and its forms in loss process. The results showed that the bio-available P (BAP) loss in runoff was positively correlated to the mixed intensity of P applied into soil. Under mixed application (MA), the dissolved phosphorus (DP) concentration, BAP concentration, DP/BAP and BAP/TP ratio in runoff were all the highest, and those under point application (PA) were the second. Under line application (LA), DP and BAP concentrations were low, DP/BAP and BAP/TP ratio were also relatively low, and the difference compared with control was insignificant. According to the reduction of P loss, the order of the three P application methods was LA > PA > MA.