Herbal Medicine Nanocrystals: A Potential Novel Therapeutic Strategy.

Herbal medicines have gained recognition among physicians and patients due to their lower adverse effects compared to modern medicines. They are extensively used to treat various diseases, including cancer, cardiovascular issues, chronic inflammation, microbial contamination, diabetes, obesity, and hepatic disorders, among others. Unfortunately, the clinical application of herbal medicines is limited by their low solubility and inadequate bioavailability. Utilizing herbal medicines in the form of nanocrystals (herbal medicine nanocrystals) has shown potential in enhancing solubility and bioavailability by reducing the particle size, increasing the specific surface area, and modifying the absorption mechanisms. Multiple studies have demonstrated that these nanocrystals significantly improve drug efficacy by reducing toxicity and increasing bioavailability. This review comprehensively examines therapeutic approaches based on herbal medicine nanocrystals. It covers the preparation principles, key factors influencing nucleation and polymorphism control, applications, and limitations. The review underscores the importance of optimizing delivery systems for successful herbal medicine nanocrystal therapeutics. Furthermore, it discusses the main challenges and opportunities in developing herbal medicine nanocrystals for the purpose of treating conditions such as cancer, inflammatory diseases, cardiovascular disorders, mental and nervous diseases, and antimicrobial infections. In conclusion, we have deliberated regarding the hurdles and forthcoming outlook in the realm of nanotoxicity, in vivo kinetics, herbal ingredients as stabilizers of nanocrystals, and the potential for surmounting drug resistance through the utilization of nanocrystalline formulations in herbal medicine. We anticipate that this review will offer innovative insights into the development of herbal medicine nanocrystals as a promising and novel therapeutic strategy.

The Underling Mechanisms Exploration of Rubia cordifolia L. Extract Against Rheumatoid Arthritis by Integrating Network Pharmacology and Metabolomics.

Purpose: Rubia cordifolia L. (RC) is a classic herbal medicine for the treatment of rheumatoid arthritis (RA) and has been used since ancient times. The ethanol extract of Rubia cordifolia L. (RCE) showed obvious anti-RA effects in our previous study. However, further potential mechanisms require more exploration. We aimed to investigate the mechanism of RCE for the treatment of RA by integrating metabolomics and network pharmacology in this study. Methods: An adjuvant-induced arthritis (AIA) rat model was established, and we evaluated the therapeutic effects of RCE. Metabolomics of serum and urine was used to identify the differential metabolites. Network pharmacology was applied to determine the key metabolites and potential targets. Finally, the potential targets and compounds of RCE were verified by molecular docking. Results: The results indicated that RCE suppressed foot swelling and alleviated joint damage and also had anti-inflammatory properties by inhibiting the expressions of tumor necrosis factor (TNF)-α, Interleukin (IL)-1ß, prostaglandin E2 (PGE2), and P65. Ten and seven differential metabolites were found in the serum and urine, respectively, of rats. Six key targets, ie, phospholipase A2 group IIA (PLA2G2A), phospholipase A2 group X (PLA2G10), cytidine deaminase (CDA), uridine-cytidine kinase 2 (UCK2), charcot-leyden crystal galectin (CLC), and 5',3'-nucleotidase, mitochondrial (NT5M), were discovered by network pharmacology and metabolite analysis and were found to be related to glycerophospholipid metabolism and pyrimidine metabolism. Molecular docking confirmed that the favorable compounds showed affinities with the key targets, including alizarin, 6-hydroxyrubiadin, ruberythric acid, and munjistin. Conclusion: This study revealed the underlying mechanisms of RCE and provided evidence that will allow researchers to further investigate the functions and components of RCE against RA.

Causal associations between polyunsaturated fatty acids and kidney function: A bidirectional Mendelian randomization study.

BACKGROUND: PUFAs were suggested to be beneficial for kidney function in observational studies. However, whether these associations are causal remains unclear. OBJECTIVES: This study explores the causality between PUFAs and chronic kidney disease (CKD) or estimated glomerular filtration rate (eGFR) using bidirectional 2-sample Mendelian randomization (MR). METHODS: Single nucleotide polymorphisms associated with PUFAs and kidney function were obtained from the largest and most recent genome-wide association studies with sample sizes of 13,544, 13,506, 13,499, 13,527, and 13,549 for omega-3 fatty acids, omega-6 fatty acids, DHA, LA, and other PUFAs than 18:2 (otPUFA), and 480,698 and 1,201,909 for CKD and eGFR, respectively. MR inverse-variance weighted (IVW) and pleiotropy residual sum and outlier test (MR-PRESSO) were used for data analysis, supplemented with a weighted median estimator, MR-Egger regression, and multivariable MR, giving ß or OR and their 95% CIs. RESULTS: There was suggestive evidence that higher omega-6 fatty acids were associated with increased eGFR using MR-PRESSO [ß: 0.005 log(mL/min/1.73 m2) per SD increase in omega-6 fatty acids; 95% CI: 0.002, 0.008; P = 0.008]. Higher LA level was also associated with higher eGFR [ß: 0.005 log(mL/min/1.73 m2) per SD increase in LA; 95% CI: 0.003, 0.007; P = 0.0007] using MR-PRESSO. Neither association of the other PUFAs, i.e., omega-3 fatty acids, DHA, and otPUFA, with CKD or eGFR nor the association of CKD and eGFR with PUFAs was found. Similar results were found in sensitivity analyses. CONCLUSIONS: Our results suggest that higher omega-6 fatty acids and LA may increase eGFR levels. Although the estimated effects were relatively small, the results provide public health and research relevance, indicating the need for further longitudinal cohorts or randomized controlled trials on omega-6 fatty acids in improving kidney function.

The Integration of Nanomedicine with Traditional Chinese Medicine: Drug Delivery of Natural Products and Other Opportunities.

The integration of progressive technologies such as nanomedicine with the use of natural products from traditional medicine (TM) provides a unique opportunity for the longed-for harmonization between traditional and modern medicine. Although several actions have been initiated decades ago, a disparity of reasons including some misunderstandings between each other limits the possibilities of a truly complementation. Herein, we analyze some common challenges between nanomedicine and traditional Chinese medicine (TCM). These challenges, if solved in a consensual way, can give a boost to such harmonization. Nanomedicine is a recently born technology, while TCM has been used by the Chinese people for thousands of years. However, for these disciplines, the regulation and standardization of many of the protocols, especially related to the toxicity and safety, regulatory aspects, and manufacturing procedures, are under discussion. Besides, both TCM and nanomedicine still need to achieve a wider social acceptance. Herein, we first briefly discuss the strengths and weaknesses of TCM. This analysis serves to focus afterward on the aspects where TCM and nanomedicine can mutually help to bridge the existing gaps between TCM and Western modern medicine. As discussed, many of these challenges can be applied to TM in general. Finally, recent successful cases in scientific literature that merge TCM and nanomedicine are reviewed as examples of the benefits of this harmonization.

Plasma polyunsaturated fatty acid concentrations and sleep apnea risk: A two-sample Mendelian randomization study.

Background: Previous observational studies have found that lower levels of circulating polyunsaturated fatty acids (PUFAs) were associated with a higher risk of sleep apnea (SA). However, the causality of the association remains unclear. Materials and methods: We used the two-sample Mendelian randomization (MR) study to assess the causal association of omega-3 and omega-6 fatty acids with SA. Single-nucleotide polymorphisms (SNPs) predicting the plasma level of PUFAs at the suggestive genome-wide significance level (p < 5 × 10-6) were selected as instrumental variables (IVs) from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) (n = ∼8,000) Consortium. For outcomes, the summary-level statistics of SA were obtained from the latest genome-wide association study (GWAS), which combined five cohorts with a total number of 25,008 SA cases and 172,050 snoring cases (total = 523,366). Results: We found no association of α-linolenic acid (ALA) [odds ratio (OR) = 1.09 per% changed, 95% confidence interval (CI) 0.67-1.78], eicosapentaenoic acid (EPA) (OR = 0.94, 95% CI 0.88-1.01), docosapentaenoic acid (DPA) (OR = 0.95, 95% CI 0.88-1.02), and docosahexaenoic acid (DHA) (OR = 0.99, 95% CI 0.96-1.02) with the risk of SA using inverse-variance weighted (IVW) method. Moreover, for omega-6 PUFAs, no association between linoleic acid (LA) (OR = 0.98, 95% CI 0.96-1.01), arachidonic acid (AA) (1.00, 95% CI 0.99-1.01), and adrenic acid (AdrA) (0.93, 95% CI 0.71-1.21) with the risk of SA was found. Similarly, no associations of PUFAs with SA were found in single-locus MR analysis. Conclusion: In the current study, we first found that there is no genetic evidence to support the causal role of omega-3 and omega-6 PUFAs in the risk of SA. From a public health perspective, our findings refute the notion that consumption of foods rich in PUFAs or the use of PUFAs supplementation can reduce the risk of SA.

Effect of Ridge Height, Row Grade, and Field Slope on Nutrient Losses in Runoff in Contour Ridge Systems under Seepage with Rainfall Condition.

Seepage plays a key role in nutrient loss and easily occurs in widely-used contour ridge systems due to the ponding process. However, the characteristics of nutrient loss and its influential factors under seepage with rainfall condition in contour ridge systems are still unclear. In this study, 23 seepage and rainfall simulation experiments are arranged in an orthogonal rotatable central composite design to investigate the role of ridge height, row grade, and field slope on Nitrate (NO3--N) and Orthophosphate (PO4+3-P) losses resulting from seepage in contour ridge systems. In total, three types of NO3--N and PO4+3-P loss were observed according to erosion processes of inter-rill-headward, inter-rill-headward-contour failure, and inter-rill-headward-contour failure-rill. Our results demonstrated that second-order polynomial regression models were obtained to predict NO3--N and PO4+3-P loss with the independent variables of ridge height, row grade, and field slope. Ridge height was the most important factor for nutrient loss, with a significantly positive effect and the greatest contribution (52.35-53.47%). The secondary factor of row grade exerted a significant and negative effect, and was with a contribution of 19.86-24.11% to nutrient loss. The interaction between ridge height and row grade revealed a significantly negative effect on NO3--N loss, whereas interactions among the three factors did not significantly affect PO4+3-P loss. Field slope only significantly affected NO3--N loss. The optimal design of a contour ridge system to control nutrient loss was obtained at ridge height of 8 cm, row grade of 2°, and field slope of 6.5°. This study provides a method to assess and model nutrient loss, and improves guidance to implement contour ridge systems in terms of nutrient loss control.

Preclinical characterization of the novel HCV NS3 protease inhibitor GS-9256.

BACKGROUND: GS-9256 is an inhibitor of HCV NS3 protease with a macrocyclic structure and novel phosphinic acid pharmacophore. METHODS: Key preclinical properties of GS-9256 including in vitro antiviral activity, cross-resistance and pharmacokinetic properties were investigated in non-human species. RESULTS: In genotype (GT) 1b Huh-luc cells with a replicon encoding luciferase, GS-9256 had a mean 50% effective concentration (EC50) value of 20.0 nM, with minimal cytotoxicity. Antiviral activity was similar in a number of additional GT1b and GT1a replicon cell lines. Similar potency was observed in chimeric replicons encoding the NS3 protease of GT1 clinical isolates. GS-9256 was less active in GT2a replicon cells (14.2-fold increase in EC50). Additive to synergistic in vitro antiviral activity was observed when GS-9256 was combined with other agents including interferon-α, ribavirin, NS5B polymerase inhibitors GS-6620 and tegobuvir, as well as the NS5A inhibitor ledipasvir. GS-9256 retained wild-type activity against all tested NS5B and NS5A inhibitor resistance mutations. GS-9256 was metabolically stable in microsomes and hepatocytes of tested species, including rodents, dogs and humans. GS-9256 had high bioavailability in mice (near 100%) and moderate bioavailability in rats (14%), dogs (21%) and monkeys (14%). Elimination half-lives were approximately 2 h in mice, 0.6 h in rats, 5 h in dogs and 4 h in monkey. A study in bile duct-cannulated rats indicated that the major route of elimination is through biliary excretion of unmetabolized GS-9256. CONCLUSIONS: GS-9256 showed a favourable preclinical profile supportive of clinical development for the treatment of chronic HCV infection in GT1 patients.

The effect of a researcher designated music intervention on hospitalised psychiatric patients with different levels of anxiety.

AIMS AND OBJECTIVES: The purpose of this study was to investigate the effects of a music intervention on hospitalised psychiatric patients with different levels of anxiety. BACKGROUND: In clinical practice, psychiatric inpatients and nurses routinely suffer from anxiety. A music intervention may possibly be useful, but knowledge as to how useful and how effective it is in patients with different levels of anxiety is limited. DESIGN: The study design was a three-group, repeated-measures experimental study. METHODS: Subjects were 22 psychiatric patients who were divided into three groups based on their level of anxiety. They listened to 20 minutes of music each day for 10 days and were assessed using the Beck Anxiety Inventory before and after the music intervention and at a one-week follow-up; an electroencephalogram and finger temperature were monitored before and during the music intervention. RESULTS: Anxiety levels of all three groups showed a significant difference (p = 0·0339) after the intervention. The difference alpha and beta electroencephalogram percentages for all three groups showed a significant difference (p = 0·04; p = 0·01). The finger temperature showed a non-significant difference (p = 0·41). CONCLUSIONS: A music intervention can effectively alleviate the anxiety of hospitalised psychiatric patients who suffer from all levels of anxiety. RELEVANCE TO CLINICAL PRACTICE: The study recommends a practice in alleviating anxiety. Effective lower-cost interventions to reduce anxiety in psychiatric inpatient settings would be of interest to nurses and benefit patients.

Molecular markers to assess short-term disease local recurrence in nasopharyngeal carcinoma.

An important challenge in nasopharyngeal carcinoma (NPC) research is to develop effective predictors of tumor recurrence following treatment to determine whether immediate adjuvant therapy is necessary. We retrospectively analyzed archived specimens collected from 45 patients with paired samples of primary NPC (pNPC) and recurrent NPC (rNPC). Clinical samples were collected from the Cancer Center Databases of the First People's Hospital of Foshan and Shantou Central Hospital (affiliates of Sun Yat-Sen University) between 2001 and 2012. Expression levels of phosphor-Stat3 (p-Stat3), signalosome complex subunit 5 (Jab1/Csn5), Akt1, C/EBP homologous protein (CHOP), Ki-67, and apoptosis were determined by immunohistochemistry in pNPC and rNPC samples from the same patients. Differences in these markers between the short-term interval to recurrence (ITR) group (ITR <18 months) and long-term ITR group (ITR ≥18 months) were further analyzed. In Cox's regression analysis, the ITR was significantly associated as an independent­negative prognostic factor for overall survival (hazard ratio, 0.211; 95% confidence interval, 0.053-0.841; P=0.027). p-Stat3 was increased in the short-term ITR group (ITR <18 months) and tended to be lower in the long-term ITR group (ITR ≥18 months). In the short-term ITR group, nuclear Akt expression was significantly increased in paired rNPC (P=0.028). In the long-term ITR group, the expression of nuclear Jab1/Csn5 (P=0.047) and assessment of apoptosis measured with TdT-mediated dUTP nick end­labeling (TUNEL) (P=0.003) was significantly increased in paired rNPC. The results suggest that differences between short- and long-term ITR may predict outcome in rNPC. Furthermore, the overexpression of Jab1/Csn5 and Akt may contribute to the carcinogenesis of rNPC, and Akt seems to promote the progression of short-term ITR. Intra-individual changes of Jab1/Csn5, Akt, and TUNEL may help to identify short-term ITR.

Spatial variation profiling of four phytochemical constituents in Gentiana straminea (Gentianaceae).

Gentiana straminea is the famous Tibetan folk medicine thought to cure various diseases. Historically, the Qinghai-Tibetan region has been considered as the geo-authentic production area of "Mahua Jiao," where large quantities of the medicine are grown. However, there is still little known about the phytochemical constituent spatial variation of this species. In order to find the differences between the main phytochemical constituents of G. straminea and to provide comprehensive information for quality evaluation, four main bioactive compounds (loganic acid, swertiamarin, gentiopicroside and sweroside) were analysed in 26 populations grown in areas with elevations ranging from 2320 to 4720 m across the Qinghai-Tibetan Plateau. The results showed that the four phytochemical constitutes' concentrations varied greatly in the spatial profiling of the Qinghai-Tibetan region. Throughout the range of distribution of this species, no altitudinal, latitudinal or longitudinal trends have proven to be significant in any of the four constitutes' concentrations or their summation. Furthermore, hierarchical clustering analysis and statistical tests showed that four populations (Liu0609-18, Liu0609-15, Liu2006-13-9 and Liu0609-22) had total constitute contents that were higher than other populations. The spatial profiling of the four phytochemical constituents suggests that the geo-authentic producing area of this species exists at a few regions within the Qinghai province, which could be attributed to specific environmental or genetic factors.

Preclinical characterization of the novel hepatitis C virus NS3 protease inhibitor GS-9451.

GS-9451 is a selective hepatitis C virus (HCV) NS3 protease inhibitor in development for the treatment of genotype 1 (GT1) HCV infection. Key preclinical properties of GS-9451, including in vitro antiviral activity, selectivity, cross-resistance, and combination activity, as well as pharmacokinetic properties, were determined. In multiple GT1a and GT1b replicon cell lines, GS-9451 had mean 50% effective concentrations (EC50s) of 13 and 5.4 nM, respectively, with minimal cytotoxicity; similar potency was observed in chimeric replicons encoding the NS3 protease gene of GT1 clinical isolates. GS-9451 was less active in GT2a replicon cells (EC50 = 316 nM). Additive to synergistic in vitro antiviral activity was observed when GS-9451 was combined with other agents, including alpha interferon, ribavirin, and the polymerase inhibitors GS-6620 and tegobuvir (GS-9190), as well as the NS5A inhibitor ledipasvir (GS-5885). GS-9451 retained wild-type activity against multiple classes of NS5B and NS5A inhibitor resistance mutations. GS-9451 was stable in hepatic microsomes and hepatocytes from human and three other tested species. Systemic clearance was low in dogs and monkeys but high in rats. GS-9451 showed good oral bioavailability in all three species tested. In rats, GS-9451 levels were ∼40-fold higher in liver than plasma after intravenous dosing, and elimination of GS-9451 was primarily through biliary excretion. Together, these results are consistent with the antiviral activity observed in a recent phase 1b study. The results of in vitro cross-resistance and combination antiviral assays support the ongoing development of GS-9451 in combination with other agents for the treatment of chronic HCV infection.

Deuterium-depleted water (DDW) inhibits the proliferation and migration of nasopharyngeal carcinoma cells in vitro.

Recent studies have demonstrated that natural water that has 65% of the deuterium concentration depleted, can exhibit anti-tumor properties. However, the anti-tumor effects of DDW on various nasopharyngeal carcinoma (NPC) cells have not previously been reported. In the present study, NPC cell lines and normal preosteoblast MC3T3-E1 cells were grown in RPMI1640 media containing different deuterium concentrations (50-150 ppm). The effects of DDW on the proliferation and migration of NPC and MC3T3-E1 cells were investigated using the MTT, plate colony formation, and Transwell assays, as well as Boyden chamber arrays, flow cytometry (FCM), western blot and immunofluorescence. We found that DDW was an effective inhibitor of NPC cell proliferation, plated colony formation, migration and invasion. In contrast, the growth of normal preosteoblast MC3T3-E1 cells was promoted when they were cultured in the presence of DDW. Cell cycle analysis revealed that DDW caused cell cycle arrest in the G1/S transition, reduced the number of cells in the S phase and significantly increased the population of cells in the G1 phase in NPC cells. Western blot analysis revealed that treatment with DDW significantly increased the expression of NADPH:quinone oxidoreductase-1 (NQO1), while immunofluorescence assay analysis revealed that treatment with DDW decreased the expression of PCNA and matrix metalloproteinase 9 (MMP9) in NPC cells. These results demonstrated that DDW is a novel, non-toxic adjuvant therapeutic agent that suppresses NPC cell proliferation, migration, and invasion by inducing the expression of NQO1 and causing cell cycle arrest, as well as decreasing PCNA and MMP9 expression.

Development of a robust luciferase reporter 1b/2a hepatitis C virus (HCV) for characterization of early stage HCV life cycle inhibitors.

The development of JFH1 based intergenotypic recombinants that exploit the unique replication characteristics of JFH1 has made it possible to study infectious hepatitis C virus (HCV) encoding the structural genes of additional HCV genotypes. To facilitate the study of 1b structural proteins, we aimed to develop a robust 1b/2a chimera encoding a humanized Renilla luciferase reporter gene (1b/2a hRluc). The unadapted genome replicated efficiently but produced very low titers of infectious virus. Adaptation by continuous passage over a novel Huh-7 Lunet clone improved viral titers approximately 100-fold but caused an unexpected decline in luciferase activity, limiting the utility of the reporter-containing virus. Genotypic analysis revealed 17 adenosine to guanosine (A to G) nucleotide mutations in the luciferase gene and two potential adaptive mutations. To overcome the problems of low viral titers and editing of the luciferase gene during viral adaptation, six adaptive mutations previously identified in a non-reporter 1b/2a HCV genome were introduced into the 1b/2a hRluc genome. This resulted in the immediate production of high-titer viral stocks (approximately 1000-fold greater than the parental virus) that could efficiently infect naïve cells and generate robust luciferase signals. The improved sensitivity of the luciferase reporter also facilitated time of addition studies validating the utility of this system for characterizing the early steps of HCV infection. Thus, the development of the 1b/2a hRluc reporter virus described here provides a versatile tool for discovery of inhibitors targeting the early steps of the viral life cycle and genotype 1b structural genes.

[Research progress of the inhibitory effect of deuterium-depleted water on cancers].

OBJECTIVE: Deuterium is an important predisposing factor for cancer. Deuterium-depleted Water, also known as low deuterium water, ultra-light water or no deuterium water, can be obtained by removing deuterium from natural water. Studies have shown that water with a low deuterium concentration (<65% percent of volume) can inhibit cancer growth. Clinical trials demonstrated that drinking DDW (10-20 ppm) caused growth arrest of malignant cells in cancer patients and significantly prolonged the patient survival with also improved quality of life. A wide range of anti-cancer drugs in current use are associated with severe adverse effects, while deuterium-depleted water appears to have virtually no pharmacological side effects and is convenient to administer. The authors review the advances in the researches of anti-cancer effects and the underlying mechanisms of deuterium-depleted water.

Biochemical evaluation of HCV NS3 protease inhibitors.

This unit describes assays for characterizing the potency and mechanism of action of NS3 protease inhibitors. Determination of IC(50) values is described using in vitro expressed and purified NS3 protease. This assay can also be used for the rapid exploration of structure-activity relationships. Another protocol describes using the full-length NS3/4A complexes expressed in HCV replicon cell lines for a rapid alternative method for assessing protease activity without requiring conventional protein expression and purification. A method is then provided for determination of inhibitor K(i), which more accurately assesses the potency of inhibitors compared to the IC(50) assay, particularly for potent inhibitors that reach the sensitivity limit for the basic IC(50) assay. The final protocol describes how to determine the reversibility of inhibitor binding to the enzyme, an important parameter that can affect the pharmacodynamic properties of a compound.

Concentrations of the active constituents of the Tibetan folk medicine Qinjiao (Gentiana sect. Cruciata) within and between taxonomic species across the Qinghai-Tibetan Plateau.

The Tibetan folk medicine Qinjiao is traditionally used to treat various conditions, and its main active constituents comprise four iridoid glycosides, i.e., loganic acid, swertiamarin, gentiopicroside, and sweroside. The traditional crude medicine Qinjiao is derived from the dried roots of three species belonging to Gentiana sect. Cruciata (Gentianaceae) growing in the Qinghai-Tibetan Plateau (QTP). In this study, we determined by HPLC the contents of the four main active constituents in the dried roots collected from 83 localities at different altitudes across the QTP. The material was classified under the seven taxonomic species G. straminea, G. dahurica, G. crassicaulis, G. waltonii, G. officinalis, G. ihassica, and G. macrophylla. Our results suggested that the four constituents were present in the roots of all seven species for all localities, but their concentrations varied greatly within and between species. The level of gentiopicroside revealed to be the most dominant for all examined localities (2.1-12.4 mg/g), and G. macrophylla Pall. contained the highest concentration of all the four constituents at the species level. Except for loganic acid in G. officinalis, there was no significant correlation between the contents of these constituents and the altitude of the sampling localities. These results suggest that all species of all origins can be used as reliable resource for the crude medicine Qinjiao. However, a few species contain higher concentrations of the main active constituents, irrespective of their origin.

[Study on effect of sho-saiko-to compound on growth of nasopharyngeal carcinoma cells in CNE-bearing nude mice].

OBJECTIVE: To investigate the role of sho-saiko-to compound (SSTC) on the growth of the well-differentiated squamous cell line 1 of nasopharyngeal carcinoma (CNE-1) and well-differentiated CNE-2 in tumor-bearing nude mouse, and try to supply scientific data for its clinical development. METHOD: SSTC were prepared by concentration gradients, and the effect of SSTC on the growth and proliferation of the CNE-1 and CNE-2 were investigated by MT assay and soft-agar colony formation test. After setting up the subcutaneous tumor-bearing nude mouse model at the right lower back (0.2 mL CNE-2 cell suspension, 5 x 10(5)/mL), we randomly divided forty mice into 5 groups and gave high, middle and low concentration groups of SSTC (0.5, 0.25, 0.125 g X mL(-1) by intragastric administration. Positive and negative groups were set up for comparison. After constant administration for 15 days, the volume and weight of the tumor were measured for inhibition rate, so as to investigate the role of SSTC on the CNE-2 bearing tumor. RESULT: In vitro, compared with negative control, SSTC at different gradient concentrations were cultured with the CNE-1 and CNE-2 for 24 h, 48 h and 72 h. It showed that the growth and proliferation of both cell lines were inhibited to some extent. The inhibition rate was increased as the concentration and culture time increasing. Both MTT assay and soft-agar colony formation test showed that the 50% inhibiting concentration (IC50) was about 2.5 g X L(-1). In vivo, compared with negative control, the SSTC could slow down the tumor growth in the SSTC treated groups. The tumor growth of the negative control group (0.76 +/- 0.28) g, (962.88 +/- 245.96) mm3 and the low concentration group of SSTC (0.88 +/- 0.40) g, (1239.66 +/- 421.93) mm3 were obviously faster than those of the high, middle concentration group of SSTC (0.22 +/- 0.14) g, (239.31 +/- 137.07) mm3; (0.20 +/- 0.16) g, (263.42 +/- 166.57) mm3 and CTX positive control group (0.20 +/- 0.10) g, (246.72 +/- 194.6) mm3 (P<0.05). CONCLUSION: SSTC could efficiently inhibit the growth and proliferation of CNE-1 and CNE-2 in vitro, and slow down the tumor growth of the CNE-2 bearing nude mice. It may be a new compound of Chinese medicine for nasopharyngeal carcinoma therapy.

Variation of active constituents of an important Tibet folk medicine Swertia mussotii Franch. (Gentianaceae) between artificially cultivated and naturally distributed.

Concentrations of seven phytochemical constituents (swertiamarin, mangiferin, swertisin, oleanolic acid, 1,5,8-trihydroxy-3-methoxyxanthone, 1,8-dihydroxy-3,7-dimethoxyxanthone and 1,8-dihydroxy-3,5-dimethoxyxanthone) of "ZangYinChen" (Swertia mussotii, a herb used in Tibetan folk medicine) were determined and compared in plants collected from naturally distributed high-altitude populations and counterparts that had been artificially cultivated at low altitudes. Levels of mangiferin, the most abundant active compound in this herb, were significantly lower in cultivated samples and showed a negative correlation with altitude. The other constituents were neither positively nor negatively correlated with cultivation at low altitude. Concentrations of all of the constituents varied substantially with growth stage and were highest at the bud stage in the cultivars, but there were no distinct differences between flowering and fruiting stages in this respect.

The hepatitis B virus polymerase mutation rtV173L is selected during lamivudine therapy and enhances viral replication in vitro.

Therapy of chronic hepatitis B virus (HBV) infection with the polymerase inhibitor lamivudine frequently is associated with the emergence of viral resistance. Genotypic changes in the YMDD motif (reverse transcriptase [rt] mutations rtM204V/I) conferred resistance to lamivudine as well as reducing the in vitro replication efficiency of HBV. A second mutation, rtL180M, was previously reported to partially restore replication fitness as well as to augment drug resistance in vitro. Here we report the functional characterization of a third polymerase mutation (rtV173L) associated with resistance to lamivudine and famciclovir. rtV173L was observed at baseline in 9 to 22% of patients who entered clinical trials of adefovir dipivoxil for the treatment of lamivudine-resistant HBV. In these patients, rtV173L was invariably found as a third mutation in conjunction with rtL180M and rtM204V. In vitro analyses indicated that rtV173L did not alter the sensitivity of wild-type or lamivudine-resistant HBV to lamivudine, penciclovir, or adefovir but instead enhanced viral replication efficiency. A molecular model of HBV polymerase indicated that residue rtV173 is located beneath the template strand of HBV nucleic acid near the active site of the reverse transcriptase. Substitution of leucine for valine at this residue may enhance polymerization either by repositioning the template strand of nucleic acid or by affecting other residues involved in the polymerization reaction. Together, these results suggest that rtV173L is a compensatory mutation that is selected in lamivudine-resistant patients due to an enhanced replication phenotype.