Protective effect of Terminalia chebula Retz. extract against Aß aggregation and Aß-induced toxicity in Caenorhabditis elegans.

ETHNOPHARMACOLOGICAL RELEVANCE: Terminalia chebula Retz. (T.chebula) is an important medicinal plant in Tibetan medicine and Ayurveda. T.chebula is known as the "King of Tibetan Medicine", due to its widespread clinical pharmacological activity such as anti-inflammatory, antioxidative, antidiabetic as well as anticancer in lots of in vivo and in vitro models. In this study, we use transgenic and/or RNAi Caenorhabditis elegans (C.elegans) model to simulation the AD pathological features induced by Aß, to detect the effect of TWE on improving Aß-induced toxicity and the corresponding molecular mechanism. AIM OF STUDY: The study aimed to tested the activities and its possible mechanism of T.chebula to against Aß1-42 induced toxicity and Aß1-42 aggregation. MATERIALS AND METHODS: Using transgenic C.elegans strain CL2006 and CL4176 as models respond to paralytic induced by Aß toxicity. The transcription factors DAF-16 and SKN-1 were analyzed used a fluorescence microscope in transgenic strains (DAF-16:GFP, SKN-1:GFP). The function of DAF-16 and SKN-1 was further investigated using loss-of-function strains by feeding RNA interference (RNAi) bacteria. To evaluate the aggregation level of Aß in the transgenic C.elegans, Thioflavin S (ThS) staining and WB visualized the levels of Aß monomers and oligomers. RESULTS: TWE treatment can significantly improve the paralysis of transgenic C.elegans caused by Aß aggregation (up to 14%). The Aß aggregates in transgenic C.elegans are significantly inhibited under TWE exposure (up to 70%). TWE increases the nuclear localization of the key transcription factor DAF-16 and HSF-1, which in turn leads to the expression of downstream Hsp-16.2 protein and exerts its inhibitory effect on Aß aggregation. Meanwhile, paralysis improved has not observed in SKN-1 mutation and/or RNAi C.elegans. CONCLUSION: Our results indicate that TWE can protect C.elegans against the Aß1-42-induced toxicity, inhibition Aß1-42 aggregation and delaying Aß-induced paralysis. The neuroprotective effect of TWE involves the activation of DAF-16/HSF-1/Hsp-16.2 pathway.

Population Pharmacokinetics and Model-Based Dosing Optimization of Teicoplanin in Pediatric Patients.

Objectives: The pharmacokinetics (PK) of teicoplanin differs in children compared with adults. Our aim was to determine the PK of teicoplanin in an Asian pediatric population and to optimize dosage regimens. Methods: This was a retrospective PK study and all the data were collected from hospitalized children. We developed a population PK model using sparse data, and Monte Carlo simulation was used to assess the ability of standard teicoplanin regimen and other different dosage regimens. The optimal dosing regimens were defined as achieving the target trough concentration (C min) of 10 mg/L and pharmacokinetic/pharmacodynamic (PK/PD, [AUC24/MIC]) of 125 for moderate infection. For severe infection, the optimal dosing regimens were defined as achieving the target 15 mg/L and AUC24/MIC of 345. Results: 159 children were included and 1.5 samples/children on average were provided. Estimated clearance of teicoplanin was 0.694 L/h (0.784/L/h/70 kg) and volume of distribution was 1.39 L. Teicoplanin standard loading dose was adequate for moderate infection, while 13 mg/kg was needed for severer infection. With standard maintenance doses, both patients with moderate and severe infection failed to achieve the target C min. 12 and 16 mg/kg/day were required to achieve a C min ≥ 10 and 15 mg/L, respectively. However, standard maintenance dose was adequate to achieve AUC24/MIC ≥ 125 for moderate infection, and 12 mg/kg/day was needed to achieve AUC24/MIC ≥ 345 for severe infection. Lower weight and serum creatinine were associated with higher dose. Conclusion: Optimal doses based on the target C min were higher than that based on the PK/PD target. To achieve the C min and PK/PD targets simultaneously, a standard loading dose was adequate for moderate infection based on simulation, while dosing higher than standard doses were required in other situation. Further clinical studies with rich sampling from children is required to confirm our findings.

Dianxianning improved amyloid ß-induced pathological characteristics partially through DAF-2/DAF-16 insulin like pathway in transgenic C. elegans.

Dianxianning (DXN) is a traditional Chinese formula, and has been approved in China for treating epilepsy since 1996. Here anti-Alzheimer's disease activity of DXN has been reported. DXN improved AD-like symptoms of paralysis and 5-HT sensitivity of transgenic Aß1-42 C. elegans. In worms, DXN significantly increased Aß monomers and decreased the toxic Aß oligomers, thus reducing Aß toxicity. DXN significantly suppressed the expression of hsp-16.2 induced by juglone, and up-regulated sod-3 expression. These results indicated that DXN increased stress resistance and protected C. elegans against oxidative stress. Furthermore, DXN could significantly promote DAF-16 nuclear translocation, but it did not activate SKN-1. The inhibitory effect of DXN on the Aß toxicity was significantly reverted by daf-16 RNAi, rather than skn-1 RNAi or hsf-1 RNAi. These results indicated that DAF-16 is at least partially required for the anti-AD effect of DXN. In conclusion, DXN improved Aß-induced pathological characteristics partially through DAF-2/DAF-16 insulin like pathway in transgenic worms. Together with our data obtained by Morris water maze test, the results showed that DXN markedly ameliorated cognitive performance impairment induced by scopolamine in mice. All the results support that DXN is a potential drug candidate to treat Alzheimer's diseases.

Realgar transforming solution displays anticancer potential against human hepatocellular carcinoma HepG2 cells by inducing ROS.

Realgar (As4S4), as a mineral drug containing arsenic compound, has been employed in clinical therapy of cancer for its good therapeutic reputation in Chinese traditional medicine. However, large dose of realgar and long period of treatment are necessary for achieving the effective blood medicine concentration due to its low bioavailability resulted from poor solubility. In this study, we obtained realgar transforming solution (RTS) using intrinsic biotransformation in microorganism, and investigated underlying mechanisms of RTS for HepG2 cells. Our results demonstrated that an effective biotransformation of realgar method by A. ferrooxidans was established, in which realgar was biologically converted into an aqueous solution, and RTS had a strong activity inducing apoptosis and interrupting G2/M progression in HepG2 cells via upregulation of cellular ROS. Importantly, RTS inhibited the cellular antioxidant defense system leading to abundant ROS accumulation, and activated cell cycle arrest and mitochondrial pathway of apoptosis mediated by activating p53 due to cellular uncontrolled ROS. Collectively, our findings suggest that RTS is a potential candidate for therapy of human hepatocellular carcinoma.