A tRNA-derived fragment from Chinese yew suppresses ovarian cancer growth via targeting TRPA1.

Drug discovery from plants usually focuses on small molecules rather than such biological macromolecules as RNAs. Although plant transfer RNA (tRNA)-derived fragment (tRF) has been associated with the developmental and defense mechanisms in plants, its regulatory role in mammals remains unclear. By employing a novel reverse small interfering RNA (siRNA) screening strategy, we show that a tRF mimic (antisense derived from the 5' end of tRNAHis(GUG) of Chinese yew) exhibits comparable anti-cancer activity with that of taxol on ovarian cancer A2780 cells, with a 16-fold lower dosage than that of taxol. A dual-luciferase reporter assay revealed that tRF-T11 directly targets the 3' UTR of oncogene TRPA1 mRNA. Furthermore, an Argonaute-RNA immunoprecipitation (AGO-RIP) assay demonstrated that tRF-T11 can interact with AGO2 to suppress TRPA1 via an RNAi pathway. This study uncovers a new role of plant-derived tRFs in regulating endogenous genes. This holds great promise for exploiting novel RNA drugs derived from nature and sheds light on the discovery of unknown molecular targets of therapeutics.

[Freeze drying process optimization of ginger juice-adjuvant for Chinese materia medica processing and stability of freeze-dried ginger juice powder].

Ginger juice， a commonly used adjuvant for Chinese materia medica， is applied in processing of multiple Chinese herbal decoction pieces. Because of the raw materials and preparation process of ginger juice， it is difficult to be preserved for a long time， and the dosage of ginger juice in the processing can not be determined base on its content of main compositions. Ginger juice from different sources is hard to achieve consistent effect during the processing of traditional Chinese herbal decoction pieces. Based on the previous studies， the freeze drying of ginger juice under different shelf temperatures and vacuum degrees were studied， and the optimized freeze drying condition of ginger juice was determined. The content determination method for 6-gingerol， 8-gingerol， 10-gingerol and 6-shagaol in ginger juice and redissolved ginger juice was established. The content changes of 6-gingerol， 8-gingerol， 10-gingerol， 6-gingerol， 6-shagaol， volatile oil and total phenol were studied through the drying process and 30 days preservation period. The results showed that the freeze drying time of ginger juice was shortened after process optimization; the compositions basically remained unchanged after freeze drying， and there was no significant changes in the total phenol content and gingerol content， but the volatile oil content was significantly decreased(P<0.05). Within 30 days， the contents of gingerol， total phenol， and volatile oil were on the decline as a whole. This study has preliminarily proved the feasibility of freeze-drying process of ginger juice as an adjuvant for Chinese medicine processing.

[Status and suggestions for adjuvant standard for Chinese materia medica processing in China].

In this paper, the status of adjuvant standard for Chinese materia medica processing in the Chinese Pharmacopoeia 2015 edition, the National Specification of Chinese Materia Medica Processing, and the 29 provincial specification of Chinese materia medica was summarized, and the the status including general requirements, specific requirements, and quality standard in the three grade official specifications was collected and analyzed according to the "medicine-adjuvant homology" and "food-adjuvant homology" features of adjuvants. This paper also introduced the research situation of adjuvant standard for Chinese materia medica processing in China; In addition, analyzed and discussed the problems existing in the standard system of adjuvant for Chinese materia medica processing, such as lack of general requirements, low level of standard, inconsistent standard references, and lack of research on the standard, and provided suggestions for the further establishment of the national standards system of adjuvant for Chinese materia medica processing.

Chemical profiling and cytotoxicity assay of bufadienolides in toad venom and toad skin.

ETHNOPHARMACOLOGICAL RELEVANCE: Toad venom and toad skin have been widely used for treating various cancers in China. Bufadienolides are regarded as the main anticancer components of toad venom, but the difference on composition and anticancer activities of bufadienolides between toad venom and toad skin remains unclear. METHODS: Fractions enriched with free and conjugated bufadienolides were prepared from toad venom and toad skin. Bufadienolides in each fraction were comprehensively profiled by using a versatile UHPLC-TOF-MS method. Relative contents of major bufadienolides were determined by using three bufogenins and one bufotoxin as marker compounds with validated UHPLC-TOF-MS method. Furthermore, cytotoxicity of the fractions was examined by MTT assay. RESULTS: Two fractions, i.e., bufogenin and bufotoxin fractions (TV-F and TV-C) were isolated from toad venom, and one bufotoxin fraction (TS-C) was isolated from toad skin. Totally 56 bufadienolides in these three fractions were identified, and 29 were quantified or semi-quantified. Bufotoxins were identified in both toad venom and toad skin, whereas bufogenins exist only in toad venom. Bufalin-3-conjugated bufotoxins are major components in toad venom, whereas cinobufotalin and cinobufagin-3-conjugated bufotoxins are main bufotoxins in toad skin. MTT assay revealed potent cytotoxicity of all the fractions in an order of TV-F>TV-C>TS-C. CONCLUSIONS: Our study represents the most comprehensive investigation on the chemical profiles of toad venom and toad skin from both qualitative and quantitative aspects. Eight bufotoxins were identified in toad skin responsible for the cytotoxicity for the first time. Our research provides valuable chemical evidence for the appropriate processing method, quality control and rational exploration of toad skin and toad venom for the development of anticancer medicines.

[Preparation and evaluation of Shedan in situ forming gel based on ocular characteristics].

To develop an ophthalmic preparation of Shedan, an in situ forming gel was prepared with the formulation containing 18% of poloxamer 407 and 5% of poloxamer 188 by response surface designs plus central composite designs. The rheology results showed that LVE range gamma should limited within 0.5%, Shedan high-frequency region, and the thixotropy recovery time is less than 5 seconds. The phase transition temperature was 33.25 °C according to curve of storage modulus and loss modulus determined by temperature scanning. Surface tension and osmometer of it determined by surface tension meter and dew point osmometer were 36.43 mN · m(-1), and 320.6 mOsm · kg(-1), respectively. Fluorescein sodium was selected as the marker to monitor the corneal residence time, and the results showed that Shedan gel could prolong drug residence for 180 min. In line with zero-order kinetics, releases of muscone and salvianolic acid B in vitro depends on gels erosion. The results of rabbit ocular irritation experiments suggested that Shedan in situ forming gel was biocompatible and nonirritant. In conclusion, a novel Shedan in situ forming gel was developed and characterized for potential drug treatment of retinal vein occlusion.

[Optimal extraction of nuciferine and flavone from lotus leaf based on central composite design and response surface methodology].

OBJECTIVE: To optimize the process of extracting effective constituents from lotus leaf. METHOD: Independent variables were ethanol concentration reflux time and solvent fold, dependent variables were extraction rates of nuciferine and flavone in lotus leaf, central composite design and response surface methodology were used for optimization of extraction of lotus leaf. RESULT: The optimum conditions of extraction process were 75% -80% ethanol, 2-3 hours for reflux, 20-25 fold solvent and 2 times for extraction. Bias between observed and predicted of rates of nuciferine and flavone values were 5.53%, -6.02%, respectively. CONCLUSION: The values observed and predicted were close to each other, which proved that the optimization of of extraction of lotus leaf by central composite design and response surface methodology was reasonable and successful.

[Comparative study on in vitro drug-release between Tuizhang ophthalmic gel and Tuizhang oculentum].

OBJECTIVE: To prepare tuizhang gel to cure cataract, the characteristics of Tuizhang gel on the drug-releasing in vitro were evaluated by compared with Tuizhang oculentum. METHOD: The emodin and chrysophanol in the releasing mediator were determined by HPLC, and the drug releasing characteristics of Tuizhang gel and Tuizhang oculentum were studied by bag filter method. RESULT: The emodin and chrysophanol in Tuizhang gel released (98.3, 1.1)%, (95.8, 1.8)% within 24 hours, respectively, while those in tuizhang oculentum released (10.62, 0.7)%, (10.46, 0.4)%, respectively. The emodin and chrysophanol in Tuizhang gel released more quickly and completely than in Tuizhang oculentum, so Tuizhang gel has enhanced the bioavailability. CONCLUSION: The Tuizhang gel is characterized by slow-release to some degree, and it shows a promising future on ophthalmic drug delivery.

[Studies on preparation technology of Flos Magnoliae essential oil-beta-cyclodextrin inclusion complex].

OBJECTIVE: To find the best condition of the preparation technology of Flos Magnoliae essential oil-beta-cyclodextrin inclusion complex. METHOD: L9(3(4)) table was used to examine the effects of 4 factors, and the inclusion rate of each test was determined of orthogonal test. RESULT: The best condition was:oil:beta-cyclodextrin:water = 1:8:60 (mL:g:mL), stirring for 1 hour at 80 degrees C. CONCLUSION: The complex prepared on the condition aforementioned is stable and stirring has a highest inclusion rate.

[Comparative studies on isolation and purification of Chinese medicine decoction].

OBJECTIVE: To evaluate different methods by treating water-decocted liquid of 6 Chinese medical herbs and 4 co-prescription respectively with alcohol, ultrafilter, macroporousresin and clarifier. METHOD: The contents of target component in those extracts were determined with HPLC or titration, and quantitative and qualitative determination of the impurity components, such as polysaccharide and protein, was made. RESULT: Each method showed its advantages and disavantages. CONCLUSION: Different method can be chosen according to the clinical and preparation demands or the characteristic of components.