AIM:Smallanthus sonchifolius(Yacon)has been used as a food and folk medicine in the Andes *** was screened the pharmacological effects of a 50% ethanol ex- tract of Yacon on spermatogenesis in *** study is carded out ...
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AIM:Smallanthus sonchifolius(Yacon)has been used as a food and folk medicine in the Andes *** was screened the pharmacological effects of a 50% ethanol ex- tract of Yacon on spermatogenesis in *** study is carded out to evaluate the possibility of using Yacon tubers extracts as a fertility agent to treat infertility caused by spermatogenic disorders. METHODS:The dried,pulverized Yacon tubers were extracted with 50% ethanol at 50℃ for 5 h under sonica- *** Yacon extracts were analyzed by using HPLC system on a Kromasil ClS column(250mm×4.6 mm). The Yacon tubers extracts,chlorogenic acid and ferulic acid were administrated to rats once daily by oral gavage. The number of sperm heads in the testis was assessed by counting the number of sperm heads using slight modifica- tion of the procedure reported by Toth et al(1989). RESULTS:After administration of chlorogenic acid and Yacon tuber extracts to rat for 5 weeks,the number of sperm in epididymis were increased by 20.33% and 34.48%,*** femlic acid which was report- ed as a metabolite of chlorogenic acid and constituent of Yacon to estimate the spermatogenic activity was also ad- *** administration of ferulic acid and Yacon tubers extracts,the sperm number were increased by 37.87% and 43.33%,*** ef- fects of chlorogenic acid and ferulic acid were 0.59 times and 0.87 times of Yacon tubers extracts,respectively. CONCLUSION:The spermatogenic effect of Yacon tu- bers extracts may result from the combined effect of chloro- genic acid or its analogues and their metabolites.
The discovery and development of new drugs is an expensive and lengthy process that can cost several hundr- ed million dollars and over a decade of *** need to repeat large-scale clinical trials in new regions for a d...
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The discovery and development of new drugs is an expensive and lengthy process that can cost several hundr- ed million dollars and over a decade of *** need to repeat large-scale clinical trials in new regions for a drug already deemed safe and efficient for human use in a specific ICH region adds to the cost and delays avail- ability of potentially useful medications in the new region. A case can also be made that this represents unnecessary human experimentation in some *** adoption of the ICH E5 guidance by Japan,US,EU has led to more streamlined development and made important new drugs available more quickly in new *** to this is the concept of a bridging study.A bridging study,while it can have multiple objectives and can take one of several designs,allows one to extrapolate to a new region,safety and efficacy data obtained in a foreign *** pharmacology principles play a key role in the E5 process and help determine the nature and extent of the bridging ***,a medicinal agent is characterized as less or more sensitive to ethnic factors based on PK/PD character- *** include pharmacokinetic linearity or lack thereof,fiat or steep dose/effect response curve,single or multiple pathways of metabolism,low potential for drug- drug and drug food interactions,and high or low bioavail- *** addition to PK/PD principles,several other as- pects need to be *** include medical prac- tice and conduct of clinical trials in different *** a medicinal agent is ethnically insensitive based on PK/PD characteristics,and medical practice and clinical conduct are similar between two regions,a bridging study may not be *** the other hand,a drug which is character- ized as more sensitive to ethnic factors is likely to need more extensive bridging studies,or if necessary,confirma- tory clinical ***,the ICH E5 guidance provides a rational scientific framework by which decisions on extrap- o
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