A new method for determination of antithrombotic activity of egg white protein hydrolysate by microplate reader

A new method for the determination of antithrombotic activity of egg white protein hydrolysate （EWPH） was developed using a microplate reader. Reaction was carried out at 37℃and pH 7.2 with fibrinogen concentration 0.1%. Microplate reading was conducted at 405 nm. Inhibition rate of EWPH on thrombin activity showed linearity （R2 = 0.9971）, when the inhibition rate was in the range of 10-90%. The lower limit of detection （LLD, at 99.7% probability） and the biological limit of detection （BLD, at 99.7% probability） of the method were 10.643 and 40 mg/mL, respectively. The repeatability standard deviation （R.S.D.） was 1.08%. The standard deviation of the method was ±0.027 AT-U.

High-Throughput Chemotyping of Cannabis and Hemp Extracts Using an Ultraviolet Microplate Reader and Multivariate Classifiers

As the use of Cannabis products as natural medicines burgeons,it is also appearing as a food ingredient.It is important to screen Cannabis samples as ingredients by profiling their chemical compositions,which is referred to as chemotyping.Two sets of botanical extracts were studied.The first set is referred to as Cannabis contained plant materials from 15 samples of the sativa,indica,and hybrids of the two species.The second set contained 20 extracts from the variety of Cannabis sativa with low tetrahydrocannabinol(THC)concentrations,i.e.,below 0.3%,and,henceforth,will be referred to as hemp.An ultraviolet(UV)microplate reader provides a cost-effective and high-throughput method for identifying chemotypes of plant extracts by their spectra.The microplate reader affords rapid measurements of small volumes,e.g.,50μL,which demonstrates a potential to significantly reduce the analysis time and cost for Cannabis and hemp chemotyping or chemi-cal profiling.Replicate samples were measured on different days to demonstrate the robustness of the method.Projected difference resolution(PDR)maps were used to visualize the separations among the classes.Five multivariate classifiers,fuzzy rule-building expert system(FuRES),super partial least squares-discriminant analysis(sPLS-DA),support vector machine(SVM),and two tree-based support vector machines(SVMtreeG and SVMtreeH)were evaluated.The classifiers were validated with ten bootstrapped Latin partitions(BLPs).For the Cannabis extracts,the SVMtreeG yielded the best performance and the classification accuracy was 99.1±0.4%for spectra collected in the nonlinear absorbance range.For the hemp extracts,the SVM classifier performed the best with a 97.4±0.6%classification accuracy.These results demonstrate that the UV microplate reader coupled with multivariate classifiers can be used as a high-throughput and cost-effective approach for chemotyping Cannabis.

Determination of Total Flavonoids in Leaves of Paliurus ramosissimus and Orthogonal Experiment Optimization Process

[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.

Comparison of in vivo antiseptic and in vitro antimicrobial effects of Peganum harmala L.seeds ethanolic extract with Betadine

Objective:To compare the antibacterial activity and antiseptic effect of ethanol extract of Peganum harmala L.(P.harmala)seeds and Betadine on eight reference strains of Streptococcus pneumoniae,Salmonella typhimurium,Escherichia coli,Corynebacterium pseudotuberculosis,Klebsiella pneumoniae,Staphylococcus aureus,Micrococcus luteus which are known to cause different types of skin infections,and Corynebacterium pseudotuberculosis isolated from an abscess on horse's neck.Methods:The antibacterial activity was assessed using a disc diffusion method.The minimum inhibitory concentration was tested by serial dilution method and the percentage of bacterial growth inhibition by absorbance microplate reader device.The minimum bactericidal concentration was then recorded.Clinical outcomes were obtained through washed up healing time of longitudinal and surface skin on the back of 16 rats with concentrations of 10,50,100,150 and 500 mg/mL of P.harmala extract.Results:The results of in vitro experiments showed that the lowest minimum inhibitory concentration(0.68-1.3 mg/mL)and minimum bactericidal concentration(1.3-5 mg/mL)values were observed in the ethanol extract of P.harmala seeds.Also the results of in vivo experiment showed that wound healing in the concentration of 50 mg/mL of this plant extract was better and quicker than Betadine.Conclusions:This study confirmed that ethanol extract of P.harmala has appropriate effect on the microorganisms and the healing of skin wounds in comparison with Betadine.