Preparation And Pharmacodynamics Of Magnolia Officinalis Extract Granules

Salmonella is a common and important zoonotic foodborne pathogen in veterinary clinical practice.It can cause digestive tract diseases such as chicken pullorum and seriously affect the production performance of laying hens and the survival rate of chicks.Polymyxin is often used to treat or prevent digestive tract diseases in poultry.However,the emergence and widespread prevalence of polymyxin resistance gene mcr-1 and its mutants carried by plasmids have seriously threatened the stable development of the poultry industry.Therefore,the research on antagonizing drug-resistance Salmonella infection has become a hot spot.Our early stage of the study found that honokiol could effectively restore the antibacterial activity of polymyxin against MCR-1-positive Gram-negative Enterobacteriaceae in vivo or in vitro.However,the expensive monomer of honokiol is not suitable for development as a new veterinary drug.Honokiol is one of the most effective components of Magnolia officinalis extract,so this study further investigates the preparation and pharmacodynamics of honokiol so as to facilitate the clinical use and ensure the stability of curative effect and content.First of all,the preparation technology of Magnolia officinalis extract granules was studied.In this subject,the composition and dosage of excipients of Magnolia officinalis extract granules were determined.Taking the content of honokiol in Magnolia officinalis extract granules as the investigation index,the optimal prescription combination of excipients was selected by three-factor and three-level L₉（3~3）orthogonal test,and the optimal molding process was optimized.The conclusion of the best preparation process of Magnolia officinalis extract granules is as follows:Take 400g Magnolia officinalis extract,400 g HPMC,25 g CMS-Na,175 g water-soluble starch and mix.Uniformly spray 30%ethanol aqueous solution of 8%prescription volume to moisten,take"hold into a group,press lightly and disperse"as the standard soft material,sieve for 24 mesh,dry at 60℃for 2.5 h,cool after drying,sieve the whole grain with10 mesh to make 1000 g granules.Secondly,in order to effectively control the product quality of Magnolia officinalis extract granules,the content determination and preliminary stability of honokiol in Magnolia officinalis extract granules were investigated.The content determination method was established by high performance liquid chromatography and the methodology.The results showed that the method had good repeatability,high sensitivity,strong specificity and was easy to use.During the characteristics,particle size,moisture and content of effective components of Magnolia officinalis extract granules were tested,and the preliminary stability experiments were carried out.Through the test of influencing factors,it was determined that Magnolia officinalis extract granules should be stored in sealed,dark and cool places.The accelerated test of Magnolia officinalis extract granules was carried out under the condition of temperature（40±2）℃and relative humidity（75±5）%.The results showed that the character,particle size,moisture and content of Magnolia officinalis extract granules had not obviously changed within the past 6 months and the stability of the product was good.The Magnolia officinalis extract granules were tested for 18 months under the condition of temperature（25±2）℃and relative humidity（60±5）%.The results showed that there was no significant change in each index.It is preliminarily valid for 18months.Furthermore,the vitro efficacy of Magnolia officinalis extract granules was studied.The results of chessboard test showed that Magnolia officinalis extract granules could effectively restore the antibacterial activity of polymyxin B sulfate against polymyxin resistant Gram-negative bacteria（including MCR-1-positive bacteria）.Magnolia officinalis extract granules combined with polymyxin B sulfate did not show synergistic effect on polymyxin sensitive MCR-1 negative strains.The results of growth curve showed that Magnolia extract granules did not inhibit the growth of MCR-1 positive bacteria in the effective concentration range（0～1024μg/m L）.In addition,the time-killing curve showed that Magnolia officinalis extract granules（64μg/m L）combined with polymyxin B sulfate（2μg/m L）had synergistic bactericidal effect on MCR-1positive bacteria,and all bacteria in the culture medium could be killed after 3 hours.Previous research of our group has found that honokiol could improve the protective effect of Polymyxin on mice infected with MCR-1 positive bacteria.Furthermore,this study established a Salmonella HYM2 infection target animal（chicken）model,to verify the therapeutic effect of Magnolia officinalis extract granules combined with Polymyxin B sulfate.The results showed that the average body weight of the combined treatment group was significantly higher than that of the infected group,which effectively alleviated the pathological damage of liver and spleen and significantly reduced the colonization number of colonies in the liver and spleen of infected chicks.The combined middle dose of Magnolia officinalis extract granules,namely 0.4 g/kg body weight Magnolia extract granules and 8 mg/kg body weight polymyxin B sulfate,can effectively restore the therapeutic effect of polymyxin B sulfate on chickens infected with MCR-1-resistant Salmonella HYM2.In summary,a preparation process and content determination method of Magnolia officinalis extract granules were established in this paper.The preparation of Magnolia officinalis extract granules can effectively restore the antibacterial activity of polymyxin sulfate B against MCR-1-positive drug-resistant bacteria in vitro,which has a significant therapeutic effect on chickens infected with MCR-1-positive Salmonella HYM2 combined with polymyxins.