ENHANCEMENT OF STABILITY, RELEASE AND IN VITRO DIGESTIBILITY OF MULBERRY STEM EXTRACT USING MICROEMULSIONS

Objective: This study was aimed to develop oral microemulsions and to evaluate their ability to enhance stability, release and intestinal digestion of mulberry stem extract (MSE).Methods: The pseudoternary phase diagrams were constructed using caprylic/capric triglyceride (oil), PEG-8 caprylic/capric glycerides (S), polyglyceryl-3 diisostearate (CoS) and an aqueous phase. The effects of S/CoS (Km) ratio and a cosolvent, i.e. polyethene glycol 400 or propylene glycol (PG), were investigated. The optimized formulations were selected and incorporated with MSE. Then, they were then subjected to stability, release and lipolysis studies. The control solution consisted of 50% PG and 50% water.Results: The formation and characteristics of the microemulsions were influenced by Km and cosolvents. The two optimized formulations (F3 and F4) consisted of 10% oil, 70% S/CoS mixture and 20% aqueous phase were chosen. The Km ratios of F3 and F4 were 4:1 and 3:1. The aqueous phase of F3 and F4 was water and water mixed with PG, respectively. These formulations could improve the stability of MSE better than the control solution. The accumulated release of MSE from F3, F4 and the control solution reached 100% while that of unformulated crude extract reached only 70% after 6 h. The lipolysis study showed that MSE incorporated in both F3 and F4 was digested more than double the percentage compared to that of MSE incorporated in the control solution.Conclusion: MSE was successfully developed in microemulsions. They are shown to be promising vehicles for oral delivery of MSE. Further animal trials are suggested

In Vitro Anti-Inflammatory Activity of Morus alba L. Stem Extract in LPS-Stimulated RAW 264.7 Cells

Morus alba L., also known as white mulberry or Mhon, has long been used in traditional medicines. This study was aimed to investigate anti-inflammatory activities of mulberry stem ethanolic extract (MSE) in lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophage cell line. The MSE was first prepared and then investigated for cell viability using the MTT assay. The anti-inflammatory activities were investigated through the inhibition of inducible nitric oxide synthase (iNOS), cyclooxygenase- (COX-) 2 mRNA expression, and iNOS protein expression using reverse transcription-polymerase chain reaction (RT-PCR) assay and immunoblotting analysis, respectively. The inhibition of nitric oxide production of the MSE was also investigated using the Griess reaction assay. The MSE concentration ranging from 10 to 40 µg/ml yielded cell viability higher than 80%. The MSE at concentrations of 20 and 40 µg/ml demonstrated anti-inflammatory activity through the inhibition of nitric oxide production via suppression of both the iNOS mRNA and protein. It was also found to inhibit the expression of COX-2 mRNA in LPS-induced RAW 264.7 cells. This study is the first to report the anti-inflammatory potential of the extract prepared from the stem of mulberry