STATISTICAL OPTIMIZATION AND STABILITY STUDY OF QUERCETIN-LOADED MICROEMULSION

Objective: This research aims to develop a quercetin microemulsion system to improve the solubility of quercetin and to study the stability of the microemulsions. Methods: The microemulsion is prepared by water titration method using isopropyl myristate (oil), Tween 60®/Span 80® (3:2) (surfactant) and ethanol (co-surfactant). Two different aqueous phases, water or NaCl solution, were used to prepare microemulsions and the influence of each parameter was described. DPPH scavenging and anti-tyrosinase activity were performed along with chemical stability to evaluate the functional stability of microemulsions. Results: The influence of percentage of oil phase (variable A) on the solubility of quercetin was less significant than that of percentage of surfactant/co-surfactant (variable B). Compared to those prepared with water (variable C), the solubility of quercetin in microemulsions prepared with NaCl solution significantly increased. The ratio of the high level to low level for solubility of three variables was 1.135, 1.315 and 1.591 respectively. Increasing variable A and B led to an increase in the particle size of microemulsions from 120.08 nm to 188.38 nm and 48.18 nm to 260.28 nm, respectively. The influence of variable B was quite significant, while variable C has no significant effect on particle size. Quercetin microemulsions showed good chemical and functional stability when stored at 4 °C. Under other conditions, especially at 40 °C, the activity of the microemulsion is considerably reduced. Conclusion: The influence of different variables on the characteristics of microemulsions was complicated. Care must be taken in the composition and storage conditions of these formulations

Optimization of Formulation Parameters in Preparation of Fructus ligustri lucidi Dropping Pills by Solid Dispersion Using 23 Full Experimental Design

Oleanolic acid (OA) is an active ingredient of the traditional Chinese medicine (TCM) Fructus ligustri lucidi (FLL). Its clinical use is restricted because it is water-insoluble and has limited dosage forms of administration at present. Hence, the FFL dropping pills were prepared by the hot-melt method of solid dispersion technology. A 23 factorial design was used to examine the effects of the materials used to prepare the dropping pills (e.g., different ratios of PEG4000 and PEG6000, FLL extract loading, and percentage of Tween 80) on parameters such as dropping pill roundness, weight variation, and disintegration time. Moreover, 23 full factorial design was utilized to search for the optimal formulation for dissolution experiments. The results showed that the percentage of Tween 80 demonstrated significant effects on dropping pill roundness, weight variation, and disintegration time; FLL extract loading affected roundness and weight variation; and different ratios of PEG4000 and PEG6000 only affected disintegration time. The optimal formulation of the dropping pills released 70% of the drug after 30 min of dissolution release, which was faster than commercially available FLL Chinese medicines. Furthermore, the amount released was higher than that of commercially available formulations. In this study, a solid dispersion technique was used to successfully produce FLL dropping pills. In addition to improving the water insolubility of FLL and increasing the dissolution release percentage of the drug, we increased the application value of FLL and reduced the issues of traditional administration dosage forms

Sclareol attenuates the development of atopic dermatitis induced by 2,4-dinitrochlorobenzene in mice

Context: Atopic dermatitis is a common chronic inflammatory skin disease affecting up to 20% of children and 1% of adults worldwide. Treatment of atopic dermatitis include corticosteroids and immunosuppressants, such as calcineurin inhibitors and methotrexate. However, these treatments often bring about adverse effects including skin atrophy, osteoporosis, skin cancer, and metabolic syndrome. Objective: In this study, we evaluated the therapeutic effects and mechanisms of sclareol, a natural diterpene, on atopic dermatitis (AD)-like skin lesions induced by 2,4-dinitrochlorobenzene (DNCB) in mice. Materials and methods: To evaluate the effect of sclareol in vivo model, BALB/c mice were repeatedly injected intraperitoneally with sclareol (50 and 100 mg/kg) in 2,4-dinitrochlorobenzene (DNCB)-induced AD-like murine model. Major assays were enzyme-linked immunosorbent assay, histological analysis, flow cytometry, western blot analysis. Results: Intraperitoneal administration of sclareol (50 and 100 mg/kg) significantly attenuated AD-like symptoms, such as serum IgE levels, epidermal/dermal hyperplasia, and the numbers of infiltrated mast cells. In addition, systemic sclareol treatments reduced local pro-inflammatory cytokine concentrations, including IL-6, IL-1b, TNF-a, IL-4, IFN-g, and IL-17A, on AD-like lesions. Furthermore, we demonstrated that sclareol also suppressed T cell activation and the capability of cytokine productions (IFN-g, IL-4 and IL-17A) in response to DNCB stimulation. By examining the skin homogenate, we found that sclareol inhibited the AD-like severity likely through suppressions of both NF-kB translocation and phosphorylation of the MAP kinase pathway. Discussion and conclusions: Cumulatively, our results indicate that sclareol induced anti-inflammatory effects against the atopic dermatitis elicited by DNCB. Thus, sclareol is worth of being further evaluated for its potential therapeutic benefits for the clinical treatment of AD

Lysophosphatidic acid alters the expression profiles of angiogenic factors, cytokines, and chemokines in mouse liver sinusoidal endothelial cells.

Lysophosphatidic acid (LPA) is a multi-function glycerophospholipid. LPA affects the proliferation of hepatocytes and stellate cells in vitro, and in a partial hepatectomy induced liver regeneration model, the circulating LPA levels and LPA receptor (LPAR) expression levels in liver tissue are significantly changed. Liver sinusoidal endothelial cells (Lsecs) play an important role during liver regeneration. However, the effects of LPA on Lsecs are not well known. Thus, we investigated the effects of LPA on the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs.Mouse Lsecs were isolated using CD31-coated magnetic beads. The mRNA expression levels of LPAR's and other target genes were determined by quantitative RT-PCR. The protein levels of angiogenesis factors, cytokines, and chemokines were determined using protein arrays and enzyme immunoassay (EIA). Critical LPAR related signal transduction was verified by using an appropriate chemical inhibitor.LPAR1 and LPAR3 mRNA's were expressed in mouse LPA-treated Lsecs. Treating Lsecs with a physiological level of LPA significantly enhanced the protein levels of angiogenesis related proteins (cyr61 and TIMP-1), cytokines (C5/C5a, M-CSF, and SDF-1), and chemokines (MCP-5, gp130, CCL28, and CXCL16). The LPAR1 and LPAR3 antagonist ki16425 significantly inhibited the LPA-enhanced expression of cyr61, TIMP-1, SDF-1, MCP-5, gp130, CCL28, and CXCL16, but not that of C5/C5a or M-CSF. LPA-induced C5/C5a and M-CSF expression may have been through an indirect regulation mechanism.LPA regulated the expression profiles of angiogenic factors, cytokines, and chemokines in Lsecs that was mediated via LPAR1 and LPAR3 signaling. Most of the factors that were enhanced by LPA have been found to play critical roles during liver regeneration. Thus, these results may prove useful for manipulating LPA effects on liver regeneration

LPA effects on angiogenesis factor, cytokine, and chemokines expression are mediated by LPAR1 and LPAR3 signaling.

<p>(A) LPAR1 and LPAR3 signaling effects on LPA induced proteins level. Liver sinusoidal endothelial cells were pre-treated with an inhibitor of LPAR1 and LPAR3, ki16425 (1 uM), for 30 minutes prior 5 uM LPA treatment. After 24 hours, conditioned media derived from vehicle (1% BSA), LPA (5uM) alone, and ki16425 plus LPA treatment were collected for protein level determinations by EIA. Data shown are fold changes of induction with LPA alone versus vehicle treatment, and ki16425 treatment combined with LPA versus vehicle treatment. Results were compared between LPA treatment alone and ki16425 treatment combined with LPA (n = 3); *<i>p</i> < 0.05. (B) Time course for LPA effects on specific genes’ mRNA expressions. Liver sinusoidal endothelial cells were treated with vehicle (1% BSA) or LPA (5 uM). After 4, 8, and 16 hours, total RNA was isolated from vehicle and LPA treated cells for mRNA determinations by qRT-PCR. Data are fold changes of induction with LPA treatment versus vehicle treatment. Results were compared with vehicle treatment (n = 3); *<i>p</i> < 0.05.</p

Schematic for LPA enhanced expression of angiogenesis factors, cytokines, and chemokines in liver sinusoidal endothelial cells mediated by LPAR1 and LPAR3 signaling.

<p>Schematic for LPA enhanced expression of angiogenesis factors, cytokines, and chemokines in liver sinusoidal endothelial cells mediated by LPAR1 and LPAR3 signaling.</p