Assessment of anti-psoriatic activity of bakuchiol-loaded solid lipid nanoparticles-based gel: design, characterization, and mechanistic insight via NF-kB signaling pathway

The aim of the current study is to evaluate the anti-psoriatic potential of bakuchiol (Bak) loaded solid lipid nanoparticles (SLNs) via modulating inflammatory and oxidative pathways. Bak-loaded SLNs were prepared using hot homogenization method and characterized by various spectroscopic techniques. Bak-SLNs suspension was formulated into gel using Carbopol. Different in vivo assays were executed to explore the role of inflammatory markers and oxidative enzymes in psoriasis. DLS (dynamic light scattering) analysis showed suitable particle size, zeta potential, and polydispersity index (PDI) of developed formulation. TEM (transmission electron microscopy) reveal the spherical shape of Bak-SLNs particles. The release studies confirmed the sustained release of Bak-SLNs-based gel. UV-B-induced psoriatic Wistar rat model showed significant anti-psoriatic effect of Bak via regulating inflammatory markers (NF-kB, IL-6, IL-4, and IL-10) and levels of anti-oxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione-S-transferase (GST). Furthermore, RT-qPCR analysis confirms that Bak downregulates the expression of inflammatory markers, while histology and immunohistology results also confirm the anti-psoriatic effect of Bak. The study indicates that Bak-loaded SLNs-based gel significantly downregulates the level of cytokines and interleukins involve in NF-kB signaling cascade; hence, it can prove to be a novel therapeutic approach to cure psoriasis.

Formulation Strategies and Therapeutic Applications of Shikonin and Related Derivatives

Shikonin and its derivatives are excellent representatives of biologically active naphthoquinones. A wide range of investigations carried out in the last few decades validated their pharmacological efficacy. Besides having magnificent therapeutic potential, shikonin and its derivatives suffer from various pharmacokinetic, toxicity, and stability issues like poor bioavailability, nephrotoxicity, photodegradation, etc. Recently, various research groups have developed an extensive range of formulations to tackle these issues to ease their path to clinical practice. The latest formulation approaches have been focused on exploiting the unique features of novel functional excipients, which in turn escalate the therapeutic effect of shikonin. Moreover, the codelivery approach in various drug delivery systems has been taken into consideration in a recent while to reduce toxicity associated with shikonin and its derivatives. This review sheds light on the essential reports and patents published related to the array of formulations containing shikonin and its derivatives.

Abstract P1-08-02: CYP2D6 gene variants and effectiveness of adjuvant tamoxifen in breast cancer: A population-based case-control study

Tamoxifen, a cornerstone of adjuvant therapy for hormone-receptor-positive breast cancer, is metabolized to the active metabolite endoxifen through enzymatic activity of cytochrome P450 2D6. CYP2D6 has numerous alleles that affect metabolizing phenotype. Among women who take tamoxifen, those homozygous for inactive alleles (poor metabolizers) have lower levels of serum endoxifen than those with two functional alleles (extensive metabolizers). Several studies have reported increased risk of breast cancer recurrence or death in women homozygous for CYP2D6 inactive alleles, but others have found no association between CYP2D6 function and outcome. We explored this question in the large member population of the Kaiser Permanente Northwest (KPNW) integrated health plan. We conducted a population-based case-control study to evaluate the hypothesis that, after adjuvant tamoxifen treatment for breast cancer, women with CYP2D6 genotypes associated with poor metabolism of tamoxifen have an elevated risk of breast cancer recurrence compared to women with CYP2D6 genotypes associated with extensive metabolism of tamoxifen. We further hypothesized that women with CYP2D6 genotypes associated with intermediate metabolism of tamoxifen are at intermediate risk of recurrence. Study subjects were women who were diagnosed from 1980 to 2011 with hormone-receptor positive breast cancer, who received at least 180 days of adjuvant tamoxifen treatment, and for whom stored formalin-fixed paraffin-embedded (FFPE) normal tissue was available for laboratory analysis. Cases (358) were women with breast cancer recurrence recorded in the KPNW Tumor Registry and validated by medical record review. Randomly selected controls (833), without recurrent breast cancer, were matched to cases on tumor stage, diagnosis year, diagnosis age, race/ethnicity, and patterns of health plan membership. We collected data from medical records and from pharmacy, laboratory, tumor registry, and membership health plan databases. The Oregon Health & Science University Molecular Genetics Laboratory extracted genomic DNA from stored FFPE tissue blocks and performed allelic discrimination assays and pyrosequencing to accurately determine CYP2D6 variant status for the alleles, *3, *4, *5, *10, *17, and *41. All assays have been completed and study subjects have been categorized according to CYP2D6 metabolizer phenotype (poor, intermediate, extensive) and activity score (0-2). Based on the ethnicities in our study population, the CYP2D6 allele frequencies are in Hardy-Weinberg equilibrium, and the frequencies of the predicted metabolizer phenotypes also fall within the expected range. Using multivariable logistic regression analysis, we will assess CYP2D6 functional status and activity score in relation to breast cancer recurrence, taking into account factors that may alter the association, including tamoxifen dose and duration of use, as well as concomitant medications that alter the activity of the CYP2D6 enzyme. Results will be available by 12/1/2015.

Citation Format: Weinmann S, Richert–Boe K, Goddard K, Chen C, Punj S, Schwarzkopf D, Kalter M, Richards CS. CYP2D6 gene variants and effectiveness of adjuvant tamoxifen in breast cancer: A population-based case-control study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-08-02.

Intracellular cyclic AMP inhibits constitutive and phorbol ester-stimulated secretory cleavage of amyloid precursor protein

alpha-Secretase cleaves the full-length Alzheimer's amyloid precursor protein (APP) within the amyloid beta peptide sequence, thus precluding amyloid formation. The resultant soluble truncated APP is constitutively secreted. This nonamyloidogenic processing of APP is increased on stimulation of the phospholipase C/protein kinase C pathway by phorbol esters. Here we used C6 cells transfected with APP751 to examine whether the alpha-secretase cleavage is regulated by the adenylate cyclase signal transduction pathway. Forskolin, an activator of adenylate cyclase, inhibited both the constitutive and phorbol ester-stimulated secretion of nexin II (NXII), the secreted product of the alpha-secretase cleavage of APP751. At 1 microM, forskolin inhibited secretion of NXII by approximately 50% without affecting either the intracellular levels of total APP or the secretion of secretory alkaline phosphatase. In contrast, 1,9-dideoxyforskolin, an inactive analogue of forskolin, did not affect secretion of NXII. These results indicated that forskolin specifically inhibited the alpha-secretase cleavage of APP751. Forskolin treatment increased the intracellular concentration of cyclic AMP (cAMP), suggesting that the forskolin effects on APP cleavage may be mediated by cAMP. In support of this suggestion, both dibutyryl cAMP, a cAMP analogue, and isoproterenol, an activator of adenylate cyclase, also inhibited secretion of NXII. These data indicate that forskolin inhibition of the nonamyloidogenic cleavage of APP is mediated by the second messenger cAMP, which together with the protein kinase C signal transduction pathway modulates the secretory cleavage of APP.