Validation of a new 96-well plate spectrophotometric method for the quantification of compound 48/80 associated with particles

Lipopolysaccharide aggravating anaphylactoid reactions caused by traditional Chinese Medicine injections via p38/ERK/NF-κB signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Currently, adverse reactions limit the development of traditional Chinese medicine injections (TCMI), and severe anaphylactoid shock is one of the serious adverse reactions, which presents a significant challenge. The presence of abnormal inflammatory mediators before the administration of TCMI will most likely result in severe anaphylactoid reactions. Not only that, the lack of clinically relevant safety evaluations impedes the widespread use of TCMI, and there is an urgent need for studies to reveal the mechanisms of anaphylactoid shock caused by TCMI.

AIM OF THE STUDY

To investigate the effects and underlying mechanisms of lipopolysaccharide (LPS)-induced inflammation, which aggravates anaphylactoid reactions caused by TCMI, utilizing a guinea pig model.

METHODS

The dose and duration of LPS administration and different doses of compound 48/80 (C48/80) were examined by using guinea pigs as a model. Shuanghuanglian (SHLI) and Qingkailing (QKLI) injections, these two representative TCMI, were used for validation. The plasma biochemical indices, including histamine, 5-hydroxytryptamine, tumor necrosis factor-α, interleukin 6, immunoglobulin E, C5a, tryptase, and platelet activating factor, as well as the pathological characteristics of the lung, were analyzed. Futhermore, plasma metabolomics was employed to reveal changes in metabolic pathways in vivo when inflammation co-exists with TCMI. In addition, Western blot analysis was conducted to assess the expression of critical signaling pathways.

RESULTS

Stimulation with 2 mg/kg of LPS for 12 h induced inflammatory responses in the guinea pig model. C48/80 (3.0 mg/kg) in combination with LPS resulted in an increase in anaphylactoid-related indicators in the plasma. High doses of SHLI and QKLI aggravated plasma indices and lung histological injury caused by LPS-induced inflammation. A total of 36 and 63 differential metabolites were significantly altered after LPS stimulation in the SHLI-and QKLI-treated guinea pig groups, respectively. The associated metabolic pathways include central carbon metabolism in cancer, the tricarboxylic acid cycle, glyoxylate and dicarboxylate metabolism. The p38/ERK/NF-κB signal pathway may be significantly affected by TCMI in vivo after LPS stimulation.

CONCLUSION

LPS-induced inflammation aggravated anaphylactoid reactions caused by SHLI and QKLI, with a correlation to dosage. After the presence of LPS, the administration of TCMI interferes with the immune response by over-activating the p38/ERK/NF-κB signaling pathway. This activation leads to an excessive release of inflammatory factors and anaphylactoid mediators. These results present a new direction for mitigating adverse clinical reactions associated with TCMI.

Sensitive and effective method with 96-well plate for determination of levamlodipine in human plasma using LC-MS/MS

we developed an effective protein precipitation method for determination of levamlodipine in human plasma using LC-MS/MS. Sample extraction was carried out by using liquid-liquid extraction in 96-well plate format. (S)-Amlodipine-d4 was used as internal standard (IS). The chromatographic separation was achieved using Philomen Chiral MX (2) column (3 μm, 2.1 × 100 mm). Mobile phase A was comprised of Acetonitrile (ACN), Mono ethanol amine (MEA) and Iso-Propyl alcohol (IPA) (1000:1:10, v/v/v), Mobile phase B was IPA-ACN (2:1, v/v). The flow rate was 0.4 mL/min. The total run time of each sample was 4.0 min with gradient elution. LC-MS/MS spectra were generated in positive ion mode, and multiple reaction monitoring (MRM) was used to detect the following transitions: m/z 409.20 → 238.15 for levamlodipine and 415.25 → 240.20 for (S)-Amlodipine-d4 (the IS). The method was linear from 50 to 10000 pg/mL（R2＝0.9988489）,and the lower limit of quantification (LLOQ) was 50 pg/mL. This method was applied to a bioequivalence study of levamlodipine.

A Sensitive Spectrofluorimetric Method for Curcumin Analysis

Curcumin (CUR), a natural polyphenolic compound extracted from the rhizomes of Curcuma longa, is used as a pharmaceutical agent, spice in food, and as a dye. Currently, CUR is being investigated for cancer treatment in Phase-II clinical trials. CUR also possesses excellent activities like anti-inflammatory, anti-microbial, and anti-oxidant, therefore quality control is crucial. The present research work was to develop a new, simple, validated and time-saving rapid 96-well plate spectrofluorimetric method for the determination of CUR. The developed method was compared with routinely used high performance liquid chromatography (HPLC) technique. The developed method were found to be linear in the concentration range of 15 to 3900 ng/mL with R2 ≥ 0.9983 for spectrofluorimetric and 50-7500 ng/mL with R2 ≥ 0.9999 for HPLC method. Accuracy, intraday and interday precision was adequate, with RSD lower than the suggested limits. The limits for the detection and the quantification of CUR were 7 and 15 ng/mL for spectrofluorimetric, and 25 and 50 ng/mL for HPLC respectively. The Bland-Altman analysis demonstrated the similarities between the two methods. The 96-well plate method was successfully applied to determine CUR in solid lipid nanoparticles (SLNs) and chitosan nanoparticles (Chi-NPs). The developed spectrofluorimetric method can hence serve as a possible replacement for the HPLC method for the quantification of CUR in healthcare and food products.

Intranasal immunization with a rNMB0315 and combination adjuvants induces protective immunity against Neisseria meningitidis serogroup B in mice

Neisseria meningitidis (N. meningitidis) is a human-specific pathogen and a major cause of meningitis and septicemia with a high case fatality rate. N. meningitidis may penetrate the nasopharyngeal mucosal membrane and cause severe meningitis, a mucosal immune response plays a key role in the defense against meningococcal infections. Our previous study demonstrated that N. meningitidis serogroup B 0315 (NMB0315) was a vaccine candidate against N. meningitidis serogroup B (NMB) through parenteral immunization. In this study, immunopotentiators (C48/80 or CpG-ODN) were loaded into chitosan nanoparticle (Chi NP) to form combination adjuvants (Chi-CpG NP and Chi-C48/80 NP) and adopted to enhance the immunogenicity of NMB0315 through intranasal immunization. The experimental results have indicated that both Chi-CpG NP and Chi-C48/80 NP are effective mucosal adjuvants for the induction of significantly higher rNMB0315-specific IgG, IgG1, IgG2a and sIgA antibodies. Meanwhile, Chi-CpG NP and Chi-C48/80 NP could change the ratio of IgG1/IgG2a, inducing a more balanced cellular/humoral immune response. Chi-CpG NP and Chi-C48/80 NP also boosted interleukin-4 (IL-4), interferon-γ (IFN-γ) and interleukin-17 A (IL-17A) production by splenocytes. The bactericidal antibodies have been detected in sera from mice immunized with rNMB0315 + Chi-CpG NP and rNMB0315 + Chi-C48/80 NP. Overall, the combination adjuvants could be applicable to the development of a mucosal vaccine against NMB.

Chitosan Plus Compound 48/80: Formulation and Preliminary Evaluation as a Hepatitis B Vaccine Adjuvant

Current vaccine research is mostly based on subunit antigens. Despite the better toxicity profile of these antigens they are often poorly immunogenic, so adjuvant association has been explored as a strategy to obtain a potent vaccine formulation. Recently, mast cell activators were recognized as a new class of vaccine adjuvants capable of potentiating mucosal and systemic immune responses. In this study, a co-adjuvanted delivery system was developed and characterized, combining the mast cell activator C48/80 with chitosan nanoparticles (Chi-C48/80 NPs), and the results were compared with plain chitosan nanoparticles. The adsorption of model antigens onto the NP surface as well as the biocompatibility of the system was not affected by the incorporation of C48/80 in the formulation. The stability of the nanoparticles was demonstrated by studying the variation of size and zeta potential at different times, and the ability to be internalized by antigen presenting cells was confirmed by confocal microscopy. Vaccination studies with hepatitis B surface antigen loaded Chi-C48/80 NPs validated the adjuvanticity of the delivery system, demonstrating for the first time a successful association between a mast cell activator and chitosan nanoparticles as a vaccine adjuvant for hepatitis B virus, applied to a nasal vaccination strategy.

Development of a novel adjuvanted nasal vaccine: C48/80 associated with chitosan nanoparticles as a path to enhance mucosal immunity

In a time in which mucosal vaccines development has been delayed by the lack of safe and effective mucosal adjuvants, the combination of adjuvants has started to be explored as a strategy to obtain potent vaccine formulations. This study describes a novel adjuvant combination as an effective approach for a nasal vaccine - the association of the mast cell activator compound 48/80 with chitosan based nanoparticles. It was hypothesized that mucoadhesive nanoparticles would promote the cellular uptake and prolong the antigen residence time on nasal cavity. Simultaneously, mast cell activation would promote a local microenvironment favorable to the development of an immune response. To test this hypothesis, two different C48/80 loaded nanoparticles (NPs) were prepared: Chitosan-C48/80 NP (Chi-C48/80 NP) and Chitosan/Alginate-C48/80 NP (Chi/Alg-C48/80 NP). The potential as a vaccine adjuvant of the two delivery systems was evaluated and directly compared. Both formulations had a mean size near 500nm and a positive charge; however, Chi-C48/80 NP was a more effective adjuvant delivery system when compared with Chi/Alg-C48/80 NP or C48/80 alone. Chi-C48/80 NP activated mast cells at a greater extent, were better internalized by antigen presenting cells than Chi/Alg-C48/80 NP and successfully enhanced the nasal residence time of a model antigen. Superiority of Chi-C48/80 NP as adjuvant was also observed in vivo. Therefore, nasal immunization of mice with Bacillus anthracis protective antigen (PA) adsorbed on Chi-C48/80 NP elicited high levels of serum anti-PA neutralizing antibodies and a more balanced Th1/Th2 profile than C48/80 in solution or Chi/Alg-C48/80 NP. The incorporation of C48/80 within Chi NP also promoted a mucosal immunity greater than all the other adjuvanted groups tested, showing that the combination of a mast cell activator and chitosan NP could be a promising strategy for nasal immunization.