Comprehensive biology of antipyretic pathways

The antipyretic effect of the famous classical formula Qingwanzi Pills on a rabbit model and its serum metabolomic study

Qingwanzi Pills (QP) were first mentioned in the "Puji Fang" of the Ming Dynasty, with a history of approximately 600 years. The formula consisted of Gypsum Fibrosum and Indigo Naturalis. It is a famous classical formula with antipyretic effects frequently utilized in ancient China, although our knowledge about the overall antipyretic mechanism of QP remains limited. Therefore, we replicated the fever model in New Zealand rabbits induced by lipopolysaccharide, performed the pharmacodynamic evaluation of QP, identified the differential metabolites among QP groups, and performed pathway enrichment analysis to comparatively analyze the effects of QP on fever-related metabolic pathways by ultra-performance liquid chromatography-mass spectrometry. The results showed that the antipyretic effect of QP was superior to that of each disassembled prescription, with Gypsum Fibrosum primarily contributing to the efficacy, followed by Indigo Naturalis and Junci Medulla. QP had an effective antipyretic effect, which was related to lowering the levels of TNF-α, IL-6, IL-1β, and calcium in rabbit serum, lowering the levels of PGE2 and cAMP in rabbit cerebrospinal fluid, and increasing the level of calcium in rabbit cerebrospinal fluid. A total of 27 endogenous biomarkers were screened by serum metabolomics for the treatment of fever with QP. It is hypothesized that the antipyretic mechanism of QP may be related to regulating α-linolenic acid, sphingolipid, tryptophan, and bile acid metabolism. In summary, QP exhibited a significant antipyretic effect in rabbits with lipopolysaccharide-induced fever.

Antipyretic effect of inhaled Tetrastigma hemsleyanum polysaccharide on substance and energy metabolism in yeast-induced pyrexia mice via TLR4/NF-κb signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum Diels et Gilg, is one of the perennial evergreen plants with grass vine, which has obvious curative effect on severe infectious diseases. Although Tetrastigma hemleyanum has long been recognized for its capacity of antipyretic and antitoxic, its specific mechanism is unknown.

AIM OF THE STUDY

To evaluate the antipyretic effect of Tetrastigma hemleyanum polysaccharide (THP) on mice with dry yeast-induced fever, and to explore its specific antipyretic mechanism.

METHODS

In this study, THP was administered by aerosol in febrile mice. The rectal temperatures of treated animals were monitored at different time points. Histopathological evaluation and various inflammatory indexes were used to assess inflammatory damage. The concentration variations of the central neurotransmitter, endocrine system, substance and energy metabolism indicators were measured to explore the physiological mechanism. Quantitative real-time PCR, Western bolt and Immunohistochemistry were performed to identify the correlation between antipyretic and TLR4/NF-κB signaling pathway.

RESULTS

THP reduced the body temperature of febrile mice induced by dry yeast, as well as the levels of thermogenic cytokines and downregulated the contents of thermoregulatory mediators. THP alleviated the pathological damage of liver and hypothalamus caused by fever. In addition, THP decreased the secretion of thyroid hormone, substance and energy metabolism related indicators. Furthermore, THP significantly suppressed TLR4/NF-κB signaling pathway-related indicators.

CONCLUSIONS

In conclusion, our results suggest that inhaled THP exerts antipyretic effect by mediating the thermoregulatory mediator, decreasing the content of pyrogenic factors to lower the body temperature, and eventually restoring the high metabolic level in the body to normal via inhibiting TLR4/NF-κB signaling pathway. The study provides a reasonable pharmacodynamic basis for the treatment of polysaccharide in febrile-related diseases.

Microbial and Host Metabolites at the Backstage of Fever: Current Knowledge about the Co-Ordinate Action of Receptors and Molecules Underlying Pathophysiology and Clinical Implications

Fever represents an elevation of body temperature, that exerts a protective effect against pathogens. Innate immune cells and neurons are implicated in the regulation of body temperature. Pathogen-associated molecular patterns, i.e., lipopolysaccharides from Gram-negative bacteria and peptidoglycan and lipoteichoic acid from Gram-positive bacteria are exogenous pyrogens, that bind to Toll-like receptors on immune and non-immune cells. The subsequent release of pro-inflammatory cytokines [interleukin-1 (IL-1), IL-6 and Tumor necrosis factor-alpha] and their passage through the brain trigger the febrile response. In fact, neurons of the pre-optic area produce prostaglandin E2 (PGE2), that, in turn, bind to the PGE2 receptors; thus, generating fever. Apart from classical non-steroidal anti-inflammatory drugs, i.e., aspirin and acetaminophen, various botanicals are currently used as antipyretic agents and, therefore, their mechanisms of action will be elucidated.

Structure-Property Relationship for Different Mesoporous Silica Nanoparticles and its Drug Delivery Applications: A Review

Mesoporous silica nanoparticles (MSNs) are widely used as a promising candidate for drug delivery applications due to silica’s favorable biocompatibility, thermal stability, and chemical properties. Silica’s unique mesoporous structure allows for effective drug loading and controlled release at the target site. In this review, we have discussed various methods of MSNs’ mechanism, properties, and its drug delivery applications. As a result, we came to the conclusion that more in vivo biocompatibility studies, toxicity studies, bio-distribution studies and clinical research are essential for MSN advancement.

The innate immune system and fever under redox control: A Narrative Review

ABSTRACT:

In living cells, redox potential is vitally important for normal physiological processes that are closely regulated by antioxidants, free amino acids and proteins that either have reactive oxygen and nitrogen species capture capability or can be compartmentalized. Although hundreds of experiments support the regulatory role of free radicals and their derivatives, several authors continue to claim that these perform only harmful and non-regulatory functions. In this paper we show that countless intracellular and extracellular signal pathways are directly or indirectly linked to regulated redox processes. We also briefly discuss how artificial oxidative stress can have important therapeutic potential and the possible negative effects of popular antioxidant supplements.

Chemical, biological and protein-receptor binding profiling of Bauhinia scandens L. stems provide new insights into the management of pain, inflammation, pyrexia and thrombosis

Bauhinia scandens L. (Family, Fabaceae) is a medicinal plant used for conventional and societal medication in Ayurveda. The present study has been conducted to screen the chemical, pharmacological and biochemical potentiality of the methanol extracts of B. scandens stems (MEBS) along with its related fractions including carbon tetrachloride (CTBS), di-chloromethane (DMBS) and n-butanol (BTBS). UPLC-QTOF-MS has been implemented to analyze the chemical compounds of the methanol extracts of Bauhinia scandens stems. Additionally, antinociceptive and anti-inflammatory effects were performed by following the acetic acid-induced writhing test and formalin-mediated paw licking test in the mice model. The antipyretic investigation was performed by Brewer Yeast induced pyrexia method. The clot lysis method was implemented to screen the thrombolytic activity in human serum. Besides, the in silico study was performed for the five selected chemical compounds of Bauhinia scandens, found by UPLC-QTOF-MS By using Discover Studio 2020, UCSF Chimera, PyRx autodock vina and online tools. The MEBS and its fractions exhibited remarkable inhibition in dose dependant manner in the antinociceptive and antiinflammatory investigations. The antipyretic results of MEBS and DMBS were close to the standard drug indomethacin. Investigation of the thrombolytic effect of MEBS, CTBS, DMBS, and BTBS revealed notable clot-lytic potentials. Besides, the phenolic compounds of the plant extracts revealed strong binding affinity to the COX-1, COX-2, mPGES-1 and plasminogen activator enzymes. To recapitulate, based on the research work, Bauhinia scandens L. stem and its phytochemicals can be considered as prospective wellsprings for novel drug development and discovery by future researchers.

Fever and Antipyretic Supported by Traditional Chinese Medicine: A Multi-Pathway Regulation

The coronavirus disease, 2019 (COVID-19), has spread rapidly around the world and become a major public health problem facing the world. Traditional Chinese medicine (TCM) has been fully committed to treat COVID-19 in China. It improved the clinical symptoms of patients and reduced the mortality rate. In light of the fever was identified as one of leading clinical features of COVID-19, this paper will first analyze the material basis of fever, including pyrogenic cytokines and a variety of the mediators of fever. Then the humoral and neural pathways of fever signal transmission will be described. The scattered evidences about fever recorded in recent years are connected in series. On this basis, the understanding of fever is further deepened from the aspects of pathology and physiology. Finally, combining with the chemical composition and pharmacological action of available TCM, we analyzed the mechanisms of TCMs to play the antipyretic effect through multiple ways. So as to further provide the basis for the research of antipyretic compound preparations of TCMs and explore the potential medicines for the prevention and treatment of COVID-19.

Effects of the Incidence Density of Fever (IDF) on Patients Resuscitated From In-Hospital Cardiac Arrest: A Mediation Analysis

Objective: The aim of this research was to study the factors contributing to the survival rate of in-hospital cardiac arrest (IHCA) and to determine whether the incidence density of fever (IDF) acts as a mediator.

Methods: Data from patients with IHCA who survived more than 48 h were collected from 2011 to 2017. IDF was defined as the fever duration divided by the hospitalization duration, prolonged fever was defined as fever lasting for more than 5 days, and early fever was defined as an initial onset within the first 2 days of IHCA. Possible clinical variables associated with IDF were examined by linear regression, and possible clinical variables associated with survival rate were examined by univariate and multivariate analyses. IDF was investigated as a mediator of the indirect effects of the risk factors on survival.

Results: In our retrospective study, the median IDF was 0, with an interquartile range from 0 to 0.42. Prolonged fever was noted in 16% (97/605) of the total, and early fever was noted in 17.2% (104/605) of the total. Linear regression results showed that positive chest X-ray, central venous catheter and Glasgow Coma Score (GCS) ≤ 8 were related to IDF. The IDF (OR: 0.36, 95% CI, 0.13–0.97, P = 0.04), prolonged fever (adjusted OR = 0.13, 95% CI, 0.06–0.29, P < 0.001), positive chest X-ray (OR: 0.67, 95% CI, 0.46–0.98, P = 0.04), central venous catheter placement (OR: 0.54, 95% CI, 0.34–0.89, P = 0.01), and endotracheal intubation (OR: 0.47, 95% CI, 0.33–0.69, P < 0.001) were also related to the negative outcome of hospital discharge after adjustment. Additionally, positive chest X-ray had a 19% effect on survival outcome through IDF as a mediator, and the indirect effect of central venous catheter mediated by IDF accounted for 10% of the total.

Conclusions: A higher IDF, prolonged fever, a positive chest X-ray, the use of a central venous catheter and endotracheal intubation reduced the survival rate of these patients, and the detrimental impacts of a positive chest X-ray and the use of a central venous catheter on survival outcomes were partially mediated by IDF.