The Anti-Inflammatory Activity of Toonaciliatin K against Adjuvant Arthritis

Limonoids with anti-inflammatory activity: A review

The natural limonoids distributed mainly in the Meliaceae and Rutaceae plants are known for their unique and complex structure with high degree oxidation and cyclic rearrangement. However, these compounds exhibit a broad range of biological activities such as insecticidal, antibacterial, antifungal, antimalarial, antioxidant, anticancer, antiviral, and anti-inflammatory. There is still limited report about the biological activity of the anti-inflammatory effect of limonoids isolated from plants. Therefore, this study aimed to examine the effect of intact, deformed and rearranged limonoids as anti-inflammatory agents. The majority of anti-inflammatory investigations were evaluated by in vitro and in vivo assays of the isolated pure compounds and their derivatives. For the in vitro study, intact and C-ring seco limonoids showed a potent inhibitory effect against NO production. The in vivo analysis of Intact, C-seco, and AD-seco limonoids showed a potent effect based on the inhibition of pro-inflammatory cytokines expression, indicating their potency as anti-inflammatory agents.

Research progress of meliaceous limonoids from 2011 to 2021

Covering: July 2010 to December 2021Limonoids, a kind of natural tetranortriterpenoids with diverse skeletons and valuable insecticidal and medicinal bioactivities, are the characteristic metabolites of most plants of the Meliaceae family. The chemistry and bioactivities of meliaceous limonoids are a continuing hot area of natural products research; to date, about 2700 meliaceous limonoids have been identified. In particular, more than 1600, including thirty kinds of novel rearranged skeletons, have been isolated and identified in the past decade due to their wide distribution and abundant content in Meliaceae plants and active biosynthetic pathways. In addition to the discovery of new structures, many positive medicinal bioactivities of meliaceous limonoids have been investigated, and extensive achievements regarding the chemical and biological synthesis have been made. This review summarizes the recent research progress in the discovery of new structures, medicinal and agricultural bioactivities, and chem/biosynthesis of limonoids from the plants of the Meliaceae family during the past decade, with an emphasis on the discovery of limonoids with novel skeletons, the medicinal bioactivities and mechanisms, and chemical synthesis. The structures, origins, and bioactivities of other new limonoids were provided as ESI. Studies published from July 2010 to December 2021 are reviewed, and 482 references are cited.

Terpenoid treatment in osteoporosis: this is where we have come in research

Lower bone resistance to load is due to the imbalance of bone homeostasis, where excessive bone resorption, compared with bone formation, determines a progressive osteopenia, leading to a high risk of fractures and consequent pain and functional limitations. Terpenoids, with their activities against bone resorption, have recently received increased attention from researchers. They are potentially more suitable for long-term use compared with traditional therapeutics. In this review of the literature of the past 5 years, we provide comprehensive information on terpenoids, with their anti-osteoporotic effects, highlighting molecular mechanisms that are often in epigenetic key and a possible pharmacological use in osteoporosis prevention and treatment.

Evodiamine attenuates adjuvant-induced arthritis in rats by inhibiting synovial inflammation and restoring the Th17/Treg balance

OBJECTIVES

Evodiamine (Evo) possesses strong anti-inflammatory activity. In this study, we determine the antiarthritic effect of Evo.

METHODS

Evo was administered to rats with adjuvant-induced arthritis (AA). We evaluated arthritis symptoms & histopathological changes and measured inflammatory cell infiltration, pro-inflammatory cytokine production and Th17 & Treg percentages in arthritic rats.

KEY FINDINGS

Evo significantly improved the clinical signs of AA in rats, including decreases in paw swelling, the polyarthritis index and the number of swollen paw joints. Based on the histopathological analysis, Evo improved synovial inflammation and bone injury by inhibiting inflammatory cell infiltration, synoviocyte proliferation, pannus formation and cartilage erosion. Furthermore, the numbers of synovial CD3+ or CD68+ inflammatory cells were reduced, and the elevated levels of tumour necrosis factor-α, interleukin-1β (IL-1β) and IL-6 were restored to control levels by the Evo treatment. In addition, Evo therapy regulated the abnormal differentiation of Treg and Th17 cells, decreasing IL-17 production and increasing IL-10 levels. Finally, Evo inhibited Stat3 phosphorylation and induced Stat5 phosphorylation in rats with AA.

CONCLUSIONS

Based on our results, Evo is a promising antiarthritic agent, potentially due to its inhibitory effect on synovial inflammation and regulatory effects on Treg and Th17 differentiation.

Toonaciliatin K attenuates the lung injury induced by lung infection of H1N1 influenza virus by regulating the NF-κB/MyD88/TLR-7 pathway in mice

INTRODUCTION

H1N1 infection has a high mortality rate due to lung injury and respiratory distress. The present study determines the protective effect of toonaciliatin K against the lung injury induced by the lung infection of H1N1 influenza mice and also postulates the molecular mechanism.

MATERIAL AND METHODS

Infection was induced by exposing the anesthetized mice to H1N1 virus (10 LD50 in a volume of 30 ml) intranasally at day zero and mice were treated with toonaciliatin K 16.5 and 33 mg/kg intragastrically for 2 weeks. The effect of toonaciliatin K was assessed by estimating survival rate and lung edema by the lung index. Histopathological changes were determined by H + E staining and western blot and an RT-PCR study was also performed on the lung tissue homogenate.

RESULTS

Data of the study suggest that toonaciliatin K treatment enhances the survival rate and reduces the lung index compared to infected mice. There was a decrease in the level of chemokines and cytokines in the lung tissue of the toonaciliatin K treated group compared to infected mice. Moreover, expression of TLR-7, NF-κB p65 and MyD88 protein was found to be reduced in the lung tissue of the toonaciliatin K treated group compared to infected mice.

CONCLUSIONS

Data of the study suggested that toonaciliatin K protects against lung injury in lung H1N1 lung infection by regulating the TLR-7/Myd88/NF-κB p65 pathway.

Pharmacokinetic-Pharmacodynamic Modeling for Coptisine Challenge of Inflammation in LPS-Stimulated Rats

Pro-inflammatory factors are important indicators for assessing inflammation severity and drug efficacy. Coptisine has been reported to inhibit LPS-induced TNF-α and NO production. In this study, we aim to build a pharmacokinetic-pharmacodynamic model to quantify the coptisine time course and potency of its anti-inflammatory effect in LPS-stimulated rats. The plasma and lung coptisine concentrations, plasma and lung TNF-α concentrations, plasma NO concentration, and lung iNOS expression were measured in LPS-stimulated rats after intravenous injection of three coptisine doses. The coptisine disposition kinetics were described by a two-compartment model. The coptisine distribution process from the plasma to the lung was described by first-order dynamics. The dynamics of plasma TNF-α generation and elimination followed zero-order kinetics and the Michaelis-Menten equation. A first-order kinetic model described the TNF-α diffusion process from the plasma to the lung. A precursor-pool indirect response model was used to describe the iNOS and NO generation induced by TNF-α. The inhibition rates of TNF-α production by coptisine (54.73%, 26.49%, and 13.25%) calculated from the simulation model were close to the decline rates of the plasma TNF-α AUC (57.27%, 40.33%, and 24.98%, respectively). Coptisine suppressed plasma TNF-α generation in a linear manner, resulting in a cascading reduction of iNOS and NO. The early term TNF-α response to stimulation is a key factor in the subsequent inflammatory cascade. In conclusion, this comprehensive PK-PD model provided a rational explanation for the interlocking relationship among TNF-α, iNOS and NO production triggered by LPS and a quantitative evaluation method for inhibition of TNF-α production by coptisine.