Asiatic acid inhibits LPS-induced inflammatory response in human gingival fibroblasts

Asiatic acid reduces lipopolysaccharides-induced pulp inflammation through activation of nuclear factor erythroid 2-related factor 2 in rats

Background

Dental pulp inflammation, often initiated by Gram-negative microorganisms and lipopolysaccharides (LPS), can lead to pulpitis and, subsequently, dental pulp necrosis, compromising tooth structure and increasing susceptibility to fracture. Asiatic acid, derived from Centella asiatica, has demonstrated pharmacological properties, including anti-inflammatory and antioxidant effects, making it a potential candidate for mitigating LPS-induced pulp inflammation. This in vivo study aims to investigate the impact of Asiatic acid on the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in Rattus norvegicus with LPS-induced pulp inflammation.

Methods

This quasi-laboratory experimental in vivo study employed a post-test-only control group design to investigate the effects of Asiatic acid on LPS-induced pulp inflammation in Wistar rats. Thirty rats were randomly divided into six groups subjected to various interventions. LPS was administered to all groups for 6 h except the standard control group (CG, n = 5). The negative control group (NCG, n = 5) received only glass ionomer cement. The positive control group (PCG, n = 5) received Eugenol with glass ionomer cement. Intervention groups 1, 2, and 3 (IG1, IG2, IG3; n = 5 each) received Asiatic acid at concentrations of 0.5%, 1%, and 2%, respectively, with glass ionomer cement. Dental pulp inflammation was confirmed through immunological (tumor necrosis factor alpha (TNF-α) levels), histopathological (inflammatory parameters), and physiological (pain assessment using the rat grimace scale) analyses. Additionally, Nrf2 levels were examined using enzyme-linked immunosorbent assay (ELISA).

Results

Asiatic acid administration significantly influenced Nrf2 levels in rats with LPS-induced pulp inflammation. Nrf2 levels were significantly higher in groups treated with 0.5% (IG1) (8.810 ± 1.092 ng/mL; p = 0.047), 1.0% (IG2) (9.132 ± 1.285 ng/mL; p = 0.020), and 2.0% (IG3) (11.972 ± 1.888 ng/mL; p = 0.000) Asiatic acid compared to NCG (7.146 ± 0.706). Notably, Nrf2 levels were also significantly higher in the 2.0% Asiatic acid group (IG3) compared to the PCG treated with Eugenol (8.846 ± 0.888 ng/mL; p = 0.001), as well as IG1 (p = 0.001) and IG2 (p = 0.002). However, no significant difference was observed between administering 0.5% Asiatic acid (IG1), 1.0% Asiatic acid (IG2), and Eugenol (PCG).

Conclusion

This research showed that Asiatic acid significantly impacted the Nrf2 levels in rats with LPS-induced pulp inflammation. This suggests that it has the potential to be used as a therapeutic agent for reducing dental pulp inflammation. These findings support the need to further explore Asiatic acid as a promising intervention for maintaining dental pulp health.

Development of solid lipid microparticles (SLMs) containing asiatic acid for topical treatment of acne: Characterization, stability, in vitro and in vivo anti-acne assessment

Solid lipid microparticles (SLMs) represent a promising approach for drug delivery in anti-acne applications. In this study, asiatic acid-loaded SLMs (AASLMs) were prepared by melt emulsification method in conjunction with freeze-drying. Comprehensive evaluations comprised particle size, %entrapment efficiency (%EE), %labeled amount (%LA), surface morphology, stability, %release, %skin permeation, and anti-acne activity. The AASLMs exhibited an average particle size ranging from 7.46 to 38.86 µm, with %EE and %LA falling within the range of 31.56 to 100.00 and 90.43 to 95.38, respectively. The AASLMs demonstrated a spherical shape under scanning electron microscopy, and maintained stability over a 3-month period. Notably, formulations with 10 % and 15 % cetyl alcohol stabilized with poloxamer-188 (specifically F6 and F12) displayed a minimum inhibitory concentration (MIC) value of 75 mg/ml against Cutibacterium acnes. Furthermore, F12 exhibited a higher %release and %skin permeation compared to F6 over 24 h. In a single-blind clinical trial involving fifteen participants with mild-to-moderate acne, F12 showcased its potential not only in reducing porphyrin intensity and enhancing skin barriers but also in significantly improving skin hydration and brightness. However, further investigations with larger subject cohorts encompassing diverse age groups and genders are necessary to thoroughly establish the performance of the developed AASLMs.

Mode of administration influences plasma levels of active Centella asiatica compounds in 5xFAD mice while markers of neuroinflammation remain unaltered

Introduction

A water extract of Centella asiatica (L.) Urban [Apiaceae] (CAW) has demonstrated cognitive-enhancing effects in mouse models of Alzheimer's disease and aging, the magnitude of which is influenced by whether CAW is delivered in the drinking water or the diet. These cognitive benefits are accompanied by improvements in oxidative stress and mitochondrial function in the brain, two pathways related to the neuroinflammatory response. The effect of CAW on neuroinflammation, however, has not been directly studied. Here, we investigated the effect of CAW on neuroinflammation in 5xFAD mice and compared plasma levels of CAW's active compounds following two modes of CAW administration.

Methods

Eight-to-nine-month-old male and female 5xFAD mice and their wild-type littermates were administered CAW in their diet or drinking water (0 or 1,000 mg/kg/day) for five weeks. Immunohistochemistry was performed for β-amyloid (Aβ), glial fibrillary acidic protein (GFAP), and Griffonia simplicifolia lectin I (GSL I) in the cortex and hippocampus. Gene expression of inflammatory mediators (IL-6, TNFα, IL-1β, TREM2, AIF1, CX3CR1, CX3CL1, CD36, C3AR1, RAGE, CCR6, CD3E) was measured in the deep grey matter.

Results

CAW decreased cortical Aβ plaque burden in female 5xFAD mice administered CAW in the drinking water but had no effect on Aβ plaques in other treatment groups. CAW did not impact elevated levels of GFAP or GSL I in 5xFAD mice, regardless of sex, brain region, or mode of CAW administration. In the deep grey matter, CAW increased C3AR1 expression in 5xFAD females administered CAW in the drinking water and decreased IL-1β expression in 5xFAD males administered CAW in the diet. CAW had no effect, however, on gene expression levels of any other inflammatory mediator in the deep grey, for either sex or mode of CAW administration. Mice administered CAW in the drinking water versus the diet had significantly higher plasma levels of CAW compounds.

Discussion

CAW had little impact on the neuroinflammatory markers selected for evaluation in the present study, suggesting that the cognitive benefits of CAW may not be mediated by an anti-inflammatory effect or that additional molecular markers are needed to fully characterize the effect of CAW on neuroinflammation.

A literature review of bioactive substances for the treatment of periodontitis: In vitro, in vivo and clinical studies

Periodontitis is a common chronic inflammatory disease of the supporting tissues of the tooth that involves a complex interaction of microorganisms and various cell lines around the infected site. To prevent and treat this disease, several options are available, such as scaling, root planning, antibiotic treatment, and dental surgeries, depending on the stage of the disease. However, these treatments can have various side effects, including additional inflammatory responses, chronic wounds, and the need for secondary surgery. Consequently, numerous studies have focused on developing new therapeutic agents for more effective periodontitis treatment. This review explores the latest trends in bioactive substances with therapeutic effects for periodontitis using various search engines. Therefore, this study aimed to suggest effective directions for therapeutic approaches. Additionally, we provide a summary of the current applications and underlying mechanisms of bioactive substances, which can serve as a reference for the development of periodontitis treatments.

Bioactive compounds from Actinidia arguta fruit as a new strategy to fight glioblastoma

In recent years, there has been a significant demand for natural products as a mean of disease prevention or as an alternative to conventional medications. The driving force for this change is the growing recognition of the abundant presence of valuable bioactive compounds in natural products. On recent years Actinia arguta fruit, also known as kiwiberry, has attracted a lot of attention from scientific community due to its richness in bioactive compounds, including phenolic compounds, organic acids, vitamins, carotenoids and fiber. These bioactive compounds contribute to the fruit's diverse outstanding biological activities such as antioxidant, anti-inflammatory, neuroprotective, immunomodulatory, and anti-cancer properties. Due to these properties, the fruit may have the potential to be used in the treatment/prevention of various types of cancer, including glioblastoma. Glioblastoma is the most aggressive form of brain cancer, displaying 90 % of recurrence rate within a span of 2 years. Despite the employment of an aggressive approach, the prognosis remains unfavorable, emphasizing the urgent requirement for the development of new effective treatments. The preclinical evidence suggests that kiwiberry has potential impact on glioblastoma by reducing the cancer self-renewal, modulating the signaling pathways involved in the regulation of the cell phenotype and metabolism, and influencing the consolidation of the tumor microenvironment. Even though, challenges such as the imprecise composition and concentration of bioactive compounds, and its low bioavailability after oral administration may be drawbacks to the development of kiwiberry-based treatments, being urgent to ensure the safety and efficacy of kiwiberry for the prevention and treatment of glioblastoma. This review aims to highlight the potential impact of A. arguta bioactive compounds on glioblastoma, providing novel insights into their applicability as complementary or alternative therapies.

Design, synthesis and anti-tumor activity of asiatic acid derivatives as VEGF inhibitors

The VEGF receptor is mock-coupled with a known active compound and the active groups of the inhibitor which can bind to VEGF were analyzed. Using asiatic acid as a lead compound, 10 novel skeleton candidate compounds were designed through introduction of the active groups onto the special location and synthesized simultaneously. Furthermore, the structure of these compounds was determined by ¹H NMR, ¹³C NMR and MS and 9 compounds were identified as the new compounds. Moreover, the in vitro anti-tumor activities of these new compounds were determined by MTT assay on two cancer cell lines (HepG2 and SGC-7901). The results showed that compounds I₁ and II₂ have more potent anticancer activity than positive control drugs such as gefitinib and paclitaxel.

Network Pharmacology Analysis and Experimental Validation to Explore the Anti-inflammatory Mechanism of Asiatic Acid on Alcoholic Steatohepatitis

Objective

The mechanism of action of asiatic acid (AA) on alcoholic steatohepatitis (ASH) was investigated using network pharmacology and experiments.

Methods

Through data retrieval, network construction, and enrichment analysis, the potential mechanism of AA in the treatment of alcoholic steatohepatitis was explored. Animal and cell models were established in this study. Animal Model. The mouse model was divided into six groups: normal group; model group; low, medium, and high AA group; and silibinin-positive group. Cell Model. An in vitro inflammatory model of RAW264.7 cells was established by alcohol stimulation.

Results

Compared with the model group, the low, medium, and high AA group showed decreased serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (T-CHO). The inflammatory factor tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) in a dose-dependent manner were decreased. In addition, hematoxylin-eosin staining showed that liver tissue damage and inflammatory cell infiltration in mice were significantly reduced with increasing doses. Further, oil red staining showed that lipid accumulation in hepatocytes in the low, medium, and high AA group was significantly reduced, with increasing dose. In addition, in the cellular model, real-time reverse transcriptase-polymerase chain reaction (Real-Time RT-PCR) and enzyme-linked immunosorbent assay (ELISA) results showed that AA could alleviate alcohol-induced cellular inflammation, while western blot and immunofluorescence results showed that AA might alleviate alcohol-induced cellular inflammation by inhibiting the nuclear factor-κB (NF-κB) pathway.

Conclusion

This study provides multiple lines of evidence that asiatic acid may alleviate alcoholic hepatitis in mice by modulating the NF-κB pathway.

Tamquam alter idem: formal similarities in a subset of reports on anti-inflammatory compounds in the years 2008–2019

A literature search on the in vitro testing of anti-inflammatory compounds of natural origin revealed a considerable number of studies adopting a similar template for data reporting in the years up to 2019. Sixty-five such reports appear to have been published between the years 2008 and 2019. Interestingly, this format template was clearly recognizable by a few hallmarks, such as a precise way of plotting cell viability data, extremely consistent endpoints, and the way these were graphically represented. In some instances the similarities extended to some textual features, such as in the case of figure legends. The similarity was so high that chance can be excluded and these studies can be safely assumed to have intentionally followed a template. By 2020, however, no new reports following this format have been published. Although a consistent and reproducible formatting for data reporting may improve report readability, this phenomenon should also be closely scrutinized to assess the rationale why it occurred, the validity of the endpoints that were chosen and why it was then abandoned. The present report reviewed the mean features of this format, traced its origin and its evolution over time, while discussing the limitations of this model.

Asiatic acid alleviates metabolism disorders in ob/ob mice: mechanistic insights

Glucolipid metabolism disorders pose a serious and global health problem, and more effective prevention and treatment methods are urgently needed. In this study, ob/ob mice were used to explore the potential mechanism explaining how asiatic acid (AA) regulates glucolipid metabolism disorders. Five-week AA treatment (30 mg kg^-1) significantly improved a host of metabolic factors in ob/ob mice, including hyperglycemia, hyperlipidemia, insulin resistance, and liver histopathology. Combined analysis of untargeted liver metabolomics, liver transcriptomics, and the gut microbiome was conducted, and the results showed that AA alleviates metabolic disorders in ob/ob mice through regulating pyrimidine metabolism, activating PPAR-γ, and modulating gut microbiota. AA treatment remarkedly increased the levels of cytosine and cytidine, two crucial endogenous metabolites related to pyrimidine metabolism, which were significantly decreased in ob/ob mice. AA treatment also affected the levels of 13-S-hydroxyoctadecadienoic acid, an endogenous PPAR-γ agonist. The abundances of Lachnospiraceae_NK4A136_group and norank_f__norank_o__Clostridia_UCG-014 were increased after AA treatment. Meanwhile, correlation analysis showed that endogenous metabolites and gut microbiota were strongly correlated. These findings indicated that AA supplements might be beneficial for the prevention of metabolic disorders.

Asiatic acid re-sensitizes multidrug-resistant A549/DDP cells to cisplatin by down regulating long non-coding RNA metastasis associated lung adenocarcinoma transcript 1/β-catenin signaling

Drug resistance becomes a challenge in the therapeutic management of non-small cell lung cancer (NSCLC). According to our former research, asiatic acid (AA) re-sensitized A549/DDP cells to cisplatin (DDP) through decreasing multidrug resistance protein 1 (MDR1) expression level. However, the relevant underlying mechanisms are still unclear. Long non-coding RNA (lncRNA) MALAT1 shows close association with chemo-resistance. As reported in this research, AA increased apoptosis rate, down regulated the expression of MALAT1, p300, β-catenin, and MDR1, up regulated the expression of miR-1297, and decreased β-catenin nuclear translocation in A549/DDP cells. MALAT1 knockdown expression abolished the drug resistance of A549/DDP cells and increased cell apoptosis. MALAT1 could potentially produce interactions with miR-1297, which targeted to degradation of p300. In addition, p300 overexpression effectively rescued the effects of MALAT1 knockdown expression on A549/DDP cells and activate the expression of β-catenin/MDR1 signaling, and these could be effectively blocked by AA treatment. Conclusively, AA could re-sensitize A549/DDP cells to DDP through down-regulating MALAT1/miR-1297/p300/β-catenin signaling.

Effects of titanium dioxide microparticles and nanoparticles on cytoskeletal organization, cell adhesion, migration, and proliferation in human gingival fibroblasts in the presence of lipopolysaccharide

BACKGROUND AND OBJECTIVE

Titanium wear particles may participate in the etiology of peri-implantitis. However, the influence of titanium wear particles on biological behavior of human gingival fibroblasts (HGFs) in the presence of LPS is still not clear. The present study demonstrated the effects of titanium dioxide micro- and nanoparticles (TiO₂  MPs and NPs) on HGF cell viability, cytoskeletal organization, adhesion, migration, and proliferation in vitro, and LPS was used to mimic the in vivo condition.

METHODS

Primary HGFs were treated with TiO₂ MPs (primary particle size <5 μm, 0.1 mg/ml) and NPs (primary particle size <100 nm, 0.1 mg/ml) with or without 1 μg/ml LPS. The effects of TiO₂ MPs and NPs on HGFs cell viability was measured by CCK-8 assay. The proliferation of HGF was detected by Ki67 nuclear staining. The confocal laser scanning microscope (CLSM) was used to detect the internalization of TiO₂ MPs and NPs in HGFs as well as the arrangement of F-actin, vinculin, and vimentin organization. Wound healing assay and transwell assay were performed to measure the migration of HGFs induced by TiO₂ MPs and NPs. Cell adhesion was measured using fibronectin-coated plates. The relative mRNA and protein expression of adhesion relative protein such as focal adhesion kinase (FAK), fibronectin (FN), and type I collagen (COL1) were measured using quantitative RT-PCR and western blot analysis. One-way analysis of variance (ANOVA) and Student's t-test were used to analyze the statistical significance, and p < .05 was considered statistically significant.

RESULTS

TiO₂ NPs significantly inhibited HGF cell viability, proliferation, and migration compared with TiO₂ MPs group and control group. Compared with control group (2.64 ± 0.09), the mean absorbance of the cells in 1 mg/ml TiO₂ MPs group and 0.25 mg/ml TiO₂ NPs group were significantly decreased to 1.93 ± 0.33 (p < .05) and 2.22 ± 0.18 (p < .01), respectively. The cytoskeleton disruption was found in TiO₂ NPs group. The mRNA and protein expression were significantly downregulated by TiO₂ NPs. Furthermore, both TiO₂ NPs and MPs induced more adverse effects on HGFs in the presence of LPS.

CONCLUSION

Our results indicate that TiO₂ NPs but not TiO₂ MPs significantly disrupt the cytoskeletal organization and inhibited cell adhesion, migration, and proliferation of HGFs. However, in the presence of LPS, TiO₂ MPs, and TiO₂ NPs enhance these negative effects in HGFs. Titanium wear particles are probably involved in the initiation and progression of peri-implant diseases.

Evaluation of the Antibacterial and Anti-Inflammatory Effects of a Natural Products-Containing Toothpaste

Fluoride-containing toothpaste is daily used in toothbrush. Some compounds derived from natural herbs that have antibacterial and anti-inflammatory activities has attracted increasing attention as potential supplements for the control of oral diseases. In this paper, a natural product mixture (NPM-8) containing eight herbs extracts was added to toothpaste, and its antibacterial and anti-inflammatory effects were investigated. The results showed that NPM-8-containing toothpaste exhibited superior and faster inhibitory and bactericidal effects against S. mutans, S. sanguinis and P. gingivalis than that of the NPM-8-free toothpaste. NPM-8-containing toothpaste significantly reduced the biomass of single-species or three-species biofilms. The cytotoxicity of the NPM-8-containing toothpaste was similar to that of the conventional fluoride toothpaste and CHX. The NPM-8-containing toothpaste could significantly inhibit IL-1β and IL-6 production in HGE cells and exhibited a better anti-inflammatory effect than that of the NPM-8-free toothpaste. In conclusion, NPM-8-containing fluoride toothpaste is superior to conventional fluoride toothpaste in regard to their antibacterial, antibiofilm, and anti-inflammatory properties. NPM-8-containing toothpaste also has good biocompatibility and is safe for daily use. It indicates that NPM-8 is a promising natural product mixture in oral health.

Chitosan Oligosaccharides Alleviate Colitis by Regulating Intestinal Microbiota and PPARγ/SIRT1-Mediated NF-κB Pathway

Chitosan oligosaccharides (COS) have been shown to have potential protective effects against colitis, but the mechanism underlying this effect has not been fully elucidated. In this study, COS were found to significantly attenuate dextran sodium sulfate-induced colitis in mice by decreasing disease activity index scores, downregulating pro-inflammatory cytokines, and upregulating Mucin-2 levels. COS also significantly inhibited the levels of nitric oxide (NO) and IL-6 in lipopolysaccharide-stimulated RAW 264.7 cells. Importantly, COS inhibited the activation of the NF-κB signaling pathway via activating PPARγ and SIRT1, thus reducing the production of NO and IL-6. The antagonist of PPARγ could abolish the anti-inflammatory effects of COS in LPS-treated cells. COS also activated SIRT1 to reduce the acetylation of p65 protein at lysine 310, which was reversed by silencing SIRT1 by siRNA. Moreover, COS treatment increased the diversity of intestinal microbiota and partly restored the Firmicutes/Bacteroidetes ratio. COS administration could optimize intestinal microbiota composition by increasing the abundance of norank_f_Muribaculaceae, Lactobacillus and Alistipes, while decreasing the abundance of Turicibacte. Furthermore, COS could also increase the levels of propionate and butyrate. Overall, COS can improve colitis by regulating intestinal microbiota and the PPARγ/SIRT1-mediated NF-κB pathway.

Inhibition of circular RNA circ_0138959 alleviates pyroptosis of human gingival fibroblasts via the microRNA-527/caspase-5 axis

Circular RNA (circRNA) plays a regulatory role in periodontitis. This study explored whether circ_0138959 affected lipopolysaccharide (LPS)-induced pyroptosis in human gingival fibroblasts (HGFs). The periodontal ligament (PDL) tissues and HGFs were derived from patients with periodontitis and healthy volunteers. HGFs treated with LPS were considered to mimic periodontitis in vitro. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate the mRNA expression levels of circRNAs, miR-527, and caspase-5 (CASP5), and Western blotting assay was used to measure protein expression levels of caspase-1, caspase-4, and cleaved N-terminal gasdermin D (GSDMD-N). Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. The concentration of lactate dehydrogenase (LDH), interleukin (IL)-1β, and IL-18 and the pyroptosis rate were determined to evaluate pyroptosis. The interaction between miR-527 and circ_0138959 or CASP5 was verified by dual-luciferase reporter and RNA pull-down assays. Circ_0138959 expression was higher in the PDL tissues of patients with periodontitis than in the healthy group; likewise, circ_0138959 was also upregulated in LPS-treated HGFs. Suppressed circ_0138959 increased cell viability and decreased pyroptosis of HGFs induced by LPS. miR-527 was a target of circ_0138959, and inhibition of miR-527 contributed to the dysfunction of LPS-treated HGFs and reversed the protective effects of downregulated circ_0138959. Additionally, miR-527 targeted CASP5. Increased CASP5 abrogated the effects of overexpressed miR-527 on cell viability and pyroptosis of LPS-treated HGFs. Inhibition of circ_0138959 promoted cell viability and suppressed pyroptosis of HGFs via the miR-527/CASP5 axis. Therefore, knockdown of circ_0138959 may be a promising therapy for periodontitis.

Superparamagnetic Iron Oxide Nanoparticles Protect Human Gingival Fibroblasts from Porphyromonas gingivalis Invasion and Inflammatory Stimulation

Introduction

Modulating the inflammatory response of human gingival fibroblasts (hGFs) is important for the control of periodontal inflammation because it is a key event in the pathogenesis of periodontitis. Here, we aimed to determine whether polyglucose sorbitol carboxymethyl ether (PSC)-coated superparamagnetic iron oxide nanoparticles (SPIONs) protect hGFs against invasion and inflammatory stimulation by Porphyromonas gingivalis (P. gingivalis).

Methods

First, we determined the cytotoxicity and antimicrobial activity of PSC-SPIONs. Then, their effects on invasion of hGFs by P. gingivalis were evaluated by counting invading P. gingivalis, fluorescence staining, and transmission electron microscopy. The effect of PSC-SPIONs on inflammation in hGFs induced by P. gingivalis lipopolysaccharide was evaluated by measurement of reactive oxygen species (ROS), and enzyme-linked immunosorbent assays, quantitative reverse transcription-polymerase chain reaction, and Western blotting of key indicator molecules. The effects of dimercaptosuccinic acid (DMSA)-coated SPIONs and the free form of PSC alone were also tested and compared with those of PSC-SPIONs.

Results

PSC-SPIONs (25 μg/mL) are cytocompatible with hGFs and exhibit no antimicrobial effects on P. gingivalis. However, they inhibit invasion of hGFs by P. gingivalis at 15 μg/mL. They also decrease ROS production and inflammatory cytokine secretion by hGFs at 5, 15, and 25 μg/mL, by downregulating activation of the nuclear factor-kappa B signaling pathway. Furthermore, PSC alone does not inhibit inflammation, while DMSA-SPIONs do. This indicates that the nanosize effects of PSC-SPIONs, rather than their coating material, play the dominant role in their anti-inflammatory activity.

Conclusion

PSC-SPIONs protect hGFs against P. gingivalis invasion and inflammatory stimulation. Thus, they have potential for clinical application in control of periodontal inflammation.

In Vivo Biocompatible Self-Assembled Nanogel Based on Hyaluronic Acid for Aqueous Solubility and Stability Enhancement of Asiatic Acid

Asiatic acid (AA), a natural triterpene found in Centalla asiatica, possesses polypharmacological properties that can contribute to the treatment and prophylaxis of various diseases. However, its hydrophobic nature and rapid metabolic rate lead to poor bioavailability. The aim of this research was to develop a thermoresponsive nanogel from hyaluronic acid (HA) for solubility and stability enhancement of AA. Poly(N-isopropylacrylamide) (pNIPAM) was conjugated onto HA using a carbodiimide reaction followed by ¹H NMR characterization. pNIPAM-grafted HA (HA-pNIPAM) nanogels were prepared with three concentrations of polymer, 0.1, 0.15 and 0.25% w/v, in water by the sonication method. AA was loaded into the nanogel by the incubation method. Size, morphology, AA loading capacity and encapsulation efficiency (EE) were analyzed. In vitro cytocompatibility was evaluated in fibroblast L-929 cells using the PrestoBlue assay. Single-dose toxicity was studied using rats. HA-pNIPAM nanogels at a 4.88% grafting degree showed reversible thermo-responsive behavior. All nanogel formulations could significantly increase AA water solubility and the stability was higher in nanogels prepared with high polymer concentrations over 180 days. The cell culture study showed that 12.5 µM AA in nanogel formulations was considered non-toxic to the L-929 cells; however, a dose-dependent cytotoxic effect was observed at higher AA-loaded concentrations. In vivo study proved the non-toxic effect of AA loaded in HA-pNIPAM nanogels compared with the control. Taken together, HA-pNIPAM nanogel is a promising biocompatible delivery system both in vitro and in vivo for hydrophobic AA molecules.

Camostat mesilate inhibits pro-inflammatory cytokine secretion and improves cell viability by regulating MFGE8 and HMGN1 in lipopolysaccharide-stimulated DF-1 chicken embryo fibroblasts

Camostat mesilate (CM) possesses potential anti-viral and anti-inflammatory activities. However, it remains unknown whether CM is involved in lipopolysaccharide (LPS)-mediated inflammatory responses and cell injury. In this project, differentially expressed proteins (DEPs, fold change ≥ 1.2 or ≤ 0.83 and Q value ≤ 0.05) in response to LPS stimulation alone or in combination with CM were identified through tandem mass tags (TMT)/mass spectrometry (MS)-based proteomics analysis in DF-1 chicken embryo fibroblasts. The mRNA expression levels of filtered genes were determined by RT-qPCR assay. The results showed that CM alleviated the detrimental effect of LPS on cell viability and inhibited LPS-induced TNF-α and IL-6 secretions in DF-1 chicken embryo fibroblasts. A total of 141 DEPs that might be involved in mediating functions of both LPS and CM were identified by proteomics analysis in DF-1 chicken embryo fibroblasts. LPS inhibited milk fat globule EGF and factor V/VIII domain containing (MFGE8) expression and induced high mobility group nucleosome binding domain 1 (HMGN1) expression, while these effects were abrogated by CM in DF-1 chicken embryo fibroblasts. MFGE8 knockdown facilitated TNF-α and IL-6 secretions , reduced cell viability, stimulated cell apoptosis in DF-1 chicken embryo fibroblasts co-treated with LPS and CM. HMGN1 loss did not influence TNF-α and IL-6 secretions, cell viability, and cell apoptosis in DF-1 chicken embryo fibroblasts co-treated with LPS and CM. In conclusion, CM exerted anti-inflammatory and pro-survival activities by regulating MFGE8 in LPS-stimulated DF-1 chicken embryo fibroblasts, deepening our understanding of the roles and molecular basis of CM in protecting against Gram-negative bacteria.

Ethnobotany, phytochemistry, pharmacology, and toxicity of Centella asiatica (L.) Urban: A comprehensive review

The well-known medicinal plant Centella asiatica (L.) Urban is an Ayurvedic and traditional Chinese medicine used in the treatment of different health problems and as an edible vegetable in a regular diet. Ease of availability in the wide range of environmental conditions plus low-cost cultivation process has made the plant popular in ethno-medicinal healthcare systems. In the present review, phytochemical analysis of plant-extract and pharmacological activities of bioactive-compounds are discussed based upon the available reports to understand their therapeutic potentialities along with the mechanisms behind. The results exhibited that C. asiatica and its triterpenoids demonstrated an array of pharmacological effects and health benefits, some of which were confirmed in many preclinical and clinical studies. Those reports also provided considerable evidences in support of the principles of folk treatment in different countries. Increase and maintenance of the prospective plant secondary metabolites would provide an enriched resource of drug molecules. Development of suitable derivatives of the therapeutic compounds can give an assurance for getting more effective drug candidates with reduced side effects. The review also enumerates the application of advanced nanotechnology, toxicology, and clinical-trial reports on the plant with notes on the shortcomings in the present research and future perspectives of using this medicinal plant.

Immunomodulatory and Anti-inflammatory Effects of Asiatic Acid in a DNCB-Induced Atopic Dermatitis Animal Model

We examined the immunomodulatory and anti-inflammatory effects of asiatic acid (AA) in atopic dermatitis (AD). AA treatment (5–20 µg/mL) dose-dependently suppressed the tumor necrosis factor (TNF)-α level and interleukin (IL)-6 protein expression in interferon (IFN)-γ + TNF-α-treated HaCaT cells. The 2,4-dinitrocholrlbenzene (DNCB)-induced AD animal model was developed by administering two AA concentrations (30 and 75 mg/kg/d: AD + AA-L and AD + AA-H groups, respectively) for 18 days. Interestingly, AA treatment decreased AD skin lesions formation and affected other AD characteristics, such as increased ear thickness, lymph node and spleen size, dermal and epidermal thickness, collagen deposition, and mast cell infiltration in dorsal skin. In addition, in the DNCB-induced AD animal model, AA treatment downregulated the mRNA expression level of AD-related cytokines, such as Th1- (TNF-α and IL-1β and -12) and Th2 (IL-4, -5, -6, -13, and -31)-related cytokines as well as that of cyclooxygenase-2 and CXCL9. Moreover, in the AA treatment group, the protein level of inflammatory cytokines, including COX-2, IL-6, TNF-α, and IL-8, as well as the NF-κB and MAPK signaling pathways, were decreased. Overall, our study confirmed that AA administration inhibited AD skin lesion formation via enhancing immunomodulation and inhibiting inflammation. Thus, AA can be used as palliative medication for regulating AD symptoms.

[Sitagliptin inhibits lipopolysaccharide-induced inflammatory response in human gingival fibroblasts by blocking nuclear factor-κB signaling pathway]

OBJECTIVES

This study was performed to clarify the effects of sitagliptin on Porphyromonas gingivalis-lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (HGFs), explore the molecular mechanism of its roles, and provide a foundation for clinical therapeutics in periodontitis.

METHODS

Healthy gingival samples were collected from the donors. HGFs were isolated with enzymic digestion method and identified. The effects of LPS and sitagliptin on cell viability were detected by cell-counting kit-8 (CCK8). The mRNA levels of inflammatory cytokines, namely, interleukin (IL)-6, IL-8, C-C motif ligand 2 (CCL2), and superoxide dismutase 2 (SOD2), were evaluated by quantity real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA) was used to measure the secretion protein levels of IL-6, IL-8, and CCL2. Western blot analysis was used to further investigate the activation of nuclear factor (NF)-κB signaling pathway. The effect of NF-κB pathway inhibitor BAY11-7082 on LPS-induced HGF inflammatory cytokines at the gene level was verified by qRT-PCR.

RESULTS

Low concentrations of sitagliptin (0.1, 0.25, and 0.5 µmol·L^-1) did not affect HGF growth in 24 and 48 h, whereas high concentrations of sitagliptin (5-1 000 µmol·L^-1) significantly inhibited cell proliferation. Sitagliptin suppressed 5 µg·mL^-1 of LPS-induced IL-6, IL-8, CCL2, and SOD2 gene expression levels in HGF in a concentration-dependent manner. Furthermore, sitagliptin significantly decreased the elevated secretion of IL-6, IL-8, and CCL2 protein induced by LPS. Western blot analysis showed that 0.5 µmol·L^-1 of sitagliptin significantly inhibited LPS-induced NF-κB signaling pathway activation. Results of qRT-PCR analysis indicated that 0.5 µmol·L^-1 of sitagliptin and 5 µmol·L^-1 of BAY11-7082 significantly inhibited LPS-induced IL-6, IL-8, CCL2, and SOD2 gene expressions.

CONCLUSIONS

Sitagliptin could significantly inhibit LPS-induced HGF inflammatory response by blocking the NF-κB signaling pathway activation.

Anti-Cancer Effects of Asiatic Acid, a Triterpene from Centilla asiatica L: A Review

BACKGROUND

Centilla asiatica L is a medicinal herb that has been widely used in folk medicine to treat various diseases. Asiatic Acid (AA), a triterpene and a known component of this herb, has been shown to display important biological activities, including anti-inflammatory, antibacterial, antidiabetic and antihyperlipidemic, neuroprotective, anxiolytic and antidepressant, hepatoprotective, pancreas protective, and cardio- protective.

OBJECTIVE

This review focuses on AA's anti-cancer effects on the basis of published literature found in a number of databases such as PubMed and Science Direct. Emphasis has been given to the mechanisms of action of its anti-cancer effect.

METHODS

A literature survey was conducted using known databases such as PubMed and Science Direct using the keywords 'Asiatic acid', pairing with 'cancer', 'tumor', 'anti-cancer effect', 'cytotoxic effect', 'anti-tumor activity', 'cell line', 'animal cancer', and 'human cancer'.

RESULTS

Findings suggest that AA exerts anti-cancer effects in several test systems through various pathways, including oxidative/antioxidant, anti-inflammatory, cytotoxicity, apoptotic cell death, necrosis, anti-angiogenesis, inhibition of proliferation and cell migration, and chemoprevention.

CONCLUSION

AA may be an effective plant-based cancer chemotherapeutic agent and a promising lead for the development of potent anticancer drugs.

Anti-Leishmania amazonensis activity of the terpenoid fraction from Eugenia pruniformis leaves

Leishmaniasis is caused by protozoan parasites belonging to the genus Leishmania and includes cutaneous, mucocutaneous and visceral clinical forms. Drugs currently available for leishmaniasis treatment present high toxicity, and development of parasite resistance. Plants constitute an important source of compounds with leishmanicidal potential. This study aimed to evaluate the anti-Leishmania amazonensis activity of the terpenoid fraction of Eugenia pruniformis leaves (TF-EpL). TF-EpL was active against the promastigote and intracellular amastigote forms of L. amazonensis with IC50(24h) value of 43.60μg/mL and 44.77μg/mL, respectively. TF-EpL altered the cell cycle of the parasite, increasing 2.32-fold the cells in the Sub-G0/G1 phase. TF-EpL also changed the ΔΨm and increased ROS and the number of annexin-V-PI positive promastigotes, which suggests incidental death. β-sitosterol, ursolic acid, corosolic acid and asiatic acid were isolated from TF-EpL. The results showed the antileishmanial activity of E. pruniformis terpenoids and its potential for further studies as a source of new drugs for leishmaniasis.

Therapeutic Potential of Centella asiatica and Its Triterpenes: A Review

Centella asiatica (also known as Centella asiatica (L.) Urb. or Gotu kola) is a traditional Chinese medicine with extensive medicinal value, which is commonly used in Southeast Asian countries. This study aimed to summarize the effects of C. asiatica and its main components on neurological diseases, endocrine diseases, skin diseases, cardiovascular diseases, gastrointestinal diseases, immune diseases, and gynecological diseases, as well as potential molecular mechanisms, to study the pathological mechanism of these diseases based on the changes at the molecular level. The results showed that C. asiatica and its triterpenoids had extensive beneficial effects on neurological and skin diseases, which were confirmed through clinical studies. They exhibited anti-inflammatory, anti-oxidative stress, anti-apoptotic effects, and improvement in mitochondrial function. However, further clinical studies are urgently required due to the low level of evidence and lack of patients.

Immunomodulatory effects and structure-activity relationship of botanical pentacyclic triterpenes: A review

Botanical pentacyclic triterpenes possessed a broad range of pharmacological activities such as anti-oxidant, anti-tumor, anti-microbial and anti-inflammatory activities. It is believed that the mechanisms involved in these bioactivities are due to the modulation of immune system. Recently, the pharmacological validation on immunomodulatory of pentacyclic triterpenes derived from higher plants is very limited and several existence review papers related for this group of compound have not been focused for this activity. In this review, we have highlighted several studies on immunomodulatory potential of botanical pentacyclic triterpenes isolated from wide array of different species of medicinal plants and herbs based on various preclinical in vitro and animal models. This review also attempts to discuss on bioactivities of compouns related with their structure-activity relationship. Hence, the evaluation of pentacyclic triterpenes offers a great opportunity to discover adjuvants and novel therapeutic agents that presented beneficial immunomodulatory properties.

Inhibitory Effect of Centella asiatica Extract on DNCB-Induced Atopic Dermatitis in HaCaT Cells and BALB/c Mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused mainly by immune dysregulation. This study explored the anti-inflammatory and immunomodulatory effects of the Centella asiatica ethanol extract (CA) on an AD-like dermal disorder. Treatment with CA inhibited the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in a dose-dependent manner in inflammatory stimulated HaCaT cells by interferon-γ (IFN-γ) and TNF-α-triggered inflammation. Eight-week-old BALB/c mice treated with 2,4-dinitrochlorobenzene (DNCB) were used as a mouse model of AD. In AD induce model, we had two types treatment of CA; skin local administration (80 µg/cm², AD+CA-80) and oral administration (200 mg/kg/d, AD+CA-200). Interestingly, the CA-treated groups exhibited considerably decreased mast cell infiltration in the ear tissue. In addition, the expression of IL-6 in mast cells, as well as the expression of various pathogenic cytokines, such as TNF-α, IL-4, IL-5, IL-6, IL-10, IL-17, iNOS, COX-2, and CXCL9, was reduced in both AD+CA-80 and AD+CA-200 groups. Collectively, our data demonstrate the pharmacological role and signaling mechanism of CA in the regulation of allergic inflammation of the skin, which supports our hypothesis that CA could potentially be developed as a therapeutic agent for AD.

Asiaticoside nitric oxide gel accelerates diabetic cutaneous ulcers healing by activating Wnt/β-catenin signaling pathway

Diabetic ulcers, gangrene, local infections and other traumatic symptoms of wound healing are all directly related. Promoting the early healing of diabetic cutaneous ulcers (DCU) and reducing the disability and treatment costs is an important research project integrating traditional Chinese and Western medicine. Nitric oxide (NO) is a key component of wound healing, and endogenous NO secretion is insufficient during the development of DCU. It has been reported that exogenous NO can promote wound healing, but exogenous NO has a short half-life and is difficult to adhere to the skin. Asiaticoside (AC) is extracted from the traditional Chinese medicine Centella asiatica, and has angiogenic, anticancer, antioxidant, anti-inflammatory, and wound-healing effects. Therefore, our study is based on the hypothesis that the combination of AC and NO to treat DCU is possible. In this study we considered gels of AC and NO, and evaluated the effects of the gel on DCU healing. Based on our study, it was found that the combined effect of asiaticoside and NO could accelerate the healing rate of DCU wounds. The asiaticoside NO gel can inhibit the growth of bacteria in the wound surface, alleviate the inflammatory reaction of wound, and increase the expression of VEGF, iNOS, eNOS and CD34. Our research shows that asiaticoside NO gel may promote DCU wound healing by regulating Wnt/β-Catenin signaling pathway. It will provide new targets and strategies for the diagnosis and treatment of DCU.

Between Innovation and Standardization, Is There Still a Room for Scientific Reports? The Rise of a Formatting Tradition in Periodontal Research

Everybody, regardless of their role, is aware that biomedical research is rapidly evolving, and the demand for reproducibility is increasing together with the amount of novel information. “Before reproducibility must come pre-producibility” “Checklists work to improve science”, just to quote some of the articles querying how to find a new bridge between ethics in science and the urgency for publishing. Looking for papers on anti-inflammatory compounds in periodontics, we came across a significant number of articles that could be considered a prototype of a consistent study format. The literature on the testing of active compounds on lipopolysaccharides- (LPS)-induced inflammation in gingival fibroblasts was searched to identify studies that followed a consistent format, to better understand their similarities and assess the appropriateness of their methods. Several studies were identified with a degree of similarity in their methods and formatting that was so high that it was possible to rule out that it was due to chance, and a format template common to these studies was outlined. Although this was most likely beyond the intentions of their authors, these studies may pose the basis for an in-vitro testing standard for anti-inflammatory compounds; however, the dangers of acritical uniformity are also apparent.

Crocin has pharmacological effects against the pathological behavior of colon cancer cells by interacting with the STAT3 signaling pathway

The aim of the present study was to investigate changes in proliferation, apoptosis, inflammation and chemokine release of colon cancer cells after treatment with crocin, as well as to investigate the signaling pathway that is regulated by crocin. The inhibition rates of different doses of crocin on the proliferation of HCT116 cells were measured by MTT assay. The IC₅₀ was calculated from the inhibition rates at 48 h. Proliferation curves of HCT116 cells were plotted after treatment with 271.18 µM (high-dose group) or 135.6 µM (low-dose group) crocin. Flow cytometry and Hoechst 33342/propidium iodide double staining were used for detecting apoptosis. ELISA was used to measure the levels of macrophage inflammatory protein 2, interleukin (IL)-8, monocyte chemoattractant protein 1, tumor necrosis factor-α, IL-6 and IL-1β in the supernatant from cultured HCT116 cells following both high- and low-dose crocin treatment. Phosphorylated (P)-STAT3/STAT3 in HCT116 cells were measured by western blotting. Crocin inhibited the proliferation of HCT116 cells in a dose-dependent manner and the high-dose treatment with crocin resulted in a lower rate of proliferation. Additionally, crocin increased the apoptosis of HCT116 cells and the high-dose treatment with crocin led to a higher level of apoptosis. Notably, crocin decreased the secretion of chemokines and inflammatory factors from HCT116 cells and the high-dose treatment with crocin caused the greatest reduction in secretion of the factors. Crocin reduced the ratio of P-STAT3/STAT3, and thereby reduced the release of cytokines. The present study demonstrated that crocin may have pharmacological effects against the pathological behavior of colon cancer cells, and its mechanism of action may be related to the STAT3 signaling pathway.

N-WASP knockdown upregulates inflammatory cytokines expression in human gingival fibroblasts

OBJECTIVE

The neuronal wiskott-aldrich syndrome protein (N-WASP) is a member of the wiskott-aldrich syndrome protein (WASP) family. N-WASP plays a vital role in promoting cell migration, receptor signaling and immune inflammatory responses. This study aimed to observe the changes in the expression of inflammatory factors and involving pathways after N-WASP knockdown in human gingival fibroblasts (HGFs).

DESIGN

Gingival inflammatory condition of N-WASP knockout mice was evaluated by H&E staining. N-WASP in HGFs was knockdown by siRNA and the best knockdown efficiency was determined by qRT-PCR and immunofluorescence. The mRNA levels of interleukin (IL)-6, IL-8, C-C motif ligand 2 (CCL2), superoxide dismutase 2 (SOD2) and prostaglandin endoperoxide synthase 2 (PTGS2) were evaluated by qRT-PCR after N-WASP knockdown with or without mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) inhibitors. The protein levels of IL-6, IL-8 and CCL2 were assessed by ELISA. Western blotting was used to detect the activation of NF-κB and MAPK signaling pathways.

RESULTS

Gingival tissue from N-WASP knockout mice exhibited an inflammatory reaction. The expression of IL-6, IL-8, CCL2, SOD2 and PTGS2 was significantly upregulated after N-WASP knockdown in HGFs for 6, 24 and 48 h, except for the SOD2 at 6 h. N-WASP knockdown significantly activated the signaling pathways of NF-κB and MAPK. The inhibitors of p65, p38, ERK and JNK clearly decreased IL-6, IL-8, CCL2, SOD2 and PTGS2 expression after N-WASP knockdown.

CONCLUSION

These data indicated that N-WASP deficiency in HGFs increases the production of inflammatory cytokine and is regulated via NF-κB and MAPK signaling pathways.

Asiatic Acid Attenuates Bone Loss by Regulating Osteoclastic Differentiation

Anti-resorptive agents like bisphosphonates have been widely used for the treatment of postmenopausal osteoporosis. However, their long-term safety and efficacy are still controversial. This study is to examine the effect of Asiatic acid (AA) in osteoclastic differentiation, and further to investigate its effect on bone quality in animals. Effect of AA on osteoclastic differentiation was measured by Tartrate-resistant acid phosphatase stain, bone resorption pit assays, and quantitative real-time polymerase chain reaction. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transforming growth factor-β (TGF-β) signaling were measured by western blot before and after AA treatment. Ovariectomized (OVX) wild-type or Smad7 partially knock out mice were used to evaluate the effects of AA on bone quality by micro-computed tomography, mechanical test, and histomorphometry. Results revealed a dose-dependent inhibitory effect of AA on osteoclastic differentiation. After AA treatment, Smad7 was upregulated, while NF-κB and TGF-β signaling were inhibited during osteoclastic differentiation. Results from animal study revealed that AA prevented bone from further loss caused by OVX and increased the mechanical properties of femur in wild-type animals. AA also prevented bone loss in the Smad7-deficient animals. When combining with OVX in the Smad7-deficient mice, AA could only partially preserve their bone mass. Taken together, we found that AA effectively inhibited osteoclastic differentiation and attenuated osteoporosis, which effects may be through TGF-β and NF-κB pathways. This study reveals that AA may be a potential anti-resorptive agent for postmenopausal osteoporosis.

Asiatic Acid Glucosamine Salt Alleviates Ultraviolet B-induced Photoaging of Human Dermal Fibroblasts and Nude Mouse Skin

Herbal extracts including asiatic acid (AA) have become popular candidates of anti-photoaging agents due to their anti-inflammatory and antioxidant properties and minimal side effect. Nevertheless, low bioavailability due to poor solubility limits their practical application. In this study, a highly bioavailable form of AA called AAGS (compounded by asiatic acid and glucosamine) was investigated for its anti-photoaging effect using both in vitro and in vivo models along with UVB irradiation. The results showed that AAGS alleviated UVB-induced cell proliferation inhibition by reducing G2 phase arrest and cell apoptosis rate as well as the gene expressions of P53, BAX, CASPASE 3 and CASPASE 9, but enhancing BCL-2 expression. It also reduced the production of reactive oxygen species along with increased gene expression of GPX-1 and downregulated the gene expression of IL-1β, IL-6, IL-8, IL-17 and TNF-α compared to nontreated cells. In vivo results demonstrated the antiphotodamaging effects by restoring skin thickness, collagen content and reducing MMPs expression, which are also supported by reduced MMPs gene expression and enhanced collagen I and TGF-β1 gene expression in vitro. Thus, AAGS may become a potential anti-photoaging agent for topical use due to its capability of self-assembling into a water gel.

Quercetin Inhibits Inflammatory Response Induced by LPS from Porphyromonas gingivalis in Human Gingival Fibroblasts via Suppressing NF-κB Signaling Pathway

Quercetin, a natural flavonol existing in many food resources, has been reported to be an effective antimicrobial and anti-inflammatory agent for restricting the inflammation in periodontitis. In this study, we aimed to investigate the anti-inflammatory effects of quercetin on Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide- (LPS-) stimulated human gingival fibroblasts (HGFs). HGFs were pretreated with quercetin prior to LPS stimulation. Cell viability was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The levels of inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), along with chemokine interleukin-8 (IL-8), were determined by enzyme-linked immunosorbent assay (ELISA). The mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IκBα, p65 subunit of nuclear factor-kappa B (NF-κB), peroxisome proliferator-activated receptor-γ (PPAR-γ), liver X receptor α (LXRα), and Toll-like receptor 4 (TLR4) were measured by real-time quantitative PCR (RT-qPCR). The protein levels of IκBα, p-IκBα, p65, p-p65, PPAR-γ, LXRα, and TLR4 were characterized by Western blotting. Our results demonstrated that quercetin inhibited the LPS-induced production of IL-1β, IL-6, IL-8, and TNF-α in a dose-dependent manner. It also suppressed LPS-induced NF-κB activation mediated by TLR4. Moreover, the anti-inflammatory effects of quercetin were reversed by the PPAR-γ antagonist of GW9662. In conclusion, these results suggested that quercetin attenuated the production of IL-1β, IL-6, IL-8, and TNF-α in P. gingivalis LPS-treated HGFs by activating PPAR-γ which subsequently suppressed the activation of NF-κB.

Oridonin inhibits LPS-induced inflammation in human gingival fibroblasts by activating PPARγ

Oridonin, the major terpene isolated from Rabdosia rubescens, has been used as dietary supplement. Recently, it has been known to exhibit anti-inflammatory effect. This study we employed an in vitro model of LPS-stimulated human gingival fibroblasts to investigate the anti-inflammatory effects and mechanism of oridonin. Oridonin (10-30 μg/mL) was administrated 1 h before LPS treatment. The results showed that oridonin significantly inhibited inflammatory mediators PGE₂, NO, IL-6, and IL-8 production. Immunoblotting experiments revealed that oridonin reduced the expression of phosphorylation levels of NF-κB p65 and IκBα. Furthermore, the expression of PPARγ was up-regulated by the treatment of oridonin. Further studies showed that PPARγ inhibitor GW9662 could reverse the inhibition of oridonin on PGE₂, NO, IL-6, and IL-8 production. In conclusion, oridonin inhibited LPS-induced microglia activation through activating PPARγ.

Protective effects of Asiatic acid against pelvic inflammatory disease in rats

Asiatic acid (AA) is one of the major components of the Chinese herb Centella asiatica and exerts a variety of pharmacological activities. However, the pharmacological effects of AA on pelvic inflammatory disease (PID) remain unknown. The purpose of the present study was to investigate the therapeutic efficacy and potential mechanisms of AA on PID in rats. A total of 75 female Sprague Dawley rats were randomly divided into the following five groups: A control group; a PID group; a PID + AA 5 mg/kg group; a PID + AA 35 mg/kg group; and a PID + AA 75 mg/kg group. Changes in cytokine and chemokine levels, myeloperoxidase (MPO) activity, nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome and nuclear factor-κB (NF-κB) activation, oxidative stress and cleaved caspase-3 were measured. AA treatment significantly decreased the excessive production of cytokines and chemokines and suppressed MPO activity and the activation of NLRP3 inflammasome, NF-κB and caspase-3, as well as oxidative stress. These results suggest that AA exhibits potent anti-inflammatory and antioxidant effects in rats with pathogen-induced PID and that the mechanism of these anti-inflammatory effects may be associated with the suppression of NLRP3 inflammasome activation and the NF-κB pathway.

Synthesis and discovery of asiatic acid based 1,2,3-triazole derivatives as antitumor agents blocking NF-κB activation and cell migration

A series of asiatic acid (AA) based 1,2,3-triazole derivatives were designed, synthesized and subjected to a cell-based NF-κB inhibition screening assay. Among the tested compounds, compound 6k displayed impressive NF-κB inhibitory activity with an IC₅₀ value in the low micromolar range. A molecular docking study was performed to reveal key interactions between 6k and NF-κB in which the 1,2,3-triazole moiety and the hydroxyl groups of the AA skeleton were important for improving the inhibitory activity. Subsequently, surface plasmon resonance analysis validated the high affinity between compound 6k and NF-κB protein with an equilibrium dissociation constant (KD) value of 0.36 μM. Further studies showed that compound 6k observably inhibited the NF-κB DNA binding, nuclear translocation and IκBα phosphorylation. Moreover, in vitro antitumor activity screening showed that compound 6k (IC₅₀ = 2.67 ± 0.06 μM) exhibited the best anticancer activity against A549 cells, at least partly, by inhibition of the activity of NF-κB. Additionally, the treatment of A549 cells with compound 6k resulted in apoptosis induction potency and in vitro cell migration inhibition. Thus, we conclude that AA based 1,2,3-triazole derivatives may be potential NF-κB inhibitors with the ability to induce apoptosis and suppress cell migration.

Asiatic acid protests against myocardial ischemia/reperfusion injury via modulation of glycometabolism in rat cardiomyocyte

Background

Asiatic acid is a reported glycogen phosphorylase inhibitor derived from the tropical medicinal plant Centella asiatica and exhibits myocardial protection both in vivo and in vitro. The purpose of this study was to evaluate the effects of asiatic acid on myocardial ischemia/reperfusion (MI/R) injury and investigate the underlying mechanisms associated with the modulation of glycometabolism in cardiomyocyte.

Materials and methods

The rats were subjected to MI/R with or without asiatic acid pretreatment. The cardiac function indexes, the size of myocardial infarction, and plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities were detected. Cardiomyocyte apoptosis was analyzed by TUNEL assay. The Akt/GSK-3β activation was measured by Western blot. The glycogen content, plasma glucose and lactate concentrations were determined following MI/R. The mRNA and protein levels of PPARγ and GLUT4 were determined by real-time PCR and Western blot, respectively.

Results

Asiatic acid pretreatment significantly improved the cardiac function indexes, attenuated the size of myocardial infarction, reduced LDH and CK activities, and suppressed cardiomyocyte apoptosis after MI/R. Asiatic acid activated Akt/GSK-3β signal pathway in the myocardium following MI/R injury. In addition, asiatic acid effectively suppressed MI/R-induced glycogen breakdown and inhibited the elevation of plasma glucose and lactate concentrations. Asiatic acid treatment increased PPARγ expression at both mRNA and protein levels, and promoted the translocation of GLUT4 to plasma membrane after MI/R insult. However, the effects mediated by asiatic acid on glycometabolism and GLUT4 translocation were reversed by the administration of LY294002, the Akt inhibitor.

Conclusion

These findings demonstrated that asiatic acid exerts beneficial effects on MI/R injury in rats. This protection may be related to the modulation of glycometabolism via Akt-dependent GLUT4 translocation and PPARγ activation in ischemic cardiomyocyte.

Pharmacological Properties, Molecular Mechanisms, and Pharmaceutical Development of Asiatic Acid: A Pentacyclic Triterpenoid of Therapeutic Promise

Asiatic acid (AA) is a naturally occurring aglycone of ursane type pentacyclic triterpenoids. It is abundantly present in many edible and medicinal plants including Centella asiatica that is a reputed herb in many traditional medicine formulations for wound healing and neuropsychiatric diseases. AA possesses numerous pharmacological activities such as antioxidant and anti-inflammatory and regulates apoptosis that attributes its therapeutic effects in numerous diseases. AA showed potent antihypertensive, nootropic, neuroprotective, cardioprotective, antimicrobial, and antitumor activities in preclinical studies. In various in vitro and in vivo studies, AA found to affect many enzymes, receptors, growth factors, transcription factors, apoptotic proteins, and cell signaling cascades. This review aims to represent the available reports on therapeutic potential and the underlying pharmacological and molecular mechanisms of AA. The review also also discusses the challenges and prospects on the pharmaceutical development of AA such as pharmacokinetics, physicochemical properties, analysis and structural modifications, and drug delivery. AA showed favorable pharmacokinetics and found bioavailable following oral or interaperitoneal administration. The studies demonstrate the polypharmacological properties, therapeutic potential and molecular mechanisms of AA in numerous diseases. Taken together the evidences from available studies, AA appears one of the important multitargeted polypharmacological agents of natural origin for further pharmaceutical development and clinical application. Provided the favorable pharmacokinetics, safety, and efficacy, AA can be a promising agent or adjuvant along with currently used modern medicines with a pharmacological basis of its use in therapeutics.

Asiatic acid suppresses neuroinflammation in BV2 microgliaviamodulation of the Sirt1/NF-κB signaling pathway

Asiatic acid promotes Sirt1 expression and inhibits NF-κB-induced microglia activation.