The major Boswellia serrata active 3-acetyl-11-keto-β-boswellic acid strengthens interleukin-1α upregulation of matrix metalloproteinase-9 via JNK MAP kinase activation

Acetyl-11-keto-β-boswellic acid restrains the progression of synovitis in osteoarthritis via the Nrf2/HO-1 pathway

Synovial inflammation plays a key role in osteoarthritis (OA) pathogenesis. Fibroblast-like synoviocytes (FLSs) represent a distinct cell subpopulation within the synovium, and their unique phenotypic alterations are considered significant contributors to inflammation and fibrotic responses. The underlying mechanism by which acetyl-11-keto-β-boswellic acid (AKBA) modulates FLS activation remains unclear. This study aims to assess the beneficial effects of AKBA through both in vitro and in vivo investigations. Network pharmacology evaluation is used to identify potential targets of AKBA in OA. We evaluate the effects of AKBA on FLSs activation in vitro and the regulatory role of AKBA on the Nrf2/HO-1 signaling pathway. ML385 (an Nrf2 inhibitor) is used to verify the binding of AKBA to its target in FLSs. We validate the in vivo efficacy of AKBA in alleviating OA using anterior cruciate ligament transection and destabilization of the medial meniscus (ACLT+DMM) in a rat model. Network pharmacological analysis reveals the potential effect of AKBA on OA. AKBA effectively attenuates lipopolysaccharide (LPS)-induced abnormal migration and invasion and the production of inflammatory mediators, matrix metalloproteinases (MMPs), and reactive oxygen species (ROS) in FLSs, contributing to the restoration of the synovial microenvironment. After treatment with ML385, the effect of AKBA on FLSs is reversed. In vivo studies demonstrate that AKBA mitigates synovial inflammation and fibrotic responses induced by ACLT+DMM in rats via activation of the Nrf2/HO-1 axis. AKBA exhibits theoretical potential for alleviating OA progression through the Nrf2/HO-1 pathway and represents a viable therapeutic candidate for this patient population.

β Boswellic Acid Blocks Articular Innate Immune Responses: An In Silico and In Vitro Approach to Traditional Medicine

Osteoarthritis (OA) is hallmarked as a silent progressive rheumatic disease of the whole joint. The accumulation of inflammatory and catabolic factors such as IL6, TNFα, and COX2 drives the OA pathophysiology into cartilage degradation, synovia inflammation, and bone destruction. There is no clinical available OA treatment. Although traditional ayurvedic medicine has been using Boswellia serrata extracts (BSE) as an antirheumatic treatment for a millennium, none of the BSE components have been clinically approved. Recently, β boswellic acid (BBA) has been shown to reduce in vivo OA-cartilage loss through an unknown mechanism. We used computational pharmacology, proteomics, transcriptomics, and metabolomics to present solid evidence of BBA therapeutic properties in mouse and primary human OA joint cells. Specifically, BBA binds to the innate immune receptor Toll-like Receptor 4 (TLR4) complex and inhibits both TLR4 and Interleukin 1 Receptor (IL1R) signaling in OA chondrocytes, osteoblasts, and synoviocytes. Moreover, BBA inhibition of TLR4/IL1R downregulated reactive oxygen species (ROS) synthesis and MAPK p38/NFκB, NLRP3, IFNαβ, TNF, and ECM-related pathways. Altogether, we present a solid bulk of evidence that BBA blocks OA innate immune responses and could be transferred into the clinic as an alimentary supplement or as a therapeutic tool after clinical trial evaluations.

α-Ionone protects against UVB-induced photoaging in epidermal keratinocytes

Objective

To evaluate whether α-ionone, an aromatic compound mainly found in raspberries, carrots, roasted almonds, fruits, and herbs, inhibits UVB-mediated photoaging and barrier dysfunction in a human epidermal keratinocyte cell line (HaCaT cells).

Methods

The anti-photoaging effect of α-ionone was evaluated by detecting the expression of barrier-related genes and matrix metalloproteinases (MMPs) in HaCaT cells. The levels of reactive oxygen species, oxidation product, antioxidant enzyme, and inflammatory factors were further analysed to underline the protective effect of α-ionone on epidermal photoaging.

Results

It was found that α-ionone attenuated UVB-induced barrier dysfunction by reversing keratin 1 and filaggrin in HaCaT cells. α-Ionone also reduced the protein amount of MMP-1 and mRNA expression of MMP-1 and MMP-3 in UVB-irradiated HaCaT cells, implying protective effects on extracellular matrix. Furthermore, HaCaT cells exposed to α-ionone showed significant decreases in interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α as compared to UVB-irradiated HaCaT cells. α-Ionone treatment significantly inhibited the UVB-induced intracellular reactive oxygen species increase and malondialdehyde accumulation. Therefore, the beneficial effects of α-ionone on inhibiting MMPs secretion and barrier damage may be related to attenuated inflammation and oxidative stress.

Conclusion

Our results highlight the protective effects of α-ionone on epidermal photoaging and promote its clinic application as a potential natural anti-photodamage agent in future.

Anti-inflammatory and anti-cancer activities of frankincense: Targets, treatments and toxicities

The oleogum resins of Boswellia species known as frankincense have been used for ages in traditional medicine in India, China and the Arabian world independent of its use for cultural and religious rituals in Europe. During the past two decades, scientific investigations provided mounting evidence for the therapeutic potential of frankincense. We conducted a systematic review on the anti-inflammatory and anti-cancer activities of Boswellia species and their chemical ingredients (e.g. 3-O-acetyl-11-keto-β boswellic acid, α- and β-boswellic acids, 11-keto-β-boswellic acid and other boswellic acids, lupeolic acids, incensole, cembrenes, triterpenediol, tirucallic acids, and olibanumols). Frankincense acts by multiple mechanisms, e.g. by the inhibition of leukotriene synthesis, of cyclooxygenase 1/2 and 5-lipoxygenase, of oxidative stress, and by regulation of immune cells from the innate and acquired immune systems. Furthermore, frankincense modulates signaling transduction responsible for cell cycle arrest and inhibition of proliferation, angiogenesis, invasion and metastasis. Clinical trials showed the efficacy of frankincense and its phytochemicals against osteoarthritis, multiple sclerosis, asthma, psoriasis and erythematous eczema, plaque-induced gingivitis and pain. Frankincense revealed beneficial effects towards brain tumor-related edema, but did not reduce glioma size. Even if there is no treatment effect on brain tumors itself, the management of glioma-associated edema may represent a desirable improvement. The therapeutic potential against other tumor types is still speculative. Experimental toxicology and clinical trials revealed only mild adverse side effects. More randomized clinical trials are required to estimate the full clinical potential of frankincense for cancer therapy.

Recombinant Prolidase Activates EGFR-Dependent Cell Growth in an Experimental Model of Inflammation in HaCaT Keratinocytes. Implication for Wound Healing

This study was conducted to investigate the proliferative capacity of recombinant human prolidase (rhPEPD) in a human model of inflammation induced by IL-1β in HaCaT keratinocytes. In this report, we provide evidence that IL-1β stimulates keratinocyte proliferation, and rhPEPD significantly augmented this process through activation of epidermal growth factor receptor (EGFR) and downstream signaling proteins as phosphorylated Akt, ERK1/2, and STAT3, which are implicated in keratinocyte migration, proliferation, and epithelialization during the wound healing process. Inhibition of PEPD-dependent EGFR signaling by gefitinib supported the finding. Moreover, during activation of EGFR in the presence of IL-1β the epithelial-to-mesenchymal transition (EMT) occurred via downregulation of E-cadherin and upregulation of N-cadherin. The phenomenon was accompanied by an increase in the activity of matrix metalloproteinase-9 (MMP-9), suggesting extracellular matrix (ECM) remodeling during the inflammatory process. MMP-9 activation may result from nuclear translocation of NF-κB through IKK-mediated IκBα degradation. Interestingly, some mutated variants of PEPD (rhPEPD-G448R, rhPEPD-231delY, and rhPEPD-E412K) evoked the ability to induce EGFR-dependent HaCaT cell proliferation. To the best of our knowledge, this is the first report on the cross-talk between PEPD and IL-1β in the process of keratinocyte proliferation. The data suggest that both enzymatically active and inactive rhPEPD may activate EGFR-dependent cell growth in an experimental model of inflammation in HaCaT keratinocytes and the knowledge may be useful for further approaches for therapy of wound healing disorders.

Acetyl-11-keto-beta-boswellic acid promotes sciatic nerve repair after injury: molecular mechanism

Previous studies showed that acetyl-11-keto-beta-boswellic acid (AKBA), the active ingredient in the natural Chinese medicine Boswellia, can stimulate sciatic nerve injury repair via promoting Schwann cell proliferation. However, the underlying molecular mechanism remains poorly understood. In this study, we performed genomic sequencing in a rat model of sciatic nerve crush injury after gastric AKBA administration for 30 days. We found that the phagosome pathway was related to AKBA treatment, and brain-derived neurotrophic factor expression in the neurotrophic factor signaling pathway was also highly up-regulated. We further investigated gene and protein expression changes in the phagosome pathway and neurotrophic factor signaling pathway. Myeloperoxidase expression in the phagosome pathway was markedly decreased, and brain-derived neurotrophic factor, nerve growth factor, and nerve growth factor receptor expression levels in the neurotrophic factor signaling pathway were greatly increased. Additionally, expression levels of the inflammatory factors CD68, interleukin-1β, pro-interleukin-1β, and tumor necrosis factor-α were also decreased. Myelin basic protein- and β3-tubulin-positive expression as well as the axon diameter-to-total nerve diameter ratio in the injured sciatic nerve were also increased. These findings suggest that, at the molecular level, AKBA can increase neurotrophic factor expression through inhibiting myeloperoxidase expression and reducing inflammatory reactions, which could promote myelin sheath and axon regeneration in the injured sciatic nerve.

BAHD acetyltransferase contributes to wound-induced biosynthesis of oleo-gum resin triterpenes in Boswellia

Triterpenes (30-carbon isoprene compounds) represent a large and highly diverse class of natural products that play various physiological functions in plants. The triterpene biosynthetic enzymes, particularly those catalyzing the late-stage regio-selective modifications are not well characterized. The bark of select Boswellia trees, e.g., B. serrata exudes specialized oleo-gum resin in response to wounding, which is enriched with boswellic acids (BAs), a unique class of C3α-epimeric pentacyclic triterpenes with medicinal properties. The bark possesses a network of resin secretory structures comprised of vertical and horizontal resin canals, and amount of BAs in bark increases considerably in response to wounding. To investigate BA biosynthetic enzymes, we conducted tissue-specific transcriptome profiling and identified a wound-responsive BAHD acetyltransferase (BsAT1) of B. serrata catalyzing the late-stage C3α-O-acetylation reactions in the BA biosynthetic pathway. BsAT1 catalyzed C3α-O-acetylation of αBA, βBA, and 11-keto-βBA in vitro and in planta assays to produce all the major C3α-O-acetyl-BAs (3-acetyl-αBA, 3-acetyl-βBA, and 3-acetyl-11-keto-βBA) found in B. serrata bark and oleo-gum resin. BsAT1 showed strict specificity for BA scaffold, whereas it did not acetylate the more common C3β-epimeric pentacyclic triterpenes. The analysis of steady-state kinetics using various BAs revealed distinct substrate affinity and catalytic efficiency. BsAT1 transcript expression coincides with increased levels of C3α-O-acetyl-BAs in bark in response to wounding, suggesting a role of BsAT1 in wound-induced biosynthesis of C3α-O-acetyl-BAs. Overall, the results provide new insights into the biosynthesis of principal chemical constituents of Boswellia oleo-gum resin.

Simultaneous determination of five bioactive components of XiaoJin Capsule in normal and mammary gland hyperplasia rat plasma using LC-MS/MS and its application to a pharmacokinetic study

XiaoJin Capsule (XJC) is a classic Traditional Chinese Medicine formula for clinical treatment of thyroid nodules, mammary gland hyperplasia and breast cancer. For the specification and rational application of XJC in the future, an accurate and specific LC-MS/MS method was developed and validated for quantitative determination of five components in rat plasma after oral administration of XJC. The collected plasma samples were extracted by protein precipitation with methanol-acetonitrile (1:3, v/v) mixture solvent and separated on a C₁₈ column using a gradient elution system. Mass spectrometry was performed on a triple quadrupole mass spectrometer, and samples were detected in positive ionization and multiple reactions monitoring mode. The method was properly validated in terms of linearity, precision, accuracy, recovery, matrix effect and stability. All calibration curves showed good linearity (r²  > 0.9910) over their concentration ranges. The intra- and inter-day precisions (RSD) were within 11.0%, and the LLOQ was 0.1, 0.2, 0.5, 7.5 and 7.5 ng/ml for aconine, songorine, neoline, 3-acetyl-11-keto-β-boswellic acid and 11-keto-β-boswellic acid, respectively. Extraction recovery, matrix effect and stability were satisfactory in rat plasma. This established method was successfully applied to a pharmacokinetics study of five compounds after oral administration of XJC to normal and mammary gland hyperplasia model rats.

Sargassum horneri (Turner) inhibit urban particulate matter-induced inflammation in MH-S lung macrophages via blocking TLRs mediated NF-κB and MAPK activation

ETHNOPHARMACOLOGICAL RELEVANCE

Sargassum horneri is a nutrient rich edible brown seaweed with numerous biological properties found in shallow coastal areas of Korean peninsula. S. horneri traditionally used as a medicinal ingredient to treat several disease conditions such as hyperlipidemia, hypertension, heart disease, and inflammatory diseases (furuncle). However, to utilize S. horneri as an active ingredient for functional foods and human health applications requires to conform the bioactive properties and underlying mechanisms of those activities.

AIM OF THE STUDY

Here, we investigated anti-inflammatory mechanisms of commercial grade 70% ethanol extract separated from S. horneri (SHE) on inflammatory response in particulate matter (PM)-induced MH-S lung macrophages; where PM in breathable air one of the major health concern in Korea.

MATERIALS AND METHODS

We compared the anti-inflammatory effects of SHE on the activity of toll-like receptors (TLR) activation, NF-κB, MAPKs, and pro-inflammatory cytokine secretion in MH-S lung macrophages exposed to PM as a lung inflammation model.

RESULTS

According to the results, PM-stimulation, induced the levels of NO, PGE2, TNF-α, IL-1β, IL-6, iNOS, and COX2 (P < 0.05) in MH-S macrophages. In addition, phosphorylation levels of NF-κB and MAPKs were also increased with the PM stimulation through the upregulated expression of TLR. However, SHE treatment significantly repressed the secretions of inflammatory cytokines and reduced protein expression such as PGE2, TNF-α, IL-6, IL-1β, NF-κB, and MAPKs from PM-activated macrophages. Specifically, SHE inhibited the upregulated mRNA expression levels of TLR2, TLR3, TLR4, and TLR7 in PM-induced MH-S cells; known biomarkers of downstream activation of NF-κB and MAPKs.

CONCLUSION

These results suggested that SHE is a potential inhibitor of PM-induced inflammatory responses in lung macrophages. Thus, SHE could inhibit PM-induced chronic inflammation in lungs via blocking TLR/NF-κB/MAPKs signal transduction. Therefore, it was concluded that SHE may be a useful substance to develop as functional product to reduce inflammation against PM-induced inflammation.

Protective Effect and Mechanism of Boswellic Acid and Myrrha Sesquiterpenes with Different Proportions of Compatibility on Neuroinflammation by LPS-Induced BV2 Cells Combined with Network Pharmacology

Frankincense and myrrha (FM), commonly used as a classical herbal pair, have a wide range of clinical applications and definite anti-inflammatory activity. However, anti-neuroinflammation effects and mechanisms are not clear. In this study, we adopted a lipopolysaccharide (LPS)-induced microglial (BV2) cell model and a network pharmacology method to reveal the anti-neuroinflammatory effects and mechanisms of boswellic acid (BA) and myrrha sesquiterpenes (MS) with different proportions of compatibility. The data showed that the different ratios of BA and MS had different degrees of inhibition of interleukin-1β (IL-1β), IL-6, and inducible nitric oxide synthase (iNOS) mRNA expression, down-regulated the phosphor-nuclear factor kappa B/nuclear factor kappa B (p-NF-ҡB)/(NF-ҡB), phosphorylated protein kinase b/protein kinase b (p-AKT/AKT), and Toll-like receptor 4 (TLR4) protein expression levels, and increased phospho-PI3 kinase (p-PI3K) protein expression levels. When the ratios of BA and MS were 10:1, 5:1, and 20:1, better effective efficacy was exhibited. According to the correlation analysis between the effect index and bioactive substances, it was suggested that 2-methoxy-5-acetoxy -fruranogermacr-1(10)-en-6-one (Compound 1), 3α-acetyloxylanosta-8,24-dien-21-oic acid (Compound 2), 11-keto-boswellic acid (Compound 3), and 3-acetyl-11-keto-β -boswellic acid (Compound 4) made important contributions to the treatment of neuroinflammation. Furthermore, based on the network pharmacological analysis, it was found that these four active compounds acted on 31 targets related to neuroinflammation and were involved in 32 signaling pathways which mainly related to the immune system, cardiovascular system, and nervous system, suggesting that BA and MS could be used to treat neuroinflammation.

Induction of developmental toxicity and cardiotoxicity in zebrafish embryos/larvae by acetyl-11-keto-β-boswellic acid (AKBA) through oxidative stress

Acetyl-11-keto-β-boswellic acid (AKBA), a triterpenoid from Boswellia serrate, is regarded as an angiogenesis inhibitor. However, its toxicity is unknown. The aim of this study was to examine its developmental toxicity and cardiotoxicity. A developmental toxicity assay in zebrafish embryos/larvae from 4 to 96 hours post-fertilization (hpf) was performed and a cardiotoxicity assay was designed from 48 to 72 hpf. Markers of oxidative stress and related genes were selected to access the possible mechanisms. According to the results, AKBA induced pericardium edema, yolk-sac edema, abnormal melanin, spinal curvature, hatching inhibition and shortened body length. Further, increased SV-BA distance, reduced heart rate, increased pericardium area and decreased blood flow velocity were detected in AKBA treated groups. The inhibition of cardiac progenitor gene expression, such as Nkx2.5 and Gata4, may be related to cardiotoxicity. The activities of antioxidant enzymes were decreased and the content of MDA was increased. In addition, AKBA treatment decreased the expression levels of Mn-Sod, Cat, and Gpx. These results suggested that AKBA induced developmental toxicity and cardiotoxicity through oxidative stress. As far as we know, this is the first report on the toxicity of AKBA. It reminds us to pay attention to developmental toxicity and cardiotoxicity of AKBA.

Protein Targets of Frankincense: A Reverse Docking Analysis of Terpenoids from Boswellia Oleo-Gum Resins

Background: Frankincense, the oleo-gum resin of Boswellia trees, has been used in traditional medicine since ancient times. Frankincense has been used to treat wounds and skin infections, inflammatory diseases, dementia, and various other conditions. However, in many cases, the biomolecular targets for frankincense components are not well established. Methods: In this work, we have carried out a reverse docking study of Boswellia diterpenoids and triterpenoids with a library of 16034 potential druggable target proteins. Results:Boswellia diterpenoids showed selective docking to acetylcholinesterase, several bacterial target proteins, and HIV-1 reverse transcriptase. Boswellia triterpenoids targeted the cancer-relevant proteins (poly(ADP-ribose) polymerase-1, tankyrase, and folate receptor β), inflammation-relevant proteins (phospholipase A2, epoxide hydrolase, and fibroblast collagenase), and the diabetes target 11β-hydroxysteroid dehydrogenase. Conclusions: The preferential docking of Boswellia terpenoids is consistent with the traditional uses and the established biological activities of frankincense.

Anti-Inflammatory Activity of Boswellia serrata Extracts: An In Vitro Study on Porcine Aortic Endothelial Cells

This study is aimed at investigating the cytotoxicity, anti-inflammatory, and angiogenic activities of two Boswellia serrata extracts on primary culture of porcine aortic endothelial cells (pAECs). Chemical characterization of a dry extract (extract A) and a hydroenzymatic extract (extract G) of B. serrata was performed by HPLC using pure boswellic acids (BAs) as standard. In cultured pAECs, extract G improved cell viability, following LPS challenge, in a dose-dependent manner and did not show any toxic effect. On the other hand, extract A was toxic at higher doses and restored pAEC viability after LPS challenge only at lower doses. Pure BAs, used at the same concentrations as those determined in the phytoextracts, did not contrast LPS-induced cytotoxicity. Extract A showed proangiogenic properties at the lowest dose, and the same result was observed using pure AKBA at the corresponding concentration, whereas extract G did not show any effect on the migration capacity of endothelial cells. In conclusion, an anti-inflammatory activity of B. serrata extracts on endothelial cells was reported, though cytotoxicity or proliferative stimulation can occur instead of a protective effect, depending on the dose and the formulation.