High-performance centrifugal partition chromatography (HPCPC) for efficient isolation of diphlorethohydroxycarmalol (DPHC) and screening of its antioxidant activity in a zebrafish model

Multifunctional Microneedle Patch with Diphlorethohydroxycarmalol for Potential Wound Dressing

BACKGROUND

Treatment of skin wounds with diverse pathological characteristics presents significant challenges due to the limited specific and efficacy of current wound healing approaches. Microneedle (MN) patches incorporating bioactive and stimulus materials have emerged as a promising strategy to overcome these limitations and integrating bioactive materials with anti-bacterial and anti-inflammatory properties for advanced wound dressing.

METHODS

We isolated diphlorethohydroxycarmalol (DPHC) from Ishige okamurae and assessed its anti-inflammatory and anti-bacterial effects on macrophages and its antibacterial activity against Cutibacterium acnes. Subsequently, we fabricated polylactic acid (PLA) MN patches containing DPHC at various concentrations (0-0.3%) (PDPHC MN patches) and evaluated their mechanical properties and biological effects using in vitro and in vivo models.

RESUTLS

Our findings demonstrated that DPHC effectively inhibited nitric oxide production in macrophages and exhibited rapid bactericidal activity against C. acnes. The PDPHC MN patches displayed potent antibacterial effects without cytotoxicity. Moreover, in 2,4-Dinitrochlorobenzene-stimulated mouse model, the PDPHC MN patches significantly suppressed inflammatory response and cutaneous lichenification.

CONCLUSION

The results suggest that the PDPHC MN patches holds promise as a multifunctional wound dressing for skin tissue engineering, offering antibacterial properties and anti-inflammatory properties to promote wound healing process.

Effect of Ishophloroglucin A Isolated from Ishige okamurae on In Vitro Osteoclastogenesis and Osteoblastogenesis

The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is essential for the bone remodeling process. This study aimed to investigate the effect of Ishophloroglucin A (IPA) isolated from Ishige okamurae on the function of osteoclasts and osteoblasts in vitro. First, we demonstrated the effect of IPA on osteoclastogenesis in receptor activator of nuclear factor κB ligand (RANKL)-induced RAW 264.7 cells. IPA inhibited the tartrate-resistant acid phosphatase (TRAP) activity and osteoclast differentiation in RANKL-induced RAW 264.7 cells. Moreover, it inhibited the RANKL-induced osteoclast-related factors, such as TRAP, matrix metalloproteinase-9 (MMP-9), and calcitonin receptor (CTR), and transcription factors, such as nuclear factor of activated T cells 1 (NFATc1) and c-Fos. IPA significantly suppressed RANKL-activated extracellular signal-regulated kinase (ERK), and NF-κB in RAW 264.7 cells. Our data indicated that the ERK and NF-κB pathways were associated with the osteoclastogenesis inhibitory activity of IPA. Next, we demonstrated the effect of IPA on osteoblastogenesis in MG-63 cells. IPA significantly promoted alkaline phosphatase (ALP) activity in MG-63 cells, along with the osteoblast differentiation-related markers bone morphogenetic protein 2 (BMP2), type 1 collage (COL1), p-Smad1/5/8, and Runx2, by activating the MAPK signaling pathways. Taken together, the study indicated that IPA could be effective in treating bone diseases, such as osteoporosis.

Novel compounds discovery approach based on UPLC-QTOF-MS/MS chemical profile reveals birch bark extract anti-inflammatory, -oxidative, and -proliferative effects

ETHNOPHARMACOLOGICAL RELEVANCE

Betula pendula subsp. Mandshurica (Regel) Ashburner & McAll. Cortex (birch bark) is a globally traditional medicine for treating multiple inflammatory diseases. Its records are included in the Compendium of Materia Medica and other ancient medical literatures. However, uncovering its chemical profile and exploring novel biologically active compounds from birch bark remains a significant challenge.

AIM OF THE STUDY

To uncover the anti-inflammatory, -oxidative, and -proliferative mechanisms and potentially effective compounds of birch bark extract by combing chemical profiling, isolation, identification, together with in vivo, in vitro, and silico evaluation.

MATERIALS AND METHODS

Ultra-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) was used to obtain the chemical profile of birch bark extract. The new compounds were obtained via column chromatography and analyzed using X-ray diffraction and electronic circular dichroism for absolute configuration confirmation. The zebrafish caudal fin inflammation-induced model, qPCR, and Western blot analysis were used to explore the effects and underlying mechanisms of birch bark extract. In vitro cytotoxicity assays and kinases screening conducted to gain preliminary insight into the anti-proliferative effects of birch bark extract and its isolated compounds. In addition, in-silico molecular docking was performed to investigate the putative mechanism.

RESULTS

UPLC-QTOF-MS/MS chemical profiles revealed 105 compounds in birch bark extract, with 80 of these were first reported in B. pendula subsp. Mandshurica cortex. We selected five compounds speculated as novel and isolated three ones (one triterpenoid derivative and two lupine series triterpenoids) for further analysis. Birch bark extract exerted antioxidative and anti-inflammatory effects on zebrafish, as shown by the downregulated reactive oxygen species levels and COX-2α, IL-1β, and TNF-α expression, which occurred through NF-ĸB signaling pathway activation. The in vitro anti-proliferative effects of birch bark extract and compound 44 were also unveiled. Moreover, the putative anti-tumor mechanism of compound 44 was revealed using kinase screening and in-silico molecular docking.

CONCLUSIONS

This study provided a predictable chemical profile and demonstrated the pharmacological effects of birch bark extract, elucidated the mechanism of this traditional Chinese medicine and suggested it as a novel anti-cancer candidate.

Polyphenolic Compounds Isolated from Marine Algae Attenuate the Replication of SARS-CoV-2 in the Host Cell through a Multi-Target Approach of 3CLpro and PLpro

A global health concern has emerged as a response to the recent SARS-CoV-2 pandemic. The identification and inhibition of drug targets of SARS-CoV-2 is a decisive obligation of scientists. In addition to the cell entry mechanism, SARS-CoV-2 expresses a complicated replication mechanism that provides excellent drug targets. Papain-like protease (PL^pro) and 3-chymotrypsin-like protease (3CL^pro) play a vital role in polyprotein processing, producing functional non-structural proteins essential for viral replication and survival in the host cell. Moreover, PL^pro is employed by SARS-CoV-2 for reversing host immune responses. Therefore, if some particular compound has the potential to interfere with the proteolytic activities of 3CL^pro and PL^pro of SARS-CoV-2, it may be effective as a treatment or prophylaxis for COVID-19, reducing viral load, and reinstating innate immune responses. Thus, the present study aims to inhibit SARS-CoV-2 through 3CL^pro and PL^pro using marine natural products isolated from marine algae that contain numerous beneficial biological activities. Molecular docking analysis was utilized in the present study for the initial screening of selected natural products depending on their 3CL^pro and PL^pro structures. Based on this approach, Ishophloroglucin A (IPA), Dieckol, Eckmaxol, and Diphlorethohydroxycarmalol (DPHC) were isolated and used to perform in vitro evaluations. IPA presented remarkable inhibitory activity against interesting drug targets. Moreover, Dieckol, Eckmaxol, and DPHC also expressed significant potential as inhibitors. Finally, the results of the present study confirm the potential of IPA, Dieckol, Eckmaxol, and DPHC as inhibitors of SARS-CoV-2. To the best of our knowledge, this is the first study that assesses the use of marine natural products as a multifactorial approach against 3CL^pro and PL^pro of SARS-CoV-2.

Antifibrosis Efficacy of Apo-9-Fucoxanthinone-Contained Sargassum horneri Ethanol Extract on Nasal Polyp: An In Vitro and Ex Vivo Organ Culture Assay

Sargassum horneri is a seaweed species with diverse bioactivities. However, its antifibrotic effects during nasal polyp (NP) formation are not clearly understood. Therefore, we investigated the inhibitory effect of S. horneri on fibrosis progression in NP-derived fibroblasts (NPDFs) and NP tissues ex vivo. NPDFs were stimulated with TGF-β1 in the presence or absence of S. horneri ethanol extract (SHE). The extracellular matrix (ECM) protein production levels, myofibroblast differentiation (α-smooth muscle actin, α-SMA), and phosphorylation of Smad 2/3 and -ERK in TGF-β1-stimulated NPDFs were investigated using western blotting. Further, the contractile activity of SHE was assessed by performing a collagen gel contraction assay. The expression levels of collagen-1, fibronectin, and α-SMA were investigated in NP organ cultures treated with SHE. TGF-β1 stimulated ECM protein expression, myofibroblast differentiation, and collagen contractile activity while these were attenuated by pretreatment with SHE. We also found antifibrotic effect of SHE on ex vivo NP tissues. The antifibrotic effects of SHE were modulated through the attenuation of Smad 2/3 and ERK signaling pathways in TGF-β1-stimulated NPDFs. In conclusion, SHE inhibited ECM protein accumulation and myofibroblast differentiation during NP remodeling. Thus, SHE may be helpful as a treatment for NP recurrence after endoscopic sinus surgery.

Isolation and Characterization of Efficient Active Compounds Using High-Performance Centrifugal Partition Chromatography (CPC) from Anti-Inflammatory Activity Fraction of Ecklonia maxima in South Africa

Ecklonia maxima is a brown seaweed, which is abundantly distributed in South Africa. This study investigated an efficient approach using high-performance centrifugal partition chromatography (HPCPC), which has been successfully developed for the isolation and purification of phlorotannins, eckmaxol, and dieckol from the ethyl acetate fraction of E. maxima (EEM). We evaluated EEM for its inhibitory effect against lipopolysaccharide (LPS)-induced inflammatory responses in zebrafish embryos. The separation of eckmaxol and dieckol from samples of EEM using HPCPC was found to be of high purity and yield under an optimal solvent system composed of n-hexane:ethyl acetate:methanol:water (2:7:3:7, v/v/v/v). To evaluate the anti-inflammatory efficacy of EEM containing active compounds, zebrafish embryos exposed to LPS were compared with and without EEM treatment for nitric oxide (NO) production, reactive oxygen species (ROS) generation, and cell death two days after fertilization. These evaluations indicate that EEM alleviated inflammation by inhibiting cell death, ROS, and NO generation induced by LPS treatment. According to these results, eckmaxol and dieckol isolated from brown seaweed E. maxima could be considered effective anti-inflammatory agents as pharmaceutical and functional food ingredients.

Ishige okamurae Ameliorates Methylglyoxal-Induced Nephrotoxicity via Reducing Oxidative Stress, RAGE Protein Expression, and Modulating MAPK, Nrf2/ARE Signaling Pathway in Mouse Glomerular Mesangial Cells

Advanced glycation end-products (AGEs) such as methylglyoxal (MGO) play a vital role in the pathogenesis of nephropathy, a diabetic complication. In the present study, we evaluated the anti-glycation and renal protective properties of Ishige okamurae extract (IOE) against AGE-induced oxidative stress. HPLC analysis confirmed that bioactive phlorotannins such as diphlorethohydroxycarmalol and ishophloroglucin A are predominantly present in IOE. IOE showed strong anti-glycation activities via inhibition of AGE formation, inhibition of AGE-protein cross-linking, and breaking of AGE-protein cross-links. In addition, in vitro studies using mesangial cells demonstrated that IOE effectively suppressed intracellular reactive oxygen species production, intracellular MGO accumulation, and apoptotic cell death by MGO-induced oxidative stress, in addition to regulating the expression of proteins involved in the receptor for AGEs and nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response elements (ARE) signaling pathways. Therefore, IOE can serve as a natural therapeutic agent for the management of AGE-related nephropathy.

Diphlorethohydroxycarmalol (DPHC) Isolated from the Brown Alga Ishige okamurae Acts on Inflammatory Myopathy as an Inhibitory Agent of TNF-α

Inflammation affects various organs of the human body, including skeletal muscle. Phlorotannins are natural biologically active substances found in marine brown algae and exhibit anti-inflammatory activities. In this study, we focused on the effects of phlorotannins on anti-inflammatory activity and skeletal muscle cell proliferation activity to identify the protective effects on the inflammatory myopathy. First, the five species of marine brown algal extracts dramatically inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells without toxicity at all the concentrations tested. Moreover, the extracts collected from Ishige okamurae (I. okamurae) significantly increased cell proliferation of C2C12 myoblasts compared to the non-treated cells with non-toxicity. In addition, as a result of finding a potential tumor necrosis factor (TNF)-α inhibitor that regulates the signaling pathway of muscle degradation in I. okamurae-derived natural bioactive compounds, Diphlorethohydroxycarmalol (DPHC) is favorably docked to the TNF-α with the lowest binding energy and docking interaction energy value. Moreover, DPHC down-regulated the mRNA expression level of pro-inflammatory cytokines and suppressed the muscle RING-finger protein (MuRF)-1 and Muscle Atrophy F-box (MAFbx)/Atrgoin-1, which are the key protein muscle atrophy via nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPKs) signaling pathways in TNF-α-stimulated C2C12 myotubes. Therefore, it is expected that DPHC isolated from IO would be developed as a TNF-α inhibitor against inflammatory myopathy.