Synergistic effect of zinc oxide-cinnamic acid nanoparticles for wound healing management: in vitro and zebrafish model studies.

Wound infections resulting from pathogen infiltration pose a significant challenge in healthcare settings and everyday life. When the skin barrier is compromised due to injuries, surgeries, or chronic conditions, pathogens such as bacteria, fungi, and viruses can enter the body, leading to infections. These infections can range from mild to severe, causing discomfort, delayed healing, and, in some cases, life-threatening complications. Zinc oxide (ZnO) nanoparticles (NPs) have been widely recognized for their antimicrobial and wound healing properties, while cinnamic acid is known for its antioxidant and anti-inflammatory activities. Based on these properties, the combination of ZnO NPs with cinnamic acid (CA) was hypothesized to have enhanced efficacy in addressing wound infections and promoting healing. This study aimed to synthesize and evaluate the potential of ZnO-CN NPs as a multifunctional agent for wound treatment. ZnO-CN NPs were synthesized and characterized using key techniques to confirm their structure and composition. The antioxidant and anti-inflammatory potential of ZnO-CN NPs was evaluated through standard in vitro assays, demonstrating strong free radical scavenging and inhibition of protein denaturation. The antimicrobial activity of the nanoparticles was tested against common wound pathogens, revealing effective inhibition at a minimal concentration. A zebrafish wound healing model was employed to assess both the safety and therapeutic efficacy of the nanoparticles, showing no toxicity at tested concentrations and facilitating faster wound closure. Additionally, pro-inflammatory cytokine gene expression was analyzed to understand the role of ZnO-CN NPs in wound healing mechanisms. In conclusion, ZnO-CN NPs demonstrate potent antioxidant, anti-inflammatory, and antimicrobial properties, making them promising candidates for wound treatment. Given their multifunctional properties and non-toxicity at tested concentrations, ZnO-CN NPs hold significant potential as a therapeutic agent for clinical wound management, warranting further investigation in human models.

Effects of dietary powdered Ficus deltoidea on the growth and health performance of African catfish, Clarias gariepinus production.

Intensive aquaculture causes a decline in the health status of fish, resulting in an increased disease incidence. To counteract this, feed additives have been utilized to improve the growth performance and health of aquaculture species. This work specifically investigates the impact of powdered Ficus deltoidea (FD) on various parameters related to growth, blood parameters, liver and intestine morphology, body proximate analysis, digestive enzymes, antioxidant capacity, and disease resistance to motile Aeromonad Septicemia (MAS) caused by Aeromonas hydrophila infection in African catfish, Clarias gariepinus. Four formulated diets were prepared: T1 (0% FD), T2 (0.5% FD), T3 (0.75% FD), and T4 (1% FD). After 8 weeks, the African catfish's growth performance fed with the T2 diet exhibited a substantial improvement (p < 0.05), along with a remarkably lower (p < 0.05) feed conversion ratio (FCR) when compared to the other treatment groups. Blood parameter analysis revealed notably higher (p < 0.05) levels of white blood cell (WBC), lymphocytosis (LYM), hemoglobin (HGB), albumin (ALB), globulin (GLOB), as well as total protein (TP) in the T2 diet group. While all treatment groups displayed normal intestinal morphology, liver deterioration was observed in groups supplemented with higher FD. The T2 diet group recorded the highest villus length, width, and crypt depth. Protease and lipase levels were also notably improved in the T2 diet group compared to other treatment groups. Additionally, catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were remarkably elevated in all FD diet groups than in the control group. The expression of immune-related genes, including transforming growth factor beta 1, heat shock protein 90, nuclear factor kappa-B gene, and lysozyme G, was upregulated in all treatments. Overall, the results of this study indicate that incorporating dietary FD at 0.5% concentration in the diet of African catfish may enhance their productivity in intensive farming.

In silico analysis of potential inhibitors for breast cancer targeting 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) catalyses.

Breast cancer (BC) is still one of the major issues in world health, especially for women, which necessitates innovative therapeutic strategies. In this study, we investigated the efficacy of retinoic acid derivatives as inhibitors of 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1), which plays a crucial role in the biosynthesis and metabolism of oestrogen and thereby influences the progression of BC and, the main objective of this investigation is to identify the possible drug candidate against BC through computational drug design approach including PASS prediction, molecular docking, ADMET profiling, molecular dynamics simulations (MD) and density functional theory (DFT) calculations. The result has reported that total eight derivatives with high binding affinity and promising pharmacokinetic properties among 115 derivatives. In particular, ligands 04 and 07 exhibited a higher binding affinity with values of -9.9 kcal/mol and -9.1 kcal/mol, respectively, than the standard drug epirubicin hydrochloride, which had a binding affinity of -8.2 kcal/mol. The stability of the ligand-protein complexes was further confirmed by MD simulations over a 100-ns trajectory, which included assessments of hydrogen bonds, root mean square deviation (RMSD), root mean square Fluctuation (RMSF), dynamic cross-correlation matric (DCCM) and principal component analysis. The study emphasizes the need for experimental validation to confirm the therapeutic utility of these compounds. This study enhances the computational search for new BC drugs and establishes a solid foundation for subsequent experimental and clinical research.

Identification of Helicobacter pylori-carcinogenic TNF-alpha-inducing protein inhibitors via daidzein derivatives through computational approaches.

Gastric cancer is considered a class 1 carcinogen that is closely linked to infection with Helicobacter pylori (H. pylori), which affects over 1 million people each year. However, the major challenge to fight against H. pylori and its associated gastric cancer due to drug resistance. This research gap had led our research team to investigate a potential drug candidate targeting the Helicobacter pylori-carcinogenic TNF-alpha-inducing protein. In this study, a total of 45 daidzein derivatives were investigated and the best 10 molecules were comprehensively investigated using in silico approaches for drug development, namely pass prediction, quantum calculations, molecular docking, molecular dynamics simulations, Lipinski rule evaluation, and prediction of pharmacokinetics. The molecular docking study was performed to evaluate the binding affinity between the target protein and the ligands. In addition, the stability of ligand-protein complexes was investigated by molecular dynamics simulations. Various parameters were analysed, including root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), radius of gyration (Rg), hydrogen bond analysis, principal component analysis (PCA) and dynamic cross-correlation matrix (DCCM). The results has confirmed that the ligand-protein complex CID: 129661094 (07) and 129664277 (08) formed stable interactions with the target protein. It was also found that CID: 129661094 (07) has greater hydrogen bond occupancy and stability, while the ligand-protein complex CID 129664277 (08) has greater conformational flexibility. Principal component analysis revealed that the ligand-protein complex CID: 129661094 (07) is more compact and stable. Hydrogen bond analysis revealed favourable interactions with the reported amino acid residues. Overall, this study suggests that daidzein derivatives in particular show promise as potential inhibitors of H. pylori.

Asiatic acid rescues intestinal tissue by suppressing molecular, biochemical, and histopathological changes associated with the development of ulcerative colitis.

Asiatic acid (AA) is a polyphenolic compound with potent antioxidative and anti-inflammatory activities that make it a potential choice to attenuate inflammation and oxidative insults associated with ulcerative colitis (UC). Hence, the present study aimed to evaluate if AA can attenuate molecular, biochemical, and histological alterations in the acetic acid-induced UC model in rats. To perform the study, five groups were applied, including the control, acetic acid-induced UC, UC-treated with 40 mg/kg aminosalicylate (5-ASA), UC-treated with 20 mg/kg AA, and UC-treated with 40 mg/kg AA. Levels of different markers of inflammation, oxidative stress, and apoptosis were studied along with histological approaches. The induction of UC increased the levels of lipid peroxidation (LPO) and nitric oxide (NO). Additionally, the nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant proteins [catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx), and glutathione reductase (GR)] were down-regulated in the colon tissue. Moreover, the inflammatory mediators [myeloperoxidase (MPO), monocyte chemotactic protein 1 (MCP1), prostaglandin E2 (PGE2), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß)] were increased in the colon tissue after the induction of UC. Notably, an apoptotic response was developed, as demonstrated by the increased caspase-3 and Bax and decreased Bcl2. Interestingly, AA administration at both doses lessened the molecular, biochemical, and histopathological changes following the induction in the colon tissue of UC. In conclusion, AA could improve the antioxidative status and attenuate the inflammatory and apoptotic challenges associated with UC.

Multifunctional curcumin mediated zinc oxide nanoparticle enhancing biofilm inhibition and targeting apoptotic specific pathway in oral squamous carcinoma cells.

BACKGROUND: Oral health remains a significant global concern with the prevalence of oral pathogens and the increasing incidence of oral cancer posing formidable challenges. Additionally, the emergence of antibiotic-resistant strains has complicated treatment strategies, emphasizing the urgent need for alternative therapeutic approaches. Recent research has explored the application of plant compounds mediated with nanotechnology in oral health, focusing on the antimicrobial and anticancer properties. METHODS: In this study, curcumin (Cu)-mediated zinc oxide nanoparticles (ZnO NPs) were synthesized and characterized using SEM, EDAX, UV spectroscopy, FTIR, and XRD to validate their composition and structural features. The antioxidant and antimicrobial activity of ZnO-CU NPs was investigated through DPPH, ABTS, and zone of inhibition assays. Apoptotic assays and gene expression analysis were performed in KB oral squamous carcinoma cells to identify their anticancer activity. RESULTS: ZnO-CU NPs showcased formidable antioxidant prowess in both DPPH and ABTS assays, signifying their potential as robust scavengers of free radicals. The determined minimal inhibitory concentration of 40 µg/mL against dental pathogens underscored the compelling antimicrobial attributes of ZnO-CU NPs. Furthermore, the interaction analysis revealed the superior binding affinity and intricate amino acid interactions of ZnO-CU NPs with receptors on dental pathogens. Moreover, in the realm of anticancer activity, ZnO-CU NPs exhibited a dose-dependent response against Human Oral Epidermal Carcinoma KB cells at concentrations of 10 µg/mL, 20 µg/mL, 40 µg/mL, and 80 µg/mL. Unraveling the intricate mechanism of apoptotic activity, ZnO-CU NPs orchestrated the upregulation of pivotal genes, including BCL2, BAX, and P53, within the KB cells. CONCLUSIONS: This multifaceted approach, addressing both antimicrobial and anticancer activity, positions ZnO-CU NPs as a compelling avenue for advancing oral health, offering a comprehensive strategy for tackling both oral infections and cancer.

Attenuation of Streptozotocin-Induced Diabetic Neuropathic Allodynia by Flavone Derivative Through Modulation of GABA-ergic Mechanisms and Endogenous Biomarkers.

Diabetic neuropathic pain is one of the most devasting disorders of peripheral nervous system. The loss of GABAergic inhibition is associated with the development of painful diabetic neuropathy. The current study evaluated the potential of 3-Hydroxy-2-methoxy-6-methyl flavone (3-OH-2'MeO6MF), to ameliorate peripheral neuropathic pain using an STZ-induced hyperglycemia rat model. The pain threshold was assessed by tail flick, cold, mechanical allodynia, and formalin test on days 0, 14, 21, and 28 after STZ administration accompanied by evaluation of several biochemical parameters. Administration of 3-OH-2'-MeO6MF (1,10, 30, and 100 mg/kg, i.p) significantly enhanced the tail withdrawal threshold in tail-flick and tail cold allodynia tests. 3-OH-2'-MeO6MF also increased the paw withdrawal threshold in mechanical allodynia and decreased paw licking time in the formalin test. Additionally, 3-OH-2'-MeO6MF also attenuated the increase in concentrations of myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS), nitrite, TNF-α, and IL 6 along with increases in glutathione (GSH). Pretreatment of pentylenetetrazole (PTZ) (40 mg/kg, i.p.) abolished the antinociceptive effect of 3-OH-2'-MeO6MF in mechanical allodynia. Besides, the STZ-induced alterations in the GABA concentration and GABA transaminase activity attenuated by 3-OH-2'-MeO6MF treatment suggest GABAergic mechanisms. Molecular docking also authenticates the involvement of α2ß2γ2L GABA-A receptors and GABA-T enzyme in the antinociceptive activities of 3-OH-2'-MeO6MF.

Quantum biochemical analysis of the binding interactions between a potential inhibitory drug and the Ebola viral glycoprotein.

Ebola virus disease (EVD) causes outbreaks and epidemics in West Africa that persist until today. The envelope glycoprotein of Ebola virus (GP) consists of two subunits, GP1 and GP2, and plays a key role in anchoring or fusing the virus to the host cell in its active form on the virion surface. Toremifene (TOR) is a ligand that mainly acts as an estrogen receptor antagonist; however, a recent study showed a strong and efficient interaction with GP. In this context, we aimed to evaluate the energetic affinity features involved in the interaction between GP and toremifene by computer simulation techniques using the Molecular Fractionation Method with Conjugate Caps (MFCC) scheme and quantum-mechanical (QM) calculations, as well as missense mutations to assess protein stability. We identified ASP522, GLU100, TYR517, THR519, LEU186, LEU515 as the most attractive residues in the EBOV glycoprotein structure that form the binding pocket. We divided toremifene into three regions and evaluated that region i was more important than region iii and region ii for the formation of the TOR-GP1/GP2 complex, which might control the molecular remodeling process of TOR. The mutations that caused more destabilization were ARG134, LEU515, TYR517 and ARG559, while those that caused stabilization were GLU523 and ASP522. TYR517 is a critical residue for the binding of TOR, and is highly conserved among EBOV species. Our results may help to elucidate the mechanism of drug action on the GP protein of the Ebola virus and subsequently develop new pharmacological approaches against EVD.Communicated by Ramaswamy H. Sarma.

Cardiovascular diseases crossroads: cGAS-STING signaling and disease progression.

It is now widely accepted that inflammation is critical in cardiovascular diseases (CVD). Here, studies are being conducted on how cyclic GMP-AMP synthase (cGAS), a component of innate immunity's DNA-sensing machinery, communicates with the STING receptor, which is involved in activating the immune system's antiviral response. Significantly, a growing body of research in recent years highlights the strong activation of the cGAS-STING signalling pathways in several cardiovascular diseases, such as myocardial infarction, heart failure, and myocarditis. This developing collection of research emphasises these pathways' crucial role in initiating and advancing cardiovascular disease. In this extensive narrative, we explore the role of the cGAS-STING pathway in the development of CVD. We elaborate on the basic mechanisms involved in the onset and progression of CVD. This review explores the most recent developments in the recognition and characterization of cGAS-STING pathway. Additionally, it considers the field's future prospects while examining how cGAS-STING pathway might be altered and its clinical applications for cardiovascular diseases.

Antimicrobial Efficacy of Allium cepa and Zingiber officinale Against the Milk-Borne Pathogen Listeria monocytogenes.

Listeria monocytogenes is an important food-borne pathogen that causes listeriosis and has a high case fatality rate despite its low incidence. Medicinal plants and their secondary metabolites have been identified as potential antibacterial substances, serving as replacements for synthetic chemical compounds. The present studies emphasize two significant medicinal plants, Allium cepa and Zingiber officinale, and their efficacy against L. monocytogenes. Firstly, a bacterial isolate was obtained from milk and identified through morphology and biochemical reactions. The species of the isolate were further confirmed through 16S rRNA analysis. Furthermore, polar solvents such as methanol and ethanol were used for the extraction of secondary metabolites from A. cepa and Z. officinale. Crude phytochemical components were identified using phytochemical tests, FTIR, and GC-MS. Moreover, the antibacterial activity of the crude extract and its various concentrations were tested against L. monocytogenes. Among all, A. cepa in methanolic extracts showed significant inhibitory activity. Since, the A. cepa for methanolic crude extract was used to perform autography to assess its bactericidal activity. Subsequently, molecular docking was performed to determine the specific compound inhibition. The docking results revealed that four compounds displayed strong binding affinity with the virulence factor Listeriolysin-O of L. monocytogenes. Based on the above results, it can be concluded that the medicinal plant A. cepa has potential antibacterial effects against L. monocytogenes, particularly targeting its virulence.

Effects of Individual Amino Acids on PPARα Transactivation, mTORC1 Activation, ApoA-I Transcription and pro-ApoA-I Secretion.

A higher concentration of apolipoprotein A-I (ApoA-I) is associated with increased high density lipoprotein functionality and reverse cholesterol transport (RCT). A promising strategy to prevent cardiovascular diseases is therefore to improve RCT by increasing de novo ApoA-I production. Since experimental animal models have suggested effects of amino acids on hepatic lipoprotein metabolism, we here examined the effects of different amino acids on hepatic ApoA-I production. Human hepatocytes (HepG2) were exposed to six individual amino acids for 48 h. ApoA-I transcription and secreted pro-ApoA-I protein concentrations were analyzed using quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assays (ELISA), respectively. Additionally, CPT1 and KEAP1 mRNA expression, peroxisome proliferator-activated receptor alpha (PPARα) transactivation, and mechanistic target of rapamycin complex 1 (mTORC1) phosphorylation were determined. Leucine, glutamic acid, and tryptophan increased ApoA-I and CPT1 mRNA expression. Tryptophan also strongly increased PPARα transactivation. Glutamine, proline, and histidine increased pro-ApoA-I protein concentrations but mTORC1 phosphorylation remained unchanged regardless of the amino acid provided. In conclusion, individual amino acids have different effects on ApoA-I mRNA expression and pro-ApoA-I production which can partially be explained by specific effects on PPARα transactivation, while mTORC1 phosphorylation remained unaffected.

Potential Contribution of Short Chain Fatty Acids to Hepatic Apolipoprotein A-I Production.

Apolipoprotein A-I (ApoA-I) is the major protein of high density lipoprotein (HDL) particles and has a crucial role in reverse cholesterol transport (RCT). It has been postulated that elevating production of de novo ApoA-I might translate into the formation of new functional HDL particles that could lower cardiovascular disease (CVD) risk via RCT. During inflammation, serum ApoA-I concentrations are reduced, which contributes to the development of dysfunctional HDL particles as Serum Amyloid A (SAA) overtakes the position of ApoA-I within the HDL particles. Therefore, instead of elevating serum HDL cholesterol concentrations, rescuing lower serum ApoA-I concentrations could be beneficial in both normal and inflamed conditions. Several nutritional compounds, amongst others short chain fatty acids (SCFAs), have shown their capacity to modulate hepatic lipoprotein metabolism. In this review we provide an overview of HDL and more specific ApoA-I metabolism, SCFAs physiology and the current knowledge regarding the influence of SCFAs on ApoA-I expression and synthesis in human liver cells. We conclude that the current evidence regarding the effect of SCFAs on ApoA-I transcription and secretion is promising, however there is a need to investigate which dietary fibres could lead to increased SCFAs formation and consequent elevated ApoA-I concentrations.

Butyric Acid Added Apically to Intestinal Caco-2 Cells Elevates Hepatic ApoA-I Transcription and Rescues Lower ApoA-I Expression in Inflamed HepG2 Cells Co-Cultured in the Basolateral Compartment.

Apolipoprotein A-I (ApoA-I) concentrations are decreased during inflammation, which may reduce high-density lipoprotein (HDL) functionality. Thus, rescuing ApoA-I concentrations during inflammation might help to prevent atherosclerosis. Recent studies have shown that butyric acid (C4) has anti-inflammatory effects and rescues ApoA-I production. However, whether intestinal short chain fatty acids (SCFAs) are able to influence hepatic processes is unknown. Therefore, we investigated C4 anti-inflammatory effects on ApoA-I transcription in the intestine-liver co-culture model. C4 dose-response experiments in the presence or absence of cytokines were performed in a co-culture system including Caco-2 cells, HepG2 cells, or both. Changes in ApoA-I transcription in Caco-2 cells and HepG2 cells were analyzed using qPCR. C4 increased ApoA-I expression in HepG2 cells that cultured alone. When both cells were cultured together, C4 decreased ApoA-I expression in Caco-2 cells and increased ApoA-I expression in HepG2 cells. However, adding C4 to apical Caco-2 cells resulted in a smaller effect in HepG2 cells compared with adding C4 directly to the hepatocytes. Moreover, C4 rescued ApoA-I expression in inflamed HepG2 cells. These findings suggests that intestinal SCFAs can affect hepatic processes. However, the smaller effect in the co-culture experiment indicates cross-talk between intestine and liver.

Short-Chain Fatty Acids (Except Hexanoic Acid) Lower NF-kB Transactivation, Which Rescues Inflammation-Induced Decreased Apolipoprotein A-I Transcription in HepG2 Cells.

Concentrations of apolipoprotein A-I (ApoA-I) decrease during inflammation, which may lead to dysfunctional ApoA-I-poor high-density lipoprotein (HDL) particles, and as such, elevate cardiovascular risk. Therefore, rescuing ApoA-I concentrations, especially during inflammation, seems beneficial. Recently, short-chain fatty acids (SCFAs) have received more attention as a strategy in reversing atherosclerosis. We here evaluated the effects of SCFAs on inflammatory pathways in relation to ApoA-I transcription. SCFAs dose-response studies were performed in the presence and absence of inflammatory cytokines. ApoA-I and interleukin 8 (IL-8) mRNA expression were analyzed using qPCR and ELISA, respectively. To study underlying mechanisms, nuclear factor kappa B (NF-κB) transactivation and changes in mRNA expressions of the genes targets of bromodomain and extra-terminal (BET) inhibition, peroxisome proliferator-activated receptor-alpha (PPARα) transactivation and activator protein 1 (AP-1) pathway were analyzed. SCFAs (except hexanoic acid) increased ApoA-I mRNA transcription in both normal and inflammatory conditions and lowered IL-8 mRNA expression. This anti-inflammatory effect of SCFAs was confirmed by inhibition of NF-κB transactivation. Moreover, butyric acid increased carnitine palmitoyltransferase 1 (CPT1), PPARα target gene, mRNA transcription in both conditions, and there was a negative correlation between CPT1 and NF-κB. Therefore, PPARα transactivation is probably involved in the anti-inflammatory effects of SCFAs, which rescues ApoA-I transcription. In conclusion, propionate, butyrate and valerate elicit anti-inflammatory effects which might rescue ApoA-I transcription in inflammatory conditions via PPARα transactivation mediated NF-κB inhibition.

Amoxicillin Modulates ApoA-I Transcription and Secretion, Predominantly via PPARα Transactivation Inhibition.

In a recent human study, we observed that amoxicillin treatment decreased HDL-C concentration. We hypothesize that antibiotics lower the transcription and secretion of ApoA-I, the responsible protein for HDL production. HepG2 and Caco-2 cells were exposed to increasing dose of amoxicillin, penicillin, and streptomycin. Secreted ApoA-I protein and mRNA transcripts were analyzed using ELISA and qPCR, respectively. To unravel underlying mechanisms, KEAP1, CPT1, and CHOP mRNA expressions were determined as well as PPARα transactivation. In HepG2 and Caco-2, amoxicillin decreased ApoA-I transcription and secretion. Effects on ApoA-I expression were clearly there for amoxicillin while no effects were observed for penicillin or streptomycin. KEAP1, CPT1, and CHOP mRNA expressions were reduced by amoxicillin treatments. Moreover, a significant correlation between ApoA-I and CPT1 mRNA expressions was found. Furthermore, amoxicillin lowered PPARα transactivation. All together, these data suggest that inhibited PPARα transactivation is involved in the effects of amoxicillin on ApoA-I. In conclusion, the direct effect of amoxicillin in treated HepG2 and Caco-2 cells was a lower ApoA-I secretion and transcription. Based on evaluating alterations in KEAP1, CPT1, and CHOP mRNA expressions plus PPARα transactivation, we suggest that a reduced PPARα activation is a potential mechanism behind the observed amoxicillin effects on ApoA-I expression.

The effects of short-chain fatty acids on the transcription and secretion of apolipoprotein A-I in human hepatocytes in vitro.

BACKGROUND: Apolipoprotein-I (ApoA-I), the major component of high-density lipoprotein (HDL) particles, mediates cholesterol efflux by which it facilitates the removal of excess cholesterol from peripheral tissues. Therefore, elevating ApoA-I production leading to the production of new pre-ß-HDL particles is thought to be beneficial in the prevention of cardiovascular diseases. Recently, we observed that amoxicillin treatment led to decreased HDL concentrations in healthy human volunteers. We questioned whether this antibiotic effect was directly or indirectly, via changed short-chain fatty acids (SCFA) concentrations through an altered gut microflora. Therefore, we here evaluated the effects of amoxicillin and various SCFA on hepatic ApoA-I expression, secretion, and the putative underlying pathways. METHODS AND RESULTS: Human hepatocytes (HepG2) were exposed to increasing dose of amoxicillin or SCFA for 48 hours. ApoA-I messenger RNA (mRNA) transcription and secreted protein were analyzed using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. To study underlying mechanisms, changes in mRNA expression of KEAP1, CPT1, and PPARα, as well as a PPARα transactivation assay, were analyzed. Amoxicillin dose-dependently decreased ApoA-I mRNA transcription as well as ApoA-I protein secretion. SCFA treatment resulted in a dose-dependent stimulation of ApoA-I mRNA transcription, however, the ApoA-I protein secretion was decreased. Furthermore, SCFA treatment increased PPARα transactivation, PPARα and CPT1 mRNA transcription, whereas KEAP1 mRNA transcription was decreased. CONCLUSION: Direct treatment of HepG2 cells with amoxicillin has either direct effects on lowering ApoA-I transcription and secretion or indirect effects via modified SCFA concentrations because SCFA were found to stimulate hepatic ApoA-I expression. Furthermore, BET inhibition and PPARα activation were identified as possible mechanisms behind the observed effects on ApoA-I transcription.

Large-Scale Screening of Natural Products Transactivating Peroxisome Proliferator-Activated Receptor α Identifies 9S-Hydroxy-10E,12Z,15Z-Octadecatrienoic Acid and Cymarin as Potential Compounds Capable of Increasing Apolipoprotein A-I Transcription in Human Liver Cells.

Increasing apolipoprotein A-I (apoA-I), the predominant protein of high-density lipoprotein (HDL) particles, has favorable effects on atherogenic risk factors. Here, we investigated the effects of peroxisome proliferator-activated receptor α (PPARα) transactivating compounds on apoA-I transcription in HepG2 cells. A transient PPARα agonist transactivation assay was used to screen 2500 natural compounds. To analyze the effects on apoA-I transcription, human hepatocellular liver carcinoma (HepG2) were exposed to 0.1, 1, and 10 µg/mL of the natural PPARα transactivators. ApoA-I mRNA expression was determined by quantitative polymerase chain reaction. Extensive dose-response experiments were performed using compounds that increased apoA-I transcription by minimally 20%. Kelch-like ECH-associated protein 1 (KEAP) and carnitine palmitoyltransferase 1 alpha (CPT1α) expression were used respectively to confirm Bromodomain-containing protein 4 inhibition or PPARα activation. Twenty-eight natural compounds increased PPARα transactivation by at least twofold. Despite the increased CPT1α expression seen after the addition of most PPARα activating compounds, CPT1α expression and PPARα transactivation did not correlate. Addition of 0.05 µg/mL 9S-hydroxy-10E,12Z,15Z-octadecatrienoic acid (9(S)-HOTrE) increased apoA-I mRNA expression by 35%, whereas 10-25 µg/mL of cymarin increased apoA-I transcription by 37%. However, combining cymarin and 9(S)-HOTrE did not result in a synergistic effect, in contrast this combination even decreased apoA-I transcription. ApoA-I transcription involves multiple regulatory players, and PPARα transactivation alone is not sufficient. A search for natural compounds resembling the molecular structure of 9(S)-HOTrE or cymarin could aid to find additional components that increase apoA-I transcription.