Investigating the synergistic antibacterial effects of chlorogenic and p-coumaric acids on Shigella dysenteriae.

Chlorogenic acid (CGA) is a well-known plant secondary metabolite exhibiting multiple physiological functions. The present study focused on screening for synergistic antibacterial combinations containing CGA. The combination of CGA and p-coumaric acid (pCA) exhibited remarkably enhanced antibacterial activity compared to that when administering the treatment only. Scanning electron microscopy revealed that a low-dose combination treatment could disrupt the Shigella dysenteriae cell membrane. A comprehensive analysis using nucleic acid and protein leakage assay, conductivity measurements, and biofilm formation inhibition experiments revealed that co-treatment increased the cell permeability and inhibited the biofilm formation substantially. Further, the polyacrylamide protein- and agarose gel-electrophoresis indicated that the proteins and DNA genome of Shigella dysenteriae severely degraded. Finally, the synergistic bactericidal effect was established for fresh-cut tomato preservation. This study demonstrates the remarkable potential of strategically selecting antibacterial agents with maximum synergistic effect and minimum dosage exhibiting excellent antibacterial activity in food preservation.

Potentilla tormentilla Extract Loaded Gel: Formulation, In Vivo and In Silico Evaluation of Anti-Inflammatory Properties.

The objective of the study was to develop a novel topical gel by mixing Potentilla tormentilla ethanolic extract, thermosensitive poloxamer 407, and carbomer 940 and evaluating its stability and rheological behavior. The irritation potential of the gel was evaluated in accordance with the Organization for Economic Cooperation and Development Guidelines 404. The potential anti-inflammatory effects of the developed gel were evaluated in vivo in rats using the carrageenan-induced paw edema test. Moreover, the in silico binding affinity for chlorogenic and ellagic acid, as dominant components in the extract, against cyclooxygenase (COX) 1 and 2 was also determined. Our findings suggest that the gel containing Potentilla tormentilla extract remained stable throughout the observation period, exhibited pseudoplastic behavior, and caused no irritation in rats, thus being considered safe for topical treatment. Additionally, the developed gel showed the capability to reduce rat paw edema, which highlights significant anti-inflammatory potential. In silico analysis revealed that chlorogenic and ellagic acid exhibited a reduced binding affinity against COX-1 but had a similar inhibitory effect on COX-2 as flurbiprofen, which was confirmed by molecular dynamics results. The study proposes the possible application of Potentilla tormentilla ethanolic extract gel for the alleviation of localized inflammatory diseases; however, future clinical evaluation is required.

Potential of Coffee Cherry Pulp Extract against Polycyclic Aromatic Hydrocarbons in Air Pollution Induced Inflammation and Oxidative Stress for Topical Applications.

Airborne particulate matter (PM) contains polycyclic aromatic hydrocarbons (PAHs) as primary toxic components, causing oxidative damage and being associated with various inflammatory skin pathologies such as premature aging, atopic dermatitis, and psoriasis. Coffee cherry pulp (CCS) extract, rich in chlorogenic acid, caffeine, and theophylline, has demonstrated strong antioxidant properties. However, its specific anti-inflammatory effects and ability to protect macrophages against PAH-induced inflammation remain unexplored. Thus, this study aimed to evaluate the anti-inflammatory properties of CCS extract on RAW 264.7 macrophage cells exposed to atmospheric PAHs, compared to chlorogenic acid (CGA), caffeine (CAF), and theophylline (THP) standards. The CCS extract was assessed for its impact on the production of nitric oxide (NO) and expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Results showed that CCS extract exhibited significant antioxidant activities and effectively inhibited protease and lipoxygenase (LOX) activities. The PAH induced the increase in intracellular reactive oxygen species, NO, TNF-α, IL-6, iNOS, and COX-2, which were markedly suppressed by CCS extract in a dose-dependent manner, comparable to the effects of chlorogenic acid, caffeine, and theophylline. In conclusion, CCS extract inhibits PAH-induced inflammation by reducing pro-inflammatory cytokines and reactive oxygen species (ROS) production in RAW 264.7 cells. This effect is likely due to the synergistic effects of its bioactive compounds. Chlorogenic acid showed strong antioxidant and anti-inflammatory activities, while caffeine and theophylline enhanced anti-inflammatory activity. CCS extract did not irritate the hen's egg chorioallantoic membrane. Therefore, CCS extract shows its potential as a promising cosmeceutical ingredient for safely alleviating inflammatory skin diseases caused by air pollution.

Chlorogenic acid ameliorates memory dysfunction via attenuating frontal lobe oxidative stress and apoptosis in diabetic rat model.

Background/aim: Diabetes mellitus, characterized by hyperglycemia, causes various complications, one of which is memory dysfunction. The frontal lobe is known to be responsible for impaired memory function due to hyperglycemia and is associated with oxidative stress-mediated neuronal cell apoptosis. Chlorogenic acid (CGA) is reported to have neuroprotective effects. However, its effect on the frontal lobe in diabetes mellitus (DM) rats is not widely known. This research aimed to elucidate the effect of CGA on the mRNA expressions of SOD1, SOD2, p53, and Bcl-2 in the frontal lobe of DM rats. Materials and methods: Thirty male Wistar rats (2-month-old, 150-200 gBW) were randomly divided into six groups: C (control), DM1.5 (1.5-month DM), DM2 (2-month DM), CGA12.5, CGA25 and CGA50 (DM+CGA 12.5, 25, and 50 mg/kgBW, respectively). A single dose of streptozotocin (60 mg/kgBW) was intraperitoneally injected. Intraperitoneal CGA injection was administered daily for DM1.5 rats for 14 days. Path length was measured in the Morris water maze (MWM) probe test. After termination, the frontal lobes were carefully harvested for RNA extraction. Reverse transcriptase PCR was performed to examine the mRNA expression of SOD1, SOD2, p53, and Bcl-2. Results: The DM2 group demonstrated significant shorter path length on the MWM probe test and significantly lower mRNA expression of SOD1 and Bcl-2, compared to the C group. After CGA administration, the CGA25 group showed a significantly shorter path length than the C group. The CGA12.5 and CGA25 groups had significantly higher mRNA expression of SOD1 than the DM1.5 group. Compared to the DM1.5 and DM2 groups, SOD2 mRNA expression of the administration of all three CGA doses increased markedly. Furthermore, Bcl-2 mRNA expression was significantly increased in the CGA12.5 and CGA50 groups, compared with the DM2 group. Conclusion: Chlorogenic acid might improve memory function through upregulation of frontal lobes' SOD1, SOD2, and Bcl-2 mRNA expression in DM rats.

Effects of isochlorogenic acid A on mitochondrial dynamics imbalance and RLR damage in PAM cells induced by combined mycotoxins.

Mycotoxins have strong immunotoxicity and can induce oxidative stress and mitochondrial dynamics imbalance. Mitochondrial antiviral signaling protein (MAVS) in the RIG-I like receptor (RLR) pathway of innate immunity is located on mitochondria, and whether it is affected by mycotoxins has not been reported yet. This experiment used porcine alveolar macrophages (PAM) to evaluate the antagonism of three isomers of chlorogenic acid (chlorogenic acid, isochlorogenic acid A, and neochlorogenic acid) against combined mycotoxins (Aflatoxin B1, Deoxynivalenol, and Ochratoxin A) induced mitochondrial damage and their effects on the RLR pathway, providing assistance for further elucidating the mechanism of mycotoxin immunotoxicity. Western blotting, enzyme linked immunosorbent assay (ELISA), and flow cytometry were used to detect relevant indicators. All three types of chlorogenic acid treatment can antagonize the cytotoxicity induced by combined mycotoxins, especially isochlorogenic acid A, which can protect cells from mycotoxins damage by maintaining mitochondrial dynamic homeostasis and improving innate immune function related to the RLR pathway.

The influence of rutin and chlorogenic acid on oxidative stress and in vivo fertility: Evaluation of the quality and antioxidant status of post-thaw semen from Azari water buffalo bulls.

BACKGROUND: The vulnerability of buffalo sperm to cryoinjury necessitates the improvement of sperm cryo-resistance as a critical strategy for the widespread use of assisted reproductive technologies in buffalo. OBJECTIVES: The main aim of the present study was to evaluate the effects of different concentrations of rutin and chlorogenic acid (CGA) on buffalo semen quality, antioxidant activity and fertility during cryopreservation. METHODS: The semen was collected and pooled from the 3 buffaloes using an artificial vagina (18 ejaculations). The pooled sperm were divided into nine different groups: control (Tris-based extender); 0.4, 0.6, 0.8 and 1 mM rutin (rutin + Tris-based extender); and 50, 100, 150 and 200 µM CGG (CGA + Tris-based extender). Sperm kinematics, viability, hypo-osmotic swelling test, mitochondrial activity, antioxidant activities and malondialdehyde (MDA) concentration of frozen and thawed buffalo sperm were evaluated. In addition, 48 buffalo were finally inseminated, and pregnancy was rectally determined 1 month after insemination. RESULTS: Compared to the control group, adding R-0.4, R-0.6, CGA-100 and CGA-150 can improve total and progressive motility, motility characteristics, viability, PMF and DNA damage in buffalo sperm. In addition, the results showed that R-0.4, R-0.6, CGA-50, CGA-100 and CGA-150 increased total antioxidant capacity, catalase, glutathione peroxidase and glutathione activities and decreased MDA levels compared to the control group. Furthermore, it has been shown that adding 150 µM CGA and 0.6 mM rutin to an extender can increase in vivo fertility compared to the control group. CONCLUSIONS: In conclusion, adding rutin and CGA to the extender improves membrane stability and in vivo fertility of buffalo sperm by reducing oxidative stress.

Chlorogenic acid alleviate kidney fibrosis through regulating TLR4/NF-қB mediated oxidative stress and inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Chlorogenic acid (CGA), a phenolic acid produced by the interaction of Caffeic acid and Quinic acid, is considered to be the main active ingredient in many heat-clearing and detoxifying Chinese medicines, such as honeysuckle, Houttuynia, Artemisia annua, Gardenia, etc. CGA has anti-inflammatory, antioxidant, anticancer, antibacterial and other properties. However, the effect and process of CGA in kidney fibrosis remain unknown. AIM OF THE STUDY: To investigate the therapeutic effects of CGA on alleviating kidney fibrosis and the underlying mechanisms. MATERIALS AND METHODS: C57BL/6 mouse kidney fibrosis model was established by unilateral uretera obstruction (UUO), followed by treatment with CGA (40, 80 mg/kg/d) for 10 days. The serum and kidney tissue were collected. Network pharmacology, molecular docking and transcriptomic analysis were conducted to explore the possible mechanisms. The HK-2 cells were cultured and treated with TGF-ß1(10 ng/mL) and CGA (50, 100 µM), to examine the role of TLR4/NF-қB signaling pathway in the therapeutic effect of CGA on kidney fibrosis. RESULTS: CGA significantly alleviated kidney injury, inflammation, oxidative stress and fibrosis in UUO models. CGA also effectively inhibited the expression of inflammatory factors and the process of oxidative stress both in vivo and in vitro fibrosis models. Further, transcriptomic analysis, molecular docking, and network pharmacology results indicated that the therapeutic effect of CGA on fibrosis was through the regulation of TLR4/NF-қB signaling pathway. CONCLUSION: CGA might provide benefits for the regulation of inflammatory response, oxidative stress and fibrogenesis by modulating TLR4/NF-қB signaling pathway on kidney fibrosis. Hence, CGA is an attractive agent for treating kidney fibrosis. The present study provided a basis for further research on the therapeutic strategies of kidney fibrosis.

Chlorogenic acid ameliorates non-proliferative diabetic retinopathy via alleviating retinal inflammation through targeting TNFR1 in retinal endothelial cells.

As a prominent complication of diabetes mellitus (DM) affecting microvasculature, diabetic retinopathy (DR) originates from blood-retinal barrier (BRB) damage. Natural polyphenolic compound chlorogenic acid (CGA) has already been reported to alleviate DR. This study delves into the concrete mechanism of the CGA-supplied protection against DR and elucidates its key target in retinal endothelial cells. DM in mice was induced using streptozotocin (STZ). CGA mitigated BRB dysfunction, leukocytes adhesion and the formation of acellular vessels in vivo. CGA suppressed retinal inflammation and the release of tumor necrosis factor-α (TNFα) by inhibiting nuclear factor kappa-B (NFκB). Furthermore, CGA reduced the TNFα-initiated adhesion of peripheral blood mononuclear cell (PBMC) to human retinal endothelial cell (HREC). CGA obviously decreased the TNFα-upregulated expression of vascular cell adhesion molecule-1 (VCAM1) and intercellular adhesion molecule-1 (ICAM1), and abrogated the TNFα-induced NFκB activation in HRECs. All these phenomena were reversed by overexpressing type 1 TNF receptor (TNFR1) in HRECs. The CGA-provided improvement on leukocytes adhesion and retinal inflammation was disappeared in mice injected with an endothelial-specific TNFR1 overexpression adeno-associated virus (AAV). CGA reduced the interaction between TNFα and TNFR1 through binding to TNFR1 in retinal endothelial cells. In summary, excepting reducing TNFα expression via inhibiting retinal inflammation, CGA also reduced the adhesion of leukocytes to retinal vessels through decreasing VCAM1 and ICAM1 expression via blocking the TNFα-initiated NFκB activation by targeting TNFR1 in retinal endothelial cells. All of those mitigated retinal inflammation, ultimately alleviating BRB breakdown in DR.

Construction of chlorogenic acid nanoparticles for effective alleviation of ulcerative colitis.

The onset and progression of ulcerative colitis (UC) are intricately linked to the worsening of intestinal inflammation, an imbalance in oxidative stress, and impairment of the intestinal mucosal barrier. Although chlorogenic acid (CA) shows potential in effectively alleviating the symptoms of UC, its clinical application is hindered by its poor bioavailability, stability, rapid metabolism, and quick excretion. This study utilized a one-step enzyme-catalyzed polymerization technique to create chlorogenic acid nanoparticles (CA NPs), aiming to improve the bioavailability and stability of CA. The CA NPs exhibited an optimal nanosize (106.65 ± 4.12 nm) and showed increased cellular uptake over time. Importantly, CA NPs significantly prolonged retention time in inflamed colonic tissues, enhancing accumulation and providing a targeted therapy for UC. Animal studies confirmed the substantial benefits of CA NPs, including reduced weight loss, lessened reduction in colon length, and a lowered disease activity index (DAI) score in DSS-induced UC mice. Moreover, CA NPs effectively reduced oxidative stress and levels of inflammatory factors in the colonic tissues of UC mice, thus mitigating tissue damage and restoring the integrity of the intestinal mucosal barrier. In conclusion, our research proposes a novel approach to increase the bioavailability and stability of CA, offering a promising avenue for its effective application in preventing UC.

Insights into impact of chlorogenic acid on multi-scale structure and digestive properties of lotus seed starch under autoclaving treatment.

The interaction between polyphenols and starch is an important factor affecting the structure and function of starch. Here, the impact of chlorogenic acid on the multi-scale structure and digestive properties of lotus seed starch under autoclaving treatment were evaluated in this study. The results showed that lotus seed starch granules were destroyed under autoclaving treatment, and chlorogenic acid promoted the formation of loose gel structure of lotus seed starch. In particular, the long- and short-range ordered structure of lotus seed starch-chlorogenic acid complexes were reduced compared with lotus seed starch under autoclaving treatment. The relative crystallinity of A-LS-CA complexes decreased from 23.4 % to 20.3 %, the value of R1047/1022 reduced from 0.87 to 0.80, and the proportion of amorphous region increased from 10.26 % to 13.85 %. In addition, thermal stability, storage modulus and loss modulus of lotus seed starch-chlorogenic acid complexes were reduced, indicating that the viscoelasticity of lotus seed starch gel was weakened with the addition of chlorogenic acid. It is remarkable that chlorogenic acid increased the proportion of resistant starch from 58.25 ± 1.43 % to 63.85 ± 0.96 % compared with lotus seed starch under autoclaving treatment. Here, the research results provided a theoretical guidance for the development of functional foods containing lotus seed starch.

Chlorogenic acid ameliorates muscle wasting by upregulating mRNA expressions of calcineurin and PGC-1α in diabetic rat model.

INTRODUCTION: Muscle health in diabetes mellitus (DM) is often neglected, which leads to muscle wasting. Increased reactive oxygen species in DM could decrease antioxidant enzymes such as superoxide dismutase-1 (SOD-1) and -2 (SOD-2) and inhibit calcineurin (CN) and PGC-1α signalling pathways. Chlorogenic acid (CGA) is known as a potent antioxidant and activators of CN and PGC-1α. This study aimed to determine the effect of CGA on mRNA expressions of SOD-1, SOD-2, CN and PGC-1α in inhibiting the progression of DM to muscle wasting. MATERIALS AND METHODS: This study was conducted at Department of Anatomy, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada starting on July 20th, 2020. A total of 24 male Wistar rats were randomly divided into six groups (four rats per group), i.e., control, DM 1.5 months (DM1.5), and DM 2 months (DM2); and DM groups treated with CGA in three different doses, namely CGA1 (12.5 mg/kg BW), CGA2 (25 mg/kg BW), and CGA3 (50 mg/kg BW). Control group was only injected with normal saline, while diabetic model was induced by intraperitoneal injection of streptozotocin. Blood glucose levels were measured twice (one week after diabetic induction and before termination). The soleus muscle tissue was harvested to analyse the mRNA expressions of SOD-1, SOD- 2, CN and PGC-1α using RT-PCR. In addition, the tissue samples were stained with immunohistochemistry for CN and haematoxylin-eosin (HE) for morphologic analysis under light microscopy. RESULTS: The mRNA expressions of SOD-1 and SOD-2 in the CGA1 group were relatively higher compared to the DM2 groups. The mRNA expression of CN in the CGA1 group was significantly higher compared to the DM2 group (p = 0.008). The mRNA expression of PGC-1α in the CGA1 group was significantly higher compared to the DM2 group (p = 0.025). Immunohistochemical staining showed that CNimmunopositive expression in the CGA1 group was more evident compared to the other groups. Haematoxylin-eosin staining showed that muscle tissue morphology in the CGA1 group was similar to that in the control group. CONCLUSION: Chlorogenic acid at a dose of 12.5 mg/kg BW shows lower blood glucose level, good skeletal muscle tissue morphology and higher mRNA expressions of SOD-1, SOD-2, CN and PGC-1α compared to the DM groups.

The inhibitory effect of chlorogenic acid on oxidative stress and apoptosis induced by PM2.5 in HaCaT keratinocytes.

Exposure to fine particulate matter with an aerodynamic diameter of less than 2.5 µm (PM2.5) can cause oxidative damage and apoptosis in the human skin. Chlorogenic acid (CGA) is a bioactive polyphenolic compound with antioxidant, antifungal, and antiviral properties. The objective of this study was to identify the ameliorating impact of CGA that might protect human HaCaT cells against PM2.5. CGA significantly scavenged the reactive oxygen species (ROS) generated by PM2.5, attenuated oxidative cellular/organelle damage, mitochondrial membrane depolarization, and suppressed cytochrome c release into the cytosol. The application of CGA led to a reduction in the expression levels of Bcl-2-associated X protein, caspase-9, and caspase-3, while simultaneously increasing the expression of B-cell lymphoma 2. In addition, CGA was able to reverse the decrease in cell viability caused by PM2.5 via the inhibition of extracellular signal-regulated kinase (ERK). This effect was further confirmed by the use of the mitogen-activated protein kinase kinase inhibitor, which acted upstream of ERK. In conclusion, CGA protected keratinocytes from mitochondrial damage and apoptosis via ameliorating PM2.5-induced oxidative stress and ERK activation.

Synthesis and Biological Evaluation of Novel Chlorogenic Acid-Apigenin Conjugates as Anti-acute Gout Agents.

Gout is the second largest metabolic disease worldwide after diabetes, with acute gouty arthritis as most common symptom. Xanthine oxidase (XOD) and the NOD like receptor-3 (NLRP3) inflammasome are the key targets for acute gout treatment. Chlorogenic acid has been reported with a good anti-inflammatory activity, and Apigenin showed an excellent potential in XOD inhibition. Therefore, a series of chlorogenic acid-apigenin (CA) conjugates with varying linkers were designed and synthesized as dual XOD/NLRP3 inhibitors, and their activities both in XOD and NLRP3 inhibition were evaluated. An in vitro study of XOD inhibitory activity revealed that the majority of CA conjugates exhibited favorable XOD inhibitory activity. Particularly, the effects of compounds 10c and 10d, with an alkyl linker on the apigenin moiety, were stronger than that of allopurinol. The selected CA conjugates also demonstrated a favorable anti-inflammatory activity in RAW264.7 cells. Furthermore, compound 10d, which showed the optimal activity both in XOD inhibition and anti-inflammatory, was chosen and its inhibitory ability on NLRP3 and related proinflammatory cytokines was further tested. Compound 10d effectively reduced NLRP3 expression and the secretion of interluekin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) with an activity stronger than the positive control isoliquiritigenin (ISL). Based on these findings, compound 10d exhibits dual XOD/NLRP3 inhibitory activity and, therefore, the therapeutic effects on acute gout is worthy of further study.

Impact of chlorogenic acid on submandibular salivary gland and liver of albino rats exposed to sodium nitrite.

AIM: The aim of the present study is to show how sodium nitrite alters the histology of submandibular salivary glands and livers of Albino rats, as well as how chlorogenic acid may have therapeutic benefits. METHODS: A sample size of thirty male Sprague Dawley Albino rats weighing between 100 and 150 g (5-6 weeks old) was randomly allocated into 3 equal groups. Group I: rats were used as controls and were given phosphate buffer solution, whereas Group II: rats were given an 80 mg/kg sodium nitrites (SN) daily dissolved in distilled water. The rats in Group III were given a daily dose of 80 mg/kg SN dissolved in distilled water and after 6 hours each rat received 50 mg/mL freshly prepared chlorogenic acid (CGA) every other day. For 12 weeks, all treatment modalities will be administered orally, every day. After the experiment, all rats were euthanized. Samples from salivary glands and livers were processed and stained with H&E and interleukin 6 (IL 6). Malondialdehyde (MDA) and superoxide dismutase (SOD) enzymes were detected using an ELISA assay. RESULTS: Groups III had nearly comparable findings to Group I regarding histological pattern with normal submandibular glands and livers features. Group III salivary gland treated with CGA exhibited higher SOD levels (20.60±4.81 U/g) in comparison to the SN group, and lower MDA levels (111.58±28.28 nmol/mg) in comparison to the SN treated samples. In comparison to the SN group, CGA treatment significantly reduced MDA levels in liver samples (167.56±21.17 nmol/mg) and raised SOD (30.85±6.77 U/g). CONCLUSIONS: Chlorogenic acid has a protective effect against salivary gland and liver toxicity induced by SN in rats. This was mediated via the anti-inflammatory and antioxidative properties of CGA and the restoration of oxidant/antioxidant balance in rat salivary gland and liver.

The protective effect of Artemisia Capillaris Thunb. Extract against UVB-induced apoptosis and inflammation through inhibiting the cGAS/STING pathway.

Exposure to ultraviolet B (UVB) radiation represents a significant environmental threat to human skin. This study investigates the protective mechanism of Artemisia Capillaris Thunb. (AC) extract against UVB-induced apoptosis and inflammation in HaCaT keratinocytes. AC extract demonstrated a significant protective effect, as evidenced by reduced early apoptosis, late apoptosis, and necrosis, as well as decreased apoptotic cell status upon UVB exposure. Additionally, AC extract effectively inhibited UVB-induced DNA damage, as indicated by diminished γ-H2AX foci formation. Restoration of mitochondrial damage and normalization of mitochondrial membrane potential, along with the reduction of intracellular and mitochondrial reactive oxygen species (ROS) levels, were observed with AC extract pre-treatment. The extract also exhibited anti-inflammatory properties, evidenced by the decreased release of IL-1α, IL-6, and PGE2 from keratinocytes. Additional research on the molecular mechanisms uncovered that the AC extract alters the cGAS/STING pathway, suppressing the mRNA (cGAS, STING, IRF3, IRF7 and TBK1) and protein levels (cGAS, STING, IRF3, IRF7 and NF-κB) linked to this particular pathway. The HPLC analysis identified chlorogenic acid and its derivatives as the major components in AC, constituting up to 16.44% of the total chlorogenic acid content. The cGAS/STING signaling pathway was found to be suppressed by chlorogenic acid and its derivatives, as indicated by molecular docking studies and RT-qPCR analysis. This suppression contributes to the protective effects against cell apoptosis and inflammation induced by UVB. To summarize, AC extract, which is abundant in chlorogenic acid and its derivatives, shows potential in protecting keratinocytes from damage caused by UVB by regulating the cGAS/STING signaling pathway.

Evaluation of chlorogenic acid and carnosol for anti-efflux pump and anti-biofilm activities against extensively drug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa.

Efflux pumps and biofilm play significant roles in bacterial antibiotic resistance. This study investigates the potential of chlorogenic acid (CGA) and carnosol (CL), as phenolic and diterpene compounds, respectively, for their inhibitory effects on efflux pumps. Among the 12 multidrug-resistant (MDR) strains of Staphylococcus aureus and Pseudomonas aeruginosa isolated from nosocomial skin infections, eight strains were identified as extensively drug resistant (XDR) using the disc diffusion method. The presence of efflux pumps in MDR strains of S. aureus and P. aeruginosa was screened using carbonyl cyanide-m-chlorophenylhydrazone. Between the 12 MDR strains of S. aureus and P. aeruginosa, 80% (4 out of 5) of the S. aureus strains and 85.7% (6 out of 7) of the P. aeruginosa strains exhibited active efflux pumps associated with gentamicin resistance. The checkerboard assay results, in combination with gentamicin, demonstrated that CGA exhibited a reduction in the minimum inhibitory concentration (MIC) for XDR S. aureus strain. Similarly, CL showed a synergistic effect and reduced the MIC for both XDR strains of S. aureus and P. aeruginosa. Flow cytometry was used to examine efflux pump activity at sub-MIC concentrations of 1/8, 1/4, and 1/2 MIC in comparison to the control. In XDR S. aureus, CGA demonstrated 39%, 70%, and 19% inhibition, while CL exhibited 74%, 73.5%, and 62% suppression. In XDR P. aeruginosa, CL exhibited inhibition rates of 25%, 10%, and 15%. The inhibition of biofilm formation was assessed using the microtiter plate method, resulting in successful inhibition of biofilm formation. Finally, the MTT assay was conducted, and it confirmed minimal cytotoxicity. Given the significant reduction in efflux pump activity and biofilm formation observed with CGA and CL in this study, these compounds can be considered as potential inhibitors of efflux pumps and biofilm formation, offering potential strategies to overcome antimicrobial resistance. IMPORTANCE: In summary, CGA and CL demonstrated promising potentiating antimicrobial effects against XDR strains of Staphylococcus aureus and Pseudomonas aeruginosa, suggesting their probably potential as candidates for addressing nosocomial pathogens. They exhibited significant suppression of efflux pump activity, indicating a possible successful inhibition of this mechanism. Moreover, all substances effectively inhibited biofilm formation, while showing minimal cytotoxicity. However, further advancement to clinical trials is needed to evaluate the feasibility of utilizing CGA and CL for reversing bacterial XDR efflux and determining their efficacy against biofilms. These trials will provide valuable insights into the practical applications of these compounds in combating drug-resistant infections.

3,4,5-tri-O-caffeoylquinic acid attenuates influenza A virus induced inflammation through Toll-like receptor 3/7 activated signaling pathway.

BACKGROUND: 3,4,5-tri-O-caffeoylquinic acid (3,4,5-TCQA), a natural polyphenolic acid, has been shown to be effective against influenza A virus (IAV) infection. Although it was found to inhibit the neuraminidase of IAV, it may also perturb other cellular functions, as polyphenolic acids have shown antioxidant, anti-inflammatory and other activities. PURPOSE: This study aimed to investigate the effect of 3,4,5-TCQA at a cell level, which is critical for protecting host cell from IAV infection. STUDY DESIGN AND METHODS: We explored the effect of 3,4,5-TCQA on H292 cells infected or un-infected with Pr8 IAV. The major genes and related pathway were identified through RNA sequencing. The pathway was confirmed by qRT-PCR and western blot analysis. The anti-inflammatory activity was evaluated using nitric oxide measurement assay. RESULTS: We showed that 3,4,5-TCQA downregulated the immune response in H292 cells, and reduced the cytokine production in Pr8-infected cells, through Toll-like receptor (TLR) signaling pathway. In addition, 3,4,5-TCQA showed anti-inflammatory activity in LPS-activated RAW264.7 cells. CONCLUSION: Collectively, our results indicated that 3,4,5-TCQA suppressed inflammation caused by IAV infection through TLR3/7 signaling pathway. This provides a new insight into the antiviral mechanism of 3,4,5-TCQA.

Alleviating effect of chlorogenic acid on oxidative damage caused by hydrogen peroxide in bovine intestinal epithelial cells.

Chlorogenic acid (CGA) is a polyphenol substance contained in many plants, which has good antioxidant activity. This experiment aimed to explore the protective effects of CGA on hydrogen peroxide (H2O2)-induced inflammatory response, apoptosis, and antioxidant capacity of bovine intestinal epithelial cells (BIECs-21) under oxidative stress and its mechanism. The results showed that compared with cells treated with H2O2 alone, CGA pretreatment could improve the viability of BIECs-21. Importantly, Chlorogenic acid pretreatment significantly reduced the formation of malondialdehyde (MDA), lowered reactive oxygen species (ROS) levels, and enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) (P<0.05). In addition, CGA can also improve the intestinal barrier by increasing the abundance of tight junction proteins claudin-1 and occludin. Meanwhile, CGA can reduce the gene expression levels of pro-inflammatory factors Interleukin-6 (IL-6) and Interleukin-8 (IL-8), increase the expression of anti-inflammatory factor Interleukin-10 (IL-10), promote the expression of the nuclear factor-related factor 2 (Nrf2) signaling pathway, enhance cell antioxidant capacity, and inhibit Nuclear Factor Kappa B (NF-κB) the activation of the signaling pathway reducing the inflammatory response, thereby alleviating inflammation and oxidative stress damage.

Chlorogenic Acid Alleviates High Glucose-induced HK-2 Cell Oxidative Damage through Activation of KEAP1/NRF2/ARE Signaling Pathway.

OBJECTIVE: To investigate the alleviating effect of chlorogenic acid (CGA) on oxidative damage in high glucose (HG)-induced HK-2 cells and to explore its potential mechanisms. METHODS: We cultured the human proximal tubular cell line HK-2 and divided them into the control group and different concentrations of CGA groups (0, 5, 10, 25, 50, 100, 200 µM). The trypan blue dye test was used to detect CGA's potential cytotoxicity on HK-2 cells. Then, we treated HK-2 with HG and CGA; the Cell Counting Kit-8 (CCK-8) method was used to detect the cell viability of HK-2 cells in each group. Flow cytometry was employed to measure the apoptosis rate of cells. Western blot was performed to detect the expression of apoptosis proteins B-cell lymphoma-2 (BCL-2), BCL-2-associated X protein (BAX), cysteinyl aspartate specific proteinase (CASPASE)-9, and CASPASE-3. In addition, enzymatic activities, including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and lipid peroxide (LPO), were measured with the corresponding detection kits. 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) assay and flow cytometry were performed to detect reactive oxygen species (ROS) production. Western blot analysis and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) were conducted to evaluate protein and mRNA expressions of the Kelch-like ECH-associated protein-1 (KEAP1)/Nuclear factor erythroid 2-related factor 2 (NRF2)/Antioxidant Response Elements (ARE) signaling pathway. RESULTS: The outcomes showed that, in a dose-dependent way, CGA dramatically increased the vitality of HK-2 induced by HG. Furthermore, CGA significantly reduced the HG-stimulated HK-2 cell apoptosis, which may be linked to the promotion of BCL-2 and the suppression of BAX, cleaved-CASPASE-3, and cleaved-CASPASE-9 expression. In HK-2 cells, CGA reduced the formation of ROS generated by HG levels and markedly boosted the activity of the antioxidant enzymes SOD, GSH-Px, and CAT. Furthermore, compared with the HG group, CGA significantly raised NRF2 nuclear expression and downregulated NRF2 cytosolic expression and increased the mRNA expression of NRF2 and its target genes, heme oxygenase-1 (HO-1), KEAP1, and NAD(P)H dehydrogenase quinone 1 (NQO1). CONCLUSION: These results show that CGA might be useful in managing oxidative damage in HG-induced HK-2 cells.

Design of chitosan colon delivery micro/nano particles for an Achillea millefolium extract with antiproliferative activity against colorectal cancer cells.

In this study, chitosan low molecular weight (LCH) and chitosan medium molecular weight (MCH) were employed to encapsulate a yarrow extract rich in chlorogenic acid and dicaffeoylquinic acids (DCQAs) that showed antiproliferative activity against colon adenocarcinoma cells. The design of CH micro/nanoparticles to increase the extract colon delivery was carried out by using two different techniques: ionic gelation and spray drying. Ionic gelation nanoparticles obtained were smaller and presented higher yields values than spray-drying microparticles, but spray-drying microparticles showed the best performance in terms of encapsulation efficiency (EE) (> 94%), also allowing the inclusion of a higher quantity of extract. Spray-drying microparticles designed using LCH with an LCH:extract ratio of 6:1 (1.25 mg/mL) showed a mean diameter of 1.31 ± 0.21 µm and EE values > 93%, for all phenolic compounds studied. The release profile of phenolic compounds included in this formulation, at gastrointestinal pHs (2 and 7.4), showed for most of them a small initial release, followed by an increase at 1 h, with a constant release up to 3 h. Chlorogenic acid presented the higher release values at 3 h (56.91% at pH 2; 44.45% at pH 7.4). DCQAs release at 3 h ranged between 9.01- 40.73%, being higher for 1,5- and 3,4-DCQAs. After gastrointestinal digestion, 67.65% of chlorogenic and most DCQAs remained encapsulated. Therefore, spray-drying microparticles can be proposed as a promising vehicle to increase the colon delivery of yarrow phenolics compounds (mainly chlorogenic acid and DCQAs) previously described as potential agents against colorectal cancer.