Protective effect of luteolin on skin ischemia-reperfusion injury through an AKT-dependent mechanism

Polymeric pH-Responsive Metal-Supramolecular Nanoparticles for Synergistic Chemo-Photothermal Therapy

Stimuli-responsive drug delivery carriers, particularly those exhibiting pH sensitivity, have attracted significant scholarly interest due to their promising potential in anticancer therapeutic applications. This phenomenon can primarily be ascribed to the inherently acidic nature of tumor microenvironments. However, pH-responsive carriers frequently require the incorporation of functional groups or materials sensitive to pH changes. Given the pH-sensitive characteristics of metal coordination with natural small-molecule drugs, organometallic supramolecules present a facile and effective strategy for integrating pH-responsive behavior into these systems. Meanwhile, utilizing the natural compound luteolin in conjunction with iron ions (Fe3+) through the advanced engineering technique of flash nanoprecipitation (FNP) results in the synthesis of stable, highly loaded nanoparticles (NPs) exhibiting a supramolecular photothermal effect. Our experimental findings substantiate that the photothermal effect persists over time, even after the pH-responsive release phase has ended. Consequently, these polymeric pH-responsive metallic supramolecular nanoparticles integrate chemotherapy and photothermal therapy, creating a synergistic approach to cancer treatment. This bifunctional platform, which exhibits both pH-responsive and photothermal properties, presents a highly promising avenue for biomedical applications, particularly in the area of tumor therapies. Its dual function offers a potentially efficacious approach to tumor treatment.

Protective effects of the bioactive peptide from maggots against skin flap ischemia‒reperfusion injury in rats

Ischemia‒reperfusion (I/R) injury is a frequently observed complication after flap surgery, and it affects skin flap survival and patient prognosis. Currently, there are no proven safe and effective treatment options to treat skin flap I/R injury. Herein, the potential efficacies of the bioactive peptide from maggots (BPM), as well as its underlying mechanisms, were explored in a rat model of skin flap I/R injury and LPS- or H2O2-elicited RAW 264.7 cells. We demonstrated that BPM significantly ameliorated the area of flap survival, and histological changes in skin tissue in vivo. Furthermore, BPM could markedly restore or enhance Nrf2 and HO-1 levels, and suppress the expression of pro-inflammatory cytokines, including TLR4, p-IκB, NFκB p65, p-p65, IL-6, and TNF-α in I/R-injured skin flaps. In addition, BPM treatment exhibited excellent biocompatibility with an adequate safety profile, while it exhibited superior ROS-scavenging ability and the upregulation of antioxidant enzymes in vitro. Mechanistically, the above benefits related to BPM involved the activation of Nrf2/HO-1 and suppression of TLR4/NF-κB pathway. Taken together, this study may provide a scientific basis for the potential therapeutic effect of BPM in the prevention of skin flap I/R injury and other related diseases.

Systematic review of pathologic markers in skin ischemia with and without reperfusion injury in microsurgical reconstruction: Biomarker alterations precede histological structure changes

BACKGROUND

Ischemia and ischemia-reperfusion injury contribute to partial or complete flap necrosis. Traditionally, skin histology has been used to evaluate morphological and structural changes, however histology does not detect early changes. We hypothesize that morphological and structural skin changes in response to ischemia and IRI occur late, and modification of gene and protein expression are the earliest changes in ischemia and IRI.

METHODS

A systematic review was performed in accordance with PRISMA guidelines. Studies reporting skin histology or gene/protein expression changes following ischemia with or without reperfusion injury published between 2002 and 2022 were included. The primary outcomes were descriptive and semi-quantitative histological structural changes, leukocyte infiltration, edema, vessel density; secondary outcomes were quantitative gene and protein expression intensity (PCR and western blot). Model type, experimental intervention, ischemia method and duration, reperfusion duration, biopsy location and time point were collected.

RESULTS

One hundred and one articles were included. Hematoxylin and eosin (H&E) showed inflammatory infiltration in early responses (12-24 h), with structural modifications (3-14 days) and neovascularization (5-14 days) as delayed responses. Immunohistochemistry (IHC) identified angiogenesis (CD31, CD34), apoptosis (TUNEL, caspase-3, Bax/Bcl-2), and protein localization (NF-κB). Gene (PCR) and protein expression (western blot) detected inflammation and apoptosis; endoplasmic reticulum stress/oxidative stress and hypoxia; and neovascularization. The most common markers were TNF-α, IL-6 and IL-1β (inflammation), caspase-3 (apoptosis), VEGF (neovascularization), and HIF-1α (hypoxia).

CONCLUSION

There is no consensus or standard for reporting skin injury during ischemia and IRI. H&E histology is most frequently performed but is primarily descriptive and lacks sensitivity for early skin injury. Immunohistochemistry and gene/protein expression reveal immediate and quantitative cellular responses to skin ischemia and IRI. Future research is needed towards a universally-accepted skin injury scoring system.

Berberine promotes the viability of random skin flaps via the PI3K/Akt/eNOS signaling pathway

Random skin flaps are often used in reconstruction operations. However, flap necrosis is still a common postoperative complication. Here, we investigated whether berberine (C₂₀ H₁₉ NO₅ , BBR), a drug with antioxidant activity, improves the survival rate of random flaps. Fifty-four rats were divided into three groups: control, BBR and BBR + _L -NAME groups (_L -NAME, _L -N^G -Nitro-arginine methyl ester). The survival condition and the percentage of survival area of the flaps were evaluated on the seventh day after surgery. After animals were sacrificed, angiogenesis, apoptosis, oxidative stress and inflammation levels were assessed by histological and protein analyses. Our findings suggest that berberine promotes flap survival. The level of angiogenesis increased; the levels of oxidative stress, inflammation and apoptosis decreased; the levels of phosphoinositide 3-kinase (PI3K), phospho-Akt (p-Akt) and phospho-endothelial nitric oxide synthase (p-eNOS) increased in the flap tissue; and _L -NAME reversed the effects of berberine on random skin flaps. Statistical analysis showed that the BBR group results differed significantly from those of the control and the BBR + _L -NAME groups (p < .05). Our results confirm that berberine is an effective drug for significantly improving the survival rate of random skin flaps by promoting angiogenesis, inhibiting inflammation, attenuating oxidative stress, and reducing apoptosis through the PI3K/Akt/eNOS signaling pathway.

Tissue-Protective Mechanisms of Bioactive Phytochemicals in Flap Surgery

Despite careful preoperative planning, surgical flaps are prone to ischemic tissue damage and ischemia–reperfusion injury. The resulting wound breakdown and flap necrosis increase both treatment costs and patient morbidity. Hence, there is a need for strategies to promote flap survival and prevent ischemia-induced tissue damage. Phytochemicals, defined as non-essential, bioactive, and plant-derived molecules, are attractive candidates for perioperative treatment as they have little to no side effects and are well tolerated by most patients. Furthermore, they have been shown to exert beneficial combinations of pro-angiogenic, anti-inflammatory, anti-oxidant, and anti-apoptotic effects. This review provides an overview of bioactive phytochemicals that have been used to increase flap survival in preclinical animal models and discusses the underlying molecular and cellular mechanisms.

Luteolin Attenuates Cognitive Dysfunction Induced By Chronic Cerebral Hypoperfusion Through the Modulation of The PI3K/Akt Pathway in Rats

Introduction

In our study, we evaluated the beneficial effect of luteolin in the treatment of cognitive dysfunction in rat models induced by cerebral hypoperfusion by two-vessel occlusion (2-VO).

Material and Methods

Seventy-five male Sprague Dawley rats were subjected to 2-VO surgery, in all but 15 (the sham group, group I) the ligation being permanent to impair cognitive abilities. The sham group rats received saline instead of a drug; 15 2-VO rats were not injected at all (the model group, group II); 15 2-VO rats were administered luteolin at 50 mg/kg b.w. (the lut 50 group, group III); to a further 15 luteolin was given at 100 mg/kg b.w. (the lut 100 group, group IV); and the final 15 received nimodipine at 16 mg/kg b.w. as positive controls (the nimodipine group, group V). Object recognition and Morris water maze tests were performed to investigate memory ability. A Western blot test was also conducted to assess expression of phosphatidylinositol 3-kinase (PI3K), its downstream target protein kinase B (Akt), and the phosphorylated form (P-Akt) in cerebral cortex and hippocampus tissue samples.

Results

Significant variations in the discrimination index in the object recognition test, the escape latencies in the Morris water maze test, and expression levels of PI3K-p110α and PI3K-p85 were observed three months after 2-VO surgery in both lut groups, with a significant change in the nimodipine group compared to the model group. P-Akt and Akt were expressed significantly higher in both lut groups and the nimodipine group than in the model group.

Conclusion

Luteolin treatment of rats cognitively dysfunctional after experimental cerebral hypo perfusion was neuroprotective by activating the PI3K/Akt signals which inhibit neuronal death in the cerebral cortex and hippocampal region.

Positive Effect of Andrographolide Induced Autophagy on Random-Pattern Skin Flaps Survival

Random-pattern skin flap replantation is generally used in the reconstruction of surgical tissues and covering a series of skin flap defects. However, ischemia often occurs at the flap distal parts, which lead to flap necrosis. Previous studies have shown that andrographolide (Andro) protects against ischemic cardiovascular diseases, but little is known about the effect of Andro on flap viability. Thus, our study aimed to building a model of random-pattern skin flap to understand the mechanism of Andro-induced effects on flap survival. In this study, fifty-four mice were randomly categorized into the control, Andro group, and the Andro+3-methyladenine group. The skin flap samples were obtained on postoperative day 7. Subsequently, the tissue samples were underwent a series of evaluations such as changes in the appearance of flap tissue, the intensity of blood flow, and neovascularization density of skin flap. In our study, the results revealed that Andro enhanced the viability of random skin flaps by enhancing angiogenesis, inhibiting apoptosis, and reducing oxidative stress. Furthermore, our results have also demonstrated that the administration of Andro caused an elevation in the autophagy, and these remarkable impact of Andro were reversed by 3-methyladenine (3-MA), the most common autophagy inhibitor. Together, our data proves novel evidence that Andro is a potent modulator of autophagy capable of significantly increasing random-pattern skin flap survival.

Butylphthalide Inhibits Autophagy and Promotes Multiterritory Perforator Flap Survival

Multiterritory perforator flap is an important plastic surgery technique, yet its efficacy can be limited by partial necrosis at the choke Ⅱ zone. Butylphthalide (NBP) has been used for many diseases but has not been studied in the multiterritory perforator flap. With the effect of NBP, we observed increasing in capillary density, inhibition of autophagy and oxidative stress, and a reduction in apoptosis of cells, all consistent with increased flap survival. However, the protective effect of NBP on multiterritory perforator flap was lost following administration of the autophagy agonist rapamycin (Rap). Through the above results, we assumed that NBP promotes flap survival by inhibiting autophagy. Thus, this study has found a new pharmacological effect of NBP on the multiterritory perforator by inhibiting autophagy to prevent distal postoperative necrosis and exert effects on angiogenesis, oxidative stress, and apoptosis within the flap.

GRK2 deletion improves the function of skin flap following ischemia-reperfusion injury by regulating Drp1

Skin flap ischemia-reperfusion (IR) injury is the key factor to the success rate of skin transplantation, the molecular mechanism of flap IR injury needs to be continuously explored to provide new ideas for its clinical treatment. G protein-coupled receptor kinase 2 (GRK2) was reported to be involved in regulating mitochondrial function, and mitochondria were essential in the process of flap IR. Thus, we aimed to investigate the function of GRK2 in flap ischemia-reperfusion injury and further explore the underlying mechanism. Sixty male C57BL/6 mice were randomly divided into four groups: sham, IR+sh-NC, IR+sh-GRK2 and IR+sh-GRK2+ dynamin-related GTPase 1 (Drp1). Flap function and mitochondrial function were determined after ischemia for 3 hours and reperfusion for 72 hours. Comparing with sham group, GRK2 was increased in flap after IR injury. Loss of GRK2 inhibited cell apoptosis and promoted cell proliferation of flap after IR injury. And deficiency of GRK2 promoted mitochondrial function in flap after IR injury. IR injury up-regulated Drp1 expression in flap, while sh-GRK2 down-regulated Drp1 expression. Furthermore, overexpression of Drp1 removed the protective effect of sh-GRK2. In conclusion, our study revealed that GRK2 deletion improved flap function and mitochondrial function by inhibiting Drp1 expression, which may provide a new insight for the clinical treatment of flap ischemia-reperfusion injury.

Effect of a Combination of Citrus Flavones and Flavanones and Olive Polyphenols for the Reduction of Cardiovascular Disease Risk: An Exploratory Randomized, Double-Blind, Placebo-Controlled Study in Healthy Subjects

A single-center, randomized, double-blind controlled trial was conducted to assess the efficacy of a food supplement based on a combination of grapefruit, bitter orange, and olive extracts administered for eight weeks (n = 51) versus placebo (n = 45) on reduction of cardiovascular risk in healthy volunteers. Study variables included flow-mediated vasodilation (FMD), blood pressure (BP), lipid profile, thrombotic status, oxidative stress biomarkers, inflammation-related biomarkers, anthropometric variables, quality of life, and physical activity. The per-protocol data set was analyzed. In the active product group, there were statistically significant within-group differences at eight weeks as compared with baseline in FMD, systolic and diastolic BP, total cholesterol, LDL-C, LDL-oxidase, oxidized/reduced glutathione ratio, protein carbonyl, and IL-6. Significant between-group differences in these variables were also found. Significant changes in anthropometric variables and quality of life were not observed in the study groups. Changes in the level of physical activity were not recorded. Treatment with the active product was well tolerated. All these findings, taken together, support a beneficial effect of supplementation with a mixture of grapefruit, bitter orange fruits, and olive leaf extracts on underlying mechanisms that may interact each other to decrease the cardiovascular risk in healthy people.

Network Pharmacology Identifies the Mechanisms of Action of TaohongSiwu Decoction Against Essential Hypertension

BACKGROUND TaohongSiwu decoction (THSWT), a traditional herbal formula, has been used to treat cardiovascular and cerebrovascular diseases such as essential hypertension (EH) in China. However, the pharmacological mechanism is not clear. To investigate the mechanisms of THSWT in the treatment of EH, we performed compounds, targets prediction and network analysis using a network pharmacology method. MATERIAL AND METHODS We selected chemical constituents and targets of THSWT according to TCMSP and UniProtKB databases and collected therapeutic targets on EH from Online Mendelian Inheritance in Man (OMIM), Drugbank and DisGeNET databases. The protein-protein interaction (PPI) was analyzed by using String database. Then network was constructed by using Cytoscape_v3.7.1, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment was performed by using Database for Annotation, Visualization and Integrated Discovery (DAVID) software. RESULTS The results of our network pharmacology research showed that the THSWT, composed of 6 Chinese herbs, contained 15 compounds, and 23 genes regulated the main signaling pathways related to EH. Moreover, the PPI network based on targets of THSWT on EH revealed the interaction relationship between targets. These core compounds were 6 of the 15 disease-related compounds in the network, kaempferol, quercetin, luteolin, Myricanone, beta-sitosterol, baicalein, and the core genes contained ADRB2, CALM1, HMOX1, JUN, PPARG, and VEGFA, which were regulated by more than 3 compounds and significantly associated with Calcium signaling pathway, cGMP-PKG signaling pathway, cAMP signaling pathway, PI3K-Akt signaling pathway, Rap1 signaling pathway, and Ras signaling pathway. CONCLUSIONS This network pharmacological study can reveal potential mechanisms of multi-target and multi-component THSWT in the treatment of EH, provide a scientific basis for studying the mechanism.

Luteolin Suppresses the Proliferation of Gastric Cancer Cells and Acts in Synergy with Oxaliplatin

Objective. Gastric cancer, one of the most common malignant tumors worldwide, arises from the gastric mucosal epithelium and severely affects patient health and quality of life. Luteolin (LUT) is a flavonoid found in vegetables and fruits with diverse functions. A large number of studies have confirmed that LUT has an antitumor effect. Therefore, this study is aimed at verifying whether LUT can exert antitumor effects in synergy with oxaliplatin (OXA). As such, we examined the effects of LUT, OXA, and their coadministration in a gastric adenocarcinoma cell line (SGC-7901). We used the MTT assay to quantify the proliferation of SGC-7901 cells, flow cytometry to detect the cell cycle and apoptosis, ELISA to detect the expression of cell-cycle-related proteins, and western blot to detect the expression of related apoptotic factors. The results of this study show that the combination of LUT and OXA inhibited SGC-7901 cell proliferation and induced apoptosis by altering cell-cycle proportions. In addition, the combination also activated Cyt c/caspase signaling in SGC-7901 cells. In summary, LUT synergy with OXA inhibited the proliferation of gastric cancer cells in vitro. The present study also elucidated the mechanism by which LUT potentiated the sensitivity of SGC-7901 cells to OXA through the Cyt c/caspase pathway.

D-allose alleviates ischemia/reperfusion (I/R) injury in skin flap via MKP-1

Background

D-allose was promising in the protection of ischemia/reperfusion (I/R) injury. We intended to investigate the function of D-allose in skin flap of rat followed by the injury of I/R and whether ERK signal pathway was involved in.

Methods

The back flap of Wistar rats was picked up with a vascular bundle of the lateral chest wall. I/R model was made by the venous clamp for 6 h. Rats received D-allose and PD-98059, the inhibitor of ERK1/2, 30 min before modeling. Morphology of tissue was observed by HE staining. Nitric oxide (NO), myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD) levels in skin flap were determined by ELISA kits. mRNA and protein levels were determined by qPCR and Western blot respectively.

Results

D-allose alleviated the condition of pathological changes and raised the survival rate of skin flap injured by I/R. Moreover, D-allose suppressed NO, MPO and MDA while elevated SOD levels during I/R status. Furthermore, D-allose decreased MCP-1, TNF-α, IL-1β and IL-6 levels in skin flap injured by I/R. In addition, D-allose inhibited MKP-1 expression and activated ERK1/2 pathway in skin flap injured by I/R. PD-98059 partially counteracted D-allose effects on I/R injury.

Conclusions

D-allose exerted its protective function via inhibiting MKP-1expression and further activated ERK1/2 pathway to suppress the progress of oxidative stress, inflammation and necrosis, contributing to the survival of skin flap injured by I/R. Thus, D-allose was promising in the transplantation of skin flap.