Enhanced Induction of Apoptosis in HaCaT Cells by Luteolin Encapsulated in PEGylated Liposomes—Role of Caspase-3/Caspase-14

Nano-scale drug delivery systems for luteolin: advancements and applications

Luteolin (Lu) is a naturally occurring flavonoid compound with a diverse array of pharmacological activities, including anti-tumor, anti-inflammatory, antibacterial, and neuroprotective properties. However, the therapeutic efficacy and clinical application of Lu are significantly hindered by inherent limitations, such as poor water solubility, short half-life, low bioavailability, and potential off-target toxicity. Recent studies have demonstrated that the utilization of nanocarriers presents a promising strategy to enhance the solubility of Lu, prolong its circulation time, and improve its targeting ability. Despite numerous reviews over the past few decades having focused on the source, pharmacological activities, and molecular mechanisms of Lu, there exists a conspicuous gap in the literature regarding a comprehensive review of Lu-loaded nanoformulations and their applications. To address this gap, we present an exhaustive overview of the advancements and applications of nano-scale drug delivery systems specifically designed for Lu. These platforms encompass micelles, nanocarrier-based systems, emulsified drug delivery systems, and vesicular drug delivery systems. We provide detailed insights into the synthetic materials, preparation methods, physicochemical properties, and significant outcomes associated with these nanoformulations. This systematic review will be particularly valuable to researchers seeking novel avenues in the field of nano-delivery strategies and exploring the potential clinical applications of Lu.

Modulation of PPAR-γ, SREBP-1c and inflammatory mediators by luteolin ameliorates β-cell dysfunction and renal damage in a rat model of type-2 diabetes mellitus

BACKGROUND

Natural products have been recommended as a complementary therapy for type 2 diabetes mellitus (T2DM) due to constraints of safety and tolerability of existing anti-diabetic agents. Luteolin exhibits anti-diabetic and anti-inflammatory effects. Hence, the impact of luteolin on glucose homoeostasis and organ damage was investigated in high-fat diet (HFD) and streptozotocin (STZ) induced T2DM in rats.

METHODS AND RESULTS

Male Wistar rats were maintained on HFD (provided 55% energy as fat) for 10 days. Subsequently, a single dose of 40 mg/kg STZ was injected intraperitoneally on the 11th day. Seventy-two hours after STZ administration, diabetic rats with established hyperglycemia (fasting serum glucose > 200 mg/dL) were randomized into different groups having six rats each and orally administered either 0.5% hydroxy propyl cellulose or pioglitazone (10 mg/kg) or luteolin (50 mg/kg or 100 mg/kg) once daily for 28 days, while continuing HFD for respective groups. Luteolin significantly reduced hyperglycaemia, homoeostasis model assessment (HOMA) of insulin resistance (HOMA-IR) levels, and improved hypoinsulinemia and HOMA of b-cell function (HOMA-B) in a dose-dependent manner. Increased TNF-α, IL-6 and NFκB levels in diabetic rats were significantly regulated. Additionally, luteolin significantly augmented PPAR-γ expression while attenuating sterol regulatory element binding protein-1c (SREBP-1c) expression. Histopathological scrutiny validated that luteolin effectively attenuated HFD-STZ-induced injury in pancreatic β-cells and kidneys to near normalcy.

CONCLUSION

Our study showed that luteolin ameliorated hyperglycemia and improved hypoinsulinemia, β-cell dysfunction, and renal impairment in HFD-STZ-induced diabetic rats by attenuating inflammation and dysregulated cytokine secretion through modulation of PPAR-γ, TNF-α, IL-6 and NF-kB expression and down-regulation of SREBP-1c.

Luteolin Mitigates Diabetic Dyslipidemia in Rats by Modulating ACAT-2, PPARα, SREBP-2 Proteins, and Oxidative Stress

Diabetic dyslipidemia is a crucial link between type-2 diabetes mellitus (T2DM) and atherosclerotic cardiovascular diseases (ASCVD). Natural biologically active substances have been advocated as complementary remedies for ASCVD and T2DM. Luteolin, a flavonoid, exhibits antioxidant, hypolipidemic, and antiatherogenic effects. Hence, we aimed to determine influence of luteolin on lipid homeostasis and hepatic damage in rats with T2DM induced by high-fat-diet (HFD) and streptozotocin (STZ). After being fed HFD for 10 days, male Wistar rats received 40 mg/kg STZ intraperitoneal injection on 11th day. Seventy-two hours later, hyperglycemic rats (fasting glucose > 200 mg/dL) were randomized into groups, and oral hydroxy-propyl-cellulose, atorvastatin (5 mg/kg), or luteolin (50 mg/kg or 100 mg/kg) administered daily, while continuing HFD for 28 days. Luteolin significantly ameliorated dyslipidemia levels and concomitantly improved atherogenic index of plasma in a dose-dependent manner. Increased levels of malondialdehyde and diminished levels of superoxide dismutase, catalase, and glutathione in HFD-STZ-diabetic rats were significantly regulated by luteolin. Luteolin significantly intensified PPARα expression while decreasing expression of acyl-coenzyme A:cholesterol acyltransferase-2 (ACAT-2) and sterol regulatory element binding protein-2 (SREBP-2) proteins. Moreover, luteolin effectively alleviated hepatic impairment in HFD-STZ-diabetic rats to near-normal control levels. The findings of the present study expound mechanisms by which luteolin mitigated diabetic dyslipidemia and alleviated hepatic impairment in HFD-STZ-diabetic rats by amelioration of oxidative stress, modulation of PPARα expression, and downregulation of ACAT-2 and SREBP-2. In conclusion, our results imply that luteolin may be efficacious in management of dyslipidemia in T2DM, and future research may be essential to substantiate our findings.

Folate receptor targeted NIR cleavable liposomal delivery system augment penetration and therapeutic efficacy in breast cancer

BACKGROUND

Liposomes are predominantly used sorts of nanocarriers for active targeted delivery through surface functionalization using targeting ligand. The folate receptors are overexpressed in various cancers including breast cancer and because of its binding aptitude specifically to folate receptors, folic acid became the attractive ligand.

METHODS

In this research, we have developed a folate and Poly-l-Lysine conjugate and coated this conjugate onto the liposomes. The prepared liposomes were characterized using DLS, FTIR, NMR, SEM, TEM, XRD, AFM, stability and drug release studies. Furthermore, In vitro studies were carried out on FR overexpressed breast cancer cell line.

RESULTS

The FA-LUT-ABC-Lip have diameter of 183 ± 3.17 nm with positive surface charge +33.65 ± 3 mV and the drug release studies confirm the NIR responsive payload cleavage. The coated formulation (in presence of NIR light) effectively reduced the IC₅₀ values and kills breast cancer cells through FR mediated internalization and accelerated drug release. Moreover, LUT Formulation shows anticancer effect due to significant inhibition of cell migration and proliferation by regulating VEGF expression and induced apoptosis through the caspase-3 up-regulation.

CONCLUSION

It is evident from the in vitro studies that the formulation was found to be very effective and can be explored for triggered and targeted delivery of the substances through active targeting.

GENERAL SIGNIFICANCE

Combining receptor mediated drug delivery with triggered release aid in more amounts of drug reaching the target site and achieving enhanced therapeutic activity.

Multi-Faceted Role of Luteolin in Cancer Metastasis: EMT, Angiogenesis, ECM Degradation and Apoptosis

Luteolin (3',4',5,7-tetrahydroxyflavone), a member of the flavonoid family derived from plants and fruits, shows a wide range of biomedical applications. In fact, due to its anti-inflammatory, antioxidant and immunomodulatory activities, Asian medicine has been using luteolin for centuries to treat several human diseases, including arthritis, rheumatism, hypertension, neurodegenerative disorders and various infections. Of note, luteolin displays many anti-cancer/anti-metastatic properties. Thus, the purpose of this review consists in highlighting the relevant mechanisms by which luteolin inhibits tumor progression in metastasis, i.e., affecting epithelial-mesenchymal transition (EMT), repressing angiogenesis and lysis of extracellular matrix (ECM), as well as inducing apoptosis.

Experimental study on the effect of luteolin on the proliferation, apoptosis and expression of inflammation-related mediators in lipopolysaccharide-induced keratinocytes

OBJECTIVE

This study aimed at exploring the effects of luteolin on psoriasis-like cell model proliferation, apoptosis regulation and the expression of inflammation-related mediators.

METHODS

A Cell Counting Kit-8 (CCK-8) assay was used to determine the survival rate of human immortalized keratinocytes (HaCaT cells) and normal human epidermal keratinocytes (NHEK cells) following stimulation with luteolin and lipopolysaccharide (LPS). Western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to detect the protein and mRNA expressions of nuclear factor (NF)-κB p65 and interleukin (IL)-6 after LPS stimulation. Then a luteolin stimulation protocol (10 μmol/L, 24 h) was determined and a reasonable LPS stimulation concentration (20 μg/mL, 24 h) was chosen to establish the psoriasis cell model. Keratinocytes in luteolin pre-treatment and control groups were stimulated with 20 μg/mL LPS for 24 h, and the expressions of NF-κB p65 and IL-6 were detected by western blot and RT-qPCR. The apoptosis of HaCaT cells was detected by flow cytometry, and the enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of psoriasis-related inflammatory factors.

RESULTS

CCK-8 assay indicated that luteolin inhibited the proliferation of keratinocytes. LPS stimulated the proliferation of keratinocytes and upregulated the expression of NF-κB p65 and IL-6 in a concentration-dependent manner, and induced psoriasis-like changes. Furthermore, the protein and mRNA expression levels of NF-κB p65 and IL-6 were decreased in the luteolin pre-stimulation group (p < 0.05). Treatment with luteolin downregulated the expression of the LPS-induced inflammatory mediators in keratinocytes (p < 0.05). The flow cytometry results showed that luteolin induced HaCaT cells apoptosis. Finally, ELISA results demonstrated that luteolin inhibited the release of the IL-17, IL-23 and tumor necrosis factor α (TNF-α) in the pre-stimulation group (p < 0.05).

CONCLUSION

This study confirmed that luteolin can effectively relieve inflammatory mediators in LPS-induced keratinocyte models of psoriasis, which suggested the potential of luteolin in treating psoriasis.

Pep27 Mutant Immunization Inhibits Caspase-14 Expression to Alleviate Inflammatory Bowel Disease via Treg Upregulation

Inflammatory bowel disease (IBD) is a highly prevalent gut inflammatory disorder. Complicated clinical outcomes prolong the use of conventional therapy and often lead to compromised immunity followed by adverse events and high relapse rates. Thus, a profound medical intervention is required. Previously, intranasal immunization of pneumococcal pep27 mutant (Δpep27) exhibited long-lasting protection against immune-related disorders. System biology analysis has predicted an inverse correlation between Δpep27 immunization and gastroenteritis. Recently, we established that Δpep27-elicited Tregs repressed Wnt5a expression and enhanced barrier integrity, suggesting the restoration of immunological tolerance. Therefore, we evaluated whether Δpep27 can alleviate IBD. Δpep27 dose-dependent response was analyzed in dextran sulfate sodium-induced mice using transcriptome analysis. Pro- and anti-inflammatory signatures were cross-correlated by quantitative PCR and western blot analyses. To address the hierarchy regulating the activity of caspase-14, an undefined marker in IBD, and regulatory T cells (Tregs), antibody-based neutralization studies were conducted. Fecal microbiome profiles were analyzed by 16S rRNA pyrosequencing. Δpep27 significantly attenuated dextran sulfate sodium-induced oxidative stress parameters, proinflammatory cytokines, caspase-14 expression level, and upregulated tight junction, anti-inflammatory genes IL-10 and TGF-β1 via upregulation of Tregs to restore healthy gut microbiota. Neutralization studies unveiled that ∆pep27 had a remedial effect via Treg upregulation. Caspase-14, being an important mediator in the pathogenesis of IBD, can be an alternate therapeutic target in IBD. ∆pep27-increased Tregs repressed caspase-14 expression and reversed gut microbial dysbiosis, aiding to re-establish immunological tolerance.

Effect of nanovesicular surface-functionalization via chitosan and/or PEGylation on cytotoxicity of tamoxifen in induced-breast cancer model

AIMS

The effect of surface-modification of Tamoxifen (Tam)-loaded-niosomes on drug cytotoxicity and bio-distribution, via functionalization with chitosan and/or PEGylation, was investigated.

MATERIALS AND METHODS

Tam-loaded hybrid-nanocarriers (Tam-loaded niosomes, chitosomes, PEGylated niosomes, and PEGylated chitosomes) were formulated and characterized.

KEY FINDINGS

Chitosanization with/without PEGylation proved to selectively enhance Tam-release at the cancerous-acidic micromilieu. Cytotoxic activity study showed that Tam-loaded PEGylated niosomes had a lower IC₅₀ value on MCF-7 cell line (0.39, 0.35, and 0.27 times) than Tam-loaded PEGylated chitosomes, Tam-loaded niosomes, and Tam-loaded chitosomes, respectively. Cell cycle analysis showed that PEGylation and/or Chitosanization significantly impact Tam efficiency in inducing apoptosis, with a preferential influence of PEGylation over chitosanization. The assay of Annexin-V/PI double staining revealed that chitosanized-nanocarriers had a significant role in increasing the incidence of apoptosis over necrosis. Besides, PEGylated-nanocarriers increased apoptosis, as well as total death and necrosis percentages more than what was shown from free Tam. Moreover, the average changes in both Bax/Bcl-2 ratio and Caspase 9 were best improved in cells treated by Tam-loaded PEGylated niosomes over all other formulations. The in-vivo study involving DMBA-induced-breast cancer rats revealed that PEGylation made the highest tumor-growth inhibition (84.9 %) and breast tumor selectivity, while chitosanization had a lower accumulation tendency in the blood (62.3 ng/ml) and liver tissues (103.67 ng/ml). The histopathological specimens from the group treated with Tam-loaded PEGylated niosomes showed the best improvement over other formulations.

SIGNIFICANCE

All these results concluded the crucial effect of both PEGylation and chitosan-functionalization of Tam-loaded niosomes in enhancing effectiveness, targetability, and safety.

Fabrication, physicochemical characterization and In vitro anticancer activity of nerolidol encapsulated solid lipid nanoparticles in human colorectal cell line

Nerolidol is a sesquiterpene that occurs naturally and possesses a diverse set of biological characteristics including anticancer activity but has limited solubility, bioavailability, and fast hepatic metabolism. The goal of this study was to develop a nanocarrier system encapsulating a bioactive as well as to evaluate its efficacy in Human Colorectal Cell Line. Solid lipid nanoparticles were fabricated by the emulsion solvent evaporation method and determined the particle size, polydispersity index (PDI), zeta potential, % entrapment efficiency, scanning electron microscopy (SEM), transmission electron microscopy (TEM), drug-excipient interaction study of developed nanoparticles. MTT assay was used to assess the cytotoxicity of formulations in vitro. Nerolidol loaded solid lipid nanoparticles (NR-LNPs) have presented satisfactory properties: mean particles diameter of 159 ± 4.89 nm, PDI of 0.32 ± 0.01, the zeta potential value was found to be -10 ± 1.97 and % entrapment efficiency 71.3% ± 6.11. The formulations demonstrated enhanced biological activity due to enhanced solubility and stability of the bioactive after loading into a nanoformulation along with the better internalization inside the cells.

Hepatoprotective Effects of Bioflavonoid Luteolin Using Self-Nanoemulsifying Drug Delivery System

Luteolin (LUT) is a natural pharmaceutical compound that is weakly water soluble and has low bioavailability when taken orally. As a result, the goal of this research was to create self-nanoemulsifying drug delivery systems (SNEDDS) for LUT in an attempt to improve its in vitro dissolution and hepatoprotective effects, resulting in increased oral bioavailability. Using the aqueous phase titration approach and the creation of pseudo-ternary phase diagrams with Capryol-PGMC (oil phase), Tween-80 (surfactant), and Transcutol-HP (co-emulsifier), various SNEDDS of LUT were generated. SNEDDS were assessed for droplet size, polydispersity index (PDI), zeta potential (ZP), refractive index (RI), and percent of transmittance (percent T) after undergoing several thermodynamic stability and self-nanoemulsification experiments. When compared to LUT suspension, the developed SNEDDS revealed considerable LUT release from all SNEDDS. Droplet size was 40 nm, PDI was <0.3, ZP was -30.58 mV, RI was 1.40, percent T was >98 percent, and drug release profile was >96 percent in optimized SNEDDS of LUT. For in vivo hepatoprotective testing in rats, optimized SNEDDS was chosen. When compared to LUT suspension, hepatoprotective tests showed that optimized LUT SNEDDS had a substantial hepatoprotective impact. The findings of this investigation suggested that SNEDDS could improve bioflavonoid LUT dissolution rate and therapeutic efficacy.

Paving Luteolin Therapeutic Potentialities and Agro-Food-Pharma Applications: Emphasis on In Vivo Pharmacological Effects and Bioavailability Traits

Luteolin is a naturally occurring secondary metabolite belonging to the class of flavones. As many other natural flavonoids, it is often found in combination with glycosides in many fruits, vegetables, and plants, contributing to their biological and pharmacological value. Many preclinical studies report that luteolin present excellent antioxidant, anticancer, antimicrobial, neuroprotective, cardioprotective, antiviral, and anti-inflammatory effects, and as a consequence, various clinical trials have been designed to investigate the therapeutic potential of luteolin in humans. However, luteolin has a very limited bioavailability, which consequently affects its biological properties and efficacy. Several drug delivery strategies have been developed to raise its bioavailability, with nanoformulations and lipid carriers, such as liposomes, being the most intensively explored. Pharmacological potential of luteolin in various disorders has also been underlined, but to some of them, the exact mechanism is still poorly understood. Given the great potential of this natural antioxidant in health, this review is aimed at providing an extensive overview on the in vivo pharmacological action of luteolin and at stressing the main features related to its bioavailability, absorption, and metabolism, while essential steps determine its absolute health benefits and safety profiles. In addition, despite the scarcity of studies on luteolin bioavailability, the different drug delivery formulations developed to increase its bioavailability are also listed here.

Topical transdermal chemoprevention of breast cancer: where will nanomedical approaches deliver us?

Despite the high incidence of breast cancer, there are few pharmacological prevention strategies for the high-risk population and those that are available have low adherence. Strategies that deliver drugs directly to the breasts may increase drug local concentrations, improving efficacy, safety and acceptance. The skin of the breast has been proposed as an administration route for local transdermal therapy, which may improve drug levels in the mammary tissue, due to both deep local penetration and percutaneous absorption. In this review, we discuss the application of nanotechnology-based strategies for the delivery of well established and new agents as well as drug repurposing using the topical transdermal route to improve the outcomes of preventive therapy for breast cancer.

Nanoencapsulation of Pomegranate Extract to Increase Stability and Potential Dermatological Protection

Pomegranate extract (PG-E) has been reported to exert a protective effect on the skin due to its antioxidant activity. Ingredients rich in phenolic compounds are unstable in extract solutions, and, therefore, the use of a suitable nanosystem to encapsulate this type of extract could be necessary in different biotechnological applications. Thus, we investigated the capacity of Brassica oleracea L. (cauliflower) inflorescence vesicles (CI-vesicles) to encapsulate PG-E and determined the stability and the antioxidant capacity of the system over time. In addition, the protective effect against UV radiation and heavy metals in HaCaT cells was also tested. The CI-vesicles had an entrapment efficiency of around 50%, and accelerated stability tests did not show significant changes in the parameters tested. The results for the HaCaT cells showed the non-cytotoxicity of the CI-vesicles containing PG-E and their protection against heavy metals (lead acetate and mercuric chloride) and UV-B radiation through a reduction of oxidative stress. The reduction of the percentage of deleted mtDNA (mtDNA4977, "common deletion") in UV-treated HaCaT cells due to the presence of CI-vesicles containing PG-E indicated the mechanism of protection. Therefore, the effects of CI-vesicles loaded with PG-E against oxidative stress support their utilization as natural cosmeceuticals to protect skin health against external damage from environmental pollution and UV radiation.

Core-Shell Encapsulation of Lipophilic Substance in Jelly Fig (Ficus awkeotsang Makino) Polysaccharides Using an Inexpensive Acrylic-Based Millifluidic Device

The polysaccharides extracted from the achenes of jelly fig, Ficus awkeotsang Makino, were mainly composed of low methyl pectin and used as a novel shell material for encapsulating lipophilic bioactives in the core of microcapsule. The polysaccharide microcapsules with oil core were prepared using a novel acrylic-based millifluidic device developed in this study. To investigate the physiochemical properties of and find the suitable formula of polysaccharide shells, the films casted with jelly fig polysaccharide were thoroughly characterized. For the preparation of microcapsules, the millifluidic device was optimized by controlling the flow rate to obtain uniform spherical shape with a core diameter of 1.4-1.9 mm and the outer diameter of 2.1-2.8 mm. The encapsulation efficiency was around 90%, and the microcapsules displayed a clear boundary between the polysaccharide shell and oil core. Encapsulation of curcumin in the microcapsules was prepared to test the applicability of the device and processes developed in this study, and the results showed that the microencapsulation could enhance the stability of curcumin against external environment. Overall, the results suggested that the jelly fig polysaccharides and the developed millifluidic device can be useful for the preparation of core-shell microcapsules for encapsulation of lipophilic bioactives.