Synergistic antitumor effects of liposomal honokiol combined with cisplatin in colon cancer models

Nanotechnology-Based Drug Delivery Systems for Honokiol: Enhancing Therapeutic Potential and Overcoming Limitations

Honokiol (HNK) is a small-molecule polyphenol that has garnered considerable attention due to its diverse pharmacological properties, including antitumor, anti-inflammatory, anti-bacterial, and anti-obesity effects. However, its clinical application is restricted by challenges such as low solubility, poor bioavailability, and rapid metabolism. To overcome these limitations, researchers have developed a variety of nano-formulations for HNK delivery. These nano-formulations offer advantages such as enhanced solubility, improved bioavailability, extended circulation time, and targeted drug delivery. However, existing reviews of HNK primarily focus on its clinical and pharmacological features, leaving a gap in the comprehensive evaluation of HNK delivery systems based on nanotechnology. This paper aims to bridge this gap by comprehensively reviewing different types of nanomaterials used for HNK delivery over the past 15 years. These materials encompass vesicle delivery systems, nanoparticles, polymer micelles, nanogels, and various other nanocarriers. The paper details various HNK nano-delivery strategies and summarizes their latest applications, development prospects, and future challenges. To compile this review, we conducted an extensive search using keywords such as "honokiol", "nanotechnology", and "drug delivery system" on reputable databases, including PubMed, Scopus, and Web of Science, covering the period from 2008 to 2023. Through this search, we identified and selected approximately 90 articles that met our specific criteria.

Effects of natural products on cisplatin ototoxicity and chemotherapeutic efficacy

INTRODUCTION

Cisplatin is a very effective chemotherapeutic agent against a variety of solid tumors. Unfortunately, cisplatin causes permanent sensorineural hearing loss in at least two-thirds of patients treated. There are no FDA approved drugs to prevent this serious side effect.

AREAS COVERED

This paper reviews various natural products that ameliorate cisplatin ototoxicity. These compounds are strong antioxidants and anti-inflammatory agents. This review includes mostly preclinical studies but also discusses a few small clinical trials with natural products to minimize hearing loss from cisplatin chemotherapy in patients. The interactions of natural products with cisplatin in tumor-bearing animal models are highlighted. A number of natural products did not interfere with cisplatin anti-tumor efficacy and some agents actually potentiated cisplatin anti-tumor activity.

EXPERT OPINION

There are a number of natural products or their derivatives that show excellent protection against cisplatin ototoxicity in preclinical studies. There is a need to insure uniform standards for purity of drugs derived from natural sources and to ensure adequate pharmacokinetics and safety of these products. Natural products that protect against cisplatin ototoxicity and augment cisplatin's anti-tumor effects in multiple studies of tumor-bearing animals are most promising for advancement to clinical trials. The most promising natural products include honokiol, sulforaphane, and thymoquinone.

Novel Delivery Systems of Polyphenols and Their Potential Health Benefits

Liposome-based delivery systems have been studied and used more frequently in recent years due to their advantages, such as low toxicity, specificity, and the ability to protect the encapsulated substance from environmental factors, which could otherwise degrade the active compound and reduce its effectiveness. Given these benefits, many researchers have encapsulated polyphenols in liposomes, thus increasing their bioavailability and stability. Similarly, polyphenols encapsulated in liposomes are known to produce more substantial effects on targeted cells than unencapsulated polyphenols, while having minimal cytotoxicity in healthy cells. Although polyphenols play a role in preventing many types of disease and generally have beneficial effects on health, we solely focused on their chemopreventive effects on cancer through liposomes in this review. Our goal was to summarize the applicability and efficacy of liposomes encapsulated with different classes of polyphenols on several types of cancer, thus opening the opportunity for future studies based on these drug delivery systems.

Systemic application of honokiol prevents cisplatin ototoxicity without compromising its antitumor effect

Cisplatin is a potent drug used in about 40% of cancer treatment but also leads to severe deafness in 60-80% of the cases. Although the mechanism is known to be related to the accumulation of reactive oxygen species (ROS), no drug or FDA approved treatment is currently available to prevent cisplatin ototoxicity. With this study, we show for the first time that honokiol (HNK), a pleiotropic poly-phenol prevents cisplatin-induced hearing loss. HNK also improves the wellbeing of the mice during the treatment, determined by the increase in the number of surviving animals. In a transgenic tumor mouse model, HNK does not hinder cisplatin's antitumor effect. The mechanism is related to the activation of sirtuin 3, a deacetylase in mitochondria essential for ROS detoxification. We expect a paradigm shift in cisplatin chemotherapy based on the current study and future clinical trials, where honokiol is applied to reduce side effects including hearing loss.

Counteracting Cisplatin-Induced Testicular Damages by Natural Polyphenol Constituent Honokiol

Cisplatin, despite its anti-cancer ability, exhibits severe testicular toxicities when applied systemically. Due to its wide application in cancer treatment, reduction of its damages to normal tissue is an imminent clinical need. Here we evaluated the effects of honokiol, a natural lipophilic polyphenol compound, on cisplatin-induced testicular injury. We showed in-vitro and in-vivo that nanosome-encapsulated honokiol attenuated cisplatin-induced DNA oxidative stress by suppressing intracellular reactive oxygen species production and elevating gene expressions of mitochondrial antioxidation enzymes. Nanosome honokiol also mitigated endoplasmic reticulum stress through down regulation of Bip-ATF4-CHOP signaling pathway. Additionally, this natural polyphenol compound diminished cisplatin-induced DNA breaks and cellular apoptosis. The reduced type I collagen accumulation in the testis likely attributed from inhibition of TGFβ1, αSMA and ER protein TXNDC5 protein expression. The combinatorial beneficial effects better preserve spermatogenic layers and facilitate repopulation of sperm cells. Our study renders opportunity for re-introducing cisplatin to systemic anti-cancer therapy with reduced testicular toxicity and restored fertility.

Honokiol: A Review of Its Anticancer Potential and Mechanisms

Cancer is characterised by uncontrolled cell division and abnormal cell growth, which is largely caused by a variety of gene mutations. There are continuous efforts being made to develop effective cancer treatments as resistance to current anticancer drugs has been on the rise. Natural products represent a promising source in the search for anticancer treatments as they possess unique chemical structures and combinations of compounds that may be effective against cancer with a minimal toxicity profile or few side effects compared to standard anticancer therapy. Extensive research on natural products has shown that bioactive natural compounds target multiple cellular processes and pathways involved in cancer progression. In this review, we discuss honokiol, a plant bioactive compound that originates mainly from the Magnolia species. Various studies have proven that honokiol exerts broad-range anticancer activity in vitro and in vivo by regulating numerous signalling pathways. These include induction of G0/G1 and G2/M cell cycle arrest (via the regulation of cyclin-dependent kinase (CDK) and cyclin proteins), epithelial-mesenchymal transition inhibition via the downregulation of mesenchymal markers and upregulation of epithelial markers. Additionally, honokiol possesses the capability to supress cell migration and invasion via the downregulation of several matrix-metalloproteinases (activation of 5' AMP-activated protein kinase (AMPK) and KISS1/KISS1R signalling), inhibiting cell migration, invasion, and metastasis, as well as inducing anti-angiogenesis activity (via the down-regulation of vascular endothelial growth factor (VEGFR) and vascular endothelial growth factor (VEGF)). Combining these studies provides significant insights for the potential of honokiol to be a promising candidate natural compound for chemoprevention and treatment.

Nanoparticulated Honokiol Mitigates Cisplatin-Induced Chronic Kidney Injury by Maintaining Mitochondria Antioxidant Capacity and Reducing Caspase 3-Associated Cellular Apoptosis

Cisplatin is a potent anti-cancer drug, however, its accompanied organ-toxicity hampers its clinical applications. Cisplatin-associated kidney injury is known to result from its accumulation in the renal tubule with excessive generation of reactive oxygen species. In this study, we encapsulated honokiol, a natural lipophilic polyphenol constituent extracted from Magnolia officinalis into nano-sized liposomes (nanosome honokiol) and examined the in vivo countering effects on cisplatin-induced renal injury. We observed that 5 mg/kg body weight. nanosome honokiol was the lowest effective dosage to efficiently restore renal functions of cisplatin-treated animals. The improvement is likely due the maintenance of cellular localization of cytochrome c and thus preserves mitochondria integrity and their redox activity, which as a consequence, reduced cellular oxidative stress and caspase 3-associated apoptosis. These improvements at the cellular level are later reflected on the observed reduction of kidney inflammation and fibrosis. In agreement with our earlier in vitro study showing protective effects of honokiol on kidney cell lines, we demonstrated further in the current study, that nanosuspension-formulated honokiol provides protective effects against cisplatin-induced chronic kidney damages in vivo. Our findings not only benefit cisplatin-receiving patients with reduced renal side effects, but also provide potential alternative and synergic solutions to improve clinical safety and efficacy of cisplatin treatment on cancer patients.

Honokiol induces apoptosis and suppresses migration and invasion of ovarian carcinoma cells via AMPK/mTOR signaling pathway

Honokiol, a natural biphenolic compound, exerts anticancer effects through a variety of mechanisms on multiple types of cancer with relatively low toxicity. Adenosine 5'‑phosphate‑activated protein kinase (AMPK), an essential regulator of cellular homeostasis, may control cancer progression. The present study aimed to investigate whether the anticancer activities of honokiol in ovarian cancer cells were mediated through the activation of AMPK. Honokiol decreased cell viability of 2 ovarian cancer cell lines, with an half‑maximal inhibitory concentration value of 48.71±11.31 µM for SKOV3 cells and 46.42±5.37 µM for Caov‑3 cells. Honokiol induced apoptosis via activation of caspase‑3, caspase‑7 and caspase‑9, and cleavage of poly‑(adenosine 5'‑diphosphate‑ribose) polymerase. Apoptosis induced by honokiol was weakened by compound C, an AMPK inhibitor, suggesting that honokiol‑induced apoptosis was dependent on the AMPK/mechanistic target of rapamycin signaling pathway. Additionally, honokiol inhibited the migration and invasion of ovarian cancer cells. The combined treatment of honokiol with compound C reversed the activities of honokiol in wound healing and Matrigel invasion assays. These results indicated that honokiol may have therapeutic potential in ovarian cancer by targeting AMPK activation.

Honokiol, a Polyphenol Natural Compound, Attenuates Cisplatin-Induced Acute Cytotoxicity in Renal Epithelial Cells Through Cellular Oxidative Stress and Cytoskeleton Modulations

Cisplatin is a potent anti-cancer drug that has been widely used in the treatment of various cancers; however, cisplatin administration results in severe nephrotoxicity and impedes its clinical applications. In this study, we showed that honokiol, a polyphenol constituent extracted from Magnolia officinalis exhibited a short-term protective effect against cisplatin-induced damages in renal epithelial cells in vitro. The protective effects of honokiol were resulted from the combination of (1) reduced cellular oxidative stress ranging from 53 to 32% reduction during a 24-h incubation, (2) the maintenance of cellular antioxidant capacity and (3) the stabilization of cytoskeletal structure of the kidney epithelial cells. By promoting the polymerization of actin (1.6-fold increase) and tubulin (1.8-fold increase) cytoskeleton, honokiol not only maintained epithelial cell morphology, but also stabilized cellular localizations of tight junction protein Occludin and adhesion junction protein E-Cadherin. With stabilized junction protein complexes and structural polymerized cytoskeleton network, honokiol preserved epithelial cell polarity and morphology and thus reduced cisplatin-induced cell disruption and damages. Our data demonstrated for the first time that honokiol could counteract with cisplatin-induced damages in renal epithelial cells in vitro, future in vivo studies would further validate the potential clinical application of honokiol in cisplatin-based cancer treatments with reduced nephrotoxicity.

Honokiol, an activator of Sirtuin-3 (SIRT3) preserves mitochondria and protects the heart from doxorubicin-induced cardiomyopathy in mice

Doxorubicin is the chemotherapeutic drug of choice for a wide variety of cancers, and cardiotoxicity is one of the major side effects of doxorubicin treatment. One of the main cellular targets of doxorubicin in the heart is mitochondria. Mitochondrial sirtuin, SIRT3 has been shown to protect against doxorubicin-induced cardiotoxicity. We have recently identified honokiol (HKL) as an activator of SIRT3, which protects the heart from developing pressure overload hypertrophy. Here, we show that HKL-mediated activation of SIRT3 also protects the heart from doxorubicin-induced cardiac damage without compromising the tumor killing potential of doxorubicin. Doxorubicin-induced cardiotoxicity is associated with increased ROS production and consequent fragmentation of mitochondria and cell death. HKL-mediated activation of SIRT3 prevented Doxorubicin induced ROS production, mitochondrial damage and cell death in rat neonatal cardiomyocytes. HKL also promoted mitochondrial fusion. We also show that treatment with HKL blocked doxorubicin-induced cardiac toxicity in mice. This was associated with reduced mitochondrial DNA damage and improved mitochondrial function. Furthermore, treatments of mice, bearing prostrate tumor-xenografts, with HKL and doxorubicin showed inhibition of tumor growth with significantly reduced cardiac toxicity. Our results suggest that HKL-mediated activation of SIRT3 protects the heart from doxorubicin-induced cardiotoxicity and represents a potentially novel adjunct for chemotherapy treatments.

Honokiol inhibits in vitro and in vivo growth of oral squamous cell carcinoma through induction of apoptosis, cell cycle arrest and autophagy

Honokiol, an active natural product derived from Magnolia officinalis, exerted anticancer effects through a variety of mechanisms on multiple types of cancers. In this study, the molecular mechanisms of honokiol in suppressing the human oral squamous cell carcinoma (OSCC) cells were evaluated. Treatment of two OSCC cell lines with honokiol resulted in reducing the cell proliferation and arresting the cell cycle at G1 stage which was correlated with the down‐regulation of Cdk2 and Cdk4 and the up‐regulation of cell cycle suppressors, p21 and p27. In addition, the caspase‐dependent programmed cell death was substantially detected, and the autophagy was induced as the autophagosome formation and autophagic flux proceeded. Modulation of autophagy by autophagic inducer, rapamycin or inhibitors, 3‐MA or bafilomycin, potentiated the honokiol‐mediated anti‐OSCC effects where honokiol exerted multiple actions in suppression of MAPK pathway and regulation of Akt/mTOR or AMPK pathways. As compared to clinical therapeutic agent, 5‐FU, honokiol exhibited more potent activity against OSCC cells and synergistically enhanced the cytotoxic effect of 5‐FU. Furthermore, orally administrated honokiol exerted effective antitumour activity in vivo in OSCC‐xenografted mice. Thus, this study revealed that honokiol could be a promising candidate in preventing human OSCCs.

Regulatory effect of astragalus polysaccharides on intestinal intraepithelial γδT cells of tumor bearing mice

Astragalus polysaccharides (APS) possess multiple immunomodulatory activities. Due to its high molecular weight, orally administration of APS is not easily absorbed into the blood stream, and how APS exerts its capacity in vivo is still not well elucidated. We assume that enteric mucosal immune response might trigger the immune regulation of APS, and our previous studies demonstrated that APS had regulatory activity on intraepithelial lymphocytes (IELs). Therefore, this study aimed to investigate the functions of APS on intestinal intraepithelial γδT cells, a major subset in IELs and an essential component of maintaining homeostasis and immune regulation in enteric mucosa. Results showed that APS could promote proliferation and function of intestinal intraepithelial γδT cells in vitro, the IFN-γ, FasL and GrB mRNA levels in γδT cells were all significantly increased. Moreover, APS also improved the activity of intestinal intraepithelial γδT cells in vivo, as cytokines production and cytotoxicity of γδT cells were all remarkably improved in tumor-bearing mice treated with APS. In addition, the levels of TNF-α and IFN-γ were significantly increased, whereas the levels of IL-10 and TGF-β were significantly decreased in tumor-bearing mice treated with APS. In conclusion, this study demonstrated that APS could improve proliferation and function of intestinal intraepithelial γδT cells, which might an important pathway for immunomodulation of APS in cancer therapy.

Inducing apoptosis of cancer cells using small-molecule plant compounds that bind to GRP78

Background:

Glucose regulated protein 78 (GRP78) functions as a sensor of endoplasmic reticulum (ER) stress. The aim of this study was to test the hypothesis that molecules that bind to GRP78 induce the unfolded protein response (UPR) and enhance cell death in combination with ER stress inducers.

Methods:

Differential scanning calorimetry (DSC), measurement of cell death by flow cytometry and the induction of ER stress markers using western blotting.

Results:

Epigallocatechin gallate (EGCG), a flavonoid component of Green Tea Camellia sinensis, and honokiol (HNK), a Magnolia grandiflora derivative, bind to unfolded conformations of the GRP78 ATPase domain. Epigallocatechin gallate and HNK induced death in six neuroectodermal tumour cell lines tested. Levels of death to HNK were twice that for EGCG; half-maximal effective doses were similar but EGCG sensitivity varied more widely between cell types. Honokiol induced ER stress and UPR as predicted from its ability to interact with GRP78, but EGCG was less effective. With respect to cell death, HNK had synergistic effects on melanoma and glioblastoma cells with the ER stress inducers fenretinide or bortezomib, but only additive (fenretinide) or inhibitory (bortezomib) effects on neuroblastoma cells.

Conclusion:

Honokiol induces apoptosis due to ER stress from an interaction with GRP78. The data are consistent with DSC results that suggest that HNK binds to GRP78 more effectively than EGCG. Therefore, HNK may warrant development as an antitumour drug.

Application of liposomes in drug development--focus on gastroenterological targets

Over the past decade, liposomes became a focal point in developing drug delivery systems. New liposomes, with novel lipid molecules or conjugates, and new formulations opened possibilities for safely and efficiently treating many diseases including cancers. New types of liposomes can prolong circulation time or specifically deliver drugs to therapeutic targets. This article concentrates on current developments in liposome based drug delivery systems for treating diseases of the gastrointestinal tract. We will review different types and uses of liposomes in the development of therapeutics for gastrointestinal diseases including inflammatory bowel diseases and colorectal cancer.