Polyphenol nanoformulations for cancer therapy: experimental evidence and clinical perspective

Development of Resveratrol-Loaded Herbal Extract-Based Nanocomposites and Their Application to the Therapy of Ovarian Cancer

Resveratrol (RSV) and the ethanol extract of Angelica gigas Nakai (AGN Ex)-based nanoparticles (NPs) were prepared using the nanocrystal concept. AGN/RSV NPs with 224 nm hydrodynamic size, unimodal size distribution, and negative zeta potential values were developed with the emulsification and solvent evaporation techniques. The crystalline properties of AGN Ex and RSV were transformed during the emulsification and solvent evaporation processes, thus, AGN NPs and AGN/RSV NPs exhibited amorphous states. AGN/RSV NPs held up their initial hydrodynamic size after 24 h of incubation in serum-included media. Sustained release profiles (for 5 days) of decursin (D) and decursinol angelate (DA) (the representative markers of AGN Ex) and RSV were observed at normal physiological pH (pH 7.4). In ovarian cancer (SKOV-3) cells, although AGN/RSV NPs showed a lower cellular entry rate rather than AGN NPs, the cellular accumulated amount of AGN/RSV NPs was similar with that of AGN NPs after 4 h of incubation. The antiproliferation efficiency of AGN/RSV NPs group was significantly higher than the AGN Ex, AGN NPs, and AGN NPs + RSV groups in SKOV-3 cells. AGN/RSV NPs can be one of the promising candidates for therapeutic nanoplatforms against ovarian cancers.

Targeting the SET and RING-associated (SRA) domain of ubiquitin-like, PHD and ring finger-containing 1 (UHRF1) for anti-cancer drug development

Ubiquitin-like containing PHD Ring Finger 1 (UHRF1) is a multi-domain protein with a methyl-DNA binding SRA (SET and RING-associated) domain, required for maintenance DNA methylation mediated by DNMT1. Primarily expressed in proliferating cells, UHRF1 is a cell-cycle regulated protein that is required for S phase entry. Furthermore, UHRF1 participates in transcriptional gene regulation by connecting DNA methylation to histone modifications. Upregulation of UHRF1 may serve as a biomarker for a variety of cancers; including breast, gastric, prostate, lung and colorectal carcinoma. To this end, overexpression of UHRF1 promotes cancer metastasis by triggering aberrant patterns of DNA methylation, and subsequently, silencing tumor suppressor genes. Various small molecule effectors of UHRF1 have been reported in the literature, although the mechanism of action may not be fully characterized. Small molecules that potentially bind to the SRA domain may affect the ability of UHRF1 to bind hemimethylated DNA; thereby reducing aberrant DNA methylation. Therefore, in a subset of cancers, small molecule UHRF1 inhibitors may restore normal gene expression and serve as useful anti-cancer therapeutics.

Nano-delivery systems for encapsulation of dietary polyphenols: An experimental approach for neurodegenerative diseases and brain tumors

Neurodegenerative diseases (NDs) and brain tumors are severe, disabling, and incurable disorders that represent a critical problem regarding human suffering and the economic burden on the healthcare system. Because of the lack of effective therapies to treat NDs and brain tumors, the challenge for physicians is to discover new drugs to improve their patients' quality of life. In addition to risk factors such as genetics and environmental influences, increased cellular oxidative stress has been reported as one of the potential common etiologies in both disorders. Given their antioxidant and anti-inflammatory potential, dietary polyphenols are considered to be one of the most bioactive natural agents in chronic disease prevention and treatment. Despite the protective activity of polyphenols, their inefficient delivery systems and poor bioavailability strongly limit their use in medicine and functional food. A potential solution lies in polymeric nanoparticle-based polyphenol delivery systems that are able to enhance their absorption across the gastrointestinal tract, improve their bioavailability, and transport them to target organs. In the present manuscript, we provide an overview of the primary polyphenols used for ND and brain tumor prevention and treatment by focusing on recent findings, the principal factors limiting their application in clinical practice, and a promising delivery strategy to improve their bioavailability.

Chrysin suppresses proliferation, migration, and invasion in glioblastoma cell lines via mediating the ERK/Nrf2 signaling pathway

Background

Chrysin, an active natural bioflavonoid, has been proven to protect against carcinogenesis. However, the role of chrysin in glioblastoma and the potential molecular mechanisms remain to be elucidated. In our previous study, we found that nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) is highly expressed in a variety of glioblastoma cell lines associated with the mitogen-activated protein kinase (MAPK) pathway. The aim of this study was to evaluate the antitumor effects of chrysin in glioblastoma cells and how chrysin is related to the MAPK/Nrf2 signaling pathway.

Methods

A Cell Counting Kit-8 assay and a plate colony formation assay were performed to evaluate cell proliferation. Cell migration ability was tested by a wound-healing assay. Transwell migration and Matrigel invasion assay were used to test the migration and invasion potential of cells. Nrf2 was knocked down by shRNA transfection. Protein expression was determined by Western blotting and immunofluorescence staining. The in vivo anticancer effect was measured using tumor xenografts in nude mice.

Results

Chrysin inhibited the proliferation, migration, and invasion capacity of glioblastoma cells in dose- and time-dependent manners. Mechanistically, chrysin deactivated the Nrf2 signaling pathway by decreasing the translocation of Nrf2 into the nucleus and suppressing the expression of hemeoxygenase-1 (HO-1) and NAD(P)H quinine oxidoreductase-1, meanwhile, Nrf2 shRNA attenuated the anticancer activity of chrysin. Furthermore, chrysin downregulated the protein expression of p-extracellular signal-regulated kinase 1 and 2 (ERK1/2), but did not significantly affect p-JNK and p-P38 expression levels. However, the downregulated level of Nrf2 and the antitumor effect of chrysin in glioblastoma cell lines were partially abrogated by the ERK1/2 signaling inhibitor (U0126). Finally, chrysin inhibited tumor growth in U87 xenografts.

Conclusion

Our results show that chrysin exerts anticancer activity in glioblastoma cell lines possibly via the ERK/Nrf2 signaling pathway and indicate the potential application of chrysin as a natural sensitizer in chemotherapy.

Recent developments in solid lipid nanoparticle and surface-modified solid lipid nanoparticle delivery systems for oral delivery of phyto-bioactive compounds in various chronic diseases

Solid lipid nanoparticle (SLN) delivery systems have a wide applicability in the delivery of phyto-bioactive compounds to treat various chronic diseases, including diabetes, cancer, obesity and neurodegenerative diseases. The multiple benefits of SLN delivery include improved stability, smaller particle size, leaching prevention and enhanced lymphatic uptake of the bioactive compounds through oral delivery. However, the burst release makes the SLN delivery systems inadequate for the oral delivery of various phyto-bioactive compounds that can treat such chronic diseases. Recently, the surface-modified SLN (SMSLN) was observed to overcome this limitation for oral delivery of phyto-bioactive compounds, and there is growing evidence of an enhanced uptake of curcumin delivered orally via SMSLNs in the brain. This review focuses on different SLN and SMSLN systems that are useful for oral delivery of phyto-bioactive compounds to treat various chronic diseases.

Potential Anticancer Properties of Osthol: A Comprehensive Mechanistic Review

Cancer is caused by uncontrolled cell proliferation which has the potential to occur in different tissues and spread into surrounding and distant tissues. Despite the current advances in the field of anticancer agents, rapidly developing resistance against different chemotherapeutic drugs and significantly higher off-target effects cause millions of deaths every year. Osthol is a natural coumarin isolated from Apiaceaous plants which has demonstrated several pharmacological effects, such as antineoplastic, anti-inflammatory and antioxidant properties. We have attempted to summarize up-to-date information related to pharmacological effects and molecular mechanisms of osthol as a lead compound in managing malignancies. Electronic databases, including PubMed, Cochrane library, ScienceDirect and Scopus were searched for in vitro, in vivo and clinical studies on anticancer effects of osthol. Osthol exerts remarkable anticancer properties by suppressing cancer cell growth and induction of apoptosis. Osthol's protective and therapeutic effects have been observed in different cancers, including ovarian, cervical, colon and prostate cancers as well as chronic myeloid leukemia, lung adenocarcinoma, glioma, hepatocellular, glioblastoma, renal and invasive mammary carcinoma. A large body of evidence demonstrates that osthol regulates apoptosis, proliferation and invasion in different types of malignant cells which are mediated by multiple signal transduction cascades. In this review, we set spotlights on various pathways which are targeted by osthol in different cancers to inhibit cancer development and progression.

Formulation, characterization and evaluation of morusin loaded niosomes for potentiation of anticancer therapy

Morusin, a water-insoluble prenylated flavonoid is known for its numerous medicinal properties. It manifests its anticancer potential by suppression of genes involved in tumor progression. However, poor solubility of the drug results in low bioavailability and rapid degradation thus hindering its clinical utilization. In order to overcome this, we have synthesized a niosome system composed of non-ionic surfactant span 60 and cholesterol using a thin-layer evaporation technique to improve the aqueous-phase solubility of the drug. Highly cytocompatible niosomes of 479 nm average size with smooth and uniform spherical morphology were synthesized in a facile manner. Unlike free morusin, nanomorusin was found to be freely dispersible in aqueous media. Having an extremely high drug entrapment efficiency (97%), controlled and sustained release of morusin resulting in enhanced therapeutic efficacy was observed in cancer cell lines of 4 different lineages. The results demonstrate that the morusin-niosome system is a promising strategy for enhanced anti-cancer activity against multiple cancer types and could be an indispensable tool for future targeted chemotherapeutic strategies.

Highly cytocompatible morusin-loaded niosomes were synthesized showing high drug loading and encapsulation efficiencies with sustained release of the drug. Enhanced therapeutic efficacy was observed against 4 different cancer cell lines.

Biological Mechanisms by Which Antiproliferative Actions of Resveratrol Are Minimized

Preclinical and clinical studies have offered evidence for protective effects of various polyphenol-rich foods against cardiovascular diseases, neurodegenerative diseases, and cancers. Resveratrol is among the most widely studied polyphenols. However, the preventive and treatment effectiveness of resveratrol in cancer remain controversial because of certain limitations in existing studies. For example, studies of the activity of resveratrol against cancer cell lines in vitro have often been conducted at concentrations in the low μM to mM range, whereas dietary resveratrol or resveratrol-containing wine rarely achieve nM concentrations in the clinic. While the mechanisms underlying the failure of resveratrol to inhibit cancer growth in the intact organism are not fully understood, the interference by thyroid hormones with the anticancer activity of resveratrol have been well documented in both in vitro and xenograft studies. Thus, endogenous thyroid hormones may explain the failure of anticancer actions of resveratrol in intact animals, or in the clinic. In this review, mechanisms involved in resveratrol-induced antiproliferation and effects of thyroid hormones on these mechanisms are discussed.

Pharmacokinetic interactions of curcuminoids with conventional drugs: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Herb-drug interactions are of great concern in health practices. Curcumin is a natural polyphenol extracted from turmeric, a spice widely used all over the world. Curcumin is clinically used due to its acceptable safety profile and therapeutic efficacy.

AIM OF THE STUDY

Current paper aims to highlight the effect of curcumin on concomitantly used drugs.

METHODS

Electronic databases including PubMed, Scopus and Science Direct were searched with the keywords "curcumin" in the title/abstract and "drug interaction," "drug metabolism," "cytochrome," "P-glycoprotein" and "P450" in the whole text.

RESULTS

Curcumin can induce pharmacokinetic alterations such as changes in C_max and AUC when concomitantly used with pharmacological agents like cardiovascular drugs, antidepressants, anticoagulants, antibiotics, chemotherapeutic agents, and antihistamines. The underlying mechanisms of these interactions include inhibition of cytochrome (CYP) isoenzymes and P-glycoprotein. There is only one clinical trial which proved a significant alteration of conventional drugs in concomitant use with curcumin indicating the need for further human studies.

CONCLUSIONS

Although in vitro and in vivo studies do not provide enough evidence to judge the clinical drug interactions of curcumin, physicians must remain cautious and avoid drug combinations which may lead to curcumin-drug interactions.

Effect of resveratrol on cognitive and memory performance and mood: A meta-analysis of 225 patients

Resveratrol is a natural dietary phenolic compound which is extensively present in many edible fruits, including grape, berries, pomegranates, and peanuts. Reseveratrol has a broad spectrum of biological activities including anti-aging, chemopreventive, anti-carcinogenic, anti-inflammatory and antioxidant effects and thus it is effective in related diseases. Particularly, the positive effects of resveratrol in neuropsychological diseases have been proven in in-vitro and in-vivo studies. Some clinical trials have reported that resveratrol possesses preventive and therapeutic effects in cognitive disorders. Therefore, the current systematic review and meta-analysis aimed to assess the effects of resveratrol on cognition and memory performance as well as mood state. Electronic databases including Scopus, PubMed, Science Direct, and Cochrane library were searched with the keywords "Memory", "Cognitive", "Cognition" or "Mood" with "Resveratrol" until June 2017. Only clinical studies were included in this review. We have provided the most reliable evidence to date counting results obtained from 226 individuals from four randomized clinical trials evaluating the mentioned specific effects of resveratrol. The results of this meta-analysis showed that resveratrol has no significant effect on memory and cognitive performance assessed by auditory verbal learning tests. Two parameters of Profile of Mood States (POMS) including vigor and fatigue, decreased significantly by resveratrol. However, decrease in other parameters of POMS including tense/anxiety, depression, anger, and confusion by resveratrol was not significant. The key findings from this meta-analysis are that resveratrol has no significant impact on factors related to memory and cognitive performance, including learning ability, delayed recall, retention, and recognition with all effect sizes non-significant and effectively at zero. However, it has the potential to enhance mood. Further randomized, controlled trials are needed to achieve more conclusive results.