Galangin inhibits cell invasion by suppressing the epithelial-mesenchymal transition and inducing apoptosis in renal cell carcinoma

Selected Flavonols Targeting Cell Death Pathways in Cancer Therapy: The Latest Achievements in Research on Apoptosis, Autophagy, Necroptosis, Pyroptosis, Ferroptosis, and Cuproptosis

The complex and multi-stage processes of carcinogenesis are accompanied by a number of phenomena related to the potential involvement of various chemopreventive factors, which include, among others, compounds of natural origin such as flavonols. The use of flavonols is not only promising but also a recognized strategy for cancer treatment. The chemopreventive impact of flavonols on cancer arises from their ability to act as antioxidants, impede proliferation, promote cell death, inhibit angiogenesis, and regulate the immune system through involvement in diverse forms of cellular death. So far, the molecular mechanisms underlying the regulation of apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis occurring with the participation of flavonols have remained incompletely elucidated, and the results of the studies carried out so far are ambiguous. For this reason, one of the therapeutic goals is to initiate the death of altered cells through the use of quercetin, kaempferol, myricetin, isorhamnetin, galangin, fisetin, and morin. This article offers an extensive overview of recent research on these compounds, focusing particularly on their role in combating cancer and elucidating the molecular mechanisms governing apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis. Assessment of the mechanisms underlying the anticancer effects of compounds in therapy targeting various types of cell death pathways may prove useful in developing new therapeutic regimens and counteracting resistance to previously used treatments.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Multi-Anticancer Activities of Phytoestrogens in Human Osteosarcoma

Phytoestrogens are plant-derived bioactive compounds with estrogen-like properties. Their potential health benefits, especially in cancer prevention and treatment, have been a subject of considerable research in the past decade. Phytoestrogens exert their effects, at least in part, through interactions with estrogen receptors (ERs), mimicking or inhibiting the actions of natural estrogens. Recently, there has been growing interest in exploring the impact of phytoestrogens on osteosarcoma (OS), a type of bone malignancy that primarily affects children and young adults and is currently presenting limited treatment options. Considering the critical role of the estrogen/ERs axis in bone development and growth, the modulation of ERs has emerged as a highly promising approach in the treatment of OS. This review provides an extensive overview of current literature on the effects of phytoestrogens on human OS models. It delves into the multiple mechanisms through which these molecules regulate the cell cycle, apoptosis, and key pathways implicated in the growth and progression of OS, including ER signaling. Moreover, potential interactions between phytoestrogens and conventional chemotherapy agents commonly used in OS treatment will be examined. Understanding the impact of these compounds in OS holds great promise for developing novel therapeutic approaches that can augment current OS treatment modalities.

Galangin as an inflammatory response modulator: An updated overview and therapeutic potential

Numerous chronic diseases, such as cancer, diabetes, rheumatoid arthritis, cardiovascular disease, and gastrointestinal disorders, all have an inflammation-based etiology. In cellular and animal models of inflammation, flavonols were used to show potent anti-inflammatory activity. The flavonols enhanced the synthesis of the anti-inflammatory cytokines transforming growth factor and interleukin-10 (IL-10) and reduced the synthesis of the prostaglandins IL-6, tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2), IL-1. Galangin (GAL), a natural flavonol, has a strong ability to control apoptosis and inflammation. GAL was discovered to suppress extracellular signal-regulated kinase (ERK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)p65 phosphorylation, which results in anti-inflammatory actions. Arthritis, inflammatory bronchitis, stroke, and cognitive dysfunction have all been treated with GAL. The current review aimed to demonstrate the anti-inflammatory properties of GAL and their protective effects in treating various chronic illnesses, including those of the heart, brain, skin, lungs, liver, and inflammatory bowel diseases.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

Synthesis and in vitro anticancer evaluation of novel flavonoid-based amide derivatives as regulators of the PI3K/AKT signal pathway for TNBC treatment

Aberrant activation of the PI3K/AKT pathway is considered in many malignant tumors and plays a crucial role in mediating malignancy progression, metastasis, and chemoresistance. Consequently, development of PI3K/AKT pathway targeted drugs is currently an attractive research field for tumor treatment. In this study, twenty-six flavonoid-based amide derivatives were synthesized and evaluated for their antiproliferation effects against seven cancer cell lines, including MDA-MB-231, MCF-7, HCC1937, A549, HepG2, GTL-16 and HeLa. Among them, compound 7t possessed the best specific cytotoxicity against triple negative breast cancer MDA-MB-231 cells with an IC₅₀ value of 1.76 ± 0.91 μM and also presented inhibitory ability on clonal-formation, migration and invasion of MDA-MB-231 cells. Further cell-based mechanistic studies demonstrated that compound 7t caused cell cycle arrest of MDA-MB-231 cells at the G₀/G₁ phase and induced apoptosis. Meanwhile, the western blot assay revealed that compound 7t could down-regulate the expression of p-PI3K, p-AKT, and Bcl-2 and up-regulate the production of PTEN, Bax, and caspase-3. Molecular docking also showed a possible binding mode of 7t with PI3Kα. Together, compound 7t was eligible as a potential TNBC therapeutic candidate for further development.

Role of the Glyoxalase System in Breast Cancer and Gynecological Cancer-Implications for Therapeutic Intervention: a Review

Methyglyoxal (MGO), an essential endogenous dicarbonyl metabolite, can lead to multiple physiological problems including hyperglycemia, kidney diseases, malignant tumors, beyond its normal concentration range. The glyoxalase system, making MGO maintained at a low level, links glycation to carcinogenesis, growth, metastasis, and cancer chemotherapy. The glyoxalase system comprises glyoxalase 1 (Glo1) and glyoxalase 2 (Glo2), which is often overexpressed in various tumor tissues. However, very little is known about the glyoxalase system in breast cancer and gynecological cancer. In this review, we introduce the role of the glyoxalase system in breast cancer, endometrial cancer, ovarian cancer and cervical cancer, and highlight the potential of the glyoxalase system to be both as a marker for diagnosis and a novel target for antitumor therapy. However, the intrinsic molecular biology and mechanisms of the glyoxalase system in breast cancer and gynecological cancer need further exploration.

Potential of natural products in osteosarcoma treatment: Focus on molecular mechanisms

Osteosarcoma is the most frequent type of bone cancer found in children and adolescents, and commonly arises in the metaphyseal region of tubular long bones. Standard therapeutic approaches, such as surgery, chemotherapy, and radiation therapy, are used in the management of osteosarcoma. In recent years, the mortality rate of osteosarcoma has decreased due to advances in treatment methods. Today, the scientific community is investigating the use of different naturally derived active principles against various types of cancer. Natural bioactive compounds can function against cancer cells in two ways. Firstly they can act as classical cytotoxic compounds by non-specifically affecting macromolecules, such as DNA, enzymes, and microtubules, which are also expressed in normal proliferating cells, but to a greater extent by cancer cells. Secondly, they can act against oncogenic signal transduction pathways, many of which are activated in cancer cells. Some bioactive plant-derived agents are gaining increasing attention because of their anti-cancer properties. Moreover, some naturally-derived compounds can significantly promote the effectiveness of standard chemotherapy drugs, and in certain cases are able to ameliorate drug-induced adverse effects caused by chemotherapy. In the present review we summarize the effects of various naturally-occurring bioactive compounds against osteosarcoma.

The Effect of Galangin on the Regulation of Vascular Contractility via the Holoenzyme Reactivation Suppressing ROCK/CPI-17 rather than PKC/CPI-17

In this study, we investigated the influence of galangin on vascular contractibility and to determine the mechanism underlying the relaxation. Isometric contractions of denuded aortic muscles were recorded and combined with western blot analysis which was performed to measure the phosphorylation of phosphorylation-dependent inhibitory protein of myosin phosphatase (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) and to evaluate the effect of galangin on the RhoA/ROCK/CPI-17 pathway. Galangin significantly inhibited phorbol ester-, fluoride- and thromboxane mimetic-induced vasoconstrictions regardless of endothelial nitric oxide synthesis, suggesting its direct effect on vascular smooth muscle. Galangin significantly inhibited the fluoridedependent increase in pMYPT1 and pCPI-17 levels and phorbol 12,13-dibutyrate-dependent increase in pERK1/2 level, suggesting repression of ROCK and MEK activity and subsequent phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that galangin-induced relaxation involves myosin phosphatase reactivation and calcium desensitization, which appears to be mediated by CPI-17 dephosphorylation via not PKC but ROCK inactivation.

Propolis Extract and Its Bioactive Compounds-From Traditional to Modern Extraction Technologies

Propolis is a honeybee product known for its antioxidant, anti-inflammatory, anticancer, and antimicrobial effects. It is rich in bioactive molecules whose content varies depending on the botanical and geographical origin of propolis. These bioactive molecules have been studied individually and as a part of propolis extracts, as they can be used as representative markers for propolis standardization. Here, we compare the pharmacological effects of representative polyphenols and whole propolis extracts. Based on the literature data, polyphenols and extracts act by suppressing similar targets, from pro-inflammatory TNF/NF-κB to the pro-proliferative MAPK/ERK pathway. In addition, they activate similar antioxidant mechanisms of action, like Nrf2-ARE intracellular antioxidant pathway, and they all have antimicrobial activity. These similarities do not imply that we should attribute the action of propolis solely to the most representative compounds. Moreover, its pharmacological effects will depend on the efficacy of these compounds’ extraction. Thus, we also give an overview of different propolis extraction technologies, from traditional to modern ones, which are environmentally friendlier. These technologies belong to an open research area that needs further effective solutions in terms of well-standardized liquid and solid extracts, which would be reliable in their pharmacological effects, environmentally friendly, and sustainable for production.

Chemopreventive effect of galangin against benzo(a)pyrene-induced stomach tumorigenesis through modulating aryl hydrocarbon receptor in Swiss albino mice

The present study was aimed to evaluate the chemopreventive potential of galangin against benzo(a)pyrene (BaP)-induced stomach carcinogenesis in Swiss albino mice. Stomach cancer was induced in experimental mice using BaP oral administration. The mice were treated with galangin (10 mg/kg b.wt.) before and during BaP administration. Oral administration of galangin at a dose of 10 mg/kg b.wt. significantly (p < 0.05) prevented the tumor incidence, tumor volume in the experimental animals. Further, galangin pretreatment prevents BaP-induced lipid peroxidation and restores BaP-mediated loss of cellular antioxidants status. It has also been found that galangin prevents BaP-induced activation of phase I detoxification enzymes. Furthermore, galangin pretreatment prevented the BaP-induced overexpression of cytochrome P450s isoform genes (CYP1A1, CYP1B1), aryl hydrocarbon receptor system (AhR, ARNT), transcriptional activators (CBP/p300, NF-kB), tumor growth factors, proto-oncogenes, invasion markers (TGFB, SRC-1, MYC, iNOS, MMP2, MMP9) and Phase II metabolic isoenzyme genes (GST) in the stomach tissue homogenate when compared to the control groups. The western blot results confirm that galangin (10 mg/kg. b.wt.) treatment significantly prevented the BaP-mediated expression of ArR, ARNT, and CYP1A1 proteins in the mouse stomach tissue. Therefore, the present results confirm that galangin prevents BaP-induced stomach carcinogenesis probably through modulating ArR and ARNT expression in the experimental mice.

Antiangiogenic Activity of Flavonoids: A Systematic Review and Meta-Analysis

Abstract: An imbalance of angiogenesis contributes to many pathologies such as cancer, arthritis and retinopathy, hence molecules that can modulate angiogenesis are of considerable therapeutic importance. Despite many reports on the promising antiangiogenic properties of naturally occurring flavonoids, no flavonoids have progressed to the clinic for this application. This systematic review and meta-analysis therefore evaluates the antiangiogenic activities of a wide range of flavonoids and is presented in two sections. The first part of the study (Systematic overview) included 402 articles identified by searching articles published before May 2020 using ScienceDirect, PubMed and Web of Science databases. From this initial search, different classes of flavonoids with antiangiogenic activities, related pathologies and use of in vitro and/or in/ex vivo angiogenesis assays were identified. In the second part (Meta-analysis), 25 studies concerning the antiangiogenic evaluation of flavonoids using the in vivo chick chorioallantoic membrane (CAM) assay were included, following a targeted search on articles published prior to June 2020. Meta-analysis of 15 out of the 25 eligible studies showed concentration dependent antiangiogenic activity of six compared subclasses of flavonoids with isoflavones, flavonols and flavones being the most active (64 to 80% reduction of blood vessels at 100 µM). Furthermore, the key structural features required for the antiangiogenic activity of flavonoids were derived from the pooled data in a structure activity relationship (SAR) study. All in all, flavonoids are promising candidates for the development of antiangiogenic agents, however further investigations are needed to determine the key structural features responsible for their activity.

Galangin (GLN) Suppresses Proliferation, Migration, and Invasion of Human Glioblastoma Cells by Targeting Skp2-Induced Epithelial-Mesenchymal Transition (EMT)

Background

Galangin (GLN), a pure natural flavonoid compound found in plants, has been shown to exert anti-cancer effects against multiple cancer types, including glioma. However, its underlying molecular mechanism remains unclear. Epithelial-to-mesenchymal transition (EMT) performs an important function in the genesis and development of cancer. Skp2, a pivotal component of SCF^Skp2 E3 ubiquitin ligase, has been shown to function as an oncogene in GBM invasion that contributes to the EMT process. Thus, we explored whether GLN inhibited Skp2-mediated EMT and the mechanism underlying the Skp2 degradation pathway.

Methods

CCK-8 assay, wound healing assay and transwell assay were used to examine cell proliferation, migration, and invasion after treatment with or without GLN. RT-PCR and Western blotting analysis were performed to evaluate mRNA and protein expression, respectively. Co-immunoprecipitation was conducted to detect ubiquitinated Skp2 levels in vitro and in vivo after GLN treatment. Bioluminescence imaging was performed to examine the intracranial tumor size of U87 xenograft mice. Microscale thermophoresis (MST) experiment was used to detect interactions between Skp2 and GLN.

Results

GLN suppressed GBM cell growth, migration, and invasion, and also downregulated the expression of Skp2 and mesenchymal markers (Zeb1, N-cadherin, snail, vimentin) in vitro. Moreover, the overexpression of Skp2 in GBM cells decreased the effect of GLN on EMT. Furthermore, we demonstrated that GLN degraded skp2 protein through the ubiquitination proteasome pathway and directly interacted with skp2 protein, as shown through the MST assay.

Conclusion

This study is the first to identify Skp2 as a novel target of GLN for the treatment of GBM and report of Skp2 protein degradation in a ubiquitination proteasome pathway. Results from our study indicated the potential of GLN for the treatment of GBM through ubiquitin-mediated degradation of Skp2.

Galangin ameliorated pulmonary fibrosis in vivo and in vitro by regulating epithelial-mesenchymal transition

Pulmonary fibrosis (PF) is a disease that is characterized by abnormal epithelial-mesenchymal transition (EMT) and persistent inflammatory injury, with high mortality and poor prognosis, but the current therapies are accompanied by certain adverse side effects. In this study, we investigated the role of galangin (GA), an anti-inflammatory and anti-tumoral phytochemical extracted from galangal, in preventing and curing bleomycin (BLM)-induced pulmonary fibrosis and the underlying mechanism. Histopathological staining confirmed that GA dramatically moderated bleomycin-induced pulmonary fibrosis in mice. Compared with the vehicle treatment, GA treatment inhibited the expression of vimentin and increased the expression of E-cadherin. The expression of α-Smooth muscle actin (α-SMA), which is a myofibroblast marker, was also suppressed. In addition, GA diminished the increase in the numbers of CD4⁺CD69⁺ and CD8⁺CD69⁺ T cells and dendritic cells induced by bleomycin, and reduced the residence of inflammatory cells in the lung tissues. Notably, GA inhibited the TGF-β1-induced EMT and fibroblast differentiation in vitro, which further confirmed the potential protective effect of GA on pulmonary fibrosis. Taken together, our results suggest that GA exerts a beneficial effect on bleomycin-induced pulmonary fibrosis by attenuating EMT and inflammatory damage and may have prevent potential of pulmonary fibrosis.

Ethanol Extracts of Dietary Herb, Alpinia nantoensis, Exhibit Anticancer Potential in Human Breast Cancer Cells

Recent advances in mammography screening, chemotherapy, and adjuvant treatment modalities have improved the survival rate of women with breast cancer. Nevertheless, the breast tumor with metastatic progression is still life-threatening. Indeed, combination therapy with Ras-ERK and PI3K inhibitors is clinically effective in malignant breast cancer treatment. Constituents from genus Alpinia plants have been implicated as potent anticancer agents in terms of their efficacy of inhibiting tumor cell metastasis. In this study, we tested the effects of ethanol extracts of Alpinia nantoensis (rhizome, stem, and leaf extracts) in cultured human breast cancer cells and particularly focused on the Ras-ERK and PI3K/AKT pathways. We found that the rhizome and leaf extracts from A nantoensis inhibited cell migration, invasion, and sphere formation in MCF-7 and MDA-MB-231 cells. The potency was extended with the inhibition of serum-induced PI3K/AKT and Ras-ERK activation and epidermal growth factor (EGF)-mediated EGFR activation in MDA-MB-231 cells. These results indicate that extracts of A nantoensis could inhibit signal transduction at least involved in EGFR as well as the PI3K/AKT and Ras-ERK pathways, which are crucial players of tumor cell migration and invasion. Our study strongly supports that the extracts of A nantoensis could be a novel botanical drug lead for the development of an antimetastatic agent for the treatment of human malignant breast cancer.

Galangin Attenuates Isoproterenol-Induced Inflammation and Fibrosis in the Cardiac Tissue of Albino Wistar Rats

Galangin (GA) is an active flavonoid of the rhizome of Alpinia galanga that belongs to the ginger family. GA exhibit potent anti-inflammatory properties. Therefore, we evaluated the preventive effects of GA against isoproterenol (ISO)-induced inflammation and myocardial fibrosis in male albino Wistar rats. We found that GA (1 mg/kg b.wt.) pretreatment attenuated the ISO-mediated (5 mg/kg b.wt. for 14 consecutive days) elevation of heart rate, activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase-MB (CKMB) in the rat serum. We also noticed that GA prevented the ISO-mediated cardiac markers i.e. cardiac troponin T and I (cTnT and cTnI) expression in the serum of rats. Further, GA pretreatment prevented ISO-mediated lipid peroxidation and diminished blood pressure and loss of antioxidants status in the heart tissue of ISO treated rats. In addition, GA treatment modulates ISO-induced alterations the expressions of tissue inhibitor of metalloproteinases-1 (TIMP-1), p-AKT, glycogen synthase kinase-3β (p-GSK-3β) and peroxisome proliferators-activated receptor-γ (PPAR-γ) in the heart tissue. Furthermore, molecular analysis (PCR array and western blot) revealed that GA pretreatment prevented inflammation and fibrosis related gene expression pattern in ISO-induced rats. Taken together, the results indicate the cardioprotective effect of GA against ISO-induced inflammation and fibrosis. The antioxidant and anti-inflammatory potential of GA could be considered for its cardioprotective effect in the ISO-treated rats.

Therapeutic and preventive properties of honey and its bioactive compounds in cancer: an evidence-based review

Despite the much improved therapeutic approaches for cancer treatment that have been developed over the past 50 years, cancer remains a major cause of mortality globally. Considerable epidemiological and experimental evidence has demonstrated an association between ingestion of food and nutrients with either an increased risk for cancer or its prevention. There is rising interest in exploring agents derived from natural products for chemoprevention or for therapeutic purposes. Honey is rich in nutritional and non-nutritional bioactive compounds, as well as in natural antioxidants, and its potential beneficial function in human health is becoming more evident. A large number of studies have addressed the anti-cancer effects of different types of honey and their phenolic compounds using in vitro and in vivo cancer models. The reported findings affirm that honey is an agent able to modulate oxidative stress and has anti-proliferative, pro-apoptotic, anti-inflammatory, immune-modulatory and anti-metastatic properties. However, despite its reported anti-cancer activities, very few clinical studies have been undertaken. In the present review, we summarise the findings from different experimental approaches, including in vitro cell cultures, preclinical animal models and clinical studies, and provide an overview of the bioactive profile and bioavailability of the most commonly studied honey types, with special emphasis on the chemopreventive and therapeutic properties of honey and its major phenolic compounds in cancer. The implications of these findings as well as the future prospects of utilising honey to fight cancer will be discussed.

A review on the ethnomedicinal uses, phytochemistry and pharmacology of Alpinia officinarum Hance

ETHNOPHARMACOLOGICAL RELEVANCE

Alpinia officinarum Hance is a perennial plant that has been traditionally used for many decades to treat several ailments including inflammation, pain, stomach-ache, cold, amongst others. Pharmacological studies over the years have demonstrated remarkable bioactivities that could be further explored for development of new therapeutic agents against various ailments.

AIM OF THE STUDY

The paper critically reviewed the ethno-medicinal uses, pharmacology, and phytochemistry of A. officinarum.

METHODS

Keywords including A. officinarum and its synonyms were searched using electronic databases including ISI web of knowledge, Science direct, Scopus, PubMed, Google scholar and relevant database for Masters and Doctoral theses.

RESULTS

A. officinarum is prepared in Asia, Turkey, Morocco and Iran as a decoction, infusion or juice as a single preparation or in combination with other herbs, food or drinks for the treatment of general health problems including cold, inflammation, digestive disorders, etc. Pharmacological studies revealed the potent in vitro and in vivo bioactivities of various parts of A. officinarum that include anti-inflammatory, cytotoxicity, homeostasis, lipid regulation, antioxidant, antiviral, antimicrobial, antiosteoporosis, etc. Over 90 phytochemical constituents have been identified and isolated from A. officinarum comprising vastly of phenolic compounds especially diarylheptanoids isolated from the rhizome and considered the most active bioactive components.

CONCLUSION

In vitro and in vivo studies have confirmed the potency of A. officinarum. However, further studies are required to establish the mechanisms mediating its bioactivities in relation to the medicinal uses as well as investigating any potential toxicity for future clinical studies.

Flavonoids in Kidney Health and Disease

This review summarizes the latest advances in knowledge on the effects of flavonoids on renal function in health and disease. Flavonoids have antihypertensive, antidiabetic, and antiinflammatory effects, among other therapeutic activities. Many of them also exert renoprotective actions that may be of interest in diseases such as glomerulonephritis, diabetic nephropathy, and chemically-induced kidney insufficiency. They affect several renal factors that promote diuresis and natriuresis, which may contribute to their well-known antihypertensive effect. Flavonoids prevent or attenuate the renal injury associated with arterial hypertension, both by decreasing blood pressure and by acting directly on the renal parenchyma. These outcomes derive from their interference with multiple signaling pathways known to produce renal injury and are independent of their blood pressure-lowering effects. Oral administration of flavonoids prevents or ameliorates adverse effects on the kidney of elevated fructose consumption, high fat diet, and types I and 2 diabetes. These compounds attenuate the hyperglycemia-disrupted renal endothelial barrier function, urinary microalbumin excretion, and glomerular hyperfiltration that results from a reduction of podocyte injury, a determinant factor for albuminuria in diabetic nephropathy. Several flavonoids have shown renal protective effects against many nephrotoxic agents that frequently cause acute kidney injury (AKI) or chronic kidney disease (CKD), such as LPS, gentamycin, alcohol, nicotine, lead or cadmium. Flavonoids also improve cisplatin- or methotrexate-induced renal damage, demonstrating important actions in chemotherapy, anticancer and renoprotective effects. A beneficial prophylactic effect of flavonoids has been also observed against AKI induced by surgical procedures such as ischemia/reperfusion (I/R) or cardiopulmonary bypass. In several murine models of CKD, impaired kidney function was significantly improved by the administration of flavonoids from different sources, alone or in combination with stem cells. In humans, cocoa flavanols were found to have vasculoprotective effects in patients on hemodialysis. Moreover, flavonoids develop antitumor activity against renal carcinoma cells with no toxic effects on normal cells, suggesting a potential therapeutic role in patients with renal carcinoma.

Galangin suppresses H2 O2 -induced aging in human dermal fibroblasts

Human skin aging is a progressive process that includes intrinsic aging and extrinsic photodamage, both of which can cause an accumulation of reactive oxygen species (ROS), resulting in dermal fibrosis dysfunction and wrinkle formation. Galangin is a flavonoid that exhibits anti-inflammatory and antioxidative potential. Previous studies have reported that galangin has antioxidative activity against ROS-mediated stress. The aim of the present study is to determine the antiaging effects of galangin on dermal fibroblasts exposed to H₂ O₂ . In this study, we established a hydrogen peroxide-induced inflammation and aging model using human HS68 dermal fibroblasts. Stimulation of fibroblasts with H₂ O₂ is associated with skin aging and increased expression of inflammation-related proteins, along with downregulation of collagen I/III formation and expression of antioxidative proteins. Galangin effectively reduced NF-κB activation, the expression of inflammation-related proteins and cell aging. Galangin also reversed H₂ O₂ -activated cell senescence in HS68 cells. Our results reveal that galangin protects human dermal fibroblasts by inhibiting NF-κB activation, decreases the expression of inflammatory factors and upregulates IGF1R/Akt-related proteins, indicating that galangin may be a potential candidate for developing natural antiaging products that protect skin from damage caused by ROS.

Galangin induces cell death by modulating the expression of glyoxalase-1 and Nrf-2 in HeLa cells

The present study was designed to understand the anticancer property and molecular mechanisms associated with chemo preventive effects of galangin. The anticancer effect was evaluated in vitro using human cervical cancer cell line (HeLa). Galangin was found to be effective in inducing cell death and inhibiting proliferation & migration significantly. The inhibitory effect of galangin could be correlated with the increase in ROS production & induction of apoptosis. Besides this the activity of glyoxalase-1, an enzyme important for the detoxification of cytotoxic metabolite methy glyoxal and Nrf-2 (a trascription factor), involved in redox signalling were found to be decreased. We concluded that galangin exerts its chemo preventive effect via redox signalling by inhibiting glyoxalase-1 & increasing oxidative & carbonyl stress.

A Mini-Review of Reactive Oxygen Species in Urological Cancer: Correlation with NADPH Oxidases, Angiogenesis, and Apoptosis

Oxidative stress refers to elevated reactive oxygen species (ROS) levels, and NADPH oxidases (NOXs), which are one of the most important sources of ROS. Oxidative stress plays important roles in the etiologies, pathological mechanisms, and treatment strategies of vascular diseases. Additionally, oxidative stress affects mechanisms of carcinogenesis, tumor growth, and prognosis in malignancies. Nearly all solid tumors show stimulation of neo-vascularity, termed angiogenesis, which is closely associated with malignant aggressiveness. Thus, cancers can be seen as a type of vascular disease. Oxidative stress-induced functions are regulated by complex endogenous mechanisms and exogenous factors, such as medication and diet. Although understanding these regulatory mechanisms is important for improving the prognosis of urothelial cancer, it is not sufficient, because there are controversial and conflicting opinions. Therefore, we believe that this knowledge is essential to discuss observations and treatment strategies in urothelial cancer. In this review, we describe the relationships between members of the NOX family and tumorigenesis, tumor growth, and pathological mechanisms in urological cancers including prostate cancer, renal cell carcinoma, and urothelial cancer. In addition, we introduce natural compounds and chemical agents that are associated with ROS-induced angiogenesis or apoptosis.

LDHA promotes tumor metastasis by facilitating epithelial‑mesenchymal transition in renal cell carcinoma

Previous studies have indicated that high expression of lactate dehydrogenase A (LDHA) exists in many human cancers. Recently, several reports showed that silencing or inhibition of LDHA could suppress metastasis of human cancer including renal cell carcinoma (RCC). However, the mechanism remains unknown. The role of LDHA in RCC migration and invasion was investigated using immunohistochemistry, western blotting, Transwell and scratch assays, and in vivo experiment. The influence of LDHA on the Warburg effect was also investigated by LDHA activity and lactate production assay. LDHA was overexpressed in RCC tissues and predicted a worse survival following renal resection. Correlation analysis demonstrated that LDHA was negatively correlated with E‑cadherin and positively with N‑cadherin. Experimentally, both in vivo and in vitro experiments found downregulation of LDHA suppressed RCC cells migration and invasion by inhibiting EMT. In addition, results indicated LDHA could promote the Warburg effect. Further research presented that the LDHA inhibitor, oxamate, suppressed tumor metastasis by inhibiting LDHA activity and EMT. These results demonstrated that LDHA mediates tumor metastasis by promoting EMT in RCC, suggesting that LDHA could be a promising therapeutic target for RCC therapy.

Redox regulation in tumor cell epithelial-mesenchymal transition: molecular basis and therapeutic strategy

Epithelial–mesenchymal transition (EMT) is recognized as a driving force of cancer cell metastasis and drug resistance, two leading causes of cancer recurrence and cancer-related death. It is, therefore, logical in cancer therapy to target the EMT switch to prevent such cancer metastasis and recurrence. Previous reports have indicated that growth factors (such as epidermal growth factor and fibroblast growth factor) and cytokines (such as the transforming growth factor beta (TGF-β) family) are major stimulators of EMT. However, the mechanisms underlying EMT initiation and progression remain unclear. Recently, emerging evidence has suggested that reactive oxygen species (ROS), important cellular secondary messengers involved in diverse biological events in cancer cells, play essential roles in the EMT process in cancer cells by regulating extracellular matrix (ECM) remodeling, cytoskeleton remodeling, cell–cell junctions, and cell mobility. Thus, targeting EMT by manipulating the intracellular redox status may hold promise for cancer therapy. Herein, we will address recent advances in redox biology involved in the EMT process in cancer cells, which will contribute to the development of novel therapeutic strategies by targeting redox-regulated EMT for cancer treatment.

Galangin inhibits human osteosarcoma cells growth by inducing transforming growth factor-β1-dependent osteogenic differentiation

Osteosarcoma is the most common primary malignancy of the musculoskeletal system, and is associated with excessive proliferation and poor differentiation of osteoblasts. Currently, despite the use of traditional chemotherapy and radiotherapy, no satisfactory and effective agent has been developed to treat the disease. Herein, we found that a flavonoid natural product, galangin, could significantly attenuate human osteosarcoma cells proliferation, without causing obvious cell apoptosis. Moreover, galangin enhanced the expression of osteoblast differentiation markers (collagen type I, alkaline phosphatase, osteocalcin and osteopontin) remarkably and elevated the alkaline phosphatase activity in human osteosarcoma cells. And galangin could also attenuated osteosarcoma growth in vivo. These bioactivities of galangin resulted from its selective activation of the transforming growth factor (TGF)-β1/Smad2/3 signaling pathway, which was demonstrated by pathway blocking experiments. These findings suggested that galangin could be a promising agent to treat osteosarcoma. In addition, targeting TGF-β1 to induce osteogenic differentiation might represent a novel therapeutic strategy to treat osteosarcoma with minimal side effects.

A Review on the Pharmacological Activities and Phytochemicals of Alpinia officinarum (Galangal) Extracts Derived from Bioassay-Guided Fractionation and Isolation

The rhizomes of Alpinia officinarum Hance have been used conventionally for the treatment of various ailments, triggering a wide interest from the scientific research community on this ethnomedicinal plant. This review summarizes the phytochemical and pharmacological properties of the extracts and fractions from A. officinarum, a plant species of the Zingiberaceae family. Different parts of the plant – leaves, roots, rhizomes, and aerial parts – have been extracted in various solvents – methanol, ethanol, ethyl acetate, hexane, dichloromethane, aqueous, chloroform, and petroleum ether, using various techniques – Soxhlet extraction, maceration, ultrasonication, and soaking, whereas fractionation of the plant extracts involves the solvent–solvent partition method. The extracts, fractions, and isolated compounds have been studied for their biological activities – antioxidant, antibacterial, anti-inflammatory, anticancer, antiproliferative, inhibition of enzymes, as well as the inhibition of nitric oxide production. More findings on A. officinarum are certainly important to further develop potential bioactive drug compounds.

Galangin suppresses human osteosarcoma cells: An exploration of its underlying mechanism

Osteosarcoma is the most common malignant bone tumor that frequently affects adolescents. Osteosarcoma cells tend to proliferate and invade other tissues such as those of the lungs. Currently, neoadjuvant chemotherapy is the primary strategy to prevent tumor progression. However, its adverse effects result in poor long-term outcomes. Previous research has shown that galangin exhibits antitumor properties on several types of cancer cells; however its effect on osteosarcoma cells is yet unknown. The aims of this study were to evaluate the effects of galangin on the proliferation, apoptosis, migration, and invasion of osteosarcoma cells and to explore the underlying mechanisms. We found that the proliferation of MG63 and U20S osteosarcoma cells decreased significantly, while the apoptosis of MG63 cells accelerated significantly after exposure to galangin. In addition, the migration and invasion of MG63 cells were significantly inhibited by galangin. Moreover, phosphoinositide 3-kinase (PI3K) and Aktp-Thr308 expression levels were found to be significantly lower in galangin-treated MG63 cells than in the control cells, and the protein expression levels of their downstream regulators cyclin D1 and matrix metalloproteinase 2/9 were also downregulated in galangin-treated groups, while those of p27Kip1, caspase-3, and caspase-8 were upregulated. These findings suggest that galangin suppresses osteosarcoma cells by inhibiting their proliferation and invasion and accelerating their apoptosis, and the mechanism may be associated with the inhibition of PI3K and its downstream signaling pathway.