Galangin Dampens Mice Lipopolysaccharide-Induced Acute Lung Injury

Galangin: A food-derived flavonoid with therapeutic potential against a wide spectrum of diseases

Galangin is an important flavonoid with natural activity, that is abundant in galangal and propolis. Currently, various biological activities of galangin have been disclosed, including anti-inflammation, antibacterial effect, anti-oxidative stress and aging, anti-fibrosis, and antihypertensive effect. Based on the above bioactivities, more and more attention has been paid to the role of galangin in neurodegenerative diseases, rheumatoid arthritis, osteoarthritis, osteoporosis, skin diseases, and cancer. In this paper, the natural sources, pharmacokinetics, bioactivities, and therapeutic potential of galangin against various diseases were systematically reviewed by collecting and summarizing relevant literature. In addition, the molecular mechanism and new preparation of galangin in the treatment of related diseases are also discussed, to broaden the application prospect and provide reference for its clinical application. Furthermore, it should be noted that current toxicity and clinical studies of galangin are insufficient, and more evidence is needed to support its possibility as a functional food.

Pharmacological activities and therapeutic potential of galangin, a promising natural flavone, in age-related diseases

BACKGROUND

The extension of average life expectancy and the aggravation of population aging have become the inevitable trend of human development. In an aging society, various problems related to medical care for the elderly have become increasingly prominent. However, most of the age-related diseases have the characteristics of multiple diseases at the same time, prone to complications, and atypical clinical manifestations, which bring great difficulties to its treatment. Galangin (3,5,7-trihydroxyflavone) is a natural active compound extracted from the root of Alpinia officinarum Hance (Zingiberaceae). Recently, many studies have shown that galangin has potential advantages in the treatment of neurodegenerative diseases and cardiovascular and cerebrovascular diseases, which are common in the elderly. In addition, it also showed that galangin had prospective activities in the treatment of tumor, diabetes, liver injury, asthma and arthritis.

PURPOSE

This review aims to systematically summarize and discuss the effects and the underlying mechanism of galangin in the treatment of age-related diseases.

METHODS

We searched PubMed, SciFinder, Web of Science and CNKI literature database resources, combined with the keywords "galangin", "neurodegenerative disease", "tumor", "diabetes", "pharmacological activity", "drug combination", "pharmacokinetics", "drug delivery system" and "safety", and comprehensively reviewed the pharmacological activities and mechanism of galangin in treating age-related diseases.

RESULTS

According to the previous studies on galangin, the anti-neurodegenerative activity, cardiovascular and cerebrovascular protective activity, anti-tumor activity, anti-diabetes activity, anti-arthritis activity, hepatoprotective activity and antiasthmatic activity of galangin were discussed, and the related mechanisms were classified and summarized in detail. In addition, the drug combination, pharmacokinetics, drug delivery system and safety of galangin were furtherly discussed.

CONCLUSIONS

This review will provide reference for galangin in the treatment of age-related diseases. Meanwhile, further experimental research and long-term clinical trials are needed to determine the therapeutic safety and efficacy of galangin.

Galangin Attenuates Myocardial Ischemic Reperfusion-Induced Ferroptosis by Targeting Nrf2/Gpx4 Signaling Pathway

Purpose

Myocardial ischemic reperfusion injury (MIRI) is a crucial clinical problem globally. The molecular mechanisms of MIRI need to be fully explored to develop new therapeutic methods. Galangin (Gal), which is a natural flavonoid extracted from Alpinia Officinarum Hance and Propolis, possesses a wide range of pharmacological activities, but its effects on MIRI remain unclear. This study aimed to determine the pharmacological effects of Gal on MIRI.

Methods

C57BL/6 mice underwent reperfusion for 3 h after 45 min of ischemia, and neonatal rat cardiomyocytes (NRCs) subjected to hypoxia and reoxygenation (HR) were cultured as in vivo and in vitro models. Echocardiography and TTC-Evans Blue staining were performed to evaluate the myocardial injury. Transmission electron microscope and JC-1 staining were used to validate the mitochondrial function. Additionally, Western blot detected ferroptosis markers, including Gpx4, FTH, and xCT.

Results

Gal treatment alleviated cardiac myofibril damage, reduced infarction size, improved cardiac function, and prevented mitochondrial injury in mice with MIRI. Gal significantly alleviated HR-induced cell death and mitigated mitochondrial membrane potential reduction in NRCs. Furthermore, Gal significantly inhibited ferroptosis by preventing iron overload and lipid peroxidation, as well as regulating Gpx4, FTH, and xCT expression levels. Moreover, Gal up-regulated nuclear transcriptive factor Nrf2 in HR-treated NRCs. Nrf2 inhibition by Brusatol abolished the protective effect of Gal against ferroptosis.

Conclusion

This study revealed that Gal alleviates myocardial ischemic reperfusion-induced ferroptosis by targeting Nrf2/Gpx4 signaling pathway.

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.

Galangin inhibits lipopolysaccharide-induced inflammation and stimulates osteogenic differentiation of bone marrow mesenchymal stem cells via regulation of AKT/mTOR signaling

BACKGROUND

Bone marrow mesenchymal stem cells (BMSCs), with the abilities of multidirectional differentiation and self-renewal, have been widely used in bone repair and regeneration of inflammation-stimulated oral diseases. Galangin is a flavonoid isolated from Alpinia officinarum, exerts anti-obesity, antitumor, and anti-inflammation pharmacological effects. The roles of galangin in lipopolysaccharide-induced inflammation and osteogenic differentiation of BMSCs were investigated.

METHODS

BMSCs were isolated from rat bone marrow and identified by flow cytometry. The isolated BMSCs were treated with 1 μg/mL lipopolysaccharides or cotreated with lipopolysaccharides and different concentrations of galangin. Cell viability and apoptosis were detected by MTT (tetrazolium component) and flow cytometry. ELISA was used to detect inflammation. Alizarin red staining was used to investigate osteogenic differentiation.

RESULTS

The rat BMSCs showed negative rate of CD34, and positive rate of CD29 and CD44. Lipopolysaccharides treatment reduced cell viability of BMSCs, and promoted the cell apoptosis. Incubation with galangin enhanced cell viability of lipopolysaccharide-stimulated BMSCs, and suppressed the cell apoptosis. Galangin decreased levels of TNF-α, IL-1β, and IL-6 in lipopolysaccharide-stimulated BMSCs through down-regulation of NF-κB phosphorylation (p-NF-κB). Galangin up-regulated expression of osteo-specific proteins, collagen type I alpha 1 (COL1A1), osteopontin (OPN), and runt-related transcription factor 2 (RUNX2), to promote the osteogenic differentiation of lipopolysaccharide-stimulated BMSCs. Protein expression of p-AKT and p-mTOR in lipopolysaccharide-stimulated BMSCs were increased by galangin treatment.

CONCLUSION

Galangin exerted an anti-inflammatory effect against lipopolysaccharide- stimulated BMSCs and promoted osteogenic differentiation through the activation of AKT/ mTOR signaling.

Galangin Nanoparticles Protect Acetaminophen-Induced Liver Injury: A Biochemical and Histopathological Approach

One of the main causes of acute liver failure is overdose with acetaminophen. Excessive consumption of acetaminophen leads to the production of NAPQI (N-acetyl-p-benzoquinone imine) through the activity of the enzyme cytochrome c oxidase. For this purpose, the effect of galangin nanoparticles with antioxidant activities will be evaluated for the treatment of acetaminophen-induced hepatotoxicity. In this study, after the synthesis of galangin nanoparticles and particle size determination, mice were divided into six groups. Before treatment, a single dose (350 mg/kg) of acetaminophen was administered by gavage in all groups. The activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), as well as biochemical factors FRAP and MDA in serum were measured and a histopathological study was performed. The prepared nanoparticles produced in this research were characterized by the SEM, DLS, and ZETA potential, and the average particle size was obtained in the range of 150 nm. Serum levels of liver enzymes (AST and ALT) in the nanoparticle group decreased significantly compared with the control group ( $P<0.05$ ). In the group without treatment, the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes increased significantly compared with the treatment groups. Also, galangin nanoparticles, at a dose of 20 mg/kg, improve cell damage in hepatocytes and preserve the tissue structure of the liver. Galangin nanoparticles reduce the acetaminophen-induced hepatotoxicity by reducing the number of liver function indices. According to our findings, the liver-protective effects of the nanoparticle may be due to its antioxidant properties.

Galangin: A metabolite that suppresses anti-neoplastic activities through modulation of oncogenic targets

With the dramatic increase in cancer incidence all over the world in the last decades, studies on identifying novel efficient anti-cancer agents have been intensified. Historically, natural products have represented one of the most important sources of new lead compounds with a wide range of biological activities. In this article, the multifaceted anti-cancer action of propolis-derived flavonoid, galangin, is presented, discussing its antioxidant, anti-inflammatory, antiproliferative, pro-apoptotic, anti-angiogenic, and anti-metastatic effects in various cancer cells. In addition, co-effects with standard chemotherapeutic drugs as well as other natural compounds are also under discussion, besides highlighting modern nanotechnological advancements for overcoming the low bioavailability issue characteristic of galangin. Although further studies are needed for confirming the anti-cancer potential of galangin in vivo malignant systems, exploring this natural compound might open new perspectives in molecular oncology.

Therapeutic Effects and Molecular Mechanisms of Bioactive Compounds Against Respiratory Diseases: Traditional Chinese Medicine Theory and High-Frequency Use

Respiratory diseases, especially the pandemic of respiratory infectious diseases and refractory chronic lung diseases, remain a key clinical issue and research hot spot due to their high prevalence rates and poor prognosis. In this review, we aimed to summarize the recent advances in the therapeutic effects and molecular mechanisms of key common bioactive compounds from Chinese herbal medicine. Based on the theories of traditional Chinese medicine related to lung diseases, we searched several electronic databases to determine the high-frequency Chinese medicines in clinical application. The active compounds and metabolites from the selected medicines were identified using the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) by analyzing oral bioavailability and drug similarity index. Then, the pharmacological effects and molecular mechanisms of the selected bioactive compounds in the viral and bacterial infections, inflammation, acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, asthma, and lung cancer were summarized. We found that 31 bioactive compounds from the selected 10 common Chinese herbs, such as epigallocatechin-3-gallate (EGCG), kaempferol, isorhamnetin, quercetin, and β-sitosterol, can mainly regulate NF-κB, Nrf2/HO-1, NLRP3, TGF-β/Smad, MAPK, and PI3K/Akt/mTOR pathways to inhibit infection, inflammation, extracellular matrix deposition, and tumor growth in a series of lung-related diseases. This review provides novel perspectives on the preclinical study and clinical application of Chinese herbal medicines and their bioactive compounds against respiratory diseases.

Flavonoids as potential phytotherapeutics to combat cytokine storm in SARS-CoV-2

Emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, COVID-19, has become the global panic since December 2019, which urges the global healthcare professionals to identify novel therapeutics to counteract this pandemic. So far, there is no approved treatment available to control this public health issue; however, a few antiviral agents and repurposed drugs support the patients under medical supervision by compromising their adverse effects, especially in emergency conditions. Only a few vaccines have been approved to date. In this context, several plant natural products-based research studies are evidenced to play a crucial role in immunomodulation that can prevent the chances of infection as well as combat the cytokine release storm (CRS) generated during COVID-19 infection. In this present review, we have focused on flavonoids, especially epicatechin, epigallocatechin gallate, hesperidin, naringenin, quercetin, rutin, luteolin, baicalin, diosmin, ge nistein, biochanin A, and silymarin, which can counteract the virus-mediated elevated levels of inflammatory cytokines leading to multiple organ failure. In addition, a comprehensive discussion on available in silico, in vitro, and in vivo findings with critical analysis has also been evaluated, which might pave the way for further development of phytotherapeutics to identify the potential lead candidatetoward effective and safe management of the SARS-CoV-2 disease.

Galangin ameliorates Imiquimod-Induced psoriasis-like skin inflammation in BALB/c mice via down regulating NF-κB and activation of Nrf2 signaling pathways

Psoriasis is a most common chronic autoimmune-arbitrated cutaneous inflammatory skin disorder by unclear pathogenesis. In this current study we demonstrated the effect of galangin (GAL) on imiquimod (IMQ)-induced psoriasis-like skin inflammation and decipher its possible protective mechanism which has not been investigated. The in vivo results revealed that GAL at 1% w/w and 2% w/w for six consecutive days markedly reduced IMQ-induced PASI scoring, skin, ear thickness, hematological markers, levels of nitrites, TBARS, MPO, histopathological, as well modulated the protein levels of pro-inflammatory mediators of COX-2, iNOS, NF-κB pathway and pro-inflammatory cytokines IL-17, IL-23, IL-1β in the skin and also IL-6, TNF-α in both skin and serum. Besides, GAL restored the levels of antioxidants markers such as SOD, CAT, GST, GSH, GR and Vit-C, anti-inflammatory cytokine of IL-10, and the protein levels of Nrf2/HO-1 in the skin compared to the IMQ group. Finally, our study demonstrates that GAL exerted its protective effect by up-regulating the anti-inflammatory and the antioxidant markers against psoriasis pre-clinical models indicating its potency for treating psoriasis in humans.

Simultaneous determination of two galangin metabolites from Alpinia Officinarum Hance in rat plasma by UF LC-MS/MS and its application in pharmacokinetics study

Galangin has multiple pharmacological efficacies, such as anti-cancer, anti-inflammation and anti-oxidation. Galangin can be rapidly converted into glucuronidated metabolites in vivo. This study aimed to establish an UFLC-MS/MS analytical method to simultaneously determine the concentrations of two glucuronidated metabolites of galangin, galangin-3-O-β-D-glucuronic acid (GG-1) and galangin-7-O-β-D-glucuronic acid (GG-2) in rat plasma. After oral administration of galangal extract (0.3 g/kg), blood samples were collected from the orbital sinus, then treated by methanol precipitation and further gradient-eluted with Phenomenex Kinetex 2.6 µm XB-C18 column. The mass spectrometer was manipulated in the negative electrospray ionization (ESI) and selected multiple reaction monitoring (MRM) mode for the analytes. The precursor-to-product ion pairs applied for GG-1, GG-2 and chrysin (as the internal standard, IS) were m/z 445.2→269.0, 445.2→268.9 and 253.0→142.9, respectively. The results showed that the linear ranges for both GG-1 and GG-2 were 2.0–2000.0 ng/mL (r² > 0.995). The inter- and intra-day precision were 89.3%–109.2%, RSD was less than 15%, and the repeatability was good. The recoveries of both metabolites and IS were over 89%, and matrix effect was within 15%. The validated analytical method was further applied to study the pharmacokinetic profiles of GG-1 and GG-2 in vivo. The pharmacokinetic parameters suggested that T_max of GG-1 was equivalent to that of GG-2, and MRT_0-t, t_1/2 of GG-2 were a little higher than those of GG-1. Importantly, AUC_0-t and C_max of GG-2 were almost twice as those of GG-1. In short, the validated UFLCMS/MS analytical method was feasible to simultaneously determine two galangin metabolites GG-1 and GG-2 in rat plasma and further analyze in vivo metabolism of galangin.

Chinese Herbs and Repurposing Old Drugs as Therapeutic Agents in the Regulation of Oxidative Stress and Inflammation in Pulmonary Diseases

Several pro-inflammatory factors and proteins have been characterized that are involved in the pathogenesis of inflammatory diseases, including acute respiratory distress syndrome, chronic obstructive pulmonary disease, and asthma, induced by oxidative stress, cytokines, bacterial toxins, and viruses. Reactive oxygen species (ROS) act as secondary messengers and are products of normal cellular metabolism. Under physiological conditions, ROS protect cells against oxidative stress through the maintenance of cellular redox homeostasis, which is important for proliferation, viability, cell activation, and organ function. However, overproduction of ROS is most frequently due to excessive stimulation of either the mitochondrial electron transport chain and xanthine oxidase or reduced nicotinamide adenine dinucleotide phosphate (NADPH) by pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor α. NADPH oxidase activation and ROS overproduction could further induce numerous inflammatory target proteins that are potentially mediated via Nox/ROS-related transcription factors triggered by various intracellular signaling pathways. Thus, oxidative stress is considered important in pulmonary inflammatory processes. Previous studies have demonstrated that redox signals can induce pulmonary inflammatory diseases. Thus, therapeutic strategies directly targeting oxidative stress may be effective for pulmonary inflammatory diseases. Therefore, drugs with anti-inflammatory and anti-oxidative properties may be beneficial to these diseases. Recent studies have suggested that traditional Chinese medicines, statins, and peroxisome proliferation-activated receptor agonists could modulate inflammation-related signaling processes and may be beneficial for pulmonary inflammatory diseases. In particular, several herbal medicines have attracted attention for the management of pulmonary inflammatory diseases. Therefore, we reviewed the pharmacological effects of these drugs to dissect how they induce host defense mechanisms against oxidative injury to combat pulmonary inflammation. Moreover, the cytotoxicity of oxidative stress and apoptotic cell death can be protected via the induction of HO-1 by these drugs. The main objective of this review is to focus on Chinese herbs and old drugs to develop anti-inflammatory drugs able to induce HO-1 expression for the management of pulmonary inflammatory diseases.

Galangin treatment during dendritic cell differentiation confers tolerogenic properties in response to lipopolysaccharide stimulation

Tolerogenic dendritic cells (tolDCs) can induce the differentiation of immunosuppressive regulatory T cells and are therefore candidates for the prevention or treatment of various inflammatory diseases. Galangin, a major component of propolis and Alpinia officinarum, has well-established anti-inflammatory effects, but its ability to induce a tolerogenic state in DCs has not been demonstrated. In this study, we investigated the effects of galangin on DC differentiation and immune responses. In particular, we compared phenotypic and functional differences between DCs (Gal-DCs) generated by galangin treatment during DC differentiation and bone marrow-derived DCs. Gal-DCs were generated by adding culture medium containing various doses of galangin (1.8-18.5 µM) on 3 and 6 day. Upon lipopolysaccharide (100 ng/mL) stimulation for 24 h, Gal-DCs generated with 7.4 µM galangin treatment showed lower levels of CD86 and lower major histocompatibility complex class II antigen-presentation than those of bone marrow-derived DCs. Furthermore, Gal-DCs showed markedly increased programmed death ligand 1 expression and IL-10 production via the activation of mitogen-activated protein kinases. Interestingly, Gal-DCs co-cultured with allogeneic CD4 T cells exhibited the reduced cell proliferation and differentiation into Th1-, Th2-, and Th17-type cell; instead, Gal-DCs contributed to the induction of CD4+CD25+Foxp3+ Tregs. Taken together, our data suggest that exposure to galangin during DC differentiation confers tolerogenic properties, efficiently inducing Th cell differentiation to immunosuppressive Tregs. These findings provide new insights into the molecular mechanism underlying the anti-inflammatory effects of galangin on DCs.

The upshot of Polyphenolic compounds on immunity amid COVID-19 pandemic and other emerging communicable diseases: An appraisal

Polyphenols are a large family of more than 10,000 naturally occurring compounds, which exert countless pharmacological, biological and physiological benefits for human health including several chronic diseases such as cancer, diabetes, cardiovascular, and neurological diseases. Their role in traditional medicine, such as the use of a wide range of remedial herbs (thyme, oregano, rosemary, sage, mint, basil), has been well and long known for treating common respiratory problems and cold infections. This review reports on the most highlighted polyphenolic compounds present in up to date literature and their specific antiviral perceptive properties that might enhance the body immunity facing COVID-19, and other viral infectious diseases. In fact, several studies and clinical trials increasingly proved the role of polyphenols in controlling numerous human pathogens including SARS and MERS, which are quite similar to COVID-19 through the enhancement of host immune response against viral infections by different biological mechanisms. Thus, polyphenols ought to be considered as a potential and valuable source for designing new drugs that could be used effectively in the combat against COVID-19 and other rigorous diseases.

An Evaluation of Traditional Persian Medicine for the Management of SARS-CoV-2

A new coronavirus causing severe acute respiratory syndrome (SARS-CoV-2) has emerged and with it, a global investigation of new antiviral treatments and supportive care for organ failure due to this life-threatening viral infection. Traditional Persian Medicine (TPM) is one of the most ancient medical doctrines mostly known with the manuscripts of Avicenna and Rhazes. In this paper, we first introduce a series of medicinal plants that would potentially be beneficial in treating SARS-CoV-2 infection according to TPM textbooks. Then, we review medicinal plants based on the pharmacological studies obtained from electronic databases and discuss their mechanism of action in SARS-CoV-2 infection. There are several medicinal plants in TPM with cardiotonic, kidney tonic, and pulmonary tonic activities, protecting the lung, heart, and kidney, the three main vulnerable organs in SARS-CoV-2 infection. Some medicinal plants can prevent "humor infection", a situation described in TPM which has similar features to SARS-CoV-2 infection. Pharmacological evaluations are in line with the therapeutic activities of several plants mentioned in TPM, mostly through antiviral, cytoprotective, anti-inflammatory, antioxidant, and anti-apoptotic mechanisms. Amongst the primarily-introduced medicinal plants from TPM, rhubarb, licorice, garlic, saffron, galangal, and clove are the most studied plants and represent candidates for clinical studies. The antiviral compounds isolated from these plants provide novel molecular structures to design new semisynthetic antiviral agents. Future clinical studies in healthy volunteers as well as patients suffering from pulmonary infections are necessary to confirm the safety and efficacy of these plants as complementary and integrative interventions in SARS-CoV-2 infection.

Flavonoids Profile, Taxonomic Data, History of Cosmetic Uses, Anti-Oxidant and Anti-Aging Potential of Alpinia galanga (L.) Willd

Alpinia galanga is a well-known medicinal plant in Southeast Asia and has been used for a long time as food and medicine. A large number of flavonoid phytochemical compounds have been identified in various parts of this medicinal herb. Flavonoids are commonly known as attractive compounds that can be applied to cosmetic or cosmeceutical product development because of their antioxidant, anti-aging and many other potential biological activities. This recent review aims to illustrate and update the taxonomic status as well as the species description that will be helpful for a rigorous identification and authenticate the raw material or living specimen from A. galanga. The flavonoid phytochemical compounds and the bioactivity of this medicinal plant are also provided. The future perspectives and research directions of A. galanga and its flavonoids are pointed out in this study as well.

The natural flavonoid galangin ameliorates dextran sulphate sodium-induced ulcerative colitis in mice: Effect on Toll-like receptor 4, inflammation and oxidative stress

This study was carried out to investigate the potential therapeutic effect of galangin, a promising active principle of honeybee propolis, in dextran sulphate sodium (DSS)-induced colitis in mice. We explored the possible underlying mechanisms for galangin action and the therapeutic benefit of adding galangin to the standard therapy sulphasalazine. A galangin dose of 40 mg/kg was selected based on a preliminary dose-selection study for investigation in a 4-week cyclical model of DSS-induced colitis. Mice received 3% DSS in their drinking water during the first and third weeks and were administered the treatments (40 mg/kg galangin, 100 mg/kg sulphasalazine and a combination of 20 mg/kg galangin and 50 mg/kg sulphasalazine) daily starting from the second week. Galangin significantly ameliorated DSS-induced histopathological alterations and tissue injury, down-regulated Toll-like receptor 4 expression, suppressed NF-κB p65 activation, lowered inflammatory cytokine levels and demonstrated antioxidant effects. The combination of galangin and sulphasalazine at half doses yielded comparable results to either drug alone at full dose. This study highlights galangin as a promising therapy for colitis management.

Protective effect of galangin against dextran sulfate sodium (DSS)-induced ulcerative colitis in Balb/c mice

OBJECTIVE AND DESIGN

Inflammatory bowel disease (IBD) is known to cause chronic inflammation in the digestive tract by the immune malfunction. Herein, we demonstrate the protective effect of galangin (GAL), a phytochemical, on LPS-induced inflammation in cultured mouse macrophages (RAW 264.7) and the treatment of DSS-induced ulcerative colitis in Balb/c mice. However, the anti-inflammatory effect of GAL in DSS-exposed experimental colitis has not been investigated.

MATERIALS AND METHODS

We determined the levels of proinflammatory cytokines by ELISA, biochemical analysis using standard protocols and protein expression level of NF-κB signaling pathway and activation of Nrf2 gene pathway were analyzed by western blot analysis in colitis-induced mice.

RESULTS

Our in vitro studies showed that LPS-stimulated RAW 264.7 cells treated with GAL reduced the levels of nitrites, IL-6, and TNF-α in a concentration-dependent manner. The results demonstrated that oral administration of GAL at 20 mg/kg (lower dose) and 40 mg/kg (higher dose) significantly reduced the severity of colitis and mitigated the clinical signs of both macroscopic and microscopic of the disease. The levels of proinflammatory cytokines (TNF-α and IL-6) in colonic tissue and serum were reduced significantly and in GAL + DSS-treated group relative to DSS alone treated group.  Increased levels of anti-inflammatory cytokine (IL-10) was detected in colon tissues in GAL + DSS-treated groups relative to DSS alone treated group. We also observed decreased levels of myeloperoxidase (MPO), nitrites and TBARS with increased SOD in colonic tissue of GAL + DSS group. Besides, GAL + DSS-treated animals significantly suppressed protein expressions of p-NF-κB and p-Ikk-βα, COX-2, iNOS, Nrf2 and increased HO-1 levels in colon tissues by inhibiting inflammation and oxidative stress.

CONCLUSION

Our study highlights the protective effect of galangin as an anti-inflammatory agent against the severe form of colitis in pre-clinical models suggesting its potency for the treatment of IBD in humans.

Myricetin attenuates LPS-induced inflammation in RAW 264.7 macrophages and mouse models

Aim: Acute lung injury is a common clinical syndrome associated with significant morbidity. Myricetin has been demonstrated to inhibit inflammation in a variety of diseases. In this study, we aimed to investigate the protective effects of myricetin on inflammation in lipopolysaccharide-stimulated RAW 264.7 cells and lipopolysaccharide-induced lung injury model. Results/methodology: In this study, we detected the anti-inflammatory effects of myricetin by ELISA, RT-PCR and Western blot, respectively. Myricetin significantly inhibited the production of the proinflammatory cytokines in vitro and in vivo. It exerted an anti-inflammatory effect through suppressing the NF-κB p65 and AKT activation in NF-κB pathway and JNK, p-ERK and p38 in MAPK signaling pathway. Conclusion: Myricetin alleviated acute lung injury by inhibiting macrophage activation, and inhibited inflammation in vitro and in vivo. It may be a potential therapeutic candidate for the prevention of inflammatory diseases.

Galangin Reduces the Loss of Dopaminergic Neurons in an LPS-Evoked Model of Parkinson's Disease in Rats

Parkinson’s disease (PD) is caused by the loss of dopaminergic (DA) neurons in the midbrain substantia nigra (SN). Neuroinflammation, which is marked by microglial activation, plays a very important role in the pathogenesis of PD. Pro-inflammatory mediators produced by activated microglia could damage DA neurons. Hence, the inhibition of microglial activation may provide a new approach for treating PD. Galangin has been shown to inhibit inflammation in a variety of diseases, but not PD. In this study, we aimed to investigate the anti-inflammatory effect of galangin and the underlying mechanisms in Lipopolysaccharide (LPS) induced PD models. We first examined the protective effect of galangin in the LPS-induced PD rat model. Specifically, we investigated the effects on motor dysfunction, microglial activation, and the loss of DA neurons. Then, galangin was used to detect the impact on the inflammatory responses and inflammatory signaling pathways in LPS-induced BV-2 cells. The in vivo results showed that galangin dose-dependently attenuates the activation of microglia, the loss of DA neurons, and motor dysfunction. In vitro, galangin markedly inhibited LPS-induced expression of tumor necrosis factor α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β), cyclooxygenase 2 (COX-2), and induced nitric oxide synthase (iNOS) via associating with the phosphorylation of c-JUN N-terminal Kinase (JNK), p38, protein kinase B (AKT), and nuclear factor κB (NF-κB) p65. Collectively, the results indicated that galangin has a role in protecting DA neurons by inhibiting microglial activation.

Application of galangin, an active component of Alpinia officinarum Hance (Zingiberaceae), for use in drug-eluting stents

In clinical pathology, stent interposition is used to treat vascular disease but can lead to restenosis. Drug-eluting stents (DES) are most commonly used to suppress restenosis but can also have side effects. Therefore, we investigated the anti-proliferative effect and its possible target in vitro and in vivo. We found that Alpinia officinarum Hance (AO) extract efficiently inhibited VSMC proliferation by arresting the transition from the G₀/G₁ to the S phase via the up-regulation of p27^KIP1 expression. Galangin (GA) was determined to be a significant component of this extract, with the same anti-proliferative activity as the raw extract. Immunoblotting and immunofluorescence staining showed that both the AO extract and GA targeted the up-regulation of p27^KIP1 expression. Therefore, we next examined the effect of these compounds in a cuff-injured neointimal hyperplasia model in vivo. In this animal model, both the AO extract and GA completely suppressed the neointima formation, and this inhibitory effect was also demonstrated to target the up-regulation of p27^KIP1, including the suppression of proliferating cell nuclear antigen expression. Our findings indicate that AO extract and GA have a potent anti-proliferative activity, targeting the up-regulation of p27 expression. Thus, GA may represent an alternative medicine for use in DES.

Arctigenin improves vascular tone and decreases inflammation in human saphenous vein

The goal of this study was to test the effects of bioactive phenylpropanoid dibenzylbutyrolactone lignan arctigenin (ATG) in vascular tone. Human bypass graft vessel, from a saphenous vein (SV), were set up in organ bath system and contracted with potassium chloride (KCl, 40mM). Two concentration-response curves of noradrenaline (NE) (10nM-100μM) separated with an incubation period of 30min without (Control) or with ATG (3-100μM) were established. Inhibitors of nitric oxide, prostaglandins, K⁺ related channels or calcium influx were used to delineate the molecular mechanisms beyond ATG effects. To investigate anti-inflammatory actions, SV were treated with 10μM or 100μM ATG and incubated for 18h in the absence or presence of both interleukin-1beta (IL-1β) and lipopolysaccharide (LPS) to mimic the physiological or inflamed tissue conditions. Proatherogenic and inflammatory mediators İnterleukine-1 beta (IL-1β), Monocyte Chemoattractant Proteine-1 (MCP-1), Tumor Necrosis Factor- α (TNF-α), İnterleukine-6 (IL-6), Prostaglandin E₂ (PGE₂) and İnterleukine-8 (IL-8) in the supernatant were measured. ATG significantly decreased vascular contractile response to NE. Moreover, it reduced contractions induced by KCl and cumulative addition of CaCl_2. The mediators were significantly increased in inflammatory conditions compared to normal conditions, an effect which was inhibited by ATG (10 and 100µM). ATG reduces contractions in SV and decreases the production of proinflammatory-proatherogenic mediators, setting the stage for further evaluating the effect of ATG in cardiovascular diseases.

Attenuation of airway smooth muscle contractility via flavonol-mediated inhibition of phospholipase-Cβ

Enhanced contractility of airway smooth muscle (ASM) is a major pathophysiological characteristic of asthma. Expanding the therapeutic armamentarium beyond β-agonists that target ASM hypercontractility would substantially improve treatment options. Recent studies have identified naturally occurring phytochemicals as candidates for acute ASM relaxation. Several flavonoids were evaluated for their ability to acutely relax human and murine ASM ex vivo and murine airways in vivo and were evaluated for their ability to inhibit procontractile signaling pathways in human ASM (hASM) cells. Two members of the flavonol subfamily, galangin and fisetin, significantly relaxed acetylcholine-precontracted murine tracheal rings ex vivo (n = 4 and n = 5, respectively, P < 0.001). Galangin and fisetin also relaxed acetylcholine-precontracted hASM strips ex vivo (n = 6-8, P < 0.001). Functional respiratory in vivo murine studies demonstrated that inhaled galangin attenuated the increase in lung resistance induced by inhaled methacholine (n = 6, P < 0.01). Both flavonols, galangin and fisetin, significantly inhibited purified phosphodiesterase-4 (PDE4) (n = 7, P < 0.05; n = 7, P < 0.05, respectively), and PLCβ enzymes (n = 6, P < 0.001 and n = 6, P < 0.001, respectively) attenuated procontractile Gq agonists' increase in intracellular calcium (n = 11, P < 0.001), acetylcholine-induced increases in inositol phosphates, and CPI-17 phosphorylation (n = 9, P < 0.01) in hASM cells. The prorelaxant effect retained in these structurally similar flavonols provides a novel pharmacological method for dual inhibition of PLCβ and PDE4 and therefore may serve as a potential treatment option for acute ASM constriction.

Antiosteoporotic effects of Alpinia officinarum Hance through stimulation of osteoblasts associated with antioxidant effects

BACKGROUND/OBJECTIVE

Alpinia officinarum Hance (AOH) is a traditional herbal medicine specific to south China and serves as a civil medication application of an antioxidant. Growing evidence demonstrates that antioxidants are beneficial for the treatment of osteoporosis. This study was designed to investigate the antiosteoporotic effects of total extracts from AOH in ovariectomised (OVX) rats and the different fractions in AOH on primary osteoblasts activities.

METHODS

The total extract of AOH was extracted by refluxing using 95% ethanol, then the five fractions (F1-F5) were separated from AOH using thin-layer chromatography according to polarity from high to low, and the galangin content was determined using high performance liquid chromatography. In an in vivo study, 36 4-month-old female Sprague-Dawley rats were used as a Sham-operated group, OVX with vehicle (OVX), OVX with epimedium flavonoids (EF, 150 mg/kg/d), and OVX with AOH (AOH, 300 mg/kg/d), respectively. Daily oral administration started on Day 3 after OVX and lasted for 12 weeks. In the in vitro study, primary osteoblasts were incubated with AOH, galangin, and five different fractions (F1-F5) with or without hydrogen peroxide (H2O2), respectively.

RESULTS

Treatment with AOH significantly attenuated osteopenia accompanied by a decreased percentage of osteoclast perimeter and bone formation rate per unit of bone surface, enhanced the bone strength, and prevented the deterioration of trabecular microarchitecture associated with a decrease in biochemical parameters of oxidative stress. Furthermore, treatment with AOH, F3, F4, and galangin increased cell viability, differentiation, and mineralisation in osteoblasts with or without H2O2 and rescued the deleterious effects of H2O2 on cell apoptosis and intracellular reactive oxygen species level. The effects on osteoblast formation were highly aligned with the amounts of flavonoids within AOH.

CONCLUSION

These data demonstrate that ethanol extracts from AOH significantly reverse bone loss, partially by increasing bone formation, and by suppressing bone resorption associated with antioxidant effects, suggesting that AOH can be developed as a promising agent for the prevention and treatment of osteoporosis.

Wnt/β-catenin coupled with HIF-1α/VEGF signaling pathways involved in galangin neurovascular unit protection from focal cerebral ischemia

Microenvironmental regulation has become a promising strategy for complex disease treatment. The neurovascular unit (NVU), as the key structural basis to maintain an optimal brain microenvironment, has emerged as a new paradigm to understand the pathology of stroke. In this study, we investigated the effects of galangin, a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, on NVU microenvironment improvement and associated signal pathways in rats impaired by middle cerebral artery occlusion (MCAO). Galangin ameliorated neurological scores, cerebral infarct volume and cerebral edema and reduced the concentration of Evans blue (EB) in brain tissue. NVU ultrastructural changes were also improved by galangin. RT-PCR and western blot revealed that galangin protected NVUs through the Wnt/β-catenin pathway coupled with HIF-1α and vascular endothelial growth factor (VEGF). VEGF and β-catenin could be the key nodes of these two coupled pathways. In conclusion, Galangin might function as an anti-ischemic stroke drug by improving the microenvironment of NVUs.

Galangin attenuates airway remodelling by inhibiting TGF-β1-mediated ROS generation and MAPK/Akt phosphorylation in asthma

Galangin, a natural flavonol, has attracted much attention for its potential anti-inflammatory properties. However, its role in the regulation of airway remodelling in asthma has not been explored. The present study aimed to elucidate the effects of galangin on chronic inflammation and airway remodelling and to investigate the underlying mechanisms both in vivo and in vitro. Ovalbumin (OVA)-sensitised mice were administered with galangin 30 min before challenge. Our results showed that severe inflammatory responses and airway remodelling occurred in OVA-induced mice. Treatment with galangin markedly attenuated the leakage of inflammatory cells into bronchoalveolar lavage fluid (BALF) and decreased the level of OVA-specific IgE in serum. Galangin significantly inhibited goblet cell hyperplasia, collagen deposition and α-SMA expression. Lowered level of TGF-β1 and suppressed expression of VEGF and MMP-9 were observed in BALF or lung tissue, implying that galangin has an optimal anti-remodelling effect in vivo. Consistently, the TGF-β1-induced proliferation of airway smooth muscle cells was reduced by galangin in vitro, which might be due to the alleviation of ROS levels and inhibition of MAPK pathway. Taken together, the present findings highlight a novel role for galangin as a promising anti-remodelling agent in asthma, which likely involves the TGF-β1-ROS-MAPK pathway.

Protective effect of galangin in Concanavalin A-induced hepatitis in mice

Galangin is an active pharmacological ingredient from propolis and Alpinia officinarum Hance, and has been reported to have anti-inflammatory and antioxidative properties. The present study aims to reveal the effect of galangin on Concanavalin A (ConA)-induced hepatitis (CIH), a well-established animal model of immune-mediated liver injury, and to clarify the related mechanism. C57BL/6 mice were pretreated with galangin followed by ConA challenge. Results indicated that galangin inhibited ConA-induced liver damage. Mice pretreated with galangin showed more reduction of liver damage when compared with control mice pretreated with vehicle solution. In galangin-pretreated mice with induced CIH, increases in serum levels of several inflammatory cytokines, including tumor necrosis factor-α, interferon-γ, and interleukin-12 were dramatically attenuated, and chemokines and adhesion molecules like interferon inducible protein-10, macrophage inflammatory protein-1α, and inter-cellular adhesion molecule-1 messenger RNA expressions in liver were decreased. Moreover, CIH mice pretreated with galangin showed less leukocyte infiltration and T-cell activation in the liver. Further, the mechanism of the anti-inflammatory effects of galangin may be attributed to its modulation of crucial inflammatory signaling pathways, including nuclear factor kappa B and interferon-gamma/signal transducer and activator of transcription 1. Collectively, these findings suggest the preventive and therapeutic potential of galangin in immune-mediated liver injury in vivo.

Zingiberaceae extracts for pain: a systematic review and meta-analysis

Background

Members of the family Zingiberaceae including turmeric, ginger, Javanese ginger, and galangal have been used for centuries in traditional medicine. Preclinical studies of Zingiberaceae extracts have shown analgesic properties. This study aims to systematically review and meta-analyze whether extracts from Zingiberaceae are clinically effective hypoalgesic agents.

Methods

Literature was screened from electronic databases using the key words Zingiberaceae AND pain OR visual analogue score (VAS) to identify randomized trials. From this search, 18 studies were identified, and of these, 8 randomized, double-blinded, placebo-controlled trials were found that measured pain by VAS for inclusion in the meta-analysis.

Results

Findings indicated significant efficacy of Zingiberaceae extracts in reducing subjective chronic pain (SMD − 0.67; 95 % CI − 1.13 to − 0.21; P = 0.004). A linear dose-effect relationship was apparent between studies (R² = 0.71). All studies included in the systematic review reported a good safety profile for extracts, without the renal risks associated with non-steroidal anti-inflammatory drugs, and with similar effectiveness.

Conclusion

Our findings indicated that Zingiberaceae extracts are clinically effective hypoalgesic agents and the available data show a better safety profile than non-steroidal anti-inflammatory drugs. However, both non-steroidal anti-inflammatory drugs and Zingiberaceae have been associated with a heightened bleeding risk, and there have been no comparator trials of this risk. Further clinical studies are recommended to identify the most effective type of Zingiberaceae extract and rigorously compare safety, including bleeding risk.