Structural analysis of a novel antimutagenic compound, 4-Hydroxypanduratin A, and the antimutagenic activity of flavonoids in a Thai spice, fingerroot (Boesenbergia pandurata Schult.) against mutagenic heterocyclic amines

Unveiling the Antiviral Properties of Panduratin A through SARS-CoV-2 Infection Modeling in Cardiomyocytes

Establishing a drug-screening platform is critical for the discovery of potential antiviral agents against SARS-CoV-2. In this study, we developed a platform based on human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to investigate SARS-CoV-2 infectivity, with the aim of evaluating potential antiviral agents for anti-SARS-CoV-2 activity and cardiotoxicity. Cultured myocytes of iPSC-CMs and immortalized human cardiomyocyte cell line (AC-16) were primarily characterized for the expression of cardiac markers and host receptors of SARS-CoV-2. An infectivity model for the wild-type SARS-CoV-2 strain was then established. Infection modeling involved inoculating cells with SARS-CoV-2 at varying multiplicities of infection (MOIs) and then quantifying infection using immunofluorescence and plaque assays. Only iPSC-CMs, not AC16 cells, expressed angiotensin-converting enzyme 2 (ACE-2), and quantitative assays confirmed the dose-dependent infection of iPSC-CMs by SARS-CoV-2, unlike the uninfectable AC16 cells lacking the expression of ACE2. Cytotoxicity was evaluated using MTT assays across a concentration range. An assessment of the plant-derived compound panduratin A (panA) showed cytotoxicity at higher doses (50% cytotoxic concentration (CC50) 10.09 μM) but promising antiviral activity against SARS-CoV-2 (50% inhibition concentration (IC50) 0.8-1.6 μM), suppressing infection at concentrations 10 times lower than its CC50. Plaque assays also showed decreased viral production following panA treatment. Overall, by modeling cardiac-specific infectivity, this iPSC-cardiomyocyte platform enables the reliable quantitative screening of compound cytotoxicity alongside antiviral efficacy. By combining disease pathogenesis and pharmacology, this system can facilitate the evaluation of potential novel therapeutics, such as panA, for drug discovery applications.

Isolation and biological activity of natural chalcones based on antibacterial mechanism classification

Bacterial infection, which is still one of the leading causes of death in humans, poses an enormous threat to the worldwide public health system. Antibiotics are the primary medications used to treat bacterial diseases. Currently, the discovery of antibiotics has reached an impasse, and due to the abuse of antibiotics resulting in bacterial antibiotic resistance, researchers have a critical desire to develop new antibacterial agents in order to combat the deteriorating antibacterial situation. Natural chalcones, the flavonoids consisting of two phenolic rings and a three-carbon α, β-unsaturated carbonyl system, possess a variety of biological and pharmacological properties, including anti-cancer, anti-inflammatory, antibacterial, and so on. Due to their potent antibacterial properties, natural chalcones possess the potential to become a new treatment for infectious diseases that circumvents existing antibiotic resistance. Currently, the majority of research on natural chalcones focuses on their synthesis, biological and pharmacological activities, etc. A few studies have been conducted on their antibacterial activity and mechanism. Therefore, this review focuses on the antibacterial activity and mechanisms of seventeen natural chalcones. Firstly, seventeen natural chalcones have been classified based on differences in antibacterial mechanisms. Secondly, a summary of the isolation and biological activity of seventeen natural chalcones was provided, with a focus on their antibacterial activity. Thirdly, the antibacterial mechanisms of natural chalcones were summarized, including those that act on bacterial cell membranes, biological macromolecules, biofilms, and quorum sensing systems. This review aims to lay the groundwork for the discovery of novel antibacterial agents based on chalcones.

Interaction of panduratin A and derivatives with the SARS-CoV-2 main protease (mpro): a molecular docking study

Panduratin A (Pa-A) is a prenylated cyclohexenyl chalcone isolated from the rhizomes of the medicinal and culinary plant Boesenbergia rotunda (L.) Mansf., commonly called fingerroots. Both an ethanolic plant extract and Pa-A have shown a marked antiviral activity against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), responsible for the COVID-19 pandemic disease. Pa-A functions as a protease inhibitor inhibiting infection of human cells by the virus. We have modeled the interaction of Pa-A, and 26 panduratin analogues with the main protease (M^pro) of SARS-CoV-2 using molecular docking. The natural product 4-hydroxypanduratin showed a higher M^pro binding capacity than Pa-A and isopanduratin A. The interaction with M^Pro of all known panduratin derivatives (Pa-A to Pa-Y) have been compared, together with more than 60 reference products. Three compounds emerged as potential robust M^Pro binders: Pa-R, Pa-V, Pa-S, with a binding capacity significantly higher than 4-OH-Pa-A and Pa-A. The empirical energy of interaction (ΔE) calculated with the best compound in the panduratin series, Pa-R bound to M^pro, surpassed that measured with the top reference protease inhibitors such a ruprintrivir, lufotrelvir, and glecaprevir. Structure-binding relationships are discussed. Compounds with a flavanone moiety (PA-R/S) are the best binders, better than those with a chromene unit (Pa-F/G). The extended molecules (such as Pa-V) exhibit good M^pro binding, but the dimeric compound Pa-Y is too long and protrudes outside the binding cavity. The work provides novel ideas to guide the design of new molecules interacting with M^pro.Communicated by Ramaswamy H. Sarma.

Boesenbergia Pandurata as an Anti-Breast Cancer Agent: Molecular Docking and ADMET Study

Background:

Boesenbergia pandurata or fingerroot is known to have various pharmacological activities, including anticancer properties. Extracts from these plants are known to inhibit the growth of cancer cells, including breast cancer. Anti-breast cancer activity is significantly influenced by the inhibition of two receptors: ER-α and HER2. However, it is unknown which metabolites of B. pandurata play the most crucial role in exerting anticancer activity.

Objective:

This study aimed to determine the metabolites of B. pandurata with the best potential as ER-α and HER2 inhibitors.

Method:

The method used was molecular docking of several B. pandurata metabolites to ER-α and HER2 receptors, followed by an ADMET study of several metabolites with the best docking results.

Results:

The docking results showed eight metabolites with the best docking results for the two receptors based on the docking score and ligand-receptor interactions. Of these eight compounds, compounds 11 ((2S)-7,8-dihydro-5-hydroxy-2-methyl-2-(4''-methyl-3''-pentenyl)-8-phenyl-2H,6H-benzo(1,2-b-5,4- b')dipyran-6-one) and 34 (geranyl-2,4-dihydroxy-6-phenethylbenzoate) showed the potential to inhibit both receptors. Both ADMET profiles also showed mixed results; however, there is a possibility of further development.

Conclusion:

In conclusion, the metabolites of B. pandurata, especially compounds 11 and 34, can be developed as anti-breast cancer agents by inhibiting ER-α and HER2.

Genome Assembly and Analysis of the Flavonoid and Phenylpropanoid Biosynthetic Pathways in Fingerroot Ginger (Boesenbergia rotunda)

Boesenbergia rotunda (Zingiberaceae), is a high-value culinary and ethno-medicinal plant of Southeast Asia. The rhizomes of this herb have a high flavanone and chalcone content. Here we report the genome analysis of B. rotunda together with a complete genome sequence as a hybrid assembly. B. rotunda has an estimated genome size of 2.4 Gb which is assembled as 27,491 contigs with an N50 size of 12.386 Mb. The highly heterozygous genome encodes 71,072 protein-coding genes and has a 72% repeat content, with class I TEs occupying ~67% of the assembled genome. Fluorescence in situ hybridization of the 18 chromosome pairs at the metaphase showed six sites of 45S rDNA and two sites of 5S rDNA. An SSR analysis identified 238,441 gSSRs and 4604 EST-SSRs with 49 SSR markers common among related species. Genome-wide methylation percentages ranged from 73% CpG, 36% CHG and 34% CHH in the leaf to 53% CpG, 18% CHG and 25% CHH in the embryogenic callus. Panduratin A biosynthetic unigenes were most highly expressed in the watery callus. B rotunda has a relatively large genome with a high heterozygosity and TE content. This assembly and data (PRJNA71294) comprise a source for further research on the functional genomics of B. rotunda, the evolution of the ginger plant family and the potential genetic selection or improvement of gingers.

Toward the use ofBoesenbergia rotundaextracts and the chalcone panduratin A to treat periodontitis

Novel affordable medications are needed to treat chronic periodontitis, which is one of the most common dental pathologies worldwide. Extracts prepared from the rhizome of the medicinal plant Boesenbergia rotunda (L.) Mansf., commonly known as fingerroot, are used to treat a variety of human pathologies. These extracts contain potent anti-inflammatory compounds, including the chalcone derivative panduratin A (Pa-A), which is the lead compound of a series of analogues, designated panduratins A to Y. The anti-inflammatory properties of the extracts of B. rotunda and the most abundant bioactive products found in these extracts (including Pa-A, 4-hydroxyoanduratin, isopanduratin, and others) have been reviewed. A standardized extract of the plant has promising utility in the treatment of gingival inflammation. The effects are characterized by three actions: (i) a direct antimicrobial effect against fungi and oral pathogens such as Porphyromonas gingivalis, (ii) a marked anti-inflammatory effect via a reduced production of mediators, like prostaglandin E2 and different interleukins, and (iii) a dual bone-preserving effect, with a reduction in bone resorption and an increase in bone formation. Acting as a protease inhibitor, Pa-A is one of the main active ingredients of the extract, implicated in these actions. A Pa-A-standardized extract of B. rotunda has been used in humans for treating dyspepsia. The product is safe and well-tolerated. The development of panduratin-containing dental products, for the prevention and treatment of periodontitis, has been proposed. The structural analogues, Pa-A to-Y, should also be investigated for the treatment of dental inflammation.

Chalcone Scaffolds, Bioprecursors of Flavonoids: Chemistry, Bioactivities, and Pharmacokinetics

Chalcones are secondary metabolites belonging to the flavonoid (C6-C3-C6 system) family that are ubiquitous in edible and medicinal plants, and they are bioprecursors of plant flavonoids. Chalcones and their natural derivatives are important intermediates of the flavonoid biosynthetic pathway. Plants containing chalcones have been used in traditional medicines since antiquity. Chalcones are basically α,β-unsaturated ketones that exert great diversity in pharmacological activities such as antioxidant, anticancer, antimicrobial, antiviral, antitubercular, antiplasmodial, antileishmanial, immunosuppressive, anti-inflammatory, and so on. This review provides an insight into the chemistry, biosynthesis, and occurrence of chalcones from natural sources, particularly dietary and medicinal plants. Furthermore, the pharmacological, pharmacokinetics, and toxicological aspects of naturally occurring chalcone derivatives are also discussed herein. In view of having tremendous pharmacological potential, chalcone scaffolds/chalcone derivatives and bioflavonoids after subtle chemical modification could serve as a reliable platform for natural products-based drug discovery toward promising drug lead molecules/drug candidates.

Naturally occurring prenylated chalcones from plants: structural diversity, distribution, activities and biosynthesis

Covering: up to July 2020Naturally occurring chalcones carrying up to three modified or unmodified C5-, C10-, and C15-prenyl moieties on both rings A and B as well as at the α- and β-carbons are widely distributed in plants of the families of Fabaceae, Moraceae, Zingiberaceae and Cannabaceae. Xanthohumol and isobavachalcone being the most investigated representatives, exhibit diverse and remarkable biological and pharmacological activities. The present review deals with their structural characters, biological activities and occurrence in the plant kingdom. Biosynthesis of prenylated chalcones and metabolism of xanthohumol are also discussed.

Bioactive Compounds from Medicinal Plants in Myanmar

Myanmar is a country with rich natural resources and of these, medicinal plants play a vital role in the primary health care of its population. The people of Myanmar have used their own system of traditional medicine inclusive of the use of medicinal plants for 2000 years. However, systematic and scientific studies have only recently begun to be reported. Researchers from Japan, Germany, and Korea have collaborated with researchers in Myanmar on medicinal plants since 2000. During the past two decades, over 50 publications have been published in peer-reviewed journals. Altogether, 433 phytoconstituents, including 147 new and 286 known compounds from 26 plant species consisting of 29 samples native to Myanmar, have been collated. In this contribution, phytochemical and biological investigations of these plants, including information on traditional knowledge are compiled and discussed.

Vasorelaxant Effect of Boesenbergia rotunda and Its Active Ingredients on an Isolated Coronary Artery

Cardiovascular diseases are a major cause of death in developed countries. The regulation of vascular tone is a major approach to prevent and ameliorate vascular diseases. As part of our ongoing screening for cardioprotective natural compounds, we investigated the vasorelaxant effect of rhizomes from Boesenbergia rotunda (L.) Mansf. [Boesenbergia pandurata (Roxb.) Schltr.] used as a spice and herbal medicine in Asian countries. The methanol extract of B. rotunda rhizomes (BRE) exhibited significant vasorelaxation effects ex vivo at EC₅₀ values of 13.4 ± 6.1 μg/mL and 40.9 ± 7.9 μg/mL, respectively, with and without endothelium in the porcine coronary artery ring. The intrinsic mechanism was evaluated by treating with specific inhibitors or activators that typically affect vascular reactivity. The results suggested that BRE induced relaxation in the coronary artery rings via an endothelium-dependent pathway involving NO-cGMP, and also via an endothelium-independent pathway involving the blockade of Ca²⁺ channels. Vasorelaxant principles in BRE were identified by subsequent chromatographic methods, which revealed that flavonoids regulate vasorelaxant activity in BRE. One of the flavonoids was a Diels-Alder type adduct, 4-hydroxypanduratin A, which showed the most potent vasorelaxant effect on porcine coronary artery with an EC₅₀ of 17.8 ± 2.5 μM. Our results suggest that rhizomes of B. rotunda might be of interest as herbal medicine against cardiovascular diseases.

Cratoxylum formosum dyer extract alleviates testicular damage in hypertensive rats

The effects of a Cratoxylum formosum (Jack) Dyer ssp. (CF) extract on testicular damage were assessed in hypertensive rats. N^ω -nitro-L-arginine methyl ester hydrochloride (L-NAME; 40 mg kg^-1  day^-1 ) was administered for 5 weeks to induce hypertension in male Sprague-Dawley rats, and treated with CF extract (100, 300 or 500 mg kg^-1  day^-1 ) or sildenafil (5 mg kg^-1  day^-1 ) during the final 2 weeks (n = 8/group). Biochemical components of the CF extract were identified and mainly contained phenolic compounds. The CF extract significantly reduced systolic blood pressure and alleviated impaired sperm quality and seminiferous tubular morphology in hypertensive rats. CF extract restored reduced serum testosterone and protein expression of steroidogenic acute regulatory protein (StAR), nuclear factor erythroid-related factor 2 (Nrf2), and haem oxygenase 1 (HO-1) in L-NAME rats. Hypertensive rats presented decreased antioxidant enzyme activities, and increased testicular and plasma malondialdehyde (MDA) levels and superoxide production, all of which were normalised by CF extract. Furthermore, endothelial nitric oxide synthase (eNOS) expression in testicular tissue and plasma nitrate/nitrite levels were restored in hypertensive rats administered CF extract. Conclusion: CF extract alleviated testicular damage in hypertensive rats. Potential molecular mechanisms may involve suppression of oxidative stress and restoration of StAR, Nrf2, HO-1 and eNOS expression in hypertensive rats.

Possible Participation of Ionotropic Glutamate Receptors and l-Arginine-Nitric Oxide-Cyclic Guanosine Monophosphate-ATP-Sensitive K+ Channel Pathway in the Antinociceptive Activity of Cardamonin in Acute Pain Animal Models

The perception of pain caused by inflammation serves as a warning sign to avoid further injury. The generation and transmission of pain impulses involves various pathways and receptors. Cardamonin isolated from Boesenbergia rotunda (L.) Mansf. has been reported to exert antinociceptive effects in thermal and mechanical pain models; however, the precise mechanism has yet to be examined. The present study investigated the possible mechanisms involved in the antinociceptive activity of cardamonin on protein kinase C, N-methyl-d-aspartate (NMDA) and non-NMDA glutamate receptors, l-arginine/cyclic guanosine monophosphate (cGMP) mechanism, as well as the ATP-sensitive potassium (K⁺) channel. Cardamonin was administered to the animals intra-peritoneally. Present findings showed that cardamonin significantly inhibited pain elicited by intraplantar injection of phorbol 12-myristate 13-acetate (PMA, a protein kinase C activator) with calculated mean ED₅₀ of 2.0 mg/kg (0.9–4.5 mg/kg). The study presented that pre-treatment with MK-801 (NMDA receptor antagonist) and NBQX (non-NMDA receptor antagonist) significantly modulates the antinociceptive activity of cardamonin at 3 mg/kg when tested with glutamate-induced paw licking test. Pre-treatment with l-arginine (a nitric oxide precursor), ODQ (selective inhibitor of soluble guanylyl cyclase) and glibenclamide (ATP-sensitive K⁺ channel inhibitor) significantly enhanced the antinociception produced by cardamonin. In conclusion, the present findings showed that the antinociceptive activity of cardamonin might involve the modulation of PKC activity, NMDA and non-NMDA glutamate receptors, l-arginine/nitric oxide/cGMP pathway and ATP-sensitive K⁺ channel.

Cardamonin: A new player to fight cancer via multiple cancer signaling pathways

Nature's pharmacy has undoubtedly served humans as an affordable and safer health-care regime for a long times. Cardamonin, a chalconoid present in several plants has been known for a longtime to have beneficial properties towards human health. In this review, we aimed to highlight the recent advances achieved in discovering the pharmacological properties of cardamonin. Cardamonin is cardamom-derived chalcone, which plays a role in cancer treatment, immune system modulation, inflammation and pathogens killing. Through the modulation of cellular signaling pathways, cardamonin activates cell death signal to induce apoptosis in malignant cells that results in the inhibition of cancer development. Moreover, cardamonin arrests cell cycle by altering the expression of regulatory proteins during malignant cells division. Due to its relatively selective cytotoxic potential against host malignant cells, cardamonin is emerging as a promising novel experimental anticancer agent. The potential of cardamonin to target various signaling molecules, transcriptional factors, cytokines and enzymes, such as mTOR, NF-κB, Akt, STAT3, Wnt/β-catenin and COX-2 enhances the opportunity to explore it as a new multi-target therapeutic agent. The pharmacokinetic and biosafety profile of cardamonin favor it as a potentially safe biomolecule for pharmaceutical drug development.

Estimation of an Appropriate Human Dose of Boesenbergia pandurata Extracts Based on Allometric Scaling Data of Panduratin A in Mice, Rats, and Dogs

It can be difficult to identify health/functional foods that exert therapeutic benefits for alleviating gingivitis and periodontitis. Recently, extracts of Boesenbergia pandurata (Roxb.), which is a tropical plant, have shown promising inhibitory activity against lipopolysaccharide-induced periodontitis. As a result, a clinical trial is being planned to assess utility of B. pandurata (Roxb.) extracts for promoting oral health; this study was designed to determine an appropriate human dose of the extracts for the trial. Pharmacokinetic studies of panduratin A, which is an active substance in fingerroot, were carried out in mice, rats, and dogs after oral administration of the extracts. The clearance data for each species were used to estimate clearance in humans through allometric scaling based on the maximum lifespan potential, and a daily dose providing sufficient anti-periodontitis activity was estimated for use in the clinical trial. The findings indicated that allometric scaling is a reasonable approach that is relatively free of safety issues and can be used to determine doses of substances for incorporation into health/functional foods appropriate for humans.

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.

Recent Advances in Kaempferia Phytochemistry and Biological Activity: A Comprehensive Review

Background: Plants belonging to the genus Kaempferia (family: Zingiberaceae) are distributed in Asia, especially in the southeast region, and Thailand. They have been widely used in traditional medicines to cure metabolic disorders, inflammation, urinary tract infections, fevers, coughs, hypertension, erectile dysfunction, abdominal and gastrointestinal ailments, asthma, wounds, rheumatism, epilepsy, and skin diseases. Objective: Herein, we reported a comprehensive review, including the traditional applications, biological and pharmacological advances, and phytochemical constituents of Kaempheria species from 1972 up to early 2019. Materials and methods: All the information and reported studies concerning Kaempheria plants were summarized from library and digital databases (e.g., Google Scholar, Sci-finder, PubMed, Springer, Elsevier, MDPI, Web of Science, etc.). The correlation between the Kaempheria species was evaluated via principal component analysis (PCA) and agglomerative hierarchical clustering (AHC), based on the main chemical classes of compounds. Results: Approximately 141 chemical constituents have been isolated and reported from Kaempferia species, such as isopimarane, abietane, labdane and clerodane diterpenoids, flavonoids, phenolic acids, phenyl-heptanoids, curcuminoids, tetrahydropyrano-phenolic, and steroids. A probable biosynthesis pathway for the isopimaradiene skeleton is illustrated. In addition, 15 main documented components of volatile oils of Kaempheria were summarized. Biological activities including anticancer, anti-inflammatory, antimicrobial, anticholinesterase, antioxidant, anti-obesity-induced dermatopathy, wound healing, neuroprotective, anti-allergenic, and anti-nociceptive were demonstrated. Conclusions: Up to date, significant advances in phytochemical and pharmacological studies of different Kaempheria species have been witnessed. So, the traditional uses of these plants have been clarified via modern in vitro and in vivo biological studies. In addition, these traditional uses and reported biological results could be correlated via the chemical characterization of these plants. All these data will support the biologists in the elucidation of the biological mechanisms of these plants.

Dinorcassane Diterpenoid from Boesenbergia rotunda Rhizomes Collected in Lower Myanmar

A new dinorcassane diterpenoid, seikphoochinal A (1), and four known compounds, pinostrobin (2), 4',7-dimethylkaempferol (3), and galanals A (4) and B (5), were isolated from the chloroform-soluble crude extract of wild type Boesenbergia rotunda rhizomes collected in Lower Myanmar. The chemical structures of these compounds were identified, using a combination of spectroscopic methods. The presence of the diterpenoids 1, 4, and 5 demonstrated the structural diversity of wild type B. rotunda. Among the isolates, compounds 4 and 5 exhibited significant antiproliferative activities against a small panel of human cancer cell lines, including lung (LK-2, A549), stomach (ECC4), breast (MCF7), cervix (HeLa), and prostate (DU145).

Effect of cardamonin on hepatic ischemia reperfusion induced in rats: Role of nitric oxide

Ischemia reperfusion (I/R) injury is a cellular damage in a hypoxic organ following the restoration of oxygen delivery. It may occur during organ transplantation, trauma and hepatectomies. Nitric oxide (NO) effects during hepatic I/R are complicated. The iNOS-derived NO has a deleterious effect, whereas eNOS-derived NO has a protective effect in liver I/R. Cardamonin (CDN) is an anti-inflammatory molecule and a novel iNOS inhibitor, and Nω-Nitro-L-arginine (L-NNA) is a NOS inhibitor. L-Arginine is a precursor of NOS. This study was designed to investigate the possible protective effects of CDN on hepatic I/R and the role of NO. Wistar rats were randomly divided into 5 groups (Sham, I/R, CDN, L-NNA and L-arginine). Liver ischemia was induced for 45min then reperfusion was allowed for 1h. L-Arginine and CDN ameliorated the deleterious effects of I/R through reducing the oxidative stress and hepatocyte degeneration. Both molecules decreased the elevated inflammatory cytokines and increased the antiapoptotic marker, Bcl2. Both agents increased NO and eNOS expression and decreased iNOS expression. In conclusion, increased NO/eNOS and suppression of iNOS expression have protective effects on I/R injury. While inhibition of eNOS and reduction of NO have deleterious effects on I/R injury. For the first time, we demonstrated that cardamonin improved functional and structural abnormalities of the liver following I/R by improving oxidative stress and inflammation and increasing the availability of NO produced by eNOS. Treatment with cardamonin could be a promising strategy in patients with hepatic I/R injury in different clinical situations.

Activation of Nrf2-driven antioxidant enzymes by cardamonin confers neuroprotection of PC12 cells against oxidative damage

Oxidative stress represents a disorder of the redox equilibrium between the production of free radicals and the capability of cells to eliminate them. As subversion of this redox balance is thought to initiate various diseases, living cells maintain a redox equilibrium diligently. More and more pieces of evidence show that oxidative stress has already become a common risk factor in the pathogenesis of neurodegenerative disorders. So, considerable importance has been given to the prevention of oxidative stress as a potential therapeutic strategy. It is well known that the Nrf2-ARE pathway represents one of the most important cellular endogenous defense mechanisms against oxidative stress. Activation of Nrf2 signaling induces the transcriptional regulation of multiple ARE-dependent antioxidant defense genes. Here, we showed that cardamonin (CD), a chalcone isolated from Alpinia katsumadai, attenuated cell death induced by hydrogen peroxide (H₂O₂) and 6-hydroxydopamine (6-OHDA) in PC12 cells. Pretreatment of PC12 cells with CD dose-dependently upregulated the expression of phase II antioxidant molecules governed by Nrf2. In contrast, CD failed to provide neuroprotection after silencing Nrf2 expression, indicating that this cytoprotection may be mediated by the activation of transcription factor Nrf2. Our results demonstrate that CD is a novel small molecule activator of Nrf2 in PC12 cells, and suggest that CD may be a potential candidate for the prevention of oxidative stress-mediated neurodegenerative disorders.

Constituents of the Rhizomes of Boesenbergia pandurata and Their Antiausterity Activities against the PANC-1 Human Pancreatic Cancer Line

Human pancreatic cancer cell lines have a remarkable tolerance to nutrition starvation, which enables them to survive under a tumor microenvironment. The search for agents that preferentially inhibit the survival of cancer cells under low nutrient conditions represents a novel antiausterity strategy in anticancer drug discovery. In this investigation, a methanol extract of the rhizomes of Boesenbergia pandurata showed potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrient-deprived conditions, with a PC₅₀ value of 6.6 μg/mL. Phytochemical investigation of this extract led to the isolation of 15 compounds, including eight new cyclohexene chalcones (1-8). The structures of the new compounds were elucidated by NMR spectroscopic data analysis. Among the isolated compounds obtained, isopanduratin A1 (14) and nicolaioidesin C (15) exhibited potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrition-deprived conditions, with PC₅₀ values of 1.0 and 0.84 μM, respectively.

Cardamonin attenuates hyperalgesia and allodynia in a mouse model of chronic constriction injury-induced neuropathic pain: Possible involvement of the opioid system

Neuropathic pain arises from the injury of nervous system. The condition is extremely difficult to be treated due to the ineffectiveness and presence of various adverse effects of the currently available drugs. In the present study, we investigated the antiallodynic and antihyperlagesic properties of cardamonin, a naturally occurring chalcone in chronic constriction injury (CCI)-induced neuropathic pain mice model. Our findings showed that single and repeated dose of intra-peritoneal administration of cardamonin (3, 10, 30mg/kg) significantly inhibited (P<0.001) the chronic constriction injury-induced neuropathic pain using the Hargreaves plantar test, Randall-Selitto analgesiometer test, dynamic plantar anesthesiometer test and the cold plate test in comparison with the positive control drug used (amitriptyline hydrochloride, 20mg/kg, i.p.). Pre-treatment with naloxone hydrochloride (1mg/kg, i.p.) and naloxone methiodide (1mg/kg, s.c) significantly reversed the antiallodynic and antihyperalgesic effects of cardamonin in dynamic plantar anesthesiometer test and Hargreaves plantar test, respectively. In conclusion, the current findings demonstrated novel antiallodynic and antihyperalgesic effects of cardamonin through the activation of the opioidergic system both peripherally and centrally and may prove to be a potent lead compound for the development of neuropathic pain drugs in the future.

A review on biological sources, chemistry and pharmacological activities of pinostrobin

Pinostrobin, a dietary bioflavonoid discovered more than 6 decades ago in the heart-wood of pine (Pinus strobus), has depicted many pharmacological activities including anti-viral, anti-oxidant, anti-leukaemic, anti-inflammatory and anti-aromatase activities. It is an inhibitor of sodium channel and Ca(2+) signalling pathways and also inhibits intestinal smooth muscle contractions. In spite of the fact that pinostrobin has an application as functional foods, till-to-date no comprehensive review on pinostrobin has been carried out. Hence, the present review deals with the biological sources, chemistry and pharmacological activities of pinostrobin.

Distribution of Flavonoids and Cyclohexenyl Chalcone Derivatives in Conventional Propagated and In Vitro-Derived Field-Grown Boesenbergia rotunda (L.) Mansf

The distribution patterns of flavonoids and cyclohexenyl chalcone derivatives in conventional propagated (CP) and in vitro-derived (CPA) field-grown plants of an important medicinal ginger, Boesenbergia rotunda, are described. A total of eight compounds were extracted from six organs (rootlet, rhizome, shoot base, maroon stem, stalk, and leaf) of the CP and CPA plants. Five major chromatographic peaks, namely, alpinetin, pinocembrin, pinostrobin, 4-hydroxypanduratin A, and panduratin A, were consistently observed by high performance liquid chromatography. Nonaerial organs had higher levels of flavonoids than the aerial ones for all types of samples. Among the compounds detected, pinostrobin and 4-hydroxypanduratin A were the most abundant flavonoid and cyclohexenyl chalcone derivative, respectively. The distribution and abundance of the bioactive compounds suggested that the shoot base could be more potentially useful for medicinal application than other organs of the plant and may be the site of storage or occurrence of biosynthetic enzymatic activities.

Drug resistance of bacterial dental biofilm and the potential use of natural compounds as alternative for prevention and treatment

Oral diseases, such as dental caries and periodontal disease are directly linked with the ability of bacteria to form biofilm. The development of dental caries involves acidogenic and aciduric Gram-positive bacteria colonizing the supragingival biofilm (Streptococcus, Lactobacillus and Actinomycetes). Periodontal diseases have been linked to anaerobic Gram-negative bacteria forming a subgingival plaque (Porphyromonas gingivalis, Actinobacillus, Prevotella and Fusobacterium). Cells embedded in biofilm are up to 1000-fold more resistant to antibiotics compared to their planctonic ones. Several mechanisms have been proposed to explain biofilms drug resistance. Given the increased bacterial resistance to antibiotics currently used in dentistry, a great importance is given to natural compounds for the prevention of oral bacterial growth, adhesion and colonization. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. It has been well documented that medicinal plants and natural compounds confer considerable antibacterial activity against various microorganisms including cariogenic and periodontal pathogens. This paper provides a review of the literature focusing on the studies on (i) biofilm in the oral cavity, (ii) drug resistance of bacterial biofilm and (iii) the potential use of plant extracts, essential oils and natural compounds as biofilm preventive agents in dentistry, involving their origin and their mechanism of biofilm inhibition.

Gender-related pharmacokinetics and bioavailability of a novel anticancer chalcone, cardamonin, in rats determined by liquid chromatography tandem mass spectrometry

A reversed phase liquid chromatography tandem mass spectrometry method was developed and validated for quantification of cardamonin, a potential anticancer chalcone, in rat serum. Curcumin was used as an internal standard. Following liquid-liquid extraction using n-hexane and ethyl acetate (60:40, v/v), the processed samples were chromatographed on a C18 column using acetonitrile and ammonium acetate buffer (0.01 M, pH 4.5) (85:15, v/v) as mobile phase at a flow rate of 0.6 mL min(-1). Mass spectrometric detection was performed in the negative electrospray ionization mode by multiple reaction monitoring (m/z 269→122 and 367→217 for cardamonin and curcumin, respectively). The method was validated in terms of selectivity, accuracy, precision, sensitivity, reproducibility, dilution integrity and stability. The linearity was established in the range of 1-200 ng mL(-1) (r≥0.999). The recovery of cardamonin from spiked serum was always >90%. The intra- and inter-day precision (%RSD) and accuracy (%bias) were well within the acceptable limits. The method was applied for single oral and intravenous dose pharmacokinetics in male and female Sprague Dawley rats. Following oral dose, cardamonin showed peak serum concentration that occurred at ∼2 h with very low bioavailability in both male (0.6%) and female (4.8%) rats. Cardamonin exhibited a significant gender influence on pharmacokinetics and bioavailability in rats.

Transcriptome profiling shows gene regulation patterns in a flavonoid pathway in response to exogenous phenylalanine in Boesenbergia rotunda cell culture

Background

Panduratin A extracted from Boesenbergia rotunda is a flavonoid reported to possess a range of medicinal indications which include anti-dengue, anti-HIV, anti-cancer, antioxidant and anti-inflammatory properties. Boesenbergia rotunda is a plant from the Zingiberaceae family commonly used as a food ingredient and traditional medicine in Southeast Asia and China. Reports on the health benefits of secondary metabolites extracted from Boesenbergia rotunda over the last few years has resulted in rising demands for panduratin A. However large scale extraction has been hindered by the naturally low abundance of the compound and limited knowledge of its biosynthetic pathway.

Results

Transcriptome sequencing and digital gene expression (DGE) analysis of native and phenylalanine treated Boesenbergia rotunda cell suspension cultures were carried out to elucidate the key genes differentially expressed in the panduratin A biosynthetic pathway. Based on experiments that show increase in panduratin A production after 14 days post treatment with exogenous phenylalanine, an aromatic amino acid derived from the shikimic acid pathway, total RNA of untreated and 14 days post-phenylalanine treated cell suspension cultures were extracted and sequenced using next generation sequencing technology employing an Illumina-Solexa platform. The transcriptome data generated 101, 043 unigenes with 50, 932 (50.41%) successfully annotated in the public protein databases; including 49.93% (50, 447) in the non-redundant (NR) database, 34.63% (34, 989) in Swiss-Prot, 24,07% (24, 316) in Kyoto Encyclopedia of Genes and Genomes (KEGG) and 16.26% (16, 426) in Clusters of Orthologous Groups (COG). Through DGE analysis, we found that 14, 644 unigenes were up-regulated and 14, 379 unigenes down-regulated in response to exogenous phenylalanine treatment. In the phenylpropanoid pathway leading to the proposed panduratin A production, 2 up-regulated phenylalanine ammonia-lyase (PAL), 3 up-regulated 4-coumaroyl:coenzyme A ligase (4CL) and 1 up-regulated chalcone synthase (CHS) were found.

Conclusions

This is the first report of Boesenbergia rotunda de novo transcriptome data that could serve as a reference for gene or enzyme functional studies in the Zingiberaceae family. Although enzymes that are directly involved in the panduratin A biosynthetic pathway were not completely elucidated, the data provides an overall picture of gene regulation patterns leading to panduratin A production.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-984) contains supplementary material, which is available to authorized users.

An overview on cardamonin

Cardamonin, as shown by the increasing number of publications, has received growing attention from the scientific community due to the expectations toward its benefits to human health. In this study, research on cardamonin is reviewed, including its natural sources, health promoting aspects, and analytical methods for its determination. Therefore, this article hopes to aid current and future researchers on the search for reliable answers concerning cardamonin's value in medicine.

Protective activity of Panduratin A against thioacetamide-induced oxidative damage: demonstration with in vitro experiments using WRL-68 liver cell line

BACKGROUND

Chalcone Panduratin A (PA) has been known for its antioxidant property, but its merits against oxidative damage in liver cells has yet to be investigated. Hence, the paper aimed at accomplishing this task with normal embryonic cell line WRL-68.

METHODS

PA was isolated from Boesenbergia rotunda rhizomes and its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and ferric reducing power (FRAP) activities were measured in comparison with that of the standard reference drug Silymarin (SI). Oxidative damage was induced by treating the cells with 0.04 g/ml of toxic thioacetamide for 60 minutes followed by treatment with 1, 10 and 100 μg/ml concentrations of either PA or SI. The severities of oxidative stress in the control and experimental groups of cells were measured by Malondialdehyde (MDA) levels, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities.

RESULTS

PA exhibited an acceptable DPPH scavenging and FRAP activities close to that of Silymarin. Treating the injured cells with PA significantly reduced the MDA level and increased the cell viability, comparable to SI. The activities of SOD, CAT and GPx were significantly elevated in the PA-treated cells in a dose dependent manner and again similar to SI.

CONCLUSION

Collectively, data suggested that PA has capacity to protect normal liver cells from oxidative damage, most likely via its antioxidant scavenging ability.

Panduratin A, a possible inhibitor in metastasized A549 cells through inhibition of NF-kappa B translocation and chemoinvasion

In the present study, we investigated the effects of panduratin A (PA), isolated from Boesenbergia rotunda, on apoptosis and chemoinvasion in A549 human non-small cell lung cancer cells. Activation of the executioner procaspase-3 by PA was found to be dose-dependent. Caspase-3 activity was significantly elevated at the 5 µg/mL level of PA treatment and progressed to a maximal level. However, no significant elevated level was detected on procaspase-8. These findings suggest that PA activated caspase-3 but not caspase-8. Numerous nuclei of PA treated A549 cells stained brightly by anti-cleaved PARP antibody through High Content Screening. This result further confirmed that PA induced apoptotic cell death was mediated through activation of caspase-3 and eventually led to PARP cleavage. Treatment of A549 cells with PA resulted in a strong inhibition of NF-κB activation, which was consistent with a decrease in nuclear levels of NF-κB/p65 and NF-κB/p50 and the elevation of p53 and p21. Besides that, we also showed that PA significantly inhibited the invasion of A549 cells in a dose-dependent manner through reducing the secretion of MMP-2 of A549 cells gelatin zymography assay. Our findings not only provide the effects of PA, but may also be important in the design of therapeutic protocols that involve targeting of either p53 or NF-κB.

Induction of selective cytotoxicity and apoptosis in human T4-lymphoblastoid cell line (CEMss) by boesenbergin a isolated from boesenbergia rotunda rhizomes involves mitochondrial pathway, activation of caspase 3 and G2/M phase cell cycle arrest

Background

Boesenbergia rotunda (Roxb.) Schlecht (family zingiberaceae) is a rhizomatous herb that is distributed from north-eastern India to south-east Asia, especially in Indonesia, Thailand and Malaysia. Previous research has shown that the crude extract of this plant has cytotoxic properties. The current study examines the cytotoxic properties of boesenbergin A isolated from Boesenbergia rotunda.

Methods

MTT assay was used to check the cytotoxicity of boesenbergin A. The morphological assessment of apoptosis was monitored using normal and fluorescence microscopy. The early and late phase of apoptosis was investigated using annexin V and DNA laddering assays, respectively. The mitochondrial membrane potential (MMP) was assessed by fluorescence microscopy. Human apoptosis proteome profiler assays were performed to investigate the mechanism of cell death. In addition, the protein levels of Bax, Bcl2 and HSP 70 were also analyzed using western blot. Assays of caspase =-3/7, -8 and =-9 were carried out in order to test for induction during treatment. Lastly, cell cycle progression was analyzed using flow cytometry.

Results

Boesenbergin A was found to have the highest toxicity towards CEMss cancer cells (IC₅₀ = 8 μg/ml). The morphology of CEMss cells after treatment showed evidence of apoptosis that included blebbing and chromatin condensation. The annexin V assay revealed that early apoptosis is induced after treatment. The DNA laddering assay confirmed that DNA fragmentation had occurred during late apoptosis. The cell cycle analysis indicated that boesenbergin A was able to induce G2/M phase arrest in CEMss cells. The activity of caspases -3/7, -8 and -9 was increased after treatment which indicates both intrinsic and extrinsic pathways are induced during apoptosis. The involvement of mitochondria was established by increased mitochondrial membrane potential and up and down regulation of Bcl2 and Bax proteins as well as HSP70.

Conclusion

In conclusion, the results demonstrated that boesenbergin A induced apoptosis of CEMss cells through Bcl2/Bax signaling pathways with the involvement of caspases and G2/M phase cell cycle arrest. The current findings warrant further research on boesenbergin A as a novel chemotherapeutic agent for leukemia intervention including studies in animal models.

Effects of pinocembrin on the initiation and promotion stages of rat hepatocarcinogenesis

Pinocembrin (5, 7-dihydroxyflavanone) is a flavanone extracted from the rhizome of Boesenbergia pandurata. Our previous studies demonstrated that pinocembrin had no toxicity or mutagenicity in rats. We here evaluated its effects on the initiation and promotion stages in diethylnitrosamine-induced rat hepatocarcinogenesis, using short- and medium-term carcinogenicity tests. Micronucleated hepatocytes and liver glutathione-S-transferase placental form foci were used as end point markers. Pinocembrin was neither mutagenic nor carcinogenic in rat liver, and neither inhibited nor prevented micronucleus formation as well as GST-P positive foci formation induced by diethylnitrosamine. Interestingly, pinocembrin slightly increased the number of GST-P positive foci when given prior to diethylnitrosamine injection.

Boesenbergia rotunda: From Ethnomedicine to Drug Discovery

Boesenbergia rotunda is a herb from the Boesenbergia genera under the Zingiberaceae family. B. rotunda is widely found in Asian countries where it is commonly used as a food ingredient and in ethnomedicinal preparations. The popularity of its ethnomedicinal usage has drawn the attention of scientists worldwide to further investigate its medicinal properties. Advancement in drug design and discovery research has led to the development of synthetic drugs from B. rotunda metabolites via bioinformatics and medicinal chemistry studies. Furthermore, with the advent of genomics, transcriptomics, proteomics, and metabolomics, new insights on the biosynthetic pathways of B. rotunda metabolites can be elucidated, enabling researchers to predict the potential bioactive compounds responsible for the medicinal properties of the plant. The vast biological activities exhibited by the compounds obtained from B. rotunda warrant further investigation through studies such as drug discovery, polypharmacology, and drug delivery using nanotechnology.

Analysis of cardamonin by square wave voltammetry

INTRODUCTION

Several biochemical studies have already shown that cardamonin has health promoting properties, such is in agreement with typical characteristics of chalcones. Although being a very promising compound for the nutraceutical field there is a lack of studies concerning its electroanalytical properties.

OBJECTIVE

To develop an electroanalytical methodology for the quantification of cardamonin in cardamom.

METHODOLOGY

Cardamonin was analysed electrochemically by means of a hanging mercury drop electrode (HMDE) using square wave voltammetry (SWV). It was extracted from cardamom spice and quantified thereafter using the standard additions method to overcome matrix effects.

RESULTS

A limit of detection (LOD) of 0.15 mg/L and good linearity (r²  = 0.9998) were obtained. Decoction using ethanol as the extraction solvent appears to be the simplest extraction technique. Spectrophotometric analysis (maximum absorbance peak was found in ethanol at 344 nm with a value of molar extinction coefficient of (2.8 ± 0.1) × 10⁴  L mol⁻¹ cm⁻¹) and mass spectrometry analysis by electrospray in the positive ion mode were also performed.

CONCLUSION

Cardamonin was detected voltammetrically. The LOD and limit of quantification (LOQ) of the proposed voltammetric methodology are adequate for trace analysis of this compound in several phytochemical matrices.

Antioxidant, Antimicrobial and Wound Healing Activities of Boesenbergia rotunda

The ethanolic extract of Boesenbergia rotunda (L.) Mansf. was studied for its wound-healing potential. Since wound healing is interrelated with microbial infection and reactive oxygen species (ROS), this study was conducted to evaluate the antimicrobial and antioxidant activity of B. rotunda. The antimicrobial activity of B. rotunda was studied against six bacterial and two yeast strains using disc diffusion, minimum inhibitory concentration (MIC), and minimum microbicidal concentration (MMC). The B. rotunda extract displayed potential antimicrobial and antifungal activities by inhibiting the Gram-positive bacteria Staphylococcus aureus (ATCC 25923), S. epidermidis, and Bacillus subtilis (ATCC 6633), and the yeasts Candida albicans (ATCC 10231), and Saccharomyces cerevisiae. MIC and MMC values varied from 0.04 to 25 mg/mL and from 0.16 to 25 mg/mL, respectively. The antioxidant activity of B. rotunda was evaluated by measuring the Ferric Reducing/Antioxidant Power (FRAP) and DPPH free radical scavenging activity. The FRAP and DPPH values were 22.2 μM /ug and 76.3 mg/mL, respectively. In the wound-healing studies, the topical application of the B. rotunda extract indicated a significantly increased percentage of wound contraction on day 12 compared with the control group. Histological studies showed the complete epidermis and found collagen fibers and hair follicles in the dermis. The results of the present study support the continued and expanded utilization of B. rotunda in Thai folk medicine.

Adaptogenic-active components from Kaempferia parviflora rhizomes

Kaempferia parviflora rhizome extracts obtained by maceration with hexane, chloroform, methanol, and ethanol were screened for their adaptogenic activities using swimming tests of mice. The effective adaptogenic extract dose was 500mg/kg of body weight and was given orally once a day. Crude hexane extract showed significantly shorter mouse immobilisation time than those of the other and control extracts. This crude hexane extract was separated into three fractions by column chromatography. Among these fractions, the fraction rich in terpenoids possessed the highest adaptogenic activity and was comparable to that of the crude ginseng root powder used as a reference control. Therefore, terpenes contained in this fraction could be attributed to the decrease in exhaustion during the swimming of mice. There was no effect on body weight, heart, liver, kidneys, and adrenal glands of the mice. Chemical characterisation of this adaptogenic-active fraction by NMR and GC-MS showed germacene D, β-elemene, α-copaene, and E-caryophyllene as major constituents. Accordingly, these terpenes are considered the adaptogenic agents of K. parviflora rhizomes.

Panduratin A inhibits the growth of A549 cells through induction of apoptosis and inhibition of NF-kappaB translocation

In the present study we investigated the effects of panduratin A, isolated from Boesenbergia rotunda, on proliferation and apoptosis in A549 human non-small cell lung cancer cells. Cell proliferation and induction of apoptosis was determined by the real-time cellular analyzer (RTCA), MTT assay and High Content Screening (HCS). The RTCA assay indicated that panduratin A exhibited cytotoxicity, with an IC₅₀ value of 4.4 µg/mL (10.8 µM). Panduratin A arrested cancer cells labeled with bromodeoxyuridine (BrdU) and phospho-Histone H3 in the mitotic phase. The cytotoxic effects of panduratin A were found to be accompanied by a dose-dependent induction of apoptosis, as assessed by DNA condensation, nuclear morphology and intensity, cell permeability, mitochondrial mass/ potential, F-actin and cytochrome c. In addition, treatment with an apoptosis-inducing concentration of panduratin A resulted in significant inhibition of Nuclear Factor-kappa Beta (NF-κB) translocation from cytoplasm to nuclei activated by tumor necrosis factor-alpha (TNF-α), as illustrated by the HCS assay. Our study provides evidence for cell growth inhibition and induction of apoptosis by panduratin A in the A549 cell line, suggesting its therapeutic potential as an NF-κB inhibitor.