Sunday, 11 June 2017

Sophoraflavanone G kháng HL60

Sophoraflavanone G

From Wikipedia, the free encyclopedia
Sophoraflavanone G
Sophoraflavanone G structure.png
Names
IUPAC name
(2S)-2-(2,4-dihydroxyphenyl)-5,7-dihydroxy-8-[(2R)-5-methyl-2-(prop-1-en-2-yl)hex-4-en-1-yl]-2,3-dihydro-4H-chromen-4-one
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
PubChem CID
Properties
C
25
H
28
O
6
Molar mass424.48622 g/mol
Hazards
Main hazardsNo known hazards
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Sophoraflavanone G[1] is a volatile phytoncide, released into the atmosphere, soil and ground water, by members of the Sophora genus. Due to an increase in the rates of antibiotic-resistant bacteria, scientific efforts have focused on finding either naturally-made or genetically modified compounds that can treat and or prevent these harmful and sometimes deadly bacteria. Sophoraflavanone G, due to its use as a phytoncide, has been found to impact the growth of antibiotic-resistant bacteria and enhance the effect of currently used antibiotics.

Background information on phytoncides[edit]

1st discovered by B.P. Tokin, the word “phytoncide” literally means, exterminated by the plant. Phytoncides are a biologically active substance of plant origin that kills or inhibits growth and development of bacteria, microscopic fungi, and protozoa. Phytoncides play an important role in plant immunity and in the relationships between organisms within an ecosystem.[2]
The ability to produce phytoncides is a quality common among plants. The release of phytoncides increase when a plant is injured. Phytoncide compound composition's vary depending on whether the compound is considered a glycosideterpenoid, or other secondary metabolites (not found in the major classes of natural compounds).[3]

Categories of phytoncides[edit]

There are two categories of phytoncides: 1) Nonexcretory phytoncides (found in the protoplasma of cells) and 2) Volatile phytoncides (released into the atmosphere, soil and water) Examples of plants releasing each type of phytoncide are: (nonexcretory)onion, garlic, and horseradish,and (volatile) pine, oak, eucalyptus, and members of the Sophora genus.[3]
Sophora Flavescens
Some phytoncides effect only insects feeding on the plant, acting on the insect’s autonomic nervous system. Other phytoncides target mainly microbes. The antimicrobial potency and range of phytoncides vary greatly among species. Some can kill many types of protozoa, bacteria, fungi, and insects within minutes or seconds, while others may take hours or only harm the pest. In addition to acting as a “plant protector”, phytoncides can also impede the reproduction of pests.[3]

General effect on environment[edit]

Regarding how phytoncides effect a plant’s immunity, for example, 1 hectare of pine forest will release approximately 5 kg of volatile phytoncides into the atmosphere in one day, reducing the amount of microflora in the air and essentially sterilizing the atmosphere among the forest, containing only about 200-300 bacterial cells/m3. This effect is found more commonly in coniferous forests as opposed to deciduous; something to consider when planning resort locations and urban landscaping.[3]

General uses of phytoncides[edit]

Because of the antimicrobial properties of phytoncides, extensive research has been done to investigate their use in medicine, as a plant protector in greenhouses, and in the shipping and storing of perishables like fruits and vegetables.
One volatile phytoncide, sophoraflavanone G, is of particular interest, due to its use in treating methicillin-resistant staphylococcus aureus and vancomycin-resistant enterococci bacteria.

Sophoraflavanone G[edit]

USDA Map of North American plant hardiness zones
Sophoraflavanone G is among the volatile category of phytoncides, released into the atmosphere, soil, and ground water by the plant species Sophora flavescens,[4] Sophora pachycarpa, and Sophora exigua; all found to grow within the United States in a variety of soil types, within temperate conditions, no lower than 0°F (US zone 6 - yellow areas shown to the right). Sophoraflavanone G is released in order to protect the plant against harmful protozoa, bacteria, and fungi. Sophoraflavanone G, also called kushenin (in traditional Chinese medicinal recipes), is a flavonoid compound.

Flavanoids[edit]

Flavonoids are a class of secondary metabolites found in plants that fulfill a wide variety of functions. They are most commonly known as plant pigments in flower petals to attract pollinators and for their antioxidant activities, providing some hope for consumers regarding medicinal uses, potentially cancer treatment. It has not been until recently that their use as a phytoncide was made known.[5]

Toxicity[edit]

No known toxicity reports against humans have been found related to phytoncides, including Sophoraflavanone G.

Uses of Sophoraflavanone G: antimicrobial agent against MRSA and VRE[edit]

In result to the increasing cases of MRSA and VRE, a tremendous amount of research has gone into finding reliable methods of controlling and potentially preventing antibiotic-resistant strains of bacteria. One promising candidate for the treatment of these deadly bacteria is sophoraflavanone G. Throughout the scientific literature, it has been cited that sophoraflavanone G has had considerable success against antibiotic-resistant bacteria like S. aureus and Enterococci.
Staphylococcus aureus and Enterococcus are two of the leading causes of nosocomial (contracted while in a health facility) infections in hospitals and nursing homes, and reports on methicillin-resistant staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in hospitals have increased worldwide.
S.aureus
Enterococcus
MRSA involves a strain of Staphylococcus aureus bacteria that normally lives on the skin and sometimes in the nasal passages of healthy people. In addition, these particular strains of S. aureus do not respond to some of the antibiotics used to treat staph infections. The bacteria can cause infection when they enter the body through a cut, sore, catheter, or breathing tube. Once infected, the case can be minor and local, or more serious, involving complications with the major tissues within the patient, specifically heart, lungs, blood, and bone. Serious staph infections are more common in people with weak immune systems, particularly patients in hospitals and long-term healthcare facilities and those who are healthy, but otherwise in close contact with many individuals through shared use of equipment and personal items, like athletes and children in daycare.[6]
Serious staph infections are quite difficult to treat, due to increasing numbers of antibiotic-resistant strains of S. aureus in the population. If left untreated, serious staph infections can result in organ failure and death.[6]
Enterococcus are normally present in the human intestines, female genital tract and often within the environment. When these bacteria cause infections, usually within the urinary tract, bloodstream, or in wounds associated with catheters or surgical procedures, the common antibiotic used to treat these cases is Vancomycin. In some instances, enterococci have become resistant to this drug and are, in result, referred to as vancomycin-resistant enterococci (VRE). Most of these infections occur within the long-term healthcare setting.[7]
Serious VRE infections are common among those who have been previously treated with the antibiotic vancomycin and hospitalized for long periods of time, those who have a weak immune system, any patients who have recently undergone surgery or those individuals with medical devices that stay inside their bodies for long periods of time (mainly catheters). VRE is often spread by the contaminated hands of caregivers, or directly after those infected with VRE, touch surfaces. VRE is not spread through the air by coughing or sneezing.[7]

Research into antimicrobial activity of Sophoraflavanone G[edit]

Research conducted in Japan, in 1995, report that the use of sophoraflavanone G completely inhibits the growth of 21 strains of methicillin-resistant S. aureus at concentrations of 3.13-6.25 ug/mL. When this compound is combined with vancomycin, minocycline, and rifampicin, the rates of inhibition increased, indicating a partially synergistic effect with anti-MRSA antibiotics (Sato et al.).[8] Similarly in Iran, in 2006, a research group reported that the antibacterial activity of gentamycin was enhanced through the use of sophoraflavanone G, citing that bacterial colonies of Staphylococcus aureus, on TLC plates showed significant decrease (4x) in growth while in the presence of small amounts (.03 ug/mL) of this compound (Fakhimi et al.).[9] Additional studies, done in South Korea in 2009 and Romania in 2010, support these findings of partially synergistic effects between sophoraflavanone G and various antibiotics, adding that when used either alone, or in conjunction with ampicillin and oxacillin (Cha et al.),[10] and ampicillin, gentamycin, minocycline, vancomycin, and hydrochloride (Duka et al.), sophoraflavanone G increases the number of antibiotic-resistant bacteria (MRSA & VRE) killed within plated colonies (based on FIC indices).

Additional uses of Sophoraflavanone G[edit]

In addition to the use of sophoraflavanone G as treatment against bacteria and other microflora present within the environment, by plants and humans alike, this compound has also been reported to be useful in the treatment of a variety of maladies, ranging from Eicosanoid-related skin inflammation such as atopic dermatitis, to treating more serious medical issues like malaria and myeloid leukemia.

Gallery[edit]

Regarding anti-inflammatory treatments, research by Kim et al. (2002) reported that sophoraflavanone G inhibited eicosanoid generating enzymes, and prostaglandin production, suggesting its potential use for eicosanoid-related skin inflammation such as atopic dermatitis.[11] In 2004, Youn et al. reported that sophoraflavanone G (in addition to other flavanoids) showed moderate anti-malarial activities based on the EC50 values within mice populations, potentially due to methoxyl groups found within the structure.[12] In addition, sophoraflavanone G has also been said to have implications for the treatment of myeloid leukemia, based on the research findings of Kang et al. (2000), who reported that sophoraflavanone G exhibited cytotoxic activity against human myeloid leukemia HL-60 cells.[13]

Withaferin A kháng HL60

Withaferin A

From Wikipedia, the free encyclopedia
Withaferin A
WithaferinA2DACS.svg
Names
IUPAC name
(4β,5β,6β,22R)-4,27-Dihydroxy-5,6:22,26-diepoxyergosta-2,24-diene-1,26-dione
Other names
Withaferine A
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
PubChem CID
Properties
C28H38O6
Molar mass470.61 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Withaferin A is a steroidal lactone, derived from Acnistus arborescens,[1] Withania somnifera[2] (Indian Winter cherry or Ashwagandha in Sanskrit) and other members of Solanaceae family. It has been traditionally used in the ayurvedic medicine. It is the first member of the withanolide class of ergostane type product to be discovered. This natural product has wide range of pharmacological activities including cardioprotective, anti-inflammatory, immuno-modulatory, anti-angiogenesis,[2] anti-metastasis and anti-carcinogenic properties.

Structure[edit]

Withanolides are a group of naturally occurring C28- steroidal lactones. They contain four cycloalkane ring structures, three cyclohexane rings and one cyclopentane ring.[3] Withaferin A is highly reactive because of the ketone containing unsaturated A ring, the epoxide in B ring and unsaturated lactone ring. The double bond in ring A and the epoxide ring are mainly responsible for the cytotoxicity. The 22nd and 26th carbon of ergostane skeleton in withaferin A and related steroidal compounds are oxidized to form six membered delta lactone unit. NMR spectral analysis identifies C3 in the unsaturated A ring as the main nucleophilic target site for ethyl mercaptanthiophenol and L-cysteine ethyl ester in vitro.[3] A library of 2, 3-dihydro-3β-substituted derivatives are synthesized by regio/stereoselective Michael addition to ring A. These analogs are tested for its activity in neuro-degenerative diseases, autoimmune and inflammatory diseases and in cancer.

Regulation[edit]

3-azido Withaferin A (3-azidoWA), a stable derivative of withaferin A, has been shown to inhibit cancer cell motility and invasion in wound healing by selectively suppressing MMP-2 activity in human cervical and prostate cell lines.[4] It enhances the secretion of Par-4 which in turn suppresses MMP-2 expression and activity that is required for tumor metastasis. 3-azidoWA acts as a tumor suppressor by inducing Par-4TIMP-1 and by reducing the levels of pAkt and pERK that are activated in various cancers. This finding has augmented the therapeutic potential of the pro-apoptotic protein Par-4 in cancer. Researchers have shown that 3-azidoWA abrogated neovascularisation in vivo in a dose dependent manner.[4]
Withaferin A has been shown to inhibit cell proliferation in HUVECs at significantly lower doses through the inhibition of Cyclin D1 expression.[2] Inhibition of cell proliferation is due to the cytostatic nature of withaferin, resulting in cell arrest in G0G1 phase of cell cycle. Researchers have shown that withaferin A has an anti-angiogenic activity in vivo at doses much lower than required for its anti-tumor activity.[2]

Regulation of transcription factor NF-κB[edit]

NF-κB is a transcription factor that regulates many genes involved in cell survival, growth, immune response and angiogenesis. Withaferin A inhibits NF-κB at a very low concentration by targeting the ubiquitin-mediated proteasome pathway (UPP) in endothelial cells.[2] Scientists believe that the site at which withaferin acts on UPP must be different from the site of action of 20s proteasome inhibitorIn vitro experiments demonstrated that withaferin A interferes with TNF-induced NF-κB activation at the level or upstream of IKKβ.[5] It also inhibits other transcription factors including Ap1[6] and Sp1[7] which are important mediators of many signalling pathways that are down-regulated by various chemotherapeutic agents. It can induce oxidative stress, alter gene expression, depolarize mitochondria. Withaferin A also down regulates VEGF gene expression[7] and can affect calcium signaling.[8] Mohan et al.[2] showed that withaferin A could inhibit endothelial cell proliferation at low concentrations and thus non-toxic to cells.

Regulation of heat shock proteins[edit]

Researchers have demonstrated the regulation of Hsp90 co-chaperone CDC37 through direct irreversible binding of withaferin A to C-terminus of Hsp90.[9] Withaferin induces aggregation of Hsp90, dissociation of Hsp90CDC37 complex and down regulation of Hsp90 target proteins mediated through proteasomal degradation. Induction of heat shock response by withaferin provides cytoprotective property whereas inhibition of heat shock protein activity will lead to apoptosis. This dual property of withaferin on heat shock protein might be due to the concentration of withaferin and cellular content.

Properties[edit]

Anti-inflammatory[edit]

Withania extracts suppresses the production of various pro-inflammatory molecules in many in vitro models. Anti-inflammatory property of withaferin A has been attributed to its ability to suppress alpha-2 macroglobulin, NF-κB and AP1.[6] Several withanolides selective inhibition of enzyme cyclooxygenase-2 (COX-2) that increases during inflammation.[6]

Anti-tumor[edit]

The anti-tumor activity of withaferin A was tested on human prostate cancer cell line, PC-3 and confirmed in PC-3 xenografts in nude mice. It exhibits androgen receptor (AR) dependent cytotoxicity. It inhibits tumor growth through ATP- independent inhibition of heat shock protein 90 (HSP90) in in vivo pancreatic model.[9] It exhibits growth- inhibitory properties in cancer cell culture experiments, suggesting its cytotoxic and apoptotic properties. It increases Mcl-1 expression levels inducing apoptosis in vitro breast cancer models. It binds to intermediate filament protein, vimentin by covalently modifying its highly conserved cysteine residue in alpha-helical colied 2B domain.[10] Withaferin A causes aggregation of vimentin to colocalize with F-actin leading to apoptosis.

Immunosuppressive[edit]

Shohat et al., have demonstrated specific immunosuppressive effects on mouse thymocytes as well as human B and T lymphocytes by withaferin A and a related steroid lactone withanolide E.[11] At very low concentrations, these molecules inhibit the E rosette and EAC rosette formation by normal B and T lymphocytes. Withaferin A has a specific action on antigen recognition and proliferative capacity of both B and T lymphocytes.[2]

Cell motility and invasion[edit]

Withaferin A inhibits cell motility and invasion capacity of cancer cells through MMP-2 by induction of Par-4.[4] Since a critical event in cancer metastasis is the ability of these cells to invade the extracellular matrix (ECM), inhibition of invasive property by withaferin can contain the cancer cells to primary site. Colony forming ability of cancer cells were attenuated by withaferin derivative in a dose dependent manner.[4]Actin is required for various cellular processes including oriented growth, adhesion and migration. Withaferin A can alter cytoskeleton architecture by covalently binding to multifunctional adaptor protein annexin II and by stimulating the basal F-actin cross linking activity.[12]

Anti-angiogenesis[edit]

It is a potent inhibitor of angiogenesis.[10] Anti-angiogenic and anti-tumor activity of withaferin A is due to the inhibition of chymotrypsin whereas the induction of apoptosis is due to the inhibition of protein kinase C.[13] Caspase-3 activation by withaferin A has also been reported.

Clinical Relevance[edit]

Cancer[edit]

Cervical cancer is caused by human papilloma virus (HPV) expressing E6 and E7 oncoproteins, which inactivate the tumor suppressor protein p53 and pRb respectively. Withaferin A was found to down regulate expression of E6 and E7 oncoproteins, induce accumulation of p53, causes G2/M cell cycle arrest, alters the expression levels of apoptotic markers Bcl2, Bax and caspase3. In athymic mice model, withaferin reduced 70% of the tumor volume.[14] Therefore, withaferin A can be a potential therapeutic agent for the treatment of cervical cancer without major side effects. Withaferin A has been shown to enhance radiation-induced apoptosis in certain cell lines. However, its mechanism of action on cell death is not well understood.[4] It has been suggested that sensitization of cancer cells to radiation is due to the inhibition of NF-κB. It exhibits anti-tumor as well as anti-inflammatory activities. It can act as an immuno-suppressant by inhibiting NF-κB activation. In animal models, it prevented skin cancer induced by ultraviolet radiation. The antioxidant property of withaferin aid in the prevention of DNA damage by mutagens; in combination with detoxifying, anti-inflammatory and immunomodulatory effects, it can contribute to the chemopreventive action.[6]
Withaferin A binds to and inhibits vimentin[10] preventing breast cancer cell growth both in vitro and in vivo. It increases the phosphorylation of JNKERK and MAPK in vitro breast cancer models. It increases the expression of tumor suppressor p53Notch 2 and Notch 4, down-regulates the expression of ERα, resulting in the inhibition of cancer cell migration and growth. Notch signaling plays a significant role in the development of colon cancer, therefore targeting the Notch pathway by withaferin A can be a potential therapeutic option in treating colon cancer. Koduru et al., demonstrated that the inhibition of Notch- mediated prosurvival by withaferin A facilitates c-Jun-NH2-kinase-mediated apoptosis in colon cancer cell lines.[15] Withaferin A downregulates vimentin expression leading to structural perturbation of intermediary filaments. Cancer cells express enhanced vimentin expression and correlates with the induction of epithelial to mesenchymal transition (EMT), metastasis, poor prognosis and decreased survival rate. Further, caspase-dependent degradation of vimentin by withaferin A was observed. Combining various properties like anti-inflammatory, pro-apoptotic, anti-angiogenic and antiproliferation makes withaferin A a potential drug candidate for treatment of cancer. Studies in animal models has shown promising results for breast cancer,[16] pancreatic cancer,[9] cervical cancer,[17] lung cancer,[18] medullary thyroid cancer[19] among others.

Other diseases[edit]

Sen et al., have demonstrated that in Leishmania donovani, withaferin A inhibits PKC resulting in depolarization of Delta Psi(m) and generation of reactive oxygen species in the cell.[13] Depolarization leads to the release of cytochrome c and activation of caspase-likeprotease and DNA fragmentation, finally leading to apoptosis. Animal and in vitro studies have shown antibacterial effects against Staphylococcus aureusListeria monocytogenesBacillus anthracisBacillus subtilisSalmonella enteridis and Salmonella typhimurium.[6] Withania roots have demonstrated chondroprotective effects in vitro arthritis model. The herb is also used in treatment of iron-deficiency anemia due to its effects on haematopoiesis and natural iron content.[6] Withaferin A is also used in the treatment of Metabolic syndrome [20].

Interaction[edit]

See also[edit]