Theaflavin

Theaflavin is a suitable natural inhibitor against influenza A (H1N1) neuraminidase.

In Vitro:Theaflavin, found in green tea, is observed to inhibit H1N1 NA proteins strongly supported by lowest docking energy. Theaflavin is a plant product traditionally used for treatment of influenza infection. Green tea is particularly rich in polyphenolic compounds like Theaflavin. Theaflavin derivatives have shown pronounced antiviral activity. Theaflavin is found to interact with the amino acid residues like Arg118, Asp151, Asp 152, Arg193, Asp199, Asn344, and Arg430 of NA by forming hydrogen bonds[1].

References:
[1]. Sahoo M, et al. Identification of Suitable Natural Inhibitor against Influenza A (H1N1) Neuraminidase Protein by Molecular Docking. Genomics Inform. 2016 Sep;14(3):96-103.

Theaflavin, a black tea polyphenol, protects nigral dopaminergic neurons against chronic MPTP/probenecid induced Parkinson's disease.[Pubmed:22138428]

Brain Res. 2012 Jan 18;1433:104-13.

Parkinson's disease (PD) is a progressive neurodegenerative disorder, characterized by loss of dopominergic neurons in substantia nigra pars compacta, and can be experimentally induced by the neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). Chronic administration of MPTP/probenecid (MPTP/p) leads to oxidative stress, induction of apoptosis, and loss of dopominergic neurons which results in motor impairments. Epidemiological studies have shown an inverse relationship between tea consumption and susceptibility to PD. Theaflavin is a black tea polyphenol, which possess a wide variety of pharmacological properties including potent anti oxidative, anti apoptotic and anti inflammatory effects. The current study is aimed to assess the effect of Theaflavin against MPTP/p induced neurodegenaration in C57BL/6 mice. We found that the Theaflavin attenuates MPTP/p induced apoptosis and neurodegeneration as evidenced by increased expression of nigral tyrosine hydroxylase (TH), dopamine transporter (DAT) and reduced apoptotic markers such as caspase-3, 8, 9 accompanied by normalized behavioral characterization. This may be due to anti oxidative and anti apoptotic activity and these data indicate that Theaflavin may provide a valuable therapeutic strategy for the treatment of progressive neurodegenerative diseases such as PD.

Theaflavins attenuate hepatic lipid accumulation through activating AMPK in human HepG2 cells.[Pubmed:17720960]

J Lipid Res. 2007 Nov;48(11):2334-43.

Black tea is one of the world's most popular beverages, and its health-promoting effects have been intensively investigated. The antiobesity and hypolipidemic effects of black tea have attracted increasing interest, but the mechanisms underlying these phenomena remain unclear. In the present study, the black tea major component Theaflavins were assessed for their hepatic lipid-lowering potential when administered in fatty acid overload conditions both in cell culture and in an animal experimental model. We found that Theaflavins significantly reduced lipid accumulation, suppressed fatty acid synthesis, and stimulated fatty acid oxidation. Furthermore, Theaflavins also inhibited acetyl-coenzyme A carboxylase activities by stimulating AMP-activated protein kinase (AMPK) through the LKB1 and reactive oxygen species pathways. These observations support the idea that AMPK is a critical component of decreased hepatic lipid accumulation by Theaflavin treatments. Our results show that Theaflavins are bioavailable both in vitro and in vivo and may be active in the prevention of fatty liver and obesity.

Antifungal synergy of theaflavin and epicatechin combinations against Candida albicans.[Pubmed:23711519]

J Microbiol Biotechnol. 2013 Sep 28;23(9):1322-6.

New antifungal agents are required to compensate for the increase in resistance to standard antifungal agents of Candida albicans, which is an important opportunistic fungal pathogen that causes minor infections in many individuals but very serious infections in those who are immune-compromised. In this study, combinations of Theaflavin and epicatechin are investigated as potential antifungal agents and also to establish whether antifungal synergy exists between these two readily accessible and cost-effective polyphenols isolated from black and green tea. The results of disc diffusion assays showed stronger antibacterial activity of Theaflavin:epicatechin combinations against C. albicans NCTC 3255 and NCTC 3179, than that of Theaflavin alone. Minimum inhibitory concentrations (MICs) of 1,024 mug/ml with Theaflavin and 128-256 mug/ml with Theaflavin:epicatechin combinations were found. The fractional inhibitory concentration indexes were calculated, and the synergy between Theaflavin and epicatechin against both isolates of C. albicans was confirmed. Theaflavin:epicatechin combinations show real potential for future use as a treatment for infections caused by C. albicans.

Theaflavin Inhibits LPS-Induced IL-6, MCP-1, and ICAM-1 Expression in Bone Marrow-Derived Macrophages Through the Blockade of NF-kappaB and MAPK Signaling Pathways.[Pubmed:22111069]

Chonnam Med J. 2011 Aug;47(2):104-10.

Theaflavin, the main polyphenol in black tea, has anti-inflammatory, antioxidative, anti-mutagenic, and anti-carcinogenic properties. The aim of this study was to evaluate the effects of Theaflavin on lipopolysaccharide (LPS)-induced innate signaling and expression of pro-inflammatory mediators in bone marrow-derived macrophages isolated from ICR mice. The effects of Theaflavin on the expression of proinflammatory mediators, LPS-induced nuclear factor-kappa B (NF-kappaB), and mitogen-activated protein kinase (MAPK) signaling pathways were examined by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting, and immunofluorescence. LPS-induced interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) expression was inhibited by Theaflavin. LPS-induced inhibitor kappa B alpha (IkappaBalpha) degradation and nuclear translocation of RelA were blocked by Theaflavin. LPS-induced phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2), c-Jun-N-terminal kinase (JNK), and p38 MAPK was inhibited by Theaflavin. The inhibitory effect of Theaflavin on IL-6, MCP-1, and ICAM-1 expression was completely inhibited by Bay11-7082 (NF-kappaB inhibitor). The inhibitory effect of Theaflavin on IL-6 and ICAM-1 expression was inhibited by SB203580 (p38 MAPK inhibitor). The inhibitory effect of Theaflavin on MCP-1 expression was inhibited by SP600125 (JNK inhibitor). These results indicate that Theaflavin prevents LPS-induced IL-6, MCP-1, and ICAM-1 expression through blockade of NF-kappaB and MAPK signaling pathways in bone marrow-derived macrophages.

Theaflavin attenuates ischemia-reperfusion injury in a mouse fatty liver model.[Pubmed:22155236]

Biochem Biophys Res Commun. 2012 Jan 6;417(1):287-93.

The incidence of non-alcoholic fatty liver disease (NAFLD) has been increasing, and there is a shortage of liver donors, which has led to the acceptance of steatotic livers for transplantation. However, steatotic livers are known to experience more severe acute ischemia-reperfusion (I/R) injury than normal livers upon transplantation. In the present study, we investigated the role of Theaflavin, a polyphenol substance extracted from black tea, in attenuating acute I/R injury in a fatty liver model. We induced I/R in normal and steatotic livers treated with or without Theaflavin. We also separated primary hepatocytes from the normal and steatotic livers, and applied RAW264.7 cells, a mouse macrophage cell line, that was pretreated with Theaflavin. We observed that liver steatosis, oxidative stress, inflammation and hepatocyte apoptosis were increased in the steatotic liver compared to the normal liver, however, these changes were significantly decreased by Theaflavin treatment. In addition, Theaflavin significantly diminished the ROS production of steatotic hepatocytes and TNF-alpha production by LPS-stimulated RAW264.7 cells. We concluded that Theaflavin has protective effects against I/R injury in fatty livers by anti-oxidant, anti-inflammatory, and anti-apoptotic mechanisms.

Antiviral activity of theaflavin digallate against herpes simplex virus type 1.[Pubmed:25818500]

Antiviral Res. 2015 Jun;118:56-67.

Tea is the second most consumed drink in the world. The beneficial effects of tea have been mostly attributed to its catechin content. Black tea is derived from the leaves of Camellia sinensis plant, and it is rich in Theaflavin polyphenols, in particular Theaflavin (TF1), Theaflavin-3-monogallate (TF2A), Theaflavin-3'-monogallate (TF2B), and Theaflavin-3,3'-digallate (TF3). Vero and A549 cells were used to evaluate the effect of purified individual black tea Theaflavins as anti-herpes simplex virus 1 agents. With the rise of HSV resistant strains, there is a critical need to develop novel antiherpesviral treatments. Results of the cytotoxicity assay tested by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-te trazolium] showed that TF1, TF2, and TF3 are not toxic to Vero and A549 cells at a concentration up to 75 muM. The antiviral activity of the individual Theaflavins was tested by plaque reduction assay, MTS assay, flow cytometric analysis and confocal microscopy observations. The results showed that TF1, TF2, and TF3 exhibit potent, dose-dependent anti-HSV-1 effect, with TF3 being the most efficient in both Vero and A549 cells. A concentration of 50 muM TF3 and above was sufficient to inhibit >99% of the production of HSV-1 viral particles. The anti-HSV-1 effect of TF3 is due to a direct effect on the virions, and treating Vero or A549 cells with TF3 for 1h prior to infection, or treating the cells at different times post infection does not inhibit HSV-1 production. TF3 is stable at vaginal pH, indicating its potential to be a promising natural and affordable remedy against herpes simplex viral infections.