Tea polyphenols exerts anti-hepatitis B virus effects in a stably HBV-transfected cell line

Antiviral Effects and Mechanisms of Active Ingredients in Tea

Viruses play a significant role in human health, as they can cause a wide range of diseases, from mild illnesses to severe and life-threatening conditions. Cellular and animal experiments have demonstrated that the functional components in tea, such as catechins, theaflavins, theanine, and caffeine, exhibit significant inhibitory effects on a diverse array of viruses, including influenza, rotavirus, hepatitis, HPV, and additional types. The inhibition mechanisms may involve blocking virus-host recognition, interfering with viral replication, enhancing host immune responses, and inhibiting viral enzyme activity. This article reviews the research progress on the antiviral effects of tea's functional components and their related mechanisms, hoping to contribute to future studies in this field.

Evaluation of the Hepatoprotective Properties of Traditional Formulations Based on Cochlospermum tinctorium Used in Benin

Hepatic diseases represent a public health problem. Among the approaches to their management is the use of traditional treatments based on the use of medicinal plants. In Benin, several recipes based on Cochlospermum tinctorium are used in the treatment of hepatitis without a real scientific basis. This study aimed to evaluate the hepatoprotective effects and acute oral toxicity of 10 of these recipes. The variables studied were the variety of C. tinctorium (wild form vs. cultivated form), the species associated with C. tinctorium (Combretum micranthum vs. Chromolaena odorata), and the proportion of C. tinctorium in the recipe (1; 4/5; 1/2). The hepatoprotective effect of these extracts at doses of 100, 200, and 400 mg/kg/bw was evaluated in Wistar rats subjected to hepatotoxicity induction through the administration of 5 g/kg of paracetamol. Acute oral toxicity was assessed following the OECD 423 protocol. The results revealed an absence of acute oral toxicity for the 10 recipes. The hepatoprotective tests conducted indicated that the hepatoprotective effect of C. tinctorium is dose dependent. The wild variety of C. tinctorium had a better hepatoprotective effect than the cultivated one. The association with C. micranthum enhances the hepatoprotective effect of C. tinctorium, unlike that with C. odorata. This study emphasizes that the combination of C. tinctorium with C. micranthum in the treatment of hepatitis is scientifically justified and it exhibits a dose-dependent hepatoprotective effect.

Molecular and biochemical investigations of the anti-fatigue effects of tea polyphenols and fruit extracts of Lycium ruthenicum Murr. on mice with exercise-induced fatigue

Background: The molecular mechanisms regulating the therapeutic effects of plant-based ingredients on the exercise-induced fatigue (EIF) remain unclear. The therapeutic effects of both tea polyphenols (TP) and fruit extracts of Lycium ruthenicum (LR) on mouse model of EIF were investigated. Methods: The variations in the fatigue-related biochemical factors, i.e., lactate dehydrogenase (LDH), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2 (IL-2), and interleukin-6 (IL-6), in mouse models of EIF treated with TP and LR were determined. The microRNAs involved in the therapeutic effects of TP and LR on the treatment of mice with EIF were identified using the next-generation sequencing technology. Results: Our results revealed that both TP and LR showed evident anti-inflammatory effect and reduced oxidative stress. In comparison with the control groups, the contents of LDH, TNF-α, IL-6, IL-1β, and IL-2 were significantly decreased and the contents of SOD were significantly increased in the experimental groups treated with either TP or LR. A total of 23 microRNAs (21 upregulated and 2 downregulated) identified for the first time by the high-throughput RNA sequencing were involved in the molecular response to EIF in mice treated with TP and LR. The regulatory functions of these microRNAs in the pathogenesis of EIF in mice were further explored based on Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses with a total of over 20,000-30,000 target genes annotated and 44 metabolic pathways enriched in the experimental groups based on GO and KEGG databases, respectively. Conclusion: Our study revealed the therapeutic effects of TP and LR and identified the microRNAs involved in the molecular mechanisms regulating the EIF in mice, providing strong experimental evidence to support further agricultural development of LR as well as the investigations and applications of TP and LR in the treatment of EIF in humans, including the professional athletes.

Role of bioactive compounds in the treatment of hepatitis: A review

Hepatitis causes liver infection leading to inflammation that is swelling of the liver. They are of various types and detrimental to human beings. Natural products have recently been used to develop antiviral drugs against severe viral infections like viral hepatitis. They are usually extracted from herbs or plants and animals. The naturally derived compounds have demonstrated significant antiviral effects against the hepatitis virus and they interfere with different stages of the life cycle of the virus, viral release, replication, and its host-specific interactions. Antiviral activities have been demonstrated by natural products such as phenylpropanoids, flavonoids, xanthones, anthraquinones, terpenoids, alkaloids, aromatics, etc., against hepatitis B and hepatitis C viruses. The recent studies conducted to understand the viral hepatitis life cycle, more effective naturally derived drugs are being produced with a promising future for the treatment of the infection. This review emphasizes the current strategies for treating hepatitis, their shortcomings, the properties of natural products and their numerous types, clinical trials, and future prospects as potential drugs.

Phytomedicines to Target Hepatitis B Virus DNA Replication: Current Limitations and Future Approaches

Hepatitis B virus infection (HBV) is one of the most common causes of hepatitis, and may lead to cirrhosis or hepatocellular carcinoma. According to the World Health Organization (WHO), approximately 296 million people worldwide are carriers of the hepatitis B virus. Various nucleos(t)ide analogs, which specifically suppress viral replication, are the main treatment agents for HBV infection. However, the development of drug-resistant HBV strains due to viral genomic mutations in genes encoding the polymerase protein is a major obstacle to HBV treatment. In addition, adverse effects can occur in patients treated with nucleos(t)ide analogs. Thus, alternative anti-HBV drugs of plant origin are being investigated as they exhibit excellent safety profiles and have few or no side effects. In this study, phytomedicines/phytochemicals exerting significant inhibitory effects on HBV by interfering with its replication were reviewed based on different compound groups. In addition, the chemical structures of these compounds were developed. This will facilitate their commercial synthesis and further investigation of the molecular mechanisms underlying their effects. The limitations of compounds previously screened for their anti-HBV effect, as well as future approaches to anti-HBV research, have also been discussed.

Research progress of epigallocatechin-3-gallate (EGCG) on anti-pathogenic microbes and immune regulation activities

At the end of 2019, the COVID-19 virus spread worldwide, infecting millions of people. Infectious diseases induced by pathogenic microorganisms such as the influenza virus, hepatitis virus, and Mycobacterium tuberculosis are also a major threat to public health. The high mortality caused by infectious pathogenic microorganisms is due to their strong virulence, which leads to the excessive counterattack by the host immune system and severe inflammatory damage of the immune system. This paper reviews the efficacy, mechanism and related immune regulation of epigallocatechin-3-gallate (EGCG) as an anti-pathogenic microorganism drug. EGCG mainly shows both direct and indirect anti-infection effects. EGCG directly inhibits early infection by interfering with the adsorption on host cells, inhibiting virus replication and reducing bacterial biofilm formation and toxin release; EGCG indirectly inhibits infection by regulating immune inflammation and antioxidation. At the same time, we reviewed the bioavailability and safety of EGCG in vivo. At present, the bioavailability of EGCG can be improved to some extent using nanostructured drug delivery systems and molecular modification technology in combination with other drugs. This study provides a theoretical basis for the development of EGCG as an adjuvant drug for anti-pathogenic microorganisms.

Anti-hepatitis B activities of Myanmar medicinal plants: a narrative review of current evidence

Hepatitis B is one of the major burdens for health services and is the leading cause of morbidity and mortality from cirrhosis of liver and hepatocellular carcinoma. Current treatment strategies using nucleos(t)ide analogue reverse-transcriptase inhibitors or interferons are targeted for the long-term suppression of hepatitis B DNA. However, functional cure of hepatitis B infection (HBsAg clearance) was difficult to attain with such treatments. Therefore, new treatment strategies or innovative treatments are urgently needed. The new treatments should focus on the potential therapeutic targets such as covalently closed circular DNA which may be important for the HBsAg clearance. Plant based medicines have been used in different traditional medicine practices and these natural products/compounds serve as a good source of information or clues for use in drug discovery and design. Many natural products were found to be effective against hepatitis B virus and some even have better therapeutic activities than currently used compounds. This review summarizes the current evidence of Myanmar medicinal plants in basic and clinical research which shows promising potential for the development of novel therapeutic agents for the treatment of hepatitis B.

Effect of aqueous extracts of Ficus vogeliana Miq and Tieghemella africana Pierre in 7,12-Dimethylbenz(a)anthracene -induced skin cancer in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Skin cancer is the most common form of cancer responsible for considerable morbidity and mortality. Tieghemella africana and Ficus vogeliana are used in traditional medicine to treat cancers.

AIM OF THE STUDY

Therefore, the aim of this study was to investigate the antioxidant, antiangiogenic and anti-tumor activities of these plant extracts.

MATERIALS AND METHODS

To achieve it, phytochemical screening, antioxidant activity and antiangiogenic activity were assessed. Thereafter, the anti-tumor activity was determined using skin tumorigenesis induced by 7,12-dimethylbenz[a]anthracene.

RESULTS

The phytochemical result analysis showed that both plant extracts were rich in polyphenols, alkaloids and terpene compounds and possessed good antioxidant activity based on DPPH radical scavenging (IC₅₀ = 9.70 μg/mL and 4.60 μg/mL and AAI values of 5.20 and 10.88) and strong total antioxidant capacity (115.44 VtCE (mg)/g of dry plant extract and 87.37 VtCE (mg)/g of dry plant extract, respectively). Additionally, both plant extracts possessed antiangiogenic activities (IC₅₀ = 53.43 μg/mL and 92.68 μg/mL, respectively), which correlated with significant antitumor activities when using 35 mg/kg (65.02% and 77.54%) and 70 mg/kg of extracts (81.07% and 88.18%).

CONCLUSIONS

In summary, this study illustrates the promising usage of Tieghemella africana and Ficus vogeliana plant extracts in treating skin cancer. However, further characterization of the extracts must be performed to isolate the most active anticancer compound.

Plant Resources, Chemical Constituents, and Bioactivities of Tea Plants from the Genus Camellia Section Thea

Tea, as one of the most popular beverages with various bioactivities, is commonly produced from the fresh leaves of two widely cultivated tea plants, Camellia sinensis and C. sinensis var. assamica. Both plants belong to the genus Camellia section Thea, which was considered to have 12 species and 6 varieties according to Min's taxonomic system. Most species, except the cultivated species, are known as wild tea plants and have been exploited and utilized to produce tea by the local people of its growing areas. Thus far, six species and varieties have been phytochemically studied, leading to the identification of 398 compounds, including hydrolyzable tannins, flavan-3-ols, flavonoids, terpenoids, alkaloids, and other phenolic and related compounds. Various beneficial health effects were reported for tea and its components, involving antioxidant, antitumor, antimutagenic, antidiabetic, hypolipidemic, anti-inflammatory, antimicrobial, antiviral, antifungal, neuroprotective, hepatoprotective, etc. In this review, the geographical distribution of tea plants and the chemical constituents (1-398) reported from the genus Camellia section Thea and some tea products (green, black, oolong, and pu-erh tea) that have ever been studied between 1970 and 2018 have been summarized, taking species as the main hint, and the main biological activities are also discussed.

Anti-infective potential of catechins and their derivatives against viral hepatitis

Polyphenols including catechins from green tea (Camellia sinensis) have been reported to have anti-infective activities against a broad spectrum of viruses and other pathogens. During the last two decades, antiviral activities of catechins with different modes of action have been demonstrated on diverse families of viruses, such as human immunodeficiency virus, Herpes simplex virus, influenza virus, hepatitis B and C virus. In this study, we focused on the antiviral properties of catechins and their derivatives against viral hepatitis which have become a key public health issue due to their serious impact on human health with liver diseases.

Inhibition of the replication of hepatitis B virus in vitro by pu-erh tea extracts

Hepatitis B virus (HBV) is one of the most widespread viral infections in the world and poses a significant global public health problem. The implementation of effective vaccination programs has resulted in a significant decrease in the incidence of acute hepatitis B. Nevertheless, there is still a need for as many effective anti-HBV drugs as possible. In this study, the role of pu-erh tea extracts (PTE) against HBV was analyzed in vitro by using a stably HBV-transfected cell line HepG2 2.2.15. The MTT assay showed that PTE and its active components (tea polyphenols, theaflavins, and theanine) presented low cytotoxicity. ELISA analysis revealed that PTE effectively reduced the secretion of HBeAg, but any one of the active components alone showed weaker efficacy, suggesting that the anti-HBV activity of PTE might be a synergetic effect of different components. RT-PCR and luciferase assay showed that PTE suppressed HBV mRNA expression while leaving four HBV promoter transcriptional activities unchanged. Fluorescence quantitative PCR results demonstrated that PTE dramatically diminished HBV DNA produced in cell supernatants as well as encapsidated DNA in intracellular core particles. Finally, PTE significantly reduced intracellular reactive oxygen species (ROS) level. This study is the first to demonstrate that PTE possesses anti-HBV ability and could be used as a potential treatment against HBV infection with an additional merit of low cytotoxicity.