Medicinal plant molecules against hepatitis C virus: Current status and future prospect

Hepatitis C virus (HCV), a global malady, causes acute and chronic hepatitis leading to permanent liver damage, hepatocellular carcinoma, and death. Modern anti-HCV therapies are efficient, but mostly inaccessible for residents of underdeveloped regions. To innovate more effective treatments at affordable cost, medicinal plant-based products need to be explored. The aim of this article is to review plant constituents in the light of putative anti-HCV mechanisms of action, and discuss existing problems, challenges, and future directions for their potential application in therapeutic settings. One hundred sixty literatures were collected by using appropriate search strings via scientific search engines: Google Scholar, PubMed, ScienceDirect, and Scopus. Bibliography was prepared using Mendeley desktop software. We found a substantial number of plants that were reported to inhibit different stages of HCV life cycle. Traditional medicinal plants such as Phyllanthus amarus Schumach. and Thonn., Eclipta alba (L.) Hassk., and Acacia nilotica (L.) Delile exhibited strong anti-HCV activities. Again, several phytochemicals such as epigallocatechin-3-gallate, honokilol, punicalagin, and quercetin have shown broad-spectrum anti-HCV effect. We have presented promising phytochemicals like silymarin, curcumin, glycyrrhizin, and camptothecin for nanoparticle-based hepatocyte-targeted drug delivery. Nevertheless, only a few animal studies have been performed to validate the anti-HCV effect of these plant products. Again, insufficient clinical evaluation of the safety and effectiveness of herbal medications remain a problem. Selected plants products could be developed as novel therapeutics for HCV patients only after scrupulous evaluation of their safety and efficacy in a clinical set-up.

Antiviral Activity Exerted by Natural Products against Human Viruses

Viral infections are responsible for several chronic and acute diseases in both humans and animals. Despite the incredible progress in human medicine, several viral diseases, such as acquired immunodeficiency syndrome, respiratory syndromes, and hepatitis, are still associated with high morbidity and mortality rates in humans. Natural products from plants or other organisms are a rich source of structurally novel chemical compounds including antivirals. Indeed, in traditional medicine, many pathological conditions have been treated using plant-derived medicines. Thus, the identification of novel alternative antiviral agents is of critical importance. In this review, we summarize novel phytochemicals with antiviral activity against human viruses and their potential application in treating or preventing viral disease.

Inhibition of CYP2E1 and activation of Nrf2 signaling pathways by a fraction from Entada africana alleviate carbon tetrachloride-induced hepatotoxicity

Entada africana is used in non-conventional medicine for the management of liver ailments. A fraction, designated EaF10 (methylene chloride/methanol 90:10, v/v) with promising hepatoprotective activity has been isolated. Since the mechanisms underlying EaF10 hepatoprotective action remain unknown, this study was undertaken to investigate the anti-hepatotoxic mechanism of the fraction against carbon tetrachloride (CCl4)-induced hepatotoxicity and its antioxidant properties. Antioxidant activities of EaF10 were assessed through four chemical antioxidant assays and its anti-hepatotoxic effect evaluated in vivo and in vitro by post-treatment (25 or 100 mg/Kg) or co-treatment (6.25-100 μg/mL) in CCl4-intoxicated mice and normal human liver cells line L-02 hepatocytes respectively; and biochemical and molecular parameters assessed respectively by spectrophotometry, and by quantitative real-time polymerase chain reaction and western blot analysis. EaF10 exhibited strong antioxidant activities correlated with its polyphenol content. Serum levels of alanine/aspartate aminotransferase (AST/ALT) and nitrite oxide, liver contents of glutathione (GSH) protein carbonylation and malondialdehyde (MDA), liver activities of catalase (CAT), glutathione-S-transferase (GST) and superoxide dismutase (SOD) and cell viability showed the anti-hepatotoxic effect of EaF10, supported by histopathological observations. The fraction decreased the protein level of Cytochrome P450 2E1 (CYP2E1) and Kelch-like ECH-associated protein-1 (Keap-1), induced nuclear translocation of Nuclear factor-erythroid 2-related factor-2 (Nrf2) coupled to an increase of the mRNA levels of CAT, SOD1 and GST in CCl4-intoxicated L-02 hepatocytes. These findings evidenced that the studied plant fraction possesses a strong antioxidant capacity and prevents CCl4-induced hepatotoxicity, likely through inhibition of CYP2E1 and activation of the Nrf2 signaling pathway.

Natural products for the management of the hepatitis C virus: a biochemical review

Chronic hepatitis C virus (HCV) infection is a significant public health problem, with a worldwide prevalence of approximately 170 million. Current therapy for HCV infection includes the prolonged administration of a combination of ribavirin and PEGylated interferon-α, for over a decade. This regimen is expensive and often associated with a poor antiviral response and unwanted side effects. A highly effective combination treatment is likely required for the future management of HCV infections and entry inhibitors could play an important role. Currently, no entry inhibitor has been licensed for the prophylactic treatment of hepatitis C. Therefore, additional agents that combat HCV infection are urgently needed and must be developed. Many phytochemical constituents have been identified that display considerable inhibition of HCV at some stage of the life cycle. This review will summarise the current state of knowledge on natural products and their possible activities in the context of HCV infection.

The phytochemical and pharmacological actions of Entada africana Guill. & Perr

Entada africana (Ea, Asteraceae) has been widely used traditionally to treat different ailments, as food, insecticides, source of gums, in some small carpentry works. Studies on the pharmacognostic characterization, nutritional, elemental and physicochemical contents has been reported. In vivo and in vitro studies on the plant validated some ethnomedicinal claims of the use of the plant as an anti-inflammatory, analgesic, antibacterial, antioxidant, antiviral, anti-angiogenic, cytotoxic agents among others. Triterpenes, saponins, flavonoids and sugars were reported as bioactive constituents which might be responsible for the aforementioned pharmacological actions of the plant. However, more researches are required in order to isolate bioactive compounds from the different parts of Ea and evaluate their effects on different ailments.

Aeginetia indica Decoction Inhibits Hepatitis C Virus Life Cycle

Chronic hepatitis C virus (HCV) infection is still a global epidemic despite the introduction of several highly effective direct-acting antivirals that are tagged with sky-high prices. The present study aimed to identify an herbal decoction that ameliorates HCV infection. Among six herbal decoctions tested, the Aeginetia indica decoction had the most profound effect on the HCV reporter activity in infected Huh7.5.1 liver cells in a dose- and time-dependent manner. The Aeginetia indica decoction exerted multiple inhibitory effects on the HCV life cycle. Pretreatment of the cells with the Aeginetia indica decoction prior to HCV infection reduced the HCV RNA and non-structural protein 3 (NS3) protein levels in the infected cells. The Aeginetia indica decoction reduced HCV internal ribosome entry site-mediated protein translation activity. It also reduced the HCV RNA level in the infected cells in association with reduced NS5A phosphorylation at serine 235, a predominant phosphorylation event indispensable to HCV replication. Thus, the Aeginetia indica decoction inhibits HCV infection, translation, and replication. Mechanistically, the Aeginetia indica decoction probably reduced HCV replication via reducing NS5A phosphorylation at serine 235.

Hepatitis C in Cameroon: What is the progress from 2001 to 2016?

Chronic hepatitis C is a major public health problem in sub-Saharan countries and particularly in Cameroon where the prevalence rate is around 7.6% in the age group of 55-59 years. Recent investigations into this infection allowed defining a national seroprevalence, characterizing virological and biological profiles of infected patients and identifying medicinal plants of potential interest in hepatitis C therapy. However, in Cameroon, no existing report currently presents a good overview of hepatitis C research in relation to these parameters. This review seeks to discuss major findings published since 2001 that have significantly advanced our understanding of the epidemiology and treatment of hepatitis C in Cameroonian patients and highlight the major challenges that remain to overcome. We performed a systematic search in Pubmed and Google Scholar. Studies evaluating prevalence, treatment, coinfection, and genetic diversity of HCV infection in Cameroon were included. Studies suggest that HCV prevalence in Cameroon would be low (around 1.1%) with a lot of disparities according to regions and age of participants. Elders, pregnant women, blood donors, health care workers, patients on hemodialysis, and homozygous sickle cell patients have been identified as risk groups. Moreover, HCV/HBV coinfection was found more prevalent than HCV/HIV coinfection. Phylogenic studies reported circulation of three main genotypes such genotypes 1, 2, and 4 but little is known about antiviral candidates from the Cameroonian pharmacopeia. In conclusion, some epidemiological data prove that hepatitis C in Cameroon is well known but efforts are still necessary to prevent or control this infection.

Litsea Species as Potential Antiviral Plant Sources

Litsea verticillata Hance (Lauraceae), a Chinese medicine used to treat swelling caused by injury or by snake bites, was the first plant identified by our National Institutes of Health (NIH)-funded International Cooperative Biodiversity Group (ICBG) project to exhibit anti-HIV activities. From this plant, we discovered a class of 8 novel litseane compounds, prototypic sesquiterpenes, all of which demonstrated anti-HIV activities. In subsequent studies, 26 additional compounds of different structural types were identified. During our continuing investigation of this plant species, we identified two new litseanes, litseaverticillols L and M, and a new sesquiterpene butenolide, litseasesquibutenolide. Litseaverticillols L and M were found to inhibit HIV-1 replication, with an IC[Formula: see text] value of 49.6[Formula: see text][Formula: see text]M. To further determine the antiviral properties of this plant, several relatively abundant isolates, including a litseane compound, two eudesmane sesquiterpenes and three lignans, were evaluated against an additional 21 viral targets. Lignans 8 and 9 were shown to be active against the Epstein-Barr Virus (EBV), with EC[Formula: see text] values of 22.0[Formula: see text][Formula: see text]M ([Formula: see text]) and 16.2[Formula: see text][Formula: see text]M ([Formula: see text]), respectively. Since many antiviral compounds have been discovered in L. verticillata, we further prepared 38 plant extracts made from the different plant parts of 9 additional Litsea species. These extracts were evaluated for their anti-HIV and cytotoxic activities, and four of the extracts, which ranged across three different species, displayed 97-100% inhibitory effects against HIV replication without showing cytotoxicity to a panel of human cell lines at a concentration of 20 μg/mL.

Entada phaseoloides extract suppresses hepatic gluconeogenesis via activation of the AMPK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The seed of Entada phaseoloides (L.) Merr. (Entada phaseoloides) has been long used as a folk medicine for the treatment of Diabetes mellitus by Chinese ethnic minorities. Recent reports have demonstrated that total saponins from Entada phaseoloides (TSEP) could reduce fasting blood glucose in type 2 diabetic rats. However, the mechanism has not been fully elucidated. The aim of this study was to explore the underlying mechanisms of TSEP on type 2 Diabetes mellitus (T2DM).

MATERIALS AND METHODS

Primary mouse hepatocytes and HepG2 cells were used to investigate the effects of TSEP on gluconeogenesis. After treatment with TSEP, glucose production, genes expression levels of Glucose-6-phosphatase (G6pase) and Phosphoenoylpyruvate carboxykinase (Pepck) were detected. The efficacy and underlying mechanism of TSEP on AMP-activated protein kinase (AMPK) signaling pathway were determinated.

RESULTS

TSEP significantly inhibited glucose production and the gluconeogenic gene expression. Treatment with TSEP elevated the phosphorylation of AMPK, which in turn promoted the phosphorylation of acetyl coenzyme A (ACC) and Akt/glycogen synthase kinase 3β (GSK3β), respectively. Furthermore, TSEP reduced lipid accumulation and improved insulin sensitivity in hepatocytes.

CONCLUSION

These findings provide evidence that TSEP exerts an antidiabetic effect by suppressing hepatic gluconeogenesis via the AMPK signaling pathway.

Ethanol Extract of Fructus ligustri lucidi Increased Circulating 1,25(OH)2D3Levels, but Did Not Improve Calcium Balance in Mature Ovariectomized Rats

Our previous studies found that different extracts or fractions of Fructus ligustri lucidi (FLL) played different roles in altering the regulation of bone and mineral metabolism in different animal models. The present study was designed to compare the actions of FLL ethanol (EE) and water extracts (WE) on bone and mineral metabolism in a 6-month-old mature ovariectomized (OVX) rat model. Our results showed that FLL extracts did not significantly improve systematic Ca balance in mature OVX rats. However, EE, but not WE treatment, significantly increased serum 1,25(OH)2D3levels in mature OVX rats. An in vitro study using human proximal tubule (HKC-8) cells showed that EE, but not WE, significantly enhanced renal 25-dihydroxyvitamin D3-1[Formula: see text]-hydroxylase (1-OHase) mRNA expressions and simultaneously repressed renal 25-dihydroxyvitamin D3-24-hydroxylase (24-OHase) mRNA expressions. Further investigation indicated that EE could significantly induce the protein expression of 1-OHase, but did not alter 24-OHase expression in HKC-8 cells. Our results demonstrated that EE increased circulating 1,25(OH)2D3levels in OVX rats, possibly via upregulation of renal 1-OHase expressions in renal proximal tubule cells. Our study indicates that FLL is a natural oral agent that could directly regulate renal vitamin D metabolism in vivo and in vitro.

Epigallocatechin-3-gallate Prevents Triptolide-Induced Hepatic Injury by Restoring the Th17/Treg Balance in Mice

Drug-induced liver injury (DILI) is the most common cause of acute liver failure. Disruption of the Th17/Treg balance can lead to hepatic inflammation, which causes the main symptoms of DILI. Here we investigate the protective mechanisms of (-)-Epigallocatechin-3-gallate (EGCG) on triptolide (TP)-induced DILI that shows the Th17/Treg imbalance. Pretreatment with EGCG (5[Formula: see text]mg/kg) for 10 days before TP (0.5[Formula: see text]mg/kg) administration in mice significantly reduced the increased alanine aminotransferase (ALT) level ([Formula: see text]) induced by TP treatment. The hepatic histology analysis further proved that EGCG protected mice from TP-induced liver injury. The imbalance of Th17/Treg was induced by TP treatment, as shown by the upregulation of TLR4 and downregulation of Tim3 expression. EGCG pretreatment can maintain the expression of TLR4 and Tim3 at normal levels to restore the Th17/Treg imbalance. In addition, EGCG can block the TP-induced expression of the downstream targets of TLR4, including MyD88, NF[Formula: see text]B, and retinoid related orphan receptor (ROR-[Formula: see text]t), while EGCG can restore the TP inhibition of forkhead/winged-helix family transcriptional repressor p3 (FoxP3) that is the downstream target of Tim3. Consequently, EGCG pretreatment can effectively inhibit the Th17-related pro-inflammatory cytokine (e.g. IL-17 and IL-6) upregulation induced by TP treatment. However, TP inhibition of Treg-related anti-inflammatory cytokine IL-10 production was restored by EGCG pretreatment. Taken together, these results suggest that EGCG possesses significant protective properties against TP-induced hepatic inflammatory injury, and that these properties are carried out via the restoration of the Th17/Treg imbalance by the inhibition of the TLR4 signaling pathway and the enhanced activation of the Tim3 signaling pathway.

In Vitro Study on Anti-Hepatitis C Virus Activity of Spatholobus suberectus Dunn

Hepatitis C virus (HCV) infects 200 million people worldwide, and 75% of HCV cases progress into chronic infections, which consequently cause cirrhosis and hepatocellular carcinoma. HCV infection is treated with currently considered standard drugs, including direct anti-viral agents (DAAs), alone or in combination with peginterferon-α plus ribavirin. However, sustained viral responses vary in different cohorts, and high costs limit the broad use of DAAs. In this study, the ethanol and water extracts of 12 herbs from Lingnan in China were examined in terms of their inhibitory effect on HCV replication. Among the examined extracts, Spatholobus suberectus ethanol extracts suppressed HCV replication. By comparison, Extracts from Fructus lycii, Radix astragali (root), Rubus chingii Hu (fruit), Flos chrysanthemi Indici (flower), Cassia obtusifolia (seed), Lonicera japonica Thunb (flower), Forsythia suspense Thunb (fruit), Poria cocos (sclerotia), Carthamus tinctorius L. (flower), Crataegus pinnatifida Bge. (fruit), and Leonurus japonicas Houtt. (leaf) extracts failed to show a similar activity. Active S. suberectus fractions containing tannins as the major component also inhibited the in vitro translation of HCV RNA. The combination treatments of single compounds, such as epigallocatechin gallate and epicatechin gallate, were not as potent as crude S. suberectus fractions; therefore, crude S. suberectus extract may be a potential alternative treatment against HCV either alone or in combination with other agents.

Emodin Decreases Hepatic Hypoxia-Inducible Factor-1[Formula: see text] by Inhibiting its Biosynthesis

Hypoxia-inducible factor-1 (HIF-1) is an [Formula: see text] dimeric transcription factor. Because HIF-1[Formula: see text] is instable with oxygen, HIF-1 is scarce in normal mammalian cells. However, HIF-1[Formula: see text] is expressed in pathological conditions such as cancer and obesity. Inhibiting HIF-1[Formula: see text] may be of therapeutic value for these pathologies. Here, we investigated whether emodin, derived from the herb of Rheum palmatum L, which is also known as Chinese rhubarb, and is native to China, regulates HIF-1[Formula: see text] expression. Male C57BL/6 mice without or with diet-induced obesity were treated with emodin for two weeks, while control mice were treated with vehicle. HIF-1[Formula: see text] expression was determined by Western blot. We found that emodin inhibited obesity-induced HIF-1[Formula: see text] expression in liver and skeletal muscle but did not regulate HIF-1[Formula: see text] expression in the kidneys or in intra-abdominal fat. In vitro, emodin inhibited HIF-1[Formula: see text] expression in human HepG2 hepatic cells and Y1 adrenocortical cells. Further, we investigated the mechanisms of HIF-1[Formula: see text] expression in emodin-treated HepG2 cells. First, we found that HIF-1[Formula: see text] had normal stability in the presence of emodin. Thus, emodin did not decrease HIF-1[Formula: see text] by stimulating its degradation. Importantly, emodin decreased the activity of the signaling pathways that led to HIF-1[Formula: see text] biosynthesis. Interestingly, emodin increased HIF-1[Formula: see text] mRNA in HepG2 cells. This may be a result of feedback in response to the emodin-induced decrease in the protein of HIF-1[Formula: see text]. In conclusion, emodin decreases hepatic HIF-1[Formula: see text] by inhibiting its biosynthesis.

Active chemical fractions of stem bark extract of Khaya grandifoliola C.DC and Entada africana Guill. et Perr. synergistically protect primary rat hepatocytes against paracetamol-induced damage

Background

Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) are traditionally used in Bamun (a western tribe of Cameroon) traditional medicine for the treatment of liver related diseases. In this study, the synergistic hepatoprotective effect of respective active fractions of the plants were investigated against paracetamol-induced toxicity in primary cultures of rat hepatocytes.

Methods

Paracetamol conferred hepatocyte toxicity, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay, alanine aminotransferase (ALT), superoxide dismutase (SOD), catalase (CAT) activities, malondialdehyde (MDA) and glutathione (GSH) content assays. The crude extracts were fractionated by flash chromatography and fractions were tested for hepato-(protective and curative) activities. The most active fractions of both plants were tested individually, and in combination based on their respective half effective concentration (EC₅₀).

Results

The methylene chloride/methanol fractions of K. grandifoliola (75:25 v/v) (KgF25) and E. africana (90:10 v/v) (EaF10) were found to be the most hepato-protective with EC₅₀ values of 10.30 ± 1.66 μg/ml and 13.47 ± 2.06 μg/ml respectively, comparable with that of silymarin (13.71 ± 3.87 μg/ml). These fractions and their combination significantly (P <0.05) improved cell viability, inhibited ALT leakage and MDA formation, and restored cellular CAT, SOD activities and GSH content. The combination was more effective in restoring biochemical parameters with coefficients of drugs interaction (CDI) less than 1.

Conclusion

These findings demonstrate that the active fractions have synergistic action in the protection of rat hepatocytes against paracetamol-induced damage and suggest that their hepatoprotective properties may be maximized by using them in combination.

Ethnobotanical Study of Medicinal Plants Used as Anti-Obesity Remedies in the Nomad and Hunter Communities of Burkina Faso

BACKGROUND

Obesity is a global epidemic that affects both developed and developing countries. According to World Health Organization (WHO), in 2014, over 1.9 billion adults were overweight. Burkina Faso, like other countries, faces the problem of obesity, with a prevalence of 7.3%. The main cause is excessive intake of caloric foods combined with low physical activity, although genetic, endocrine and environmental influences (pollution) can sometimes be predisposing factors. This metabolic imbalance often leads to multiple pathologies (heart failure, Type II diabetes, cancers, etc.). Drugs have been developed for the treatment of these diseases; but in addition to having many side effects, locally these products are not economically accessible to the majority of the population. Burkina Faso, like the other countries bordering the Sahara, has often been confronted in the past with periods of famine during which populations have generally used anorectic plants to regulate their food needs. This traditional ethnobotanical knowledge has not been previously investigated. An ethnobotanical survey was conducted in Burkina Faso in the provinces of Seno (North) and Nayala (Northwest) to list the plants used by local people as an anorectic and/or fort weight loss.

METHODS

The survey, conducted in the two provinces concerned traditional healers, herbalists, hunters, nomads and resourceful people with knowledge of plants. It was conducted over a period of two months and data were collected following a structured interview with the respondents. The approach was based on dialogue in the language of choice of the respondent and the use of a questionnaire. The data have been structured and then statistically analyzed.

RESULTS

The fifty-five (55) respondents of the survey were aged between 40 and 80 years. Sixty-one (61) plant species, belonging to thirty-one (31) families were listed as appetite suppressants and/or for their anti-obesity properties. The main families of plants are Mimosaceae, Rubiaceae, Asclepiadaceae and Cesalpiniaceae. Fruits are the most used part of the plant organs. Consumption in the raw state or as a decoction are the two main forms of preparation.

CONCLUSION

The great diversity of plants cited by informants demonstrates the existence of rich local knowledge to address obesity in Burkina Faso. Evaluation of the biochemical activity of the extracts of the most cited species could allow the development of a phytomedicine economically accessible to the majority of the population. This could allow for the preservation of biodiversity in this region which is weakened by climate change because some of the species cited are in fragile state or are threatened with extinction.

Medicinal Plants Used in Mali for the Treatment of Malaria and Liver Diseases

Today, ethno-pharmacology is a very important resource in order to discover new therapies for the current diseases. Moreover, another good justification for the ethno-pharmacological approach is to obtain new, effective, less expensive and simple therapies, limiting at the same time the cost of pharmaceutical research. Two major anti-malarial drugs widely used today, i.e. quinine and artemisinin, came respectively from Peruvian and Chinese ancestral treatments reported in the traditional medicines. In this contest, there is an urgent need for the discovery of new drugs, due to the critical epidemiological situation of this disease and to the growth of resistances. In Mali, malaria and liver diseases remain one of the leading public health problems. Many medicinal plants are often used, in local traditional medicine, for the treatment at the same time of malaria and liver diseases, including hepatic syndromes, jaundice, hepatitis and other hepatic disorders. Moreover, in the local language Bamanan, the word “ Sumaya” is used both for malaria and some liver diseases. In addition, we noted that some of the improved traditional phytomedicines produced by the Department of Traditional Medicine are prescribed by modern doctors both for malaria and liver diseases. In this review, pharmacological, toxicological and phytochemical data on Argemone mexicana L. (Papaveraceae), Cochlospermum tinctorium Perr. ex A. Rich (Cochlospermaceae), Combretum micranthum G.Don (Combretaceae), Entada africana Guillet Perr. (Mimosaceae), Erythrina senegalensis A. DC (Fabaceae), Mitragyna inermis (Willd) Kuntze (Rubiaceae), Nauclea latifolia Smith syn. Sarcocephalus latifolius (Smith) Bruce (Rubiaceae), Securidaca longepedunculata Fresen (Polygalaceae), Trichilia emetica Vahl. (Meliaceae), and Vernonia colorata (Willd) Drake (Asteraceae) are reported. Some of the collected data could be used to improve the actual herbal drugs and to propose new phytomedicines for the management of malaria and liver diseases.

Mechanism of Taiwan Mingjian Oolong Tea to Inhibit Isoproterenol-Induced Hypertrophy and Apoptosis in Cardiomyoblasts

This study investigates the cardio-protective effect of Nos. 1 and 5 extracts from Taiwan Mingjian Oolong Tea on H9c2 cardiomyoblast cells treated with isoproterenol (ISO). Treatment with Nos. 1 and 5 extracts increased cell viability and blocked apoptosis in ISO exposed H9c2 cells. Moreover, Nos. 1 and 5 extracts blocked hypertrophy markers like G[Formula: see text]s, calcineurin, NFATc3, and BNP, thereby increasing cell proliferation markers -PI3K and AKT in a dose dependent manner. In contrast, apoptotic proteins, such as caspase-3 and cytochrome c were decreased in H9c2 cells treated with Nos. 1 and 5 extracts. We confirmed that the protective effect of No. 1 extract was partially mediated through the expression of ERK and p38, however, the No. 5 extract showed a protective effect via the ERK, JNK, and p38 pathways. This evidence provides new insights into the pharmacological role and therapeutic mechanism of Taiwan Mingjian Oolong Tea in heart diseases.

Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells

The in vitro antioxidant properties, cytoprotective activity, and ability to induce nuclear translocation of nuclear factor E2-related factor-2 (Nrf-2) of five solvent fractions of the methylene chloride/methanol (1:1 v/v) extract of Khaya grandifoliola (Meliaceae) and Entada africana (Fabaceae) were evaluated. Five antioxidant endpoints were used in the antioxidant activity investigation. The total phenolic content of the fractions was assessed as to the Folin-Ciocalteu method and the profile of interesting fractions analyzed by high-performance liquid chromatography (HPLC). The cytoprotective activity of fractions was determined by H2O2-induced oxidative stress in HC-04 cells by measuring lactate dehydrogenase (LDH) leakage into culture medium. HC-04 cells were used to investigate the ability to induce nuclear translocation of Nrf2. For both plants, the methylene chloride/methanol (90/10; v/v) fraction (F10), methylene chloride/methanol (75/25; v/v) (F25), and the methanolic fraction (F100) were found to have the highest total polyphenol content and exhibited high antioxidant activity strongly correlated with total polyphenol content. The cytoprotective activity of fraction F25 from both plants was comparable to that of quercetin (3.40 ± 0.05 μg/mL), inhibiting LDH leakage with a low half inhibition concentration (IC50) of 4.05 ± 0.03 and 3.8 ± 0.02 μg/mL for K. grandifoliola and E. africana, respectively. Lastly, fraction F25 of K. grandifoliola significantly (P < 0.05) induced nuclear Nrf2 translocation by sixfold, whereas that from E. africana and quercetin was only twofold. The results indicate for the first time that fraction F25 of the studied plants is more antioxidant and cytoprotective and induces nuclear translocation of Nrf2 in a human hepatocyte cell line.

Antiproliferative activity and phenotypic modification induced by selected Peruvian medicinal plants on human hepatocellular carcinoma Hep3B cells

ETHNOPHARMACOLOGICAL RELEVANCE

The high incidence of human hepatocellular carcinoma (HCC) in Peru and the wide use of medicinal plants in this country led us to study the activity against HCC cells in vitro of somes species used locally against liver and digestive disorders.

MATERIALS AND METHODS

Ethnopharmacological survey: Medicinal plant species with a strong convergence of use for liver and digestive diseases were collected fresh in the wild or on markets, in two places of Peru: Chiclayo (Lambayeque department, Chiclayo province) and Huaraz (Ancash department, Huaraz province). Altogether 51 species were collected and 61 ethanol extracts were prepared to be tested. Biological assessment: All extracts were first assessed against the HCC cell line Hep3B according a 3-step multi-parametric phenotypic assay. It included 1) the evaluation of phenotypic changes on cells by light microscopy, 2) the measurement of the antiproliferative activity and 3) the analysis of the cytoskeleton and mitosis by immunofluorescence. Best extracts were further assessed against other HCC cell lines HepG2, PLC/PRF/5 and SNU-182 and their toxicity measured in vitro on primary human hepatocytes.

RESULTS

Ethnopharmacological survey: Some of the species collected had a high reputation spreading over the surveyed locations for treating liver problems, i.e. Baccharis genistelloides, Bejaria aestuans, Centaurium pulchellum, Desmodium molliculum, Dipsacus fullonum, Equisetum bogotense, Gentianella spp., Krameria lapacea, Otholobium spp., Schkuhria pinnata, Taraxacum officinale. Hep3B evaluation: Fourteen extracts from 13 species (Achyrocline alata, Ambrosia arborescens, Baccharis latifolia, Hypericum laricifolium, Krameria lappacea, Niphidium crassifolium, Ophryosporus chilca, Orthrosanthus chimboracensis, Otholobium pubescens, Passiflora ligularis, Perezia coerulescens, Perezia multiflora and Schkuhria pinnata) showed a significant antiproliferative activity against Hep3B cells (IC50≤ 50µg/mL). This was associated with a lack of toxicity on primary human hepatocytes in vitro. Immunofluorescence experiments on Hep3B cells showed that crude extracts of Schkuhria pinnata and Orthrosanthus chimboracensis could block Hep3B cells in mitosis with an original phenotype. Crude extracts of Perezia coerulescens, Perezia multiflora, Achyrocline alata, Ophryosporus chilca, Otholobium pubescens and Hypericum laricifolium could modify the overall microtubule cytoskeletal dynamics of Hep3B cells in interphase by an original mechanism.

CONCLUSIONS

Our method allowed us to select 9 extracts which displayed antiproliferative activities associated with original cellular phenotypes on Hep3B cells, regarding known microtubule-targeting drugs. Both chemical and cellular studies are ongoing in order to elucidate natural compounds and cellular mechanisms responsible of the activities described.

Plant extracts from Cameroonian medicinal plants strongly inhibit hepatitis C virus infection in vitro

According to some recent studies, Cameroon is one of the sub-Saharan African countries most affected by hepatitis C, with low access to the standard therapy based on the combination of pegylated interferon and ribavirin. A first ethnobotanical survey, conducted in the Western region of Cameroon, reported the use of several medicinal plants in traditional medicine for the healing of liver-related disorders. Crude organic extracts of five plants surveyed were prepared and their effect against hepatitis C virus (HCV) infection investigated. The HCV JFH1 strain cell culture system HCVcc was used. The antiviral activity was quantified by immunofluorescent labeling of HCV E1 envelope protein at 30 h post-infection in the presence of the plant extracts. Active compounds were then tested in time course infection experiments. Dose-response and cellular toxicity assays were also determined. Three extracts, methanol extracts from roots of Trichilia dregeana, stems of Detarium microcarpum and leaves of Phragmanthera capitata, showed anti-HCV activity, with half-maximal inhibitory concentration of 16.16, 1.42, and 13.17 μg/mL, respectively. Huh-7 cells were incubated with the extracts for 72 h and it appears that T. dregeana extract is not toxic up to 200 μg/mL, D. microcarpum up to 100 μg/mL and P. capitata up to 800 μg/mL. All the three extracts showed a strong inhibition of HCV entry and no effect on replication or secretion. Taken together, these results showed that extracts from Cameroonian medicinal plants are promising sources of anti-HCV agents.