Andrographis paniculata (Burm. F) Wall ex Nees: Antiviral properties

Anti-inflammatory effect and pharmacokinetics of dehydroandrographolide, an active component of Andrographis paniculata, on Poly(I:C)-induced acute lung injury

Acute lung injury (ALI) is a common and critical respiratory disorder caused by various factors, with viral infection being the leading contributor. Dehydroandrographolide (DAP), a constituent of the Chinese herbal plant Andrographis paniculata, exhibits a range of activities including anti-inflammatory, in vitro antiviral and immune-enhancing effects. This study evaluated the anti-inflammatory effects and pharmacokinetics (PK) profile of DAP in ALI mice induced by intratracheal instillation of Poly(I:C) (PIC). The results showed that oral administration of DAP (10-40 mg/kg) effectively suppressed the increase in lung wet-dry weight ratio, total cells, total protein content, accumulation of immune cells, inflammatory cytokines and neutrophil elastase levels in bronchoalveolar lavage fluid of PIC-treated mice. DAP concentrations, determined by an LC-MS/MS method, in plasma after receiving DAP (20 mg/kg) were unchanged compared to those in normal mice. However, DAP concentrations and relative PK parameters in the lungs were significantly altered in PIC-treated mice, exhibiting a relatively higher maximum concentration, larger AUC, and longer elimination half-life than those in the lungs of normal mice. These results demonstrated that DAP could improve lung edema and inflammation in ALI mice, and suggested that lung injury might influence the PK properties of DAP, leading to increased lung distribution and residence. Our study provides evidence that DAP displays significant anti-inflammatory activity against viral lung injury and is more likely to distribute to damaged lung tissue.

Comparison of diterpenoid contents and dissolution profiles of selected Andrographis paniculata crude and extract capsules

INTRODUCTION

Andrographis paniculata (AP) has been approved by the Thai government for the treatment of mild cases of COVID-19 patients. Increasing use of AP products requires quality control to ensure efficacy and safety. At present, there is no requirement for dissolution test of AP products in the Thai Herbal Pharmacopoeia (THP).

OBJECTIVE

This work aimed to examine the contents and dissolution profiles of active diterpenoids, andrographolide (AP1), 14-deoxy-11,12-didehydroandrographolide (AP3), neoandrographolide (AP4), and 14-deoxyandrographolide (AP6) in AP capsules available in Thai markets.

MATERIALS AND METHODS

Four extract products (EXT. A-D) and three crude powder products (CRD. A-C) were tested for contents by using HPLC-DAD. Dissolution profiles of four diterpenoids were investigated in different media (pH 1.2, 4.5, 6.8, and 0.01 N HCl + SLS) with apparatus II (paddle type).

RESULTS

The AP1 contents were 1.99%-2.90% w/w for crude capsules and 2.84%-16.27% w/w for extract capsules. In the dissolution test, the dissolution percentages of four diterpenoids from crude capsules were higher than those from extract capsules except EXT. A. AP1 in most extract products (EXT. B, C, D) was dissolved in all dissolution media at a lower percentage than the other three diterpenoids. EXT. A (aqueous extract) was the only extract capsule showing the amounts of all diterpenoids dissolved in all media >80% in 45 min.

CONCLUSION

The study demonstrated that AP1 content in AP products complied with the acceptance criteria in the THP (80%-120%), and the weight variation also met the United States Pharmacopeia (USP) requirements. However, different dissolution profiles of AP products may lead to different bioavailability of diterpenoids and further affect their efficacy.

Andrographolide acts with dexamethasone to inhibit the growth of acute lymphoblastic leukemia CEM‑C1 cells via the regulation of the autophagy‑dependent PI3K/AKT/mTOR signaling pathway

Acute lymphoblastic leukemia (ALL) is one of the most common malignant tumor types of the circulatory system. Dexamethasone (DEX) acts on the glucocorticoid (GC) receptor (GR) and is a first-line chemotherapy drug for ALL. However, long-term or high-dose applications of the drug can not only cause adverse reactions, such as osteoporosis and high blood pressure, but can also cause downregulation of GR and lead to drug resistance. In the present study, reverse transcription-quantitative PCR, western blotting and LysoTracker Red staining were used to observe the effects of DEX and andrographolide (AND; a botanical with antitumorigenic properties) combined treatment. It was found that AND enhanced the sensitivity of CEM-C1 cells, a GC-resistant cell line, to DEX, and synergistically upregulated GR both at the transcriptional and post-transcriptional level with DEX. The combination of AND with DEX synergistically alkalized lysosomal lumen and downregulated the expression of autophagy-related genes Beclin1 and microtubule-associated 1 protein light chain 3 (LC3), thereby inhibiting autophagy. Knocking down LC3 expression enhanced GR expression, suggesting that GR was regulated by autophagy. Furthermore, compared with the monotherapy group (AND or DEX in isolation), AND interacted with DEX to activate the autophagy-dependent PI3K/AKT/mTOR signaling pathway by enhancing the phosphorylation of PI3K, AKT and mTOR, thereby decreasing GR degradation and increasing the sensitivity of cells to GCs. In conclusion, the present study demonstrated that AND exhibited a synergistic anti-ALL effect with DEX via upregulation of GR, which was orchestrated by the autophagy-related PI3K/AKT/mTOR signaling pathway. The results of the present study therefore provided novel research avenues and strategies for the treatment of ALL.

Inhibitory efficiency of Andrographis paniculata extract on viral multiplication and nitric oxide production

Andrographis paniculata (Burm. F.) Nees is a medicinal plant previously reported with broad-spectrum antivirals but the mode of inhibition remains elusive. The objective of this study was to identify the most active fraction from A. paniculata ethanol extract (APE, APE-2A, APE-2B and APE-2C) and dry powder extract (APSP) against influenza A (H3N2), representing RNA viruses, and herpes simplex virus-1 (HSV-1), representing DNA viruses. The results showed that the fractions APSP, APE, APE-2B, and APE-2C directly neutralized the HSV-1 and influenza A (H3N2) when incubated at room temperature for 60 min before infecting the cells. The results also showed that the additional APE-2A fraction also directly neutralized the influenza A (H3N2), but not the HSV-1. The APE, APE-2B and APE-2C inhibited the HSV-1 by more than 0.5 log when the fractions were introduced after infection. Similarly, the APSP and APE inhibited the influenza A (H3N2) more than 0.5 log after infection. Only 50 μg/mL APE-2C inhibited the viruses greater than 0.5 log. In addition, A. paniculata extracts were also evaluated for their interfering capacities against nitric oxide (NO) production in LPS-activated RAW 264.7 macrophages. As well, APE-2C potently inhibited NO production at the IC50 of 6.08 μg/mL. HPLC and LC-MS analysis indicated that the most actively antiviral fractions did not contain any andrographolide derivatives, whereas the andrographolide-rich fractions showed moderate activity.

Andrographis paniculata methanol extract suppresses the phosphorylation of ETV6‑NTRK3

ETS variant transcription factor 6 (ETV6)-neurotrophic receptor tyrosine kinase 3 (NTRK3) (EN) fusions are typically found in rare diseases, such as primary renal fibrosarcoma (only six cases have been reported), secretory carcinoma of the breast and salivary gland (1 case), and AML (4 cases). Few cases have been reported, and expression of the EN gene fusion requires additional clinical data and fundamental research to be supported. The aim of the present study was to determine the inhibitory effect of Andrographis paniculata methanol extract (MeAP) on EN-related cell lines, IMS-M2 and BaF3/EN, as well as evaluate the mechanism of action. Vero cells were used as control cells. Trypan blue staining and MTT were used to evaluate the inhibitory effect of MeAP on tested cells. Western blotting and immunoprecipitation were used to detect the activation of EN after MeAP treatment. The IC₅₀ values of MeAP were found to be 12.38±0.57 µg/ml (IMS-M2) and 13.06±0.49 µg/ml (BaF3/EN). MeAP was observed to inhibit cell proliferation in a time, dose, and cell density-dependent manner. The IC₅₀ value for MeAP in Vero cells was markedly higher, at 109.97±4.24 (µg/ml), indicating a much less sensitive effect. Furthermore, MeAP treatment inhibited EN phosphorylation and induced apoptosis in these cells. Collectively, the present study demonstrated that MeAP has an oncogenic effect on EN fusion-positive cell lines, in particular.

An improved strategy for identification and annotation of easily in-sourced dissociation diterpene lactones from plant natural products: Taking Andrographis paniculata (Burm. f.) as an example

RATIONALE

Diterpene lactones (DL) in Andrographis paniculata (AP) are known as "natural antibiotics" for their excellent antibacterial activity. During mass spectrometry (MS) analysis, the hydroxyl groups in the AP DL skeleton are prone to neutral loss of H₂ O, producing high in-source fragment peaks and affecting the characterization of these components.

METHODS

Mass tags were applied during the MS data acquisition step, and special adduct ion form was used to guide the data processing and characterization steps. Besides, the total number of characterized AP DLs significantly increased when combining the number of neutrally lost H₂ O from AP DLs, incorporating information on the diagnostic ions, and adopting molecular networks generated with the Global Natural Products Social Molecular Networking database.

RESULTS

Ninety-nine DLs, comprising 6 monohydroxyl groups, 20 dihydroxyl groups, 27 trihydroxy groups, and 46 DLs with more than 3 hydroxyl groups, were characterized from AP. In addition, based on the characteristic fragments in the product ions (C₃ H₄ , Δm/z = 40.03 Da), it could be assumed that 90 DLs had the C19-OH structure among the identified DLs. The current study provides a new approach for collecting, processing, and characterizing MS analysis of natural DLs prone to in-source fragmentation.

CONCLUSIONS

MS characterization of AP DLs was significantly improved, and many potential new compounds were identified in AP. This characterization provides new methods for the purification and identification of AP DLs.

In Silico Identification of 1-DTP Inhibitors of Corynebacterium diphtheriae Using Phytochemicals from Andrographis paniculata

A number of phytochemicals have been identified as promising drug molecules against a variety of diseases using an in-silico approach. The current research uses this approach to identify the phyto-derived drugs from Andrographis paniculata (Burm. f.) Wall. ex Nees (AP) for the treatment of diphtheria. In the present study, 18 bioactive molecules from Andrographis paniculata (obtained from the PubChem database) were docked against the diphtheria toxin using the AutoDock vina tool. Visualization of the top four molecules with the best dockscore, namely bisandrographolide (-10.4), andrographiside (-9.5), isoandrographolide (-9.4), and neoandrographolide (-9.1), helps gain a better understanding of the molecular interactions. Further screening using molecular dynamics simulation studies led to the identification of bisandrographolide and andrographiside as hit compounds. Investigation of pharmacokinetic properties, mainly ADMET, along with Lipinski's rule and binding affinity considerations, narrowed down the search for a potent drug to bisandrographolide, which was the only molecule to be negative for AMES toxicity. Thus, further modification of this compound followed by in vitro and in vivo studies can be used to examine itseffectiveness against diphtheria.

Role of ethno-phytomedicine knowledge in healthcare of COVID-19: advances in traditional phytomedicine perspective

Background

Since the outbreak of the COVID-19 virus, ethnomedicinal plants have been used in diverse geographical locations for their purported prophylactic and pharmacological effects. Medicinal plants have been relied on by people around the globe for centuries, as 80% of the world’s population rely on herbal medicines for some aspect of their primary health care needs, according to the World Health Organization.

Main body

This review portrays advances in traditional phytomedicine by bridging the knowledge of ethno-phytomedicine and COVID-19 healthcare. Ethnomedicinal plants have been used for symptoms related to COVID-19 as antiviral, anti-infective, anti-inflammatory, anti-oxidant, antipyretic, and lung–gut immune boosters. Traditionally used medicinal plants have the ability to inhibit virus entry and viral assembly, bind to spike proteins, membrane proteins, and block viral replications and enzymes. The efficacy of traditional medicinal plants in the terms of COVID-19 management can be evaluated by in vitro, in vivo as well as different in silico techniques (molecular docking, molecular dynamics simulations, machine learning, etc.) which have been applied extensively to the quest and design of effective biotherapeutics rapidly. Other advances in traditional phytomedicines against COVID-19 are controlled clinical trials, and notably the roles in the gut microbiome. Targeting the gut microbiome via medicinal plants as prebiotics is also found to be an alternative and potential strategy in the search for a COVID-19 combat strategy.

Conclusions

Since medicinal plants are the sources of modern biotherapeutics development, it is essential to build collaborations among ethnobotanists, scientists, and technologists toward developing the most efficient and the safest adjuvant therapeutics against the pandemic of the twenty-first century, COVID-19.

Medicinal plants and natural compounds against acyclovir-resistant HSV infections

Herpes simplex virus (HSV), an alphaherpesvirus, is highly prevalent in the human population and is known to cause oral and genital herpes and various complications. Represented by acyclovir (ACV), nucleoside analogs have been the main clinical treatment against HSV infection thus far. However, due to prolonged and excessive use, HSV has developed ACV-resistant strains. Therefore, effective treatment against ACV-resistant HSV strains is urgently needed. In this review, we summarized the plant extracts and natural compounds that inhibited ACV-resistant HSV infection and their mechanism of action.

Ellagic Acid as a Potential Inhibitor against the Nonstructural Protein NS3 Helicase of Zika Virus: A Molecular Modelling Study

Zika virus is a member of the Flaviviridae family and genus Flavivirus, which has a phylogenetic relationship with spondweni virus. It spreads to humans through a mosquito bite. To identify potential inhibitors for the Zika virus with biosafety, we selected natural antiviral compounds isolated from plant sources and screened against NS3 helicase of the Zika virus. The enzymatic activity of the NS3 helicase is associated with the C-terminal region and is concerned with RNA synthesis and genome replication. It serves as a crucial target for the Zika virus. We carried out molecular docking for the target NS3 helicase against the selected 25 phytochemicals using AutoDock Vina software. Among the 25 plant compounds, we identified NS3 helicase-ellagic acid (-9.9 kcal/mol), NS3 helicase-hypericin (-9.8 kcal/mol), and NS3 helicase-pentagalloylglucose (-9.5 kcal/mol) as the best binding affinity compounds based on their binding energies. To understand the stability of these complexes, molecular dynamic simulations were executed and the trajectory analysis exposed that the NS3 helicase-ellagic acid complex possesses greater stability than the other two complexes such as NS3 helicase-hypericin and NS3 helicase-pentagalloylglucose. The ADMET property prediction of these compounds resulted in nontoxicity and noncarcinogenicity.

Efficacy of Kan Jang® in Patients with Mild COVID-19: Interim Analysis of a Randomized, Quadruple-Blind, Placebo-Controlled Trial

Kan Jang^®, the fixed combination of Andrographis paniculata (Burm. F.) Wall. ex. Nees and Eleutherococcus senticosus (Rupr. & Maxim.) Maxim extracts, is a herbal medicinal product for relieving symptoms of upper respiratory tract infections. This study aimed to assess the efficacy of Kan Jang^®/Nergecov® on duration and the relief of inflammatory symptoms in adults with mild COVID-19. 86 patients with laboratory-confirmed COVID-19 and mild symptoms for one to three days received supportive treatment (paracetamol) and six Kan Jang^® (daily dose of andrographolides—90 mg) or placebo capsules a day for 14 consecutive days in this randomized, quadruple-blinded, placebo-controlled, two-parallel-group study. The primary efficacy outcomes were the decrease in the acute-phase duration and the severity of symptoms score (sore throat, runny nose, cough, headache, fatigue, loss of smell, taste, pain in muscles), an increase in cognitive functions, physical performance, quality of life, and decrease in IL-6, c-reactive protein, and D-dimer in blood. Kan Jang^®/Nergecov^® was effective in reducing the risk of progression to severe COVID-19, decreasing the disease progression rate by almost 2.5-fold compared to placebo. Absolute risk reduction by Kan Jang treatment is 14%, the relative risk reduction is 243.9%, and the number Needed to Treat is 7.14. Kan Jang^®/Nergecov^® reduces the duration of disease, virus clearance, and days of hospitalization and accelerates recovery of patients, relief of sore throat, muscle pain, runny nose, and normalization of body temperature. Kan Jang^®/Nergecov^® significantly relieves the severity of inflammatory symptoms such as sore throat, runny nose, and muscle pain, decreases pro-inflammatory cytokine IL-6 level in the blood, and increases patients’ physical performance (workout) compared to placebo. In this study, for the first time we demonstrate that Kan Jang^®/Nergecov^® is effective in treating mild COVID-19.

Andrographolide induces anti-SARS-CoV-2 response through host-directed mechanism: an in silico study

Aim: Considering the present alarming situation of COVID-19 pandemic, we concentrated on evaluating the efficacy of a novel natural antiviral drug-candidate andrographolide against SARS-CoV-2 through an in silico model of study. Materials & methods: Interaction of andrographolide against the major host molecules that are responsible for SARS-CoV-2 pathogenesis were determined using bio-computational tools, in other words, molecular docking, molecular dynamics simulation and pharmacodynamics–pharmacokinetics analysis. Result: Computational findings represent that andrographolide efficiently interacts with the major human–host-associated putative drug-targets of viral-entry points like furin (-10.54 kcal/mol), TMPRSS-2 (-9.50 kcal/mol), ACE2 (-8.99 kcal/mol) and Cathepsin L (-8.98 kcal/mol). Moreover, it also blocks the inflammatory regulators including TLR4-MD2 and IL-6, which promote virus-induced inflammation leading to cytokine storm in the host body. Conclusion: This work elucidates that, the candidature of andrographolide can be utilized as a potent natural agent for the therapeutic intervention of SARS-CoV-2 through host-directed treatment.

Proteomics and UHPLC-DAD-Q/Orbitrap-MS used to identify impurities in andrographolide

INTRODUCTION

Andrographolide active pharmaceutical ingredient (API) is a semidiurnal diterpene lactone with significant antipyretic, antiviral, anti-inflammatory and anticancer activities. A large amount of andrographolide API could only be obtained by extraction from Andrographis paniculata. Therefore, there may be related compounds, plant proteins and other impurities in andrographolide API.

OBJECTIVE

In order to improve the safety of andrographolide related preparations, it was necessary to clarify the impurities and improve the quality standard of andrographolide API.

METHODS

The related compounds were identified by ultrahigh-performance liquid chromatography with diode-array detector quadrupole Orbitrap mass spectrometry (UHPLC-DAD-Q/Orbitrap-MS), and the residual proteins were determined by ultrafiltration combined with proteomics. The proteomics method included protein extraction, content determination, digestion, desalination and nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS) analysis. Then, MS results were compared with Andrographis paniculata protein database by Peaks Studio.

RESULTS

The results showed that 32 related compounds were putatively identified, of which 30 impurities were identified for the first time. Seven residual proteins together with 11 highly suspected proteins were uniquely identified, including the T1UNN5_ANDPA protein with the highest intensity.

CONCLUSIONS

This study will provide useful information on the composition of andrographolide API, which is important for the quality control and clinical safety assurance of API and related prescriptions. Reasonable guidance will also be provided on the necessity of ultrafiltration in the production process of related injections.

Ethnobotanical Survey on Bitter Tea in Taiwan

Ethnopharmacological evidence: In Taiwan, herbal tea is considered a traditional medicine and has been consumed for hundreds of years. In contrast to regular tea, herbal teas are prepared using plants other than the regular tea plant, Camellia sinensis (L.) Kuntze. Bitter tea (kǔ-chá), a series of herbal teas prepared in response to common diseases in Taiwan, is often made from local Taiwanese plants. However, the raw materials and formulations have been kept secret and verbally passed down by store owners across generations without a fixed recipe, and the constituent plant materials have not been disclosed.

Aim of the study: The aim was to determine the herbal composition of bitter tea sold in Taiwan, which can facilitate further studies on pharmacological applications and conserve cultural resources.

Materials and methods: Interviews were conducted through a semi-structured questionnaire. The surveyed respondents were traditional sellers of traditional herbal tea. The relevant literature was collated for a systematic analysis of the composition, characteristics, and traditional and modern applications of the plant materials used in bitter tea. We also conducted an association analysis of the composition of Taiwanese bitter tea with green herb tea (qing-cao-cha tea), another commonly consumed herbal tea in Taiwan, as well as herbal teas in neighboring areas outside Taiwan.

Results: After visiting a total of 59 stores, we identified 32 bitter tea formulations and 73 plant materials. Asteraceae was the most commonly used family, and most stores used whole plants. According to a network analysis of nine plant materials used in high frequency as drug pairs, Tithonia diversifolia and Ajuga nipponensis were found to be the core plant materials used in Taiwanese bitter tea.

Conclusion: Plant materials used in Taiwanese bitter tea were distinct, with multiple therapeutic functions. Further research is required to clarify their efficacy and mechanisms.

Andrographolide Derivatives Target the KEAP1/NRF2 Axis and Possess Potent Anti-SARS-CoV-2 Activity

Naturally occurring compounds represent a vast pool of pharmacologically active entities. One of such compounds is andrographolide, which is endowed with many beneficial properties, including the activity against severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2). To initiate a drug repurposing or hit optimization campaign, it is imperative to unravel the primary mechanism(s) of the antiviral action of andrographolide. Here, we showed by means of a reporter gene assay that andrographolide exerts its anti‐SARS‐CoV‐2 effects by inhibiting the interaction between Kelch‐like ECH‐associated protein 1 (KEAP1) and nuclear factor erythroid 2‐related factor 2 (NRF2) causing NRF2 upregulation. Moreover, we demonstrated that subtle structural modifications of andrographolide could lead to derivatives with stronger on‐target activities and improved physicochemical properties. Our results indicate that further optimization of this structural class is warranted to develop novel COVID‐19 therapies.

In Silico Screening of Potential Phytocompounds from Several Herbs against SARS-CoV-2 Indian Delta Variant B.1.617.2 to Inhibit the Spike Glycoprotein Trimer

In October 2020, the SARS-CoV-2 B.1.617 lineage was discovered in India. It has since become a prominent variant in several Indian regions and 156 countries, including the United States of America. The lineage B.1.617.2 is termed the delta variant, harboring diverse spike mutations in the N-terminal domain (NTD) and the receptor-binding domain (RBD), which may heighten its immune evasion potentiality and cause it to be more transmissible than other variants. As a result, it has sparked substantial scientific investigation into the development of effective vaccinations and anti-viral drugs. Several efforts have been made to examine ancient medicinal herbs known for their health benefits and immune-boosting action against SARS-CoV-2, including repurposing existing FDA-approved anti-viral drugs. No efficient anti-viral drugs are available against the SARS-CoV-2 Indian delta variant B.1.617.2. In this study, efforts were made to shed light on the potential of 603 phytocompounds from 22 plant species to inhibit the Indian delta variant B.1.617.2. We also compared these compounds with the standard drug ceftriaxone, which was already suggested as a beneficial drug in COVID-19 treatment; these compounds were compared with other FDA-approved drugs: remdesivir, chloroquine, hydroxy-chloroquine, lopinavir, and ritonavir. From the analysis, the identified phytocompounds acteoside (−7.3 kcal/mol) and verbascoside (−7.1 kcal/mol), from the plants Clerodendrum serratum and Houttuynia cordata, evidenced a strong inhibitory effect against the mutated NTD (MT-NTD). In addition, the phytocompounds kanzonol V (−6.8 kcal/mol), progeldanamycin (−6.4 kcal/mol), and rhodoxanthin (−7.5 kcal/mol), from the plant Houttuynia cordata, manifested significant prohibition against RBD. Nevertheless, the standard drug, ceftriaxone, signals less inhibitory effect against MT-NTD and RBD with binding affinities of −6.3 kcal/mol and −6.5 kcal/mol, respectively. In this study, we also emphasized the pharmacological properties of the plants, which contain the screened phytocompounds. Our research could be used as a lead for future drug design to develop anti-viral drugs, as well as for preening the Siddha formulation to control the Indian delta variant B.1.617.2 and other future SARS-CoV-2 variants.

Andrographolide: A review of its pharmacology, pharmacokinetics, toxicity and clinical trials and pharmaceutical researches

Andrographis paniculata (Burm. f.) Wall. ex Nees, a renowned herb medicine in China, is broadly utilized in traditional Chinese medicine (TCM) for the treatment of cold and fever, sore throat, sore tongue, snake bite with its excellent functions of clearing heat and toxin, cooling blood and detumescence from times immemorial. Modern pharmacological research corroborates that andrographolide, the major ingredient in this traditional herb, is the fundamental material basis for its efficacy. As the main component of Andrographis paniculata (Burm. f.) Wall. ex Nees, andrographolide reveals numerous therapeutic actions, such as antiinflammatory, antioxidant, anticancer, antimicrobial, antihyperglycemic and so on. However, there are scarcely systematic summaries on the specific mechanism of disease treatment and pharmacokinetics. Moreover, it is also found that it possesses easily ignored security issues in clinical application, such as nephrotoxicity and reproductive toxicity. Thereby it should be kept a lookout over in clinical. Besides, the relationship between the efficacy and security issues of andrographolide should be investigated and evaluated scientifically. In this review, special emphasis is given to andrographolide, a multifunctional natural terpenoids, including its pharmacology, pharmacokinetics, toxicity and pharmaceutical researches. A brief overview of its clinical trials is also presented. This review intends to systematically and comprehensively summarize the current researches of andrographolide, which is of great significance for the development of andrographolide clinical products. Noteworthy, those un-cracked issues such as specific pharmacological mechanisms, security issues, as well as the bottleneck in clinical transformation, which detailed exploration and excavation are still not to be ignored before achieving integration into clinical practice. In addition, given that current extensive clinical data do not have sufficient rigor and documented details, more high-quality investigations in this field are needed to validate the efficacy and/or safety of many herbal products.

Discovery of 14S-(2'-chloro-4'-nitrophenoxy)-8R/S,17-epoxy andrographolide as EV-A71 infection inhibitor

Human enterovirus A71 (EV-A71) is a major etiological agent of hand-foot-and-mouth disease (HFMD) and there is presently no internationally approved antiviral against EV-A71. In this study, it is disclosed that 14S-(2'-chloro-4'-nitrophenoxy)-8R/S,17-epoxy andrographolide (2) was discovered to be an effective inhibitor against EV-A71 infection showing significant reduction of viral titre. In addition to EV-A71, compound 2 exerts broad-spectrum antiviral effects against other enteroviruses. It is revealed that compound 2 inhibits the post-entry stages of EV-A71 viral replication cycle and significantly reduces viral protein expression of structural proteins such as VP0 and VP2 via inhibiting EV-A71 RNA replication. Moreover, the inhibitory property of compound 2 is specific to viral RNA replication. Furthermore, compound 2 is more likely to target a host factor in EV-A71 RNA replication. As a result, introduction of epoxide at positions 8 and 17 of andrographolide is effective for anti-EV-A71 infection and is a potential anti-EV-A71 strategy. Further work to discover more potent andrographolide derivatives and elucidate comprehensive SAR is under way.