Synthesis and Biological Evaluation of Andrographolide Derivatives as Potent Anti-HIV Agents

Synthesis of 12-quinoline substituted andrographolide derivatives and their preliminary evaluation as anti-aggregation drugs

Based on the structure of the natural product andrographolide, a series of novel 12-quinoline substituted derivatives 9 were designed and synthesized. In preliminary biological evaluation, these synthesized compounds showed prominent anti-platelet aggregation activities in response to thrombin and adenosine diphosphate (ADP) agonists. Among them, compound 9o (inhibition rate 55.73%, IC50 0.36 µM/L) had the highest anti-platelet aggregation activity induced by ADP. Compound 9q (inhibition rate 54.31%, IC50 0.30 µM/L) showed the highest anti-platelet aggregation activity induced by thrombin. Most of the derivatives had no significant cytotoxicity. Our research results provide a novel candidate drug structure for anti-platelet aggregation and enrich the scope of application of andrographolide derivatives.

Andrographolide: A Herbal-Chemosynthetic Approach for Enhancing Immunity, Combating Viral Infections, and Its Implication on Human Health

Plants consistently synthesize and accumulate medically valuable secondary metabolites which can be isolated and clinically tested under in vitro conditions. An advancement with such important phytochemical production has been recognized and utilized as herbal drugs. Bioactive andrographolide (AGL; C20H30O5) isolated from Andrographis paniculate (AP) (Kalmegh) is a diterpenoid lactones having multifunctional medicinal properties including anti-manic, anti-inflammatory, liver, and lung protective. AGL is known for its immunostimulant activity against a variety of microbial infections thereby, regulating classical and alternative macrophage activation, Ag-specific antibody production during immune disorder therapy. In vitro studies with AGL found it to be effective against multiple tumors, neuronal disorders, diabetes, pneumonia, fibrosis, and other diverse therapeutic misadventures. Generally, virus-based diseases like ZIKA, influenza A virus subtype (H1NI), Ebola (EBOV), Dengue (DENV), and coronavirus (COVID-19) epidemics have greatly increased scientific interest and demands to develop more effective and economical immunomodulating drugs with minimal side effects. Trials and in vitro pharmacological studies with AGL and medicinally beneficial herbs might contribute to benefit the human population without using chemical-based synthetic drugs. In this review, we have discussed the possible role of AGL as a promising herbal-chemo remedy during human diseases, viral infections and as an immunity booster.

Andrographolide and its derivatives: Current achievements and future perspectives

Natural product andrographolide isolated from the plant Andrographis paniculata shows a plethora of biological activities, including anti-tumor, anti-bacterial, anti-inflammation, anti-virus, anti-fibrosis, anti-obesity, immunomodulatory and hypoglycemic activities. Based on extensive chemical structural modifications, a series of andrographolide derivatives with improved bioavailability and druggability has been developed. Moreover, greater understanding of their mechanisms of action at the molecular and cellular level has been thoroughly investigated. In this review, we give an outlook for the therapeutical potential of andrographolide and its derivatives in diverse diseases and highlighted the drug design, pharmacokinetic and mechanistic studies for the past ten years, together with a brief overview of the pharmacological effects. Notably, we focused to provide a critical enlightenment of the area of andrographolide and its derivatives with the intent of indicating the future perspectives, challenges and limitations. We believe that this review paper will benefit drug discovery where andrographolide was used as a template, shed light on the identification of drug targets for andrographolide and its analogs, as well as increase our knowledge for using them for therapeutic application, including the treatment for various forms of cancers.

Synthesis of 3,15-Disuccinate-12-Coumarin Substituted Andrographolide Derivatives and Their Antiplatelet Aggregation Activities In Vitro

In order to develop a series of novel compounds with antiplatelet aggregation activities, 3,15-disuccinate-12-coumarin substituted derivatives were designed and synthesized based on the natural product andrographolide. In vitro antiplatelet aggregation activities were evaluated by the turbidimetric method with thrombin, adenosine diphosphate (ADP), arachidonic acid (AA), and collagen as inducers. The biological evaluation revealed that compound 11k showed significant inhibition activity for thrombin, AA, and collagen-induced platelet aggregation at the same time and exhibited a dose-dependent behavior. Compound 11c showed the highest antiplatelet aggregation activity induced by ADP. Most of the derivatives had no significant cytotoxicity. Therefore, our work proved that 3,15-disuccinate-12-coumarin substituted andrographolide derivatives had the potential to become a novel candidate structure for antiplatelet aggregation and deserved further study.

Adaptogens in chemobrain (Part III): Antitoxic effects of plant extracts towards cancer chemotherapy-induced toxicity - transcriptome-wide microarray analysis of neuroglia cells

BACKGROUND

Toxicity of chemotherapeutics is a serious problem in cancer therapy. Adaptogens are known to increase adaptability and survival organisms.

AIM

The aim of this study was to assess the effects of selected adaptogenic herbal extracts on FEC (fixed combination of 5-fluorouracil, epirubicin and cyclophosphamide) induced changes in transcriptome-wide microarray profiles of neuroglia cells. Another task of the study was to identify those genes, which are associated with FEC-induced hepato-, cardio- and nephrotoxicity to predict potential effects of andrographolide (AND), Andrographis herb, Eleutherococcus roots genuine extracts (ES), their fixed combination (AE) and the combination of Rhodiola roots, Schisandra berries and Eleutherococcus roots (RSE) on the organismal level.

METHODS

Gene expression profiling was performed by transcriptome-wide mRNA microarray in the human T98G neuroglia cells after treatment with adaptogens. Interactive pathways downstream analysis was performed with data sets of significantly up- or down-regulated genes and predicted effects on cellular functions and diseases were identified by Ingenuity IPA database software.

RESULT

Significant differences of transcriptome-wide microarray profiles were observed after treatment of T98G cells with FEC and after co-incubation with adaptogens. FEC induced deregulation of certain genes with suggested toxicity associated with liver fibroses, necrosis and congenital heart diseases. Co-incubation of AE with FEC prevented FEC-induced deregulation of 66 genes increasing organismal death, 37 genes decreasing cell survival, 37 genes decreasing DNA repair, 37 genes decreasing viral infection and some other functions, indicating on potential beneficial effects of AE. Furthermore, FEC-induced hepato-, nephro- and cardiotoxicity related to deregulation of genes was predictably attenuated by AE. Moreover, co-incubation of AE with FEC caused differential expression of genes, which presumably are beneficial for an organism during chemotherapy. They include predicted activation of DNA repair, activation of movement of antigen presenting cells and inhibition of muscle cells death. The main active constituent of AE is AND. Co-incubation of FEC only with AND results in deregulation of 10 genes causing death of breast cancer cells, decrease of liver toxicity and attenuation of organismal death. Co-incubation of ES extract with FEC showed that ES suppressed FEC-induced deregulation of genes, which inhibit organismal death and fertility. Co-incubation of FEC with RSE indicated potential hepatoprotective effect against FEC-induced apoptosis of liver cells presumably due to suppression of FEC-induced expressions of genes, which increased liver cell apoptosis. Simultaneously, RSE activated expression of genes inhibiting tumor growth. Though, microarray analysis did not provide final proof that the genes induced by the AE, AP and ES are responsible for the physiological effects observed in human patients following their oral administration, it provided insights into putative genes and directions for future research and possible implementation into practice.

CONCLUSION

Application of cytostatic drugs in combination with adaptogenic plant extracts induced significant changes in transcriptome-wide microarray profiles of neuroglial cells. These changes indicate on potential beneficial effects of adaptogens on FEC induced adverse events in cancer chemotherapy.

Adaptogens in chemobrain (Part I): Plant extracts attenuate cancer chemotherapy-induced cognitive impairment - Transcriptome-wide microarray profiles of neuroglia cells

BACKGROUND

Cancer chemotherapy-induced cognitive impairments are presumably associated with undesirable effects of chemotherapy on physiological functions of brain cells. Adaptogens are natural compounds or plant extracts increasing an organism's adaptability and survival in stress. They exhibited neuroprotective effects and increased cognitive functions in clinical studies in human beings.

HYPOTHESIS

We hypothesized that selected adaptogenic plant extracts attenuate or prevent cancer chemotherapy-induced cognitive impairments.

AIM

We assessed the effects of selected adaptogenic herbal extracts on FEC (fixed combination 5-fluorouracil, epirubicin and cyclophosphamide) induced changes in transcriptome-wide RNA microarray profiles of neuroglia cells. The aim of the study was to predict potential effects of andrographolide, Andrographis herb, Eleutherococcus root genuine extracts, their fixed combination (AE) and the combination of Rhodiola roots, Schisandra berries and Eleutherococcus roots (RSE) on cellular and physiological, mostly cognitive functions.

METHODS

Gene expression profiling was performed by transcriptome-wide mRNA microarray in the human T98G neuroglia cells after treatment with adaptogens. Interactive pathways downstream analysis was performed with data sets of significantly up- or down-regulated genes and predicted effects on cellular functions and diseases were identified by Ingenuity IPA database software.

RESULTS

FEC deregulated 67 genes involved in decrease of neuronal development, 37 genes involved in development of the sensory system, 12 genes in extension of axons, and 3 genes in migration of neurons. Co-incubation with Andrographis paniculata (AP) suppressed FEC-induced deregulation of a large number of genes involved in predicted activation of neuronal death and inhibition of neurogenesis, and 16 genes related to inhibition of several functions in the nervous system. Co-incubation with AE suppressed FEC-induced deregulation of a number of genes involved in predicted inhibition of axon extension, migration of T98G neuroglia cells, conduction of nerves and other genes related to regulations of some other functions in the nervous system.

CONCLUSION

Application of cytostatic drugs in combination with apoptogenic plant extracts induced significant changes in transcriptome-wide mRNA microarray profiles of neuroglial cells. These changes indicate on potential beneficial effects on neuronal functions associated with mild cognitive impairments in cancer chemotherapy.

Design, synthesis, and biological evaluation of novel nitric oxide releasing dehydroandrographolide derivatives

A series of new hybrids of dehydroandrographolide (TAD), a biologically active natural product, bearing nitric oxide (NO)-releasing moieties were synthesized and designated as NO-donor dehydroandrographolide. The biological activities of target compounds were studied in human erythroleukemia K562 cells and breast cancer MCF-7 cells. Biological evaluation indicated that the most active compound I-5 produced high levels of NO and inhibited the proliferation of K562 (IC₅₀ 1.55 μmol·L^-1) and MCF-7 (IC₅₀ 2.91 μmol·L^-1) cells, which were more potent than the lead compound TAD and attenuated by an NO scavenger. In conclusion, I-5 is a novel hybrid with potent antitumor activity and may become a promising candidate for future intensive study.

Andrographolide: progression in its modifications and applications - a patent review (2012 - 2014)

INTRODUCTION

Extraction, isolation and modifications of andrographolide (Androg) is extensively investigated and patented. The prominent activities were vastly modified for anticancer and antivirals. Many products related to Androg are commercially available, thus the section 'Interaction of Androg and Andrographis paniculata dried extract with drugs' is included.

AREAS COVERED

The data in this review are searched and selected from SciFinder and Espacenet for the patents, with the keywords: Andrographolide and Andrographolide analogs, and the results were refined by the years.

EXPERT OPINION

Modifications of Androg have been done to nearly all of the possible sites, and now screening tests for any new activities had been settled down. Categorizing the analogs that have been developed is not clear cut since some diseases can develop into others, for example, inflammation and some viral infections can develop into cancer. Currently, investigation of the mode of action and the mechanisms at the molecular level are intensively ongoing. Producing new chemotherapeutic agents from Androg looks promising. The main problem of using Androg in therapeutic applications is its insolubility in aqueous media. Those modified analogs' esters, ethers or salts, have to be considered for the stability of pharmaceutical preparations, and transformation in biological fluids after administration. Further stages of drug development are required for those promising analogs.

Synthesis, structure-activity relationships and biological evaluation of dehydroandrographolide and andrographolide derivatives as novel anti-hepatitis B virus agents

Dehydroandrographolide and andrographolide, two natural diterpenoids isolated from Andrographis paniculata possessed activity against HBV DNA replication with IC50 values of 22.58 and 54.07μM and low SI values of 8.7 and 3.7 in our random assay. Consequently, 48 derivatives of dehydroandrographolide and andrographolide were synthesized and evaluated for their anti-HBV properties to yield a series of active derivatives with lower cytotoxicity, including 14 derivatives against HBsAg secretion, 19 derivatives against HBeAg secretion and 38 derivatives against HBV DNA replication. Interestingly, compound 4e could inhibit not only HBsAg and HBeAg secretions but also HBV DNA replication with SI values of 20.3, 125.0 and 104.9. Furthermore, the most active compound 2c with SI value higher than 165.1 inhibiting HBV DNA replication was revealed with the optimal logP value of 1.78 and logD values. Structure-activity relationships (SARs) of the derivatives were disclosed for guiding the future research toward the discovery of new anti-HBV drugs.

A classical genetic solution to enhance the biosynthesis of anticancer phytochemicals in Andrographis paniculata Nees

Andrographolides, the diterpene lactones, are major bioactive phytochemicals which could be found in different parts of the medicinal herb Andrographis paniculata. A number of such compounds namely andrographolide (AG), neoandrographolide (NAG), and 14-deoxy-11,12-didehydroandrographolide (DDAG) have already attracted a great deal of attention due to their potential therapeutic effects in hard-to-treat diseases such as cancers and HIV. Recently, they have also been considered as substrates for the discovery of novel pharmaceutical compounds. Nevertheless, there is still a huge gap in knowledge on the genetic pattern of the biosynthesis of these bioactive compounds. Hence, the present study aimed to investigate the genetic mechanisms controlling the biosynthesis of these phytochemicals using a diallel analysis. The high performance liquid chromatography analysis of the three andrographolides in 210 F₁ progenies confirmed that the biosynthesis of these andrographolides was considerably increased via intraspecific hybridization. The results revealed high, moderate and low heterosis for DDAG, AG and NAG, respectively. Furthermore, the preponderance of non-additive gene actions was affirmed in the enhancement of the three andrographolides contents. The consequence of this type of gene action was the occurrence of high broad-sense and low narrow-sense heritabilities for the above mentioned andrographolides. The prevalence of non-additive gene action suggests the suitability of heterosis breeding and hybrid seed production as a preferred option to produce new plant varieties with higher andrographolide contents using the wild accessions of A. paniculata. Moreover, from an evolutionary point of view, the occurrence of population bottlenecks in the Malaysian accessions of A. paniculata was unveiled by observing a low level of additive genetic variance (V_A) for all the andrographolides.