Ardisiphenols A-C, novel antioxidants from the fruits of Ardisia colorata

The ethnomedicinal and functional uses, phytochemical and pharmacology of compounds from Ardisia species: An updated review

Medicinal plants are considered to be a critical source of novel compounds and pharmacophores. The genus Ardisia, consisting of approximately 500 species, is the largest genus in the Myrsinaceae family. Ardisia species are widely distributed throughout tropical and subtropical regions of the world and have been used for the treatment of cancer, hypertension, irregular menstruation, gonorrhea, diarrhea and postnatal syndromes, among others. Phytochemical studies of Ardisia species have resulted in the isolation and identification of 111 compounds, including triterpenoid saponins, quinones, phenols, coumarins, cyclic depsipepetide and flavonoids. Crude extracts and isolates from Ardisia have been reported to have in vitro and in vivo efficacies, including but not limited to anticancer, antiinflammatory, antimicrobial, antioxidant, antithrombotic and antidiabetic, antitubercular compounds. This review focuses on the medical and functional uses, phytochemical profile and pharmacological efficacies of Ardisia species over the past 15 years. This review will provide information indicating that Ardisia species represent an invaluable source of potential therapeutic compounds.

Comparative Evaluation of Antioxidant and Anti-Inflammatory Activity of Active Compounds Identified in Ardisia elliptica Extracts from Different Plant Parts

Ardisia elliptica Thunb. (AE) has been used as food and in traditional medicine to prevent and treat fever, diarrhea, chest pain, liver poisoning, and parturition complications in Southeast Asian countries. This study focused on phytochemical constituents of AE extracts and their antioxidant and anti-inflammatory activity in vitro by evaluating nitric oxide production, and DPPH and FRAP radical scavenging activity. The bioactive compounds from different plant parts, including old leaves, young leaves, flowers, roots, and fruits, were identified. The results showed the highest phenolic and flavonoid content in the root extract among all extracts, which resulted in the most potent free radical scavenging activity revealed by the DPPH and FRAP assay. The roots and flowers showed the highest bergenin (3.36±0.22 mg/g dry weight) and quercetin (2.99±0.10 mg/g dry weight) content, respectively. In contrast, embelin was found only in the fruits. Interestingly, AE extracts significantly suppressed the mRNA expression of inducible nitric oxide synthase, leading to inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Conclusively, the results suggest the natural products of AE extracts as effective antioxidant and anti-inflammatory agents that can be utilized for food and pharmaceutical applications.

Metabolomic analysis reveals the valuable bioactive compounds of Ardisia elliptica

INTRODUCTION

Ardisia elliptica Thunb. (Primulaceae) is a medicinal herb that is traditionally used for the treatment of fever, diarrhoea, measles and herpes. However, there is limited information regarding the correlation of its phytoconstituents with the bioactivity. Optimisation of solvent extraction is vital for maximising retention of bioactive molecules.

OBJECTIVE

This study investigated the metabolite variations in A. elliptica leaves and the correlation with antioxidant activities.

METHODOLOGY

Total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radicals scavenging assays were performed on A. elliptica leaves extracted with four different ethanol ratios (0%, 50%, 70% and absolute ethanol). The correlation of metabolites with antioxidant activities was evaluated using a nuclear magnetic resonance (NMR)-based metabolomics approach.

RESULTS

The results showed that the 50% and 70% ethanolic extracts retained the highest TPC, and the 70% ethanolic extract was the most active, exhibiting half maximal inhibitory concentration (IC₅₀ ) values of 10.18 ± 0.83 and 43.05 ± 1.69 μg/mL, respectively, in both radical scavenging assays. A total of 46 metabolites were tentatively identified, including flavonoids, benzoquinones, triterpenes and phenolic derivatives. The 50% and 70% ethanolic extracts showed similarities in metabolites content and were well discriminated from water and absolute ethanol extracts in a principal component analysis (PCA) model. Moreover, 31 metabolites were found to contribute significantly to the differentiation and antioxidant activity.

CONCLUSION

This study provides information on bioactive compounds in A. elliptica leaves, which is promising as a functional ingredient for food production or for the development of phytomedicinal products.

Biological Activities of Selected Plants and Detection of Bioactive Compounds from Ardisia elliptica Using UHPLC-Q-Exactive Orbitrap Mass Spectrometry

Plants and plant-based products have been used for a long time for medicinal purposes. This study aimed to determine the antioxidant and anti-α-glucosidase activities of eight selected underutilized plants in Malaysia: Leucaena leucocephala, Muntingia calabura, Spondias dulcis, Annona squamosa, Ardisia elliptica, Cynometra cauliflora, Ficus auriculata, and Averrhoa bilimbi. This study showed that the 70% ethanolic extract of all plants exhibited total phenolic content (TPC) ranging from 51 to 344 mg gallic acid equivalent (GAE)/g dry weight. A. elliptica showed strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) scavenging activities, with half maximal inhibitory concentration (IC₅₀) values of 2.17 and 49.43 μg/mL, respectively. Most of the tested plant extracts showed higher inhibition of α-glucosidase enzyme activity than the standard, quercetin, particularly A. elliptica, F. auriculata, and M. calabura extracts with IC₅₀ values of 0.29, 0.36, and 0.51 μg/mL, respectively. A total of 62 metabolites including flavonoids, triterpenoids, benzoquinones, and fatty acids were tentatively identified in the most active plant, i.e., A. elliptica leaf extract, by using ultra-high-performance liquid chromatography (UHPLC)–electrospray ionization (ESI) Orbitrap MS. This study suggests a potential natural source of antioxidant and α-glucosidase inhibitors from A. elliptica.

Non-volatile pungent compounds isolated from Zingiber officinale and their mechanisms of action

In this study, an efficient strategy developed by integrating UPLC-Q/TOF-MS, network pharmacology, and molecular simulation, was proposed and applied for rapidly screening bioactive candidates from ginger. A UPLC-Q/TOF MS-guided isolation targeting non-volatile pungent compounds resulted in the isolation and identification of 19 compounds in the rhizome of Zingiber officinale, including six new compounds (1-6). Based on target prediction and Gene Ontology (GO), the primary biological function of compounds was predicted to be associated with cancer and the key target was VEGFR2 (vascular endothelial growth factor receptor 2). Moreover, cytotoxic activity assays demonstrated that the isolated compounds had potential anti-proliferative effects on MDA-MB-231, A549 and HCT116 cells. In particular, compounds 7 and 8 exhibited the highest cytotoxicity against HCT116 compared with the other cell lines, with IC50 values ranging from 4.70 to 7.40 μM. In addition, VEGFR2 inhibition of compounds 7 and 8 was validated based on enzyme activity assays and their interaction mechanisms were illuminated through molecular simulations. These experimental data are consistent with the calculated results, indicating the veracity of the proposed method. In conclusion, the integrated strategy is a quick and efficient way to explore bioactive compounds as well as research the possible targets, providing us with a good possibility of screening new lead compounds from natural sources.

The Potential of Sub-Saharan African Plants in the Management of Human Immunodeficiency Virus Infections: A Review

Acquired immunodeficiency syndrome, caused by human immunodeficiency virus (HIV), is a leading cause of mortality and morbidity in Sub-Saharan Africa, particularly in Southern Africa. Phytomedicines are an integral part of African health care. The Southern African flora is composed of at least 23 400 taxa. Despite this richness, only a handful of botanical products have been assessed for activities against HIV. This study aimed to summarize the potential of Sub-Saharan African plants, based on their composition and the established bioactivities, as sources of agents to manage HIV symptoms and as retroviral therapy. At least 109 plant species from 42 families and 94 genera that are found in Southern Africa were shown to have potential or actual activities against HIV. Only 12 of these plant species from 6 families and 10 genera were shown to harbour anti-HIV properties. Phytochemicals that include β-sitosterols, terpenoids, glycosides, saponins, flavonoids, triterpenoids, tannins and alkaloids, which harbour anti-HIV properties, were found to have a near cosmopolitan presence across the plant families in the region. Bioactivities of multiple phytochemicals are comparable to those for standard allopathic antiretroviral drugs. Research to determine the anti-HIV activities of the identified and other plants, including clinical trials, is long overdue.

Ardisiphenol D, a resorcinol derivative identified from Ardisia brevicaulis, exerts antitumor effect through inducing apoptosis in human non-small-cell lung cancer A549 cells

CONTEXT

The in vitro and in vivo antitumor activities of ardisiphenol D, a natural product isolated from the roots of Ardisa brevicaulis Diels (Myrsinaceae), have been studied.

OBJECTIVE

Previously, we have isolated and identified some chemical constituents from this plant. Furthermore, these compounds showed significant inhibition of the proliferation of human pancreatic PANC-1, human lung A549, human gastrointestinal carcinoma SGC 7901, human breast MCF-7, and human prostate PC-3 cancer cells. In the present paper, a major resorcinol derivative called ardisiphenol D was further studied for its antitumor mechanism.

MATERIALS AND METHODS

MTT assay was used to detect the proliferation of A549 cancer cells. Apoptosis induced by ardisiphenol D was observed by Hoechst 33258 fluorescence staining. Caspase-3 enzyme activity was measured by a commercial caspase-3 enzyme activity detection kit. Protein expression of bax, bcl-2, and caspase-3 was tested by Western blots. In vivo antitumor activity of ardisiphenol D was evaluated by determination of A549 tumor growth in nude mice.

RESULTS

Ardisiphenol D significantly inhibited the proliferation of A549 cells with an IC50 of 0.997 μM with a 48 h treatment. Hoechst 33258 fluorescence staining results indicated the apoptosis of A549 cells induced by 3.125 μM of ardisiphenol D. About 0.39 and 0.78 μM of ardisiphenol D also potently increased the caspase-3 enzyme activity in 24 h. Furthermore, 0.39-3.125 μM of ardisiphenol D induced the activation of caspase-3 protein and the up-regulation of the ratio of bax/bcl-2 protein expression in A549 cells. After i.p. injection, ardisiphenol D (5 mg/kg) also strongly suppressed the A549 tumor growth in nude mice.

DISCUSSION AND CONCLUSION

Ardisiphenol D induced apoptosis of A549 cells via activation of caspase-3 and up-regulation of the ratio of bax/bcl-2 protein expression. Ardisiphenol D also strongly suppressed the A549 tumor growth in nude mice and exerted antitumor activity in vivo.

Antiproliferative and antimicrobial activities of alkylbenzoquinone derivatives from Ardisia kivuensis

CONTEXT

Medicinal plants are continuously screened for their pharmacological properties. Despite the diversity and the numerous phytochemicals found in Ardisia (Myrsinaceae) species, its full biological potential has not been fully explored.

OBJECTIVE

Four naturally occurring alkylbenzoquinone derivatives, namely ardisiaquinone N (1), ardisiaquinone J (2), ardisiaquinone K (3) and a mixture of ardisiaquinone P (4) and K (3) from Ardisia kivuensis Taton (Myrsinaceae) were investigated in vitro for their cytotoxicity and antimicrobial activity.

MATERIALS AND METHODS

Minimal inhibitory concentration (MIC) was determined using the broth micro-dilution assay. Tumor cells growth inhibition was performed by sulphorhodamine B (SRB) assay while sub-diploid DNA fraction was measured by flow cytometry.

RESULTS

Compounds 1, 2 and 3 showed significant antimicrobial activity against two Gram-positive bacteria and one fungus (with MICs varying between 3.12 and 6.25 µg/ml). The four compounds exhibited remarkable antiproliferative activity against the leukemia cell line TPH-1 with IC₅₀ inhibition values between 2 and 2.1 µg/ml. Cytotoxic activity was found to be related to apoptosis induction.

DISCUSSION AND CONCLUSION

These findings suggest that natural compounds herein studied are interesting potential candidates for the development of new therapeutic agents, especially against leukemia and Gram-positive bacterial infections.

Ardisia: health-promoting properties and toxicity of phytochemicals and extracts

Ardisia species (Myrsinaceae) are found throughout tropical and subtropical regions of the world. Traditional medicinal uses attributed to Ardisia include alleviation of liver cancer, swelling, rheumatism, earache, cough, fever, diarrhea, broken bones, dysmenorrhea, respiratory tract infections, traumatic injuries, inflammation, pain, snake and insect bites, birth complications and to improve general blood circulation, among others. Ardisia species are rich in polyphenols, triterpenoid saponins, isocoumarins, quinones and alkylphenols. A summary of the uses, potential health benefits, adverse reactions and important bioactive phytochemicals isolated from the Ardisia species is presented. Future research needs to include more toxicological studies, more comprehensive chemical characterization of extracts, bioavailability, extract standardization, investigation of possible herb-drug interactions, plant improvement with regards to bioactivity and composition, and additional human and animal studies to confirm the health-promoting properties claimed for Ardisia species. The information presented here exemplifies the potential of Ardisia species as a source of chemotherapeutic, chemo-modulating and/or chemopreventive agents.

Antitumor effect of resorcinol derivatives from the roots of Ardisia brevicaulis by inducing apoptosis

Two new resorcinol derivatives 2-methoxy-4-hydroxy-6-(8Z-pentadecenyl)-benzene-1-O-acetate (1) and 2-methoxy-4-hydroxy-6-pentadecyl-benzene-1-O-acetate (2), together with four known compounds 2-methoxy-4-hydroxy-6-tridecyl-benzene-1-O-acetate (ardisiphenol D, 3), 5-(8Z-pentadecenyl)resorcinol (4), 5-pentadecylresorcinol (5), 5-tridecylresorcinol (6), have been isolated from the roots of Ardisia brevicaulis in our previous work. In the present study, the inhibitory effect of 1-6 on the proliferation of human pancreatic PANC-1, human lung A549, human gastrointestinal carcinoma SGC 7901, human breast MCF-7, and human prostate PC-3 cancer cells was evaluated by the methyl thiazolyl tetrazolium method. Compounds 1-6 all showed inhibitory activities against the proliferation of PANC-1, A549, SGC7901, MCF-7, and PC-3 cancer cells. Compound 3, the most active agent and the main constituent with the highest yield, induced apoptosis of PANC-1 cells (the most sensitive cell line among the cell lines screened) via the activation of caspase-3 and caspase-9, up-regulation of the ratio of bax/bcl-2 protein expression.

A nitrogen-containing 3-alkyl-1,4-benzoquinone and a gomphilactone derivative from Embelia ribes

An unusual nitrogen-containing 3-alkyl-1,4-benzoquinone derivative, N-(3-carboxylpropyl)-5-amino-2-hydroxy-3-tridecyl-1,4-benzoquinone (1), and a gomphilactone derivative, 5,6-dihydroxy-7-tridecyl-3-[4-tridecyl-3-hydroxy-5-oxo-2(5H)-furylidene]-2-oxo-3(2H)-benzofuran (2), together with 14 known compounds, as well as the common plant metabolites sitosterol and daucosterol, were isolated from the ethanolic extract of the roots of Embelia ribes. Their structures were elucidated by means of spectroscopic methods. Cytotoxicities of the purified compounds were tested.

The genus Ardisia: a novel source of health-promoting compounds and phytopharmaceuticals

Approximately 500 species of Ardisia (Myrsinaceae) are found throughout tropical and subtropical regions of the world. Several of those Ardisia species have been used as ornamental plants, food and medicines. Due to taxonomic confusions, correct identification and acquisition of plant materials remain difficult for some species. Although species of Ardisia are a rich source of novel and biologically potent phytochemical compounds, such as bergenin and ardisin, the utilization of Ardisia species or their phytochemical constituents have not been fully explored, resulting in underexploitation of their uses. The present article reviews the usage and biological activities of Ardisia compounds, as well as recent progress regarding the use of this genus in clinical research. The information presented here also illustrates the potential of the genus as a source of therapeutic agents.

Ardisiphenols and other antioxidant principles from the fruits of Ardisia colorata

Novel alkylphenols, ardisiphenols A-C (1-3) and a novel bergenin derivative, demethoxybergenin (10) were isolated from the fruits of Ardisia colorata (Myrsinaceae), together with known alkylresorcinols (4-6), embelin (7), myricetin (8), quercetin (9), bergenin (11), norbergenin (12), kaempferol (13), quercetin-3-O-beta-D-glucopyranoside (14) and gallic acid (15). Their structures were determined by NMR, MS(/MS) analyses and other spectroscopic methods. Ardisiphenols showed moderate scavenging activities toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and showed cytotoxicity against the murine breast cancer cell line, FM3A.