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

Comparative chloroplast genomes study of five officinal Ardisia Species: Unraveling interspecific diversity and evolutionary insights in Ardisia

Ardisia S.W. (Primulaceae), naturally distributed in tropical and subtropical regions, has edible and medicinal values and is prevalent in clinical and daily use in China. More genetic information for distinct species delineation is needed to support the development and utilization of the genus Ardisia. We sequenced, annotated, and compared the chloroplast genomes of five Ardisia species: A. brunnescens, A. pusilla, A. squamulosa, A. crenata, and A. brevicaulis in this study. We found a typical quadripartite structure in all five chloroplast genomes, with lengths ranging from 155,045 to 156,943 bp. Except for A. pusilla, which lacked the ycf15 gene, the other four Ardisia species contained 114 unique genes, including 79 protein-coding genes, 30 tRNAs, and four rRNAs. In addition, the rps19 pseudogene gene was present only in A. brunnescens. Five highly variable DNA barcodes were identified for five Ardisia species, including trnT-GGU-psbD, trnT-UGU-trnL-UAA, rps4-trnT-UGU, rpl32-trnL-UAG, and rpoB-trnC-GAA. The RNA editiing sites of protein-coding genes in the five Ardisia plastome were characterized and compared, and 274 (A. crenata)-288 (A. brevicaulis) were found. The results of the phylogenetic analysis were consistent with the morphological classification. Sequence alignment and phylogenetic analysis showed that ycf15 genes were highly divergent in Primulaceae. Reconstructions of ancestral character states indicated that leaf margin morphology is critical for classifying the genus Ardisia, with a rodent-like character being the most primitive. These results provide valuable information on the taxonomy and evolution of Ardisia plants.

Phytochemicals for the prevention and treatment of pancreatic cancer: Current progress and future prospects

Pancreatic cancer is the third leading cause of cancer-related deaths in the United States, owing to its aggressive nature and suboptimal treatment options, emphasizing the need for novel therapeutic approaches. Emerging studies have exhibited promising results regarding the therapeutic utility of plant-derived compounds (phytochemicals) in pancreatic cancer. The purpose of this review is to evaluate the potential of phytochemicals in the treatment and prevention of pancreatic cancer. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was applied to collect articles for this review. Scholarly databases, including PubMed, Scopus and ScienceDirect, were queried for relevant studies using the following keywords: phytochemicals, phenolics, terpenoids, alkaloids, sulfur-containing compounds, in vitro, in vivo, clinical studies, pancreatic cancer, tumour, treatment and prevention. Aggregate results pooled from qualified studies indicate phytochemicals can inhibit pancreatic cancer cell growth or decrease tumour size and volume in animal models. These effects have been attributed to various mechanisms, such as increasing proapoptotic factors, decreasing antiapoptotic factors, or inducing cell death and cell cycle arrest. Notable signalling pathways modulated by phytochemicals include the rat sarcoma/mitogen activated protein kinase, wingless-related integration site/β-catenin and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signal transduction pathways. Clinically, phytochemicals have been found to increase survival while being well-tolerated and safe, though research is scarce. While these promising results have produced great interest in this field, further in-depth studies are required to characterize the anticancer activities of phytochemicals before they can be utilized to prevent or treat pancreatic cancer in clinical practice.

The complete chloroplast genome of Ardisia brevicaulis Diels 1900, one traditional medicinal plant in southern China

The complete chloroplast (cp) genome of Ardisia brevicaulis Diels 1900, one traditionally medicinal plant usually used in southern China, was first assembled and reported in this study. The genome size is 156,742 bp (37.1% GC content), containing a large single-copy (LSC) region of 86,329 bp, a small single-copy (SSC) region of 18,417 bp, and a pair of inverted repeat regions (IRs) of 25,998 bp. 134 genes (89 protein-coding, 37 tRNA, and 8 rRNA genes) are annotated in the whole cp genome, including 115 unique genes (81 protein-coding, 30 tRNA, and 4 rRNA genes). Phylogenetic analysis showed that A. brevicaulis is closely related to A. primulifolia and A. villosa, indicating their close phylogenetic relationship. The cp genome of A. brevicaulis could provide valuable genomic information for the phylogeny, molecular identification and discovery of new medicinal plant resources in Ardisia Swartz 1788.

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.

Comprehensive utilization of sucrose resources via chemical and biotechnological processes: A review

Sucrose, one of the most widespread disaccharides in nature, has been available in daily human life for many centuries. As an abundant and cheap sweetener, sucrose plays an essential role in our diet and the food industry. However, it has been determined that many diseases, such as obesity, diabetes, hyperlipidemia, etc., directly relate to the overconsumption of sucrose. It arouses many explorations for the conversion of sucrose to high-value chemicals. Production of valuable substances from sucrose by chemical methods has been studied since a half-century ago. Compared to chemical processes, biotechnological conversion approaches of sucrose are more environmentally friendly. Many enzymes can use sucrose as the substrate to generate functional sugars, especially those from GH68, GH70, GH13, and GH32 families. In this review, enzymatic catalysis and whole-cell fermentation of sucrose for the production of valuable chemicals were reviewed. The multienzyme cascade catalysis and metabolic engineering strategies were addressed.

Enzymatic glucosylation of polyphenols using glucansucrases and branching sucrases of glycoside hydrolase family 70

Polyphenols exhibit various beneficial biological activities and represent very promising candidates as active compounds for food industry. However, the low solubility, poor stability and low bioavailability of polyphenols have severely limited their industrial applications. Enzymatic glycosylation is an effective way to improve the physicochemical properties of polyphenols. As efficient transglucosidases, glycoside hydrolase family 70 (GH70) glucansucrases naturally catalyze the synthesis of polysaccharides and oligosaccharides from sucrose. Notably, GH70 glucansucrases show broad acceptor substrate promiscuity and catalyze the glucosylation of a wide range of non-carbohydrate hydroxyl group-containing molecules, including benzenediol, phenolic acids, flavonoids and steviol glycosides. Branching sucrase enzymes, a newly established subfamily of GH70, are shown to possess a broader acceptor substrate binding pocket that acts efficiently for glucosylation of larger size polyphenols such as flavonoids. Here we present a comprehensive review of glucosylation of polyphenols using GH70 glucansucrase and branching sucrases. Their catalytic efficiency, the regioselectivity of glucosylation and the structure of generated products are described for these reactions. Moreover, enzyme engineering is effective for improving their catalytic efficiency and product specificity. The combined information provides novel insights on the glucosylation of polyphenols by GH70 glucansucrases and branching sucrases, and may promote their applications.

Uremic Toxins and Their Relation with Oxidative Stress Induced in Patients with CKD

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.

Cytotoxic and anti-inflammatory resorcinol and alkylbenzoquinone derivatives from the leaves of Ardisia sieboldii

Medicinal plants belonging to the genus Ardisia are traditionally used to cure various human diseases including inflammation and cancer. This study aimed to purify and characterize cytotoxic and anti-inflammatory compounds from Ardisia sieboldii leaves. Bioassay-guided chromatographic analyses yielded three compounds, 2-methyl-5-(8Z-heptadecenyl) resorcinol (1), 5-(8Z-heptadecenyl) resorcinol (2), and ardisiaquinone A (3), whereas liquid chromatography-electrospray ionisation-mass spectrometry chemical profiling revealed the presence of diverse resorcinol and alkylbenzoquinone derivatives in cytotoxic 70% methanol extracts. Chemical structures of 1-3 were confirmed by spectroscopic methods including 1H NMR (nuclear magnetic resonance), 13C NMR, and electrospray ionisation-mass spectrometry. Compounds 1 and 2 were purified from A. sieboldii for the first time, and all three compounds showed cytotoxicity against a panel of cancer cell lines and brine shrimps in a dose-response manner. Among them, compound 2 exhibited the highest cytotoxicity on cancer cells (IC50 values of 8.8-25.7 μM) as well as on brine shrimps (IC50 value of 5.1 μM). Compounds 1-3 exhibited anti-inflammatory effects through inhibiting protein denaturation (IC50 values of 5.8-9.6 μM), cyclooxygenase-2 activity (IC50 values of 34.5-60.1 μM), and nitrite formation in RAW 264.7 cells. Cytotoxic and anti-inflammatory activities of 1-3 demonstrated in this study deserve further investigation for considering their suitability as candidates or leads to develop anticancer and anti-inflammatory drugs.

p44/42 MAPK signaling is a prime target activated by phenylethyl resorcinol in its anti-melanogenic action

BACKGROUND

Melanin plays a crucial role in protecting human skin against exposure to ultraviolet (UV) radiation. However, its overproduction induces hyperpigmentation disorders of the skin.

PURPOSE

To investigate effects of phenylethyl resorcinol as one resorcinol derivative on melanogenesis and its mechanisms using B16F10 mouse melanoma cells and human epidermal melanocytes.

METHODS

Effects of phenylethyl resorcinol on melanogenesis and its mechanism of action were examined using several in vitro assays (i.e., cell survival, melanin content, cellular tyrosinase activity, real-time PCR analysis, luciferase-reporter assay, Western blot analysis, and ELISAs for cyclic AMP (cAMP), protein kinase A (PKA), cAMP response element binding (CREB) protein, and mitogen-activated protein kinases (MAPKs)).

RESULTS

Phenylethyl resorcinol reduced both melanin content and tyrosinase activity in these cells. Phenylethyl resorcinol also suppressed tyrosinase activity in cell-free tyrosinase enzyme assay. Although phenylethyl resorcinol decreased mRNA levels of tyrosinase and tyrosinase-related protein (TRP)-2, it did not affect mRNA levels of melanogenic gene microphthalmia-associated transcriptional factor (MITF) or TRP-1. Phenylethyl resorcinol had no effects on cAMP signaling or NF-κB signaling based on results of cyclic AMP response element (CRE)-luciferase reporter assay, cAMP production, protein kinase A (PKA) activity, Western blot assays for phosphorylated CRE-binding protein (CREB), NF-κB-luciferase reporter assay, and Western blot assays for phosphorylated NF-κB. However, phenylethyl resorcinol induced activation of activator protein-1 (AP-1) signaling. Specifically, phenylethyl resorcinol increased AP-1 reporter activity and increased phosphorylation of p44/42 MAPK, but not p38 MAPK or c-Jun N-terminal kinase (JNK). MEK1/2 and Src, upstream molecules of p44/42 MAPK were also phosphorylated by phenylethyl resorcinol. In addition, phenylethyl resorcinol-induced decreases in melanin content, tyrosinase activity, and MITF protein levels were attenuated by PD98059, a p44/42 MAPK inhibitor.

CONCLUSION

These data indicate that the anti-melanogenic activity of phenylethyl resorcinol is mediated by activation of p44/42 MAPK, indicating that phenylethyl resorcinol may be a potential therapeutic agent for treating hyperpigmentation skin disorders.

Chemical Diversity and Biological Activity of African Propolis

Natural remedies have for centuries played a significant role in traditional medicine and continue to be a unique reservoir of new chemical entities in drug discovery and development research. Propolis is a natural substance, collected by bees mainly from plant resins, which has a long history of use as a folk remedy to treat a variety of ailments. The highly variable phytochemical composition of propolis is attributed to differences in plant diversity within the geographic regions from which it is collected. Despite the fact that the last five decades has seen significant advancements in the understanding of the chemistry and biological activity of propolis, a search of the literature has revealed that studies on African propolis to date are rather limited. The aim of this contribution is to report on the current body of knowledge of African propolis, with a particular emphasis on its chemistry and biological activity. As Africa is a continent with a rich flora and a vast diversity of ecosystems, there is a wide range of propolis phytochemicals that may be exploited in the development of new drug scaffolds.

Anti-melanogenic effects of resorcinol are mediated by suppression of cAMP signaling and activation of p38 MAPK signaling

In this study, we investigated the inhibitory mechanisms of resorcinol in B16F10 mouse melanoma cells. We found that resorcinol reduced both the melanin content and tyrosinase activity in these cells. In addition, resorcinol suppressed the expression of melanogenic gene microphthalmia-associated transcriptional factor (MITF) and its downstream target genes tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2. In addition, we found that resorcinol reduced intracellular cAMP levels and protein kinase A (PKA) activity, and increased phosphorylation of the p38 mitogen-activated protein kinase (MAPK). Resorcinol was also found to directly inhibit tyrosinase activity. However, resorcinol-induced decrease in melanin content, tyrosinase activity, and tyrosinase protein levels were attenuated by SB203580, a p38 MAPK inhibitor. Taken together, these data indicate that anti-melanogenic activity of resorcinol is be mediated through the inhibition of cAMP signaling and activation of p38 MAPK, indicating that resorcinol may be a possible ameliorating agent in the treatment of hyperpigmentation skin disorders.

BAX/BCL-2 mRNA and protein expression in human breast MCF-7 cells exposed to drug vehicles-methanol and dimethyl sulfoxide (DMSO) for 24 hrs

Background:

Methanol and DMSO are commonly used as carrier solvents for lipophilic chemicals in in-vitro experiments. However, very little information is available regarding the effects of these solvents on the expression of pro and anti-apoptotic genes and proteins.

Materials and Methods:

In this study, we examined the cytotoxic effects of methanol and dimethylsulfoxide at 0.5% (final concentrations recommended for in-vitro toxicity assays) on human breast cancer MCF-7 cells. We also investigated the effects of these solvents on the mRNA and immunocytochemical expression of apoptotic proteins BAX and BCL-2.

Results:

The results of neutral red cell viability assay showed that methanol and DMSO concentrations of 0.5% exhibited no cytotoxic effects on MCF-7 cells following a 24 hour exposure. Gene expression and Immunofluorescence results showed that methanol but not DMSO reduced the expression of the BAX pro-apoptotic protein, while both solvents did not alter the expression of the BCL-2 oncoprotein.

Conclusion:

Our results suggest that while methanol concentrations at 0.5% may be appropriate for in vitro toxicity studies in human breast cancer MCF-7 cells, it could alter the results of gene and protein expression experiments.

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.

Alkylphenols from the roots of Ardisia brevicaulis induce G1 arrest and apoptosis through endoplasmic reticulum stress pathway in human non-small-cell lung cancer cells

From the roots of Ardisia brevicaulis DIELS, two new alkylphenol derivatives, named ardisiphenol E (2) and F (3), have been isolated together with a known alkylphenol, ardisiphenol D (1). The structures of 1-3 were elucidated by chemical and spectroscopic techniques. Compounds 1 and 2 exhibited strong cytotoxicities on two human non-small-cell lung cancer cell lines (H1299 and A549). We found that compounds 1 and 2 upregulated mRNA and protein expressions of endoplasmic reticulum (ER) stress markers including C/EBP homologous protein (CHOP), binding immunoglobulin protein (Bip) and inositol-requiring enzyme 1 (IRE1) indicating 1 and 2 are novel natural ER stress inducers. Treatments with 1 and 5 µM of 1 or 2 triggered G1 arrest in H1299 and A549 cells with concomitant downregulation of ubiquitin fusion degradation protein 1 (Ufd1) and S-phase kinase-associated protein 2 (Skp2) proteins and the accumulation of p27, the key axes of ER stress-mediated G1 arrest. Compounds 1 and 2 also induced apoptosis at high concentrations (10, 20 µM) which was shown to be coupled with the upregulation of CHOP and Bim, the activation of caspase-9, caspase-3 and poly(ADP-ribose) polymerase (PARP) cleavage. These results indicate that compounds 1 and 2 induce ER stress that subsequently causes G1 arrest and apoptosis in human non-small-cell lung cancer cells and they may have potential anticancer effects.

Resorcinol ninhydrin complex: 1,5,9-trihy-droxy-8-oxatetra-cyclo-[7.7.0.0(2,7).0(10,15)]hexa-deca-2,4,6,10(15),11,13-hexaen-16-one

In the title compound, C₁₅H₁₀O₅, the cyclo­penta­none (r.m.s. deviation = 0.049 Å) and oxolane (r.m.s. deviation = 0.048 Å) rings make a dihedral angle of 67.91 (4)°. An intra­molecular O—H⋯O hydrogen bond is observed. In the crystal, mol­ecules associate via O—H⋯O hydrogen bonds, forming a three-dimensional network.