Establishment and Phytochemical Analysis of a Callus Culture from Ageratina pichinchensis (Asteraceae) and Its Anti-Inflammatory Activity

Golden thistle (Scolymus hispanicus L.) hydromethanolic extracts ameliorated glucose absorption and inflammatory markers in vitro

Golden thistle (GT, Scolymus hispanicus L.) is an edible plant native to the Mediterranean. Several activities have been reported for the GT, as it is used for traditional medicinal purposes in some cultures. In this study, we aimed to investigate the effects of GT crude extract on phenolic bioavailability, antidiabetic, and anti-inflammatory activities by using colonic epithelium (CaCo-2) and murine macrophage (RAW 264.7) cell lines. The CaCo-2 cells were grown on the bicameral membrane system for intestinal bioavailability and glucose efflux. Lipopolysaccharide (LPS, 0.5 μg/mL) was used to induce systemic inflammation on RAW 264.7. The inflammatory medium of RAW 264.7 cells was given to Caco-2 cells to mimic colonic inflammation. Our results showed that 5-o-caffeoylquinic acid had an apparent permeability of (1.82 ± 0.07) × 10-6 cm/s after 6 h. The extract lowered the glucose efflux by 39.4%-42.6%, in addition to the reductions in relative GLUT2 mRNA expressions by 49%-66% in pre- and co-treatments (p < .05). Decreases in systemic inflammation markers of nitric oxide, tumor necrosis factor-alpha, and interleukin-6 (IL-6) were also detected in 30%-45% range after pre-treatments with the GT extract (p < .05). Lastly, colonic inflammation markers of IL-6 and IL-8 were reduced by 8.7%-19.5% as a result of GT pre-treatments (p < .05). Thus, an in vitro investigation of GT extract revealed promising results on antidiabetic and anti-inflammatory activities.

Calmodulin-Targeting Molecules from Ageratina grandifolia

Four new natural chemical entities, including 2-hydroxy-α-truxillic acid (2), (3R,4S)-2,2-dimethyl-3-hydroxy-4-(1-angeloyloxy)-6-acetyl-7-methoxychromane (3), N-tricosanoyltyramine (4), and grandifolamide (5), were isolated along with 11 known compounds (1, 6-15) from the aerial parts of Ageratina grandifolia. The chemical structures were elucidated using chemical derivatization and HR-MS, NMR, and DFT-calculated chemical shifts, combined with DP4+ statistical analysis. It was found that 2 decomposed into its biogenetic precursor, o-coumaric acid, upon standing at room temperature for a few weeks. 3,5-Diprenyl-4-hydroxyacetophenone (8), O-methylencecalinol (10), encecalin (11), and encecalinol (12) bound to calmodulin (CaM) with higher affinity than chlorpromazine, a well-known CaM inhibitor. Molecular dynamics studies revealed that the complexes of these compounds with CaM remained stable during the simulation. Altogether these results revealed the therapeutic and research tool potential of compounds 8, 10, 11, and 12.

High variability of perezone content in rhizomes of Acourtia cordata wild plants, environmental factors related, and proteomic analysis

With the aim of exploring the source of the high variability observed in the production of perezone, in Acourtia cordata wild plants, we analyze the influence of soil parameters and phenotypic characteristics on its perezone content. Perezone is a sesquiterpene quinone responsible for several pharmacological effects and the A. cordata plants are the natural source of this metabolite. The chemistry of perezone has been widely studied, however, no studies exist related to its production under natural conditions, nor to its biosynthesis and the environmental factors that affect the yield of this compound in wild plants. We also used a proteomic approach to detect differentially expressed proteins in wild plant rhizomes and compare the profiles of high vs. low perezone-producing plants. Our results show that in perezone-producing rhizomes, the presence of high concentrations of this compound could result from a positive response to the effects of some edaphic factors, such as total phosphorus (Pt), total nitrogen (Nt), ammonium (NH4), and organic matter (O. M.), but could also be due to a negative response to the soil pH value. Additionally, we identified 616 differentially expressed proteins between high and low perezone producers. According to the functional annotation of this comparison, the upregulated proteins were grouped in valine biosynthesis, breakdown of leucine and isoleucine, and secondary metabolism such as terpenoid biosynthesis. Downregulated proteins were grouped in basal metabolism processes, such as pyruvate and purine metabolism and glycolysis/gluconeogenesis. Our results suggest that soil parameters can impact the content of perezone in wild plants. Furthermore, we used proteomic resources to obtain data on the pathways expressed when A. cordata plants produce high and low concentrations of perezone. These data may be useful to further explore the possible relationship between perezone production and abiotic or biotic factors and the molecular mechanisms related to high and low perezone production.

Cytotoxic Activity of Wild Plant and Callus Extracts of Ageratina pichinchensis and 2,3-Dihydrobenzofuran Isolated from a Callus Culture

Ageratina pichinchensis (Kunth) R.M. King & H. Rob. belongs to the Asteraceae family and is a plant native to Mexico to which several biological properties are attributed. In this study, the cytotoxic effect of four extracts from the wild plants and two extracts from A. pichinchensis callus culture were evaluated against carcinogenic cell lines including prostate carcinoma, cervical cancer, hepatocellular carcinoma, hepatoma human, lung cancer, and cellular keratinocytes. The extracts were obtained with ethyl acetate and methanol using both leaves and stems or the callus. Only the ethyl acetate extract of the callus culture influenced the cervical cancer cell line (HeLa) with an IC50 of 94.79 ± 2.0 µg/mL. From the ethyl acetate callus extract, 2,3-dihydrobenzofuran was isolated and purified and also evaluated against cancer cells. The cytotoxic evaluation of this compound showed a significant effect against the HeLa cell line with an IC50 of 23.86 ± 2.5 µg/mL. Our results contribute to the development of biotechnological alternatives and extraction processes to produce compounds with possible potential against certain types of human cancer.

Phenolic Compounds from Wild Plant and In Vitro Cultures of Ageratina pichichensis and Evaluation of Their Antioxidant Activity

Ageratina pichichensis, is commonly used in traditional Mexican medicine. In vitro cultures were established from wild plant (WP) seeds, obtaining in vitro plant (IP), callus culture (CC), and cell suspension culture (CSC) with the objective to determine total phenol content (TPC) and flavonoids (TFC), as well as their antioxidant activity by DPPH, ABTS and TBARS assays, added to the compound's identification and quantification by HPLC, from methanol extracts obtained by sonication. CC showed significantly higher TPC and TFC than WP and IP, while CSC produced 2.0-2.7 times more TFC than WP, and IP produced only 14.16% TPC and 38.8% TFC compared with WP. There were identified compounds such as epicatechin (EPI), caffeic acid (CfA), and p-coumaric acid (pCA) in in vitro cultures that were not found in WP. The quantitative analysis shows gallic acid (GA) as the least abundant compound in samples, whereas CSC produced significantly more EPI and CfA than CC. Despite these results, in vitro cultures show lower antioxidant activity than WP, for DPPH and TBARS WP > CSC > CC > IP and ABTS WP > CSC = CC > IP. Overall, A. pichichensis WP and in vitro cultures produce phenolic compounds with antioxidant activity, especially CC and CSC, which are shown to be a biotechnological alternative for obtaining bioactive compounds.

Obtaining 2,3-Dihydrobenzofuran and 3-Epilupeol from Ageratina pichinchensis (Kunth) R.King & Ho.Rob. Cell Cultures Grown in Shake Flasks under Photoperiod and Darkness, and Its Scale-Up to an Airlift Bioreactor for Enhanced Production

Ageratina pichinchensis (Kunth) R.King & Ho.Rob. is a plant used in traditional Mexican medicine, and some biotechnological studies have shown that its calluses and cell suspension cultures can produce important anti-inflammatory compounds. In this study, we established a cell culture of A. pichinchensis in a 2 L airlift bioreactor and evaluated the production of the anti-inflammatory compounds 2,3-dihydrobenzofuran (1) and 3-epilupeol (2). The maximum biomass production (11.90 ± 2.48 g/L) was reached at 11 days of culture and cell viability was between 80% and 90%. Among kinetic parameters, the specific growth rate (µ) was 0.2216 days^-1 and doubling time (td) was 3.13 days. Gas chromatography coupled with mass spectrometry (GC-MS) analysis of extracts showed the maximum production of compound 1 (903.02 ± 41.06 µg/g extract) and compound 2 (561.63 ± 10.63 µg/g extract) at 7 and 14 days, respectively. This study stands out for the significant production of 2,3-dihydrobenzofuran and 3-epilupeol and by the significant reduction in production time compared to callus and cell suspension cultures, previously reported. To date, these compounds have not been found in the wild plant, i.e., its production has only been reported in cell cultures of A. pichinchensis. Therefore, plant cell cultured in an airlift reactor can be an alternative for the improved production of these anti-inflammatory compounds.

In Vitro and In Vivo Anti-Inflammatory Effects of Cannabis sativa Stem Extract

With growing scientific interest in cannabinoids, a number of studies have focused on biological activities of cannabidiol and its major source, inflorescence and leaf of Cannabis sativa plant. However, recent analytical chemistry studies have reported the pharmacological significance of non-cannabinoid phytochemicals that are rich in other parts of the plant. Thus, the objective of this study was to investigate the anti-inflammatory effects of Cannabis extracts from plant parts of shelled seeds, roots, and stems containing no or trace amounts of cannabinoids. Among water and ethanol extracts from three plant parts, Cannabis stem ethanol extract (CSE) had the most potent free radical scavenging activities and suppressive effects on the production of nitric oxide from macrophages. In further studies using macrophages, CSE effectively inhibited lipopolysaccharide (LPS)-induced inflammatory responses by suppressing proinflammatory cytokines, nuclear factor-κB and mitogen-activated protein kinase phosphorylations, and cellular accumulation of reactive oxygen species. Moreover, in mice exposed to LPS, CSE reduced tumor necrosis factor-α production and normalized activations of proapoptotic proteins in the liver, kidney, and spleen. Gas chromatography/mass spectrometry analyses of CSE showed several active compounds that might be associated with its antioxidant and anti-inflammatory effects. Collectively, these findings indicate that CSE counteracts LPS-induced acute inflammation and apoptosis, suggesting pharmaceutical applications for the stem part of C. sativa.

Phytochemical, Pharmacological, and Biotechnological Study of Ageratina pichinchensis: A Native Species of Mexico

Ageratina pichinchensis (Asteraceae) has been used for a long time in traditional Mexican medicine for treating different skin conditions and injuries. This review aimed to provide an up-to-date view regarding the traditional uses, chemical composition, and pharmacological properties (in vitro, in vivo, and clinical trials) that have been achieved using crude extracts, fractions, or pure compounds. Moreover, for a critical evaluation of the published literature, key databases (Pubmed, Science Direct, and SciFinder, among others) were systematically searched using keywords to retrieve relevant publications on this plant. Studies that reported on crude extracts, fractions, or isolated pure compounds of A. pichinchensis have found a varied range of biological effects, including antibacterial, curative, antiulcer, antifungal, and anti-inflammatory activities. Phytochemical analyses of different parts of A. pichinchensis revealed 47 compounds belonging to chromenes, furans, glycosylated flavonoids, terpenoids, and essential oils. Furthermore, biotechnological studies of A. pichinchensis such as callus and cell suspension cultures have provided information for future research perspectives to improve the production of valuable bioactive compounds.

Synthesis of new methoxy derivatives of trans 2,3-diaryl-2,3-dihydrobenzofurans and evaluation of their anti-inflammatory activity

In the present study we synthesized new methoxy derivatives of trans 2,3-diaryl-2,3-dihydrobenzofurans, starting from suitable trans 2,3-diaryloxiranes, using regio- and stereoselective nucleophilic oxiranyl ring-opening reactions. The compounds were tested as anti-inflammatories in U937 cells. All compounds showed a significant role in inhibiting the NF-κB pathway and were able to restore normal ROS and NO level upon LPS activation. Moreover, regarding inhibition of ACLY, enantioenriched (50% ee) 7a₅₀ showed more potency than the racemic counterpart 7arac, together with a higher reduction of prostaglandin E₂ production, thus suggesting a stereoselective interaction in this pathway.

Acankoreagenin and acankoreosides, a family of lupane triterpenoids with anti-inflammatory properties: an overview

Acankoreagenin (ACK, also known as acankoreanogenin and HLEDA) and impressic acid are two lupane-type triterpenes that can be isolated from various Acanthopanax and Schefflera species. They efficiently block activation of the NF-κB signaling pathway and the release of proinflammatory cytokines and/or the action of inflammation mediators (HMGB1, iNOS, and NO). These effects are the basis for the antiviral and anticancer activities reported with these pentacyclic compounds or their various glycoside derivatives. More than 15 acankoreosides (Ack-A to -O, and -R) and a few other mono- and bidesmosidic saponins (acantrifoside A and acangraciliside S) derive from the ACK aglycone. Compounds like Ack-A and -B are remarkable anti-inflammatory agents, inhibiting cytokine release from activated macrophages. Despite their effectiveness, ACK and impressic acid are far much less known and studied than the structurally related compounds betulinic acid and 23-hydroxybetulinic acid (anemosapogenin). The structural differences (notably the R/S stereoisomerism of the 3-hydroxyl group) and functional similarities of these compounds are discussed. The complete series of acankoreosides is presented for the first time. These natural products deserve further attention as anti-inflammatory agents, and ACK is recommended as a template for the design of new anticancer and antiviral drugs.

α-Glucosidase Inhibitors from Ageratina grandifolia

Fractionation of an aqueous extract from the aerial parts of Ageratina grandifolia yielded a new natural product, namely, 4-hydroxy-3-((S)-1'-angeloyloxy-(R)-2',3'-epoxy-3'-methyl)butylacetophenone (1), along with eight known compounds, including three flavonoids (2-4) and five chromenes (5-9). NMR data interpretation and DFT-calculated chemical shifts combined with DP4+ statistical and J-DP4 probability analyses allowed for the complete characterization of compound 1. The presence of compound 1 in a plant that biosynthesizes 2,2-dimethylchromenes is noteworthy, because an epoxy derivative has long been postulated as the reaction intermediate from the prenylated p-hydroxyacetophenones to cyclic dimethylchromenes. So far, this key intermediate has not been isolated, due to its purported chemical instability. Thus, this is the first report of a potential epoxide intermediate, leading to any of the chromene constituents of this plant. Compounds 1-9 inhibited yeast α-glucosidase with IC₅₀ values ranging from 0.79 to 460 μM (acarbose, IC₅₀ = 278.7 μM). The most active compounds were quercetagetin-7-O-(6-O-caffeoyl-β-d-glucopyranoside (3) and 6-hydroxykaempferol-7-O-(6-O-caffeoyl-β-d-glucopyranoside (4). Kinetic analysis of 3 revealed its mixed-type inhibitor nature. Docking studies into the crystallographic structure of yeast α-glucosidase (pdb 3A4A) predicted that 3 and 4 bind at the catalytic site of the enzyme.

Establishment of a Cell Suspension Culture of Ageratina pichinchensis (Kunth) for the Improved Production of Anti-Inflammatory Compounds

Ageratina pichinchensis (Kunth) is a plant used in traditional Mexican medicine to treat multiple ailments. However, there have not been biotechnological studies on producing compounds in in vitro cultures. The aim of this study was to establish a cell suspension culture of A. pichinchensis, quantify the anti-inflammatory constituents 2,3-dihydrobenzofuran (2) and 3-epilupeol (3), evaluate the anti-inflammatory potential of its extracts, and perform a phytochemical analysis. Cell suspension cultures were established in a MS culture medium of 30-g L⁻¹ sucrose, 1.0-mg L⁻¹ α-naphthaleneacetic acid, and 0.1-mg L⁻¹ 6-furfurylaminopurine. The ethyl acetate extract of the cell culture analyzed by gas chromatography (GC) revealed that the maximum production of anti-inflammatory compounds 2 and 3 occurs on days eight and 16, respectively, improving the time and previously reported yields in callus cultures. The anti-inflammatory activity of these extracts exhibited a significant inhibition of nitric oxide (NO) production. Furthermore, a phytochemical study of the ethyl acetate (EtOAc) and methanol (MeOH) extracts from day 20 led to the identification of 17 known compounds. The structures of the compounds were assigned by an analysis of 1D and 2D NMR data and the remainder by GC–MS. This is the first report of the production of (-)-Artemesinol, (-)-Artemesinol glucoside, encecalin, and 3,5-diprenyl-acetophenone by a cell suspension culture of A. pichinchensis.