Judith González-Christen

Bursera bipinnata (DC.) Engl. (B. bipinnata), commonly known as “copal chino,” is a widely distributed Mexican tree found in transitional zones between pine-oak and deciduous forests. It is valued for its high-quality copal resin, traditionally used in ceremonies and offerings. Additionally, B. bipinnata is recognized for its significant value in traditional medicine, particularly in treating ailments associated with inflammation. In this work, the inhibition of nitric oxide (NO) production of the volatile fraction and resin of B. bipinnata in LPS-stimulated RAW 264.7 macrophage cells were demonstrated. In contrast, the volatile fraction exhibited 37.43 ± 7.13% inhibition at a concentration of 40 µg/mL. Chromatographic analyses of the total resin enabled the chemical characterization of eleven pentacyclic triterpenes belonging to the ursane, oleanane, and lupane series, as well as eight monoterpenes. Notably, the structures of compounds 15, 17, and 29–35 are reported for the first time from the resin of Bursera bipinnata. The anti-inflammatory activity observed for B. bipinnata resin in this study may be attributed to its high content of the triterpenes α-amyrin (15, 29.7%) and 3-epilupeol (17, 38.1%), both known for their anti-inflammatory properties. These findings support the traditional use of this copal resin.

Bursera bipinnata is known as “copal chino, is a small tree that grows in steep areas and is part of the transitional populations of pine and oak forests and lowland deciduous forests. It is the taxon with the widest geographic distribution in México and considered a source of high-grade copal resin used in ceremonies and offerings. Also, B. bipinnata is considered to have great value in traditional medicine to treat ailments related to in-flammation. In this work, the anti-inflammatory effects of the volatile fraction and resin of B. bipinnata in LPS-stimulated RAW 264.7 macrophage cells were demonstrated. The resin extract was the best inhibitor with a 65.83 ± 8.53 % of inhibition of NO production with IC50 = 30 ± 3.3 µg/mL. In contrast, its volatile fraction showed a 37.43± 7.13 % of inhibition at 40 µg/mL. GC/MS and LC analysis of the total resin allowed the chemical characterization of eleven pentacyclic triterpenes with ursane, oleanane, and lupane skeletons, and eight monoterpenes. The structures of compounds (15, 17, 29-35) are reported for the first time from the resin of Bursera bipinnata. The anti-inflammatory activity of the most abundant constituents of the resin of B. bipinnata (α-amyrin (15), 3-epilupeol (17) and α-phellandrene (1) has been previously demonstrated which con-firms the activity showed by the resin as well as the traditional use of this important copal resin. The chemical profile of B. bippinata differs from that of other copal resins (e.g. B. copallifera) in the presence of a greater variety of triterpenes in the resin.

In this study, we report on the isolation, purification, and anti-inflammatory evaluation of compounds from the plant species Ageratina pichinchensis. Using open-column chromatography, 11 known compounds were purified, which chemical structures were elucidated by nuclear magnetic resonance techniques (1D and 2D). All compounds were evaluated in an in vitro model of RAW 264.7 mouse macrophage cells, measuring the nitric oxide inhibition to determine the anti-inflammatory effect. The compound betuletol 3-O-β-glucoside (11) inhibited nitric oxide with a half-maximal inhibitory concentration (IC₅₀) of 75.08 ± 3.07% at 75 µM; additionally, it inhibited the secretion of interleukin 6 (IL-6) and activation of the nuclear factor (NF-kβ). These results suggest that the anti-inflammatory effect attributed to A. pichinchensis species is promoted by compound 11, which could be considered a potential anti-inflammatory agent by suppressing the expression of NF-kβ target genes, such as those involved in the proinflammatory pathway and inducible nitric oxide synthase (iNOS).

This work reports the isolation, purification, and anti-inflammatory evaluation of compounds from the plant species Ageratina pichinchesis. Using open-column chromatography, 11 known compounds were purified, whose chemical structures were elucidated by nuclear magnetic resonance techniques (1D and 2D). All compounds were evaluated in the in vitro model of RAW 264.7 mouse macrophage cells measuring nitric oxide inhibition as a determination of the anti-inflammatory effect. Outstandingly, the compound betuletol 3-O-β-glucoside (11) exhibited inhibition of nitric oxide with an IC50 of 75.08 ± 3.07% at 75 µM, additionally, it inhibited the secretion of interleukin 6 (IL-6) and activation of nuclear factor (NF-kβ). These results show that compound 11 could be considered as a potential anti-inflammatory agent in suppressing the expression of NF-kβ target genes such as the proinflammatory pathway and inducible nitric oxide synthase (iNOS). Consequently, the medicinal use attributed in traditional medicine to the A. pichinchensis species is due to the diversity of compounds that the plant biosynthesizes, demonstrating that its effect relates to anti-inflammatory effects associated with compound 11.

Medicines for chronic inflammation can cause gastric ulcers and hepatic and renal issues. An alternative treatment for chronic inflammation is that of natural bioactive compounds, which present low side effects. Extracts of Jatropha cordata (Ortega) Müll. Arg. have been evaluated for their cytotoxicity and anti-inflammatory activity; however, testing pure compounds would be of greater interest. Campesteryl palmitate, n-heptyl ferulate, palmitic acid, and a mixture of sterols, i.e., brassicasterol, campesterol, β-sitosterol, and stigmasterol, were obtained from an ethyl acetate extract from J. cordata (Ortega) Müll. Arg. bark using column chromatography. The toxicity and in vitro anti-inflammatory activities were evaluated using RAW 264.7 murine macrophage cells. None of the products assessed exhibited toxicity. The sterol mixture exhibited greater anti-inflammatory activity than the positive control, and nitric oxide (NO) inhibition percentages were 37.97% and 41.68% at 22.5 μg/mL and 30 μg/mL, respectively. In addition, n-heptyl ferulate decreased NO by 30.61% at 30 μg/mL, while campesteryl palmitate did not show anti-inflammatory activity greater than the positive control. The mixture and n-heptyl ferulate showed NO inhibition; hence, we may conclude that these compounds have anti-inflammatory potential. Additionally, further research and clinical trials are needed to fully explore the therapeutic potential of these bioactive compounds and their efficacy in treating chronic inflammation.

The inflammatory process, although beneficial, can produce tissue damage and systemic damage when uncontrolled. Effective therapeutic alternatives with little or no side effects are of great therapeutic interest. This study aimed to determine the phytochemical composition of bark extracts from J. cordata, an endemic plant from México, and evaluate their in vitro anti-inflammatory activity. Hexane, ethyl acetate, and methanol extracts were characterized by qualitative phytochemical tests, and their bioactive groups were identified by ¹H NMR and gas chromatography coupled to mass spectrometry (GC–MS). The extract’s anti-inflammatory activity was evaluated as nitric oxide (NO) production and their cytotoxicity by an MTS cell proliferation assay in lipopolysaccharide (LPS)-activated RAW 264.7 cells at concentrations of 1–100 μg/mL. The hexane extract contained fatty acids, fatty esters, phytosterols, alkanes, vitamin E, and terpenoids; the ethyl acetate extract showed fatty acids, fatty esters, aromatic aldehyde, phytosterols, vitamin E, and terpenoids, while the methanolic extract showed fatty esters, fatty acid, aromatics aldehydes, and alcohol. The ethyl acetate extract showed the highest inhibition of NO production, followed by the methanolic extract and the hexane extract, without affecting the viability of RAW 264.7 macrophage cells. The results suggest that J. cordata extracts are a potential source of bioactive compounds with anti-inflammatory potential.

Podophyllotoxins are natural lignans with known cytotoxic activity on several cell lines. The structural basis for their actions is mainly by the aryltetralin-lignan skeleton. Authors have proposed a cytotoxic mechanism of podophyllotoxins through the topoisomerase-II inhibition activity; however, several studies have also suggested that podophyllotoxins can inhibit the microtubules polymerization. In this work, the two possible mechanisms of action of two previously isolated compounds from the stem bark of Bursera fagaroides var. fagaroides: acetylpodophyllotoxin (1) and 5’-desmethoxydeoxypodophyllotoxin (2), was analyzed. An in vitro anti-tubulin epifluorescence on the MCF10A cell line and enzymatic topoisomerase II assays were performed. The binding affinities of compounds 1 and 2 in the colchicine binding site of tubulin by using rigid- and semiflexible-residues were calculated and compared using in silico docking methods. The two lignans were active by the in vitro anti-tubulin assay but could not inhibit TOP2 activity. In the in silico analysis, the binding modes of compounds into both rigid- and semiflexible-residues of tubulin were predicted, and only for the semiflexible docking method, a linear correlation between the dissociation constant and IC₅₀ previously reported was found. Our results suggest that a simple semiflexible-residues modification in docking methods could provide an in vitro correlation when analyzing very structurally similar compounds.

The activation of the innate immune response requires sialic acid residues removal. Nevertheless, it is unknown the role for these changes during the Dengue virus infection. We determine if during Dengue virus infection, the sialic acid residues alter on the macrophages. The human monocytic cell line THP-1 was differentiated into macrophages and were infected with Dengue virus. The changes in sialic acid were evaluated by lectin blot in the cellular lysate. The activity of neuraminidase was defined by RT-PCR and fluorescence assays. Macrophages infection with DENV-2 reduces α-2,6 sialic acid residues at 24 h, and α-2,3 sialic acid residues lower at 48 h in some proteins. Transcriptional profile and enzymatic activities of Neu-1 showed a narrow decrease. Sialic acid residues oscillation in varied conformations and times suggest it a role of a selective mechanism to remove these residues. The lesser participation of Neu-1 in this process could be concomitant to other similar enzymes such as sialyl-transferases, or the phenomenon requires minimal activity to have a relevant biological function.

Several pathogenic mechanisms have been linked to the severity of dengue virus infection, like viral cytotoxicity, underlying host genetics and comorbidities such as diabetes and dyslipidemia. It has been observed that patients with severe manifestations develop an uncontrolled immune response, with an increase in pro-inflammatory cytokines such as TNF, IL-1β, IL-8, IL-6 and chemokines that damage the human microvascular endothelium, and also in anti-inflammatory cytokines IL-4, IL-10 and TGF-β1. The role of TGF-β1 on dengue is not clear; few studies have been published, and most of them from patient sera data, with both protective and pathological roles have described. The aim of this study was to evaluate the ability of TGF-β1 to regulate the secretion of IL-1β in macrophages infected by DENV using THP-1 cells treated with recombinant TGF-β1 before or after DENV infection. By RT-PCR we did not observe a difference in IL-1β expression between infected cells pretreated with TGF-β1 and those that were not. However, secretion of IL-1β was reduced only in cells stimulated with TGF-β1 before infection, and not in those treated 2 hours post-infection. TGF-β1 receptor blockage with SB505124 inhibitor, prior to the addition of TGF-β1 and infection, abrogated the inhibitory effect of TGF-β1. Our results suggest that DENV could regulate the function of TGF-β1 on macrophages. This negative regulation of the TGF-β1 pathway could be used by DENV to evade the immune response and could contribute to the immunopathology.

Three polyisoprenoid alcohols were isolated from the leaves of Tournefortia hirsutissima by a bioassay-guided phytochemical investigation. The compounds were identified as 16-hydroxy-lycopersene (Compound 1), (Z₈,E₃,ω)-dodecaprenol (Compound 2) and (Z₉,E₃,ω)-tridecaprenol (Compound 3). Compound 1, an unusual polyisoprenoid, was characterized by 1D and 2D NMR. We also determined the absolute configuration at C-16 by the modified Mosher’s method. The in vitro antiproliferative and anti-inflammatory activities of the isolated compounds were evaluated. Among isolates, Compound 1 moderately inhibited the nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. On the other hand, Compound 1 displayed selective antiproliferative activity against HeLa, PC3, HepG2 and Hep3B cancer cells and was less potent against IHH non-cancerous cells. Compound 1 in Hep3B cells showed significant inhibition of cell cycle progression increasing the sub-G₁ phase, suggesting cell death. Acridine orange/ethidium bromide staining and Annexin V-FITC/PI staining demonstrated that cell death induced by Compound 1 in cells Hep3B was by apoptosis. Further study showed that apoptosis induced by Compound 1 in Hep3b cells is associated with the increase of the ratio of Bax/Bcl-2, and caspase 3/7 activation. These results suggest that Compound 1 induce apoptotic cell death by the mitochondrial pathway. To our knowledge, this is the first report about the presence of polyprenol Compounds 1–3 in T. hirsutissima, and the apoptotic and anti-inflammatory action of Compound 1.