Anti-inflammatory, pro-proliferative and antimicrobial potential of the compounds isolated from Daemonorops draco (Willd.) Blume

Ethno-pharmacological relevance: Daemonorops draco (D. draco) commonly known as “Dragon's blood” is one of the most used plants by Momok, Anak Dalam and Talang Mamak tribes from Indonesia as a remedy for wound healing. Aim of the study: This study aimed to identify the extract, fractions and compounds responsible for the anti-inflammatory and pro-proliferative activities of the D. draco resin. Additionally, the antimicrobial activity against two bacteria and one yeast species was analysed. Materials and methods: Bio-guided isolation of compounds with anti-inflammatory, pro-proliferative and antimicrobial activities from the D. draco resin was carried out by measuring: the inhibition of NF-κB and activation of Nrf2 in THP-1, HaCaT, NIH-3T3 cells; cell proliferation in NIH-3T3 and HaCaT cells; and the antimicrobial effect on E. coli, S. aureus and C. albicans. Results: Guided isolation by bioassay gave rise to the isolation and characterisation by nuclear magnetic resonance and mass spectrometry of three compounds: 1 (Bexarotene), 2 (Taspine) and 3 (2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone). All compounds showed NF-κB inhibitory activity with IC50 values of 0.10–0.13, 0.22–0.24 and 3.75–4.78 μM, respectively, while the positive control, Celastrol, had an IC50 of 7.96 μM. Likewise, all compounds showed an activating effect of Nrf2 with EC50 values of 5.34–5.43, 163.20–169.20 and 300.82–315.56 nM, respectively, while the positive control, CDDO-Me, had an EC50 of 0.11 nM. In addition, concerning the pro-proliferative activity, compound 1 (IC50 = 8.62–8.71 nM) showed a capacity of 100%, compound 2 (IC50 = 166–171 nM) showed a capacity of 75%, and compound 3 (IC50 = 469–486 nM) showed a capacity of 65%, while FSB 10% (positive control) had a pro-proliferative activity of 100% in the NIH3T3 cell lines (fibroblasts) and HaCaT (keratinocytes). Finally, all the compounds showed antimicrobial activity with MIC values of 0.12–0.16, 0.31–0.39 and 3.96–3.99 μM, respectively, in S. aureus, E. coli and C. albicans strains, while the positive control, Ofloxacin, had a MIC of 27.65 μM. Conclusion: This study managed to isolate, for the first time, three compounds (Bexarotene, Taspine and 2-hydroxy-1-naphthaldehyde isonicotinoyl hydrazone) from the resin of D. draco, with anti-inflammatory, and pro-proliferative as well as antimicrobial activitie

Isolation and characterisation of antibacterial and anti-inflammatory compounds from Gnaphalium polycaulon

Ethno-pharmacological relevance: Gnaphalium polycaulon commonly known as “cudweed” has been used throughout South America as an infusion to treat colds, bronchitis, fever or pneumonia. Aim of the study: This study aimed to determine the antibacterial and anti-inflammatory activities of the aqueous extract of Gnaphalium polycaulon and identify the related compounds. Materials and methods: A bio-guided isolation of the active compounds of Gnaphalium polycaulon was carried out, selecting the fractions depending on their antibacterial, anti-inflammatory and cytotoxic activities. The antibacterial effect was studied against Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pneumoniae; and the anti-inflammatory study was performed by measuring the inhibition of NF-κB in BEAS-2B and IMR-90 cell cultures. Results: Three compounds were obtained and characterised by nuclear magnetic resonance and mass spectrometry. These compounds are 2-(4-(1-H-tetrazol-1-yl) phenyl)-2-aminopropanoic acid (1), N-phenyl-4-(3- phenyl-1,2,4-thiadiazol-5-yl) piperazine-1-carboxamide (2) and N-(4-ethoxyphenyl)-4-(2-methylimidazo-[1,2-α] pyridine-3-yl) thiazol-2-amine (3). All compounds showed antibacterial activity with MIC values of 44.80–44.85, 0.017–0.021 and 0.0077–0.0079 μM, respectively, in the Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pneumoniae strains, while the positive control, Ofloxacin, had a MIC value of 27.64–27.67 μM. This was corroborated through a zone inhibition assay, where compound 3 (11.36–11.67 mm) was much more active than the positive control (Ofloxacin, 23.41–24.12 mm), while compounds 2 (26.47–27.64 mm) and 1 (28.39–29.76 mm) displayed similar antibacterial potential to the positive control. Finally, all the compounds presented NF-κB inhibitory activity, compounds 3 (IC50 = 0.0071–0.0073 μM) and 2 (IC50 = 0.016–0.019 μM) being the most promising. Compound 1 (IC50 = 44.24–44.26 μM) had less anti-inflammatory potential, being also the closest to the values displayed by the positive control (Celastrol, IC50 = 7.41 μM). Conclusion: In the present study, three compounds were isolated for the first time from the aqueous extract of Gnaphalium polycaulon. Their antibacterial and anti-inflammatory potential was tested and showcasedThis work was supported by the National Herbarium of Bolivia, the Fundación de la Universidad Autónoma de Madrid (FUAM

Ethanolic extract of Artemisia campestris subsp. glutinosa (Besser) Batt. inhibits HIV–1 replication in vitro through the activity of terpenes and flavonoids on viral entry and NF–κB pathway

Ethno–pharmacological relevance: The genus Artemisia spp. is well known for its anti–infectious properties and its high content in anti–infectious compounds, like the well–known sweet wormwood (Artemisia annua L.). Another Artemisia species, Artemisia campestris subsp. glutinosa (Besser) Batt., field wormwood, has been traditionally used as medicinal plant in the Mediterranean region. Aim of the study: The aim of this study is to investigate the anti–HIV activity of field wormwood, to identify the compounds responsible for this activity and their structure and mechanism of action. Materials and methods: Antiviral activity of isolated compounds and extracts was evaluated in HIV–1 infections of lymphoblastoid cells. We also evaluated the mechanism of action of isolated compounds. Viral entry was studied comparing the inhibitory effect of isolated compounds on wild type HIV–1 and VSV pseudotyped HIV–1. To assess the viral transcriptional effect, plasmids encoding luciferase reporter genes under the control of the whole genome of HIV–1 or NF–κB or Sp1 transcription factors were transfected in the presence of the compounds under evaluation. Finally, antioxidant activity was assessed by quantitation of reduced and total glutathione in treated cell cultures. Results: Ethanolic and aqueous extracts of Artemisia campestris subsp. glutinosa (Besser) Batt. subsp. glutinosa displayed anti–HIV activity in vitro, although ethanolic extract was more powerful (IC50 14.62 μg/mL). Bio–guided ethanolic extract fractionation leads to the isolation and characterization of two terpenes, damsin and canrenone, and four flavonoids, 6, 2′, 4′–trimethoxyflavone, acerosin, cardamonin and xanthomicrol. All the isolated compounds inhibited HIV–1 replication in vitro with IC50 values between the middle nanomolar and the low micromolar range. Their anti–HIV mechanism of action is due to the bloking of viral entry and/or transcription inhibition, without correlation with the antioxidant activity, through interference with the cellular transcription factors NF–κB and Sp1, which are targets that are not currently reached by antiretroviral therapy. Conclusion: We describe here the anti–HIV activity of field wormwood, Artemisia campestris subsp. glutinosa (Besser) Batt., and the isolation and study of the mechanism of action of two terpenes and four flavonoids, responsible, at least in part, for its activity, through the inhibition of two different cellular targets affecting the HIV replication cycle. The activity of these compounds in cellular targets could explain why plant extracts can be used in the treatment of different diseases. Besides, the presence of several compounds with dual and different mechanisms of action could prove useful in the treatment of HIV–1 infection, since it could aid to overcome drug resistances and simplify drug therapy. This work is a further step in understanding the anti–infectious activity of wormwood species and their use in treating infectious diseasesThis project was supported by the Spanish Agency for International Cooperation and Development (AECID) (D/020523/08) and the Universidad Complutense de Madrid UCM–Santander (PR87/19–22685). This work was partially supported by Instituto de Salud Carlos III and co–funded by European Regional Development Fund (ERDF) “A way to build Europe” (projects AIDS Research Network RD16CIII/0002/0001 and RD16CIII/0002/0001 to JA