Antifungal potential of Avicennia schaueriana Stapf & Leech. (Acanthaceae) against Cladosporium and Colletotrichum species

Folk medicine, biological activity, and chemical profiles of Brazilian Acanthaceae (Lamiales) - A review

INTRODUCTION

The botanical family Acanthaceae (order Lamiales) potentially comprises 4900 species in 191 genera with extensive morphological, habit and habitat diversity. The family is widely distributed throughout the world but is especially rich in tropical and subtropical regions. Many of its species have great ornamental importance and are broadly used for medicinal purposes in several countries of Asia and Africa. Brazil is a main center of diversity of the family, where they are distributed across all its biomes, mainly in the herbaceous-shrub stratum. Medicinal investigations about Brazilian species are scarce, the exception being a single native species, Justicia pectoralis Jacq., that is widely used and studied chemically.

AIM OF THE REVIEW

This work compiled studies that indicated folk medicinal use, investigated biological activity, or evaluated the chemical composition of Brazilian species of Acanthaceae.

MATERIAL AND METHODS

Medicinal uses, investigations of biological activities and chemical data were collected and summarized through bibliographic surveys. Tables were compiled to standardize the information and the appropriate references were gathered for each species. Registration of chemical components used in the treatment of ailments and in preserving health were emphasized with the aim of stimulating future investigations.

RESULTS

The breadths of habitats and morphologies of the family are directly related to its chemical diversity, as confirmed here for Brazilian species. Although the investigated species represent less than 9% of the total richness of the family in Brazil, they encompass a great diversity of chemical substances. The data indicated folk medicinal uses for 26 species and biological tests for 23, while 30 species were investigated chemically. Ruellia and Justicia were the most researched genera with 12 and 11 species, representing approximately 14% and 7% of Brazilian species of each genus, respectively. Two species are native to other countries but become naturalized in Brazil. Studies of native species were carried out in different countries around the world, with many reports of medicinal uses and biological tests. Examples of uses include anticancer and antidepressant actions, as well as activities against respiratory problems and other diseases.

CONCLUSIONS

This work highlights the chemical and biological diversity of the studied Brazilian species of Acanthaceae, which emphasizes the need to expand studies with native Brazilian species.

Rapid qualitative profiling of metabolites present in Fusarium solani, a rhizospheric fungus derived from Senna spectabilis, using GC/MS and UPLC-QTOF/MSE techniques assisted by UNIFI information system

Fungi are an important source of natural products found in a variety of plant species. A wide range of methods for the detection of metabolites present in fungi have been reported in the literature. The search for methodologies that allow the rapid detection of compounds present in crude extracts is crucial to enable the metabolite annotation doing a qualitative analysis of the complex matrix. Mass spectrometry is an important ally when it comes to in silico detection of previously reported metabolites. In this work, the ethyl acetate extract of Fusarium solani was analyzed by gas chromatography coupled to mass spectrometry (GC/MS) after derivatization process. The ethyl acetate extract was also investigated by liquid chromatography coupled with high-resolution tandem mass spectrometry assisted by the UNIFI software system. A library containing previously reported metabolites from the Fusarium genus was added to the UNIFI platform. Simultaneously, the extract was analyzed through anticholinesterase and antifungal assays. The analysis of the derivatized extract by GC/MS led to the putative identification of five metabolites, and the investigation using Ultra-High Performance Liquid Chromatography - Quadrupole Time-of-Flight Mass Spectrometry (UPLC-QTOF) analysis in data-independent acquisition mode (mass spectrometry) led to the annotation of 15 compounds present in the built-in Fusarium library added to the UNIFI system. The Fusarium solani extract showed potential anticholinesterase and in vitro antifungal activity supported by the detection of bioactive metabolites.

Gastroprotective effect of ethyl acetate extract from Avicennia schaueriana Stapf & Leechman and underlying mechanisms

OBJECTIVE

Avicennia schaueriana Stapf is an endemic mangrove species widely used by traditional Brazilian communities as a folk remedy for the treatment of rheumatism, ulcers, and skin wounds. The aim of the present study was to evaluate the gastroprotective potential of the ethyl acetate extract from the leaves of A. schaueriana (As-AcOEt).

METHODS

Ultra-performance liquid chromatography coupled with diode-array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS/MS) was performed to identify chemical constituents of the ethyl acetate extract from the leaves ofA. schaueriana. Total phenols, flavonoids and tannins were determined and antioxidant activity was evaluated using the DPPH and ABTS methods. The acute toxicity of As-AcOEt and gastroprotective activity on HCl/ethanol-induced gastric ulcers were assessed and mechanisms of action involving the role of nitric oxide, sulfhydryl compounds, and prostaglandins were investigated.

RESULTS

Terpenes, flavonoids and tannins were detected in the extract. As-AcOEt exhibited antioxidant activity, with an EC₅₀ of 42.2 ± 4.4 μg/mL (DPPH) and 73.2% inhibition of ABTS radicals. UPLC-DAD-QTOF-MS/MS analysis identified gallic acid, gallic acid derivative, ellagic acid, myricetin pentoside, myricetin deoxyhexose, quercetin pentoside, quercetin deoxyhexose, and other compounds. Gallic acid was isolated in this species for the first time. During the acute toxicity test, no deaths or changes occurred in the variables evaluated. In the ethanol-induced ulcer model, As-AcOEt reduced the ulcerative lesion index, with 50, 100 and 200 mg/kg achieving 83.8, 88.5 and 86.9% inhibition, respectively. MPO levels decreased and the gastric mucosa of the animals treated with the extract was preserved. Pre-treatment with N-omega-nitro-l-arginine methyl ester (L-NAME; NO blocker) or carbenoxolone (CBXN; NP-SH blocker) reversed the gastroprotective effect of As-AcOEt, but this effect was not reversed with the previous administration of indomethacin.

CONCLUSION

The present findings reveal that the extract from the leaves ofA. schaueriana has gastroprotective effects, suggesting the involvement of nitric oxide and nonprotein sulfhydryl compounds, but not prostaglandin. Therefore, the use of A. schaueriana in Brazilian folk medicine for the treatment of gastric disorders has a scientific basis.

Polyphenol-rich Avicennia marina leaf extracts induce apoptosis in human breast and liver cancer cells and in a nude mouse xenograft model

Avicennia marina is the most abundant and common mangrove species and has been used as a traditional medicine for skin diseases, rheumatism, ulcers, and smallpox. However, its anticancer activities and polyphenol contents remain poorly characterized. Thus, here we investigated anticancer activities of secondary A. marina metabolites that were purified by sequential soxhlet extraction in water, ethanol, methanol, and ethyl acetate (EtOAc). Experiments were performed in three human breast cancer cell lines (AU565, MDA-MB-231, and BT483), two human liver cancer cell lines (HepG2 and Huh7), and one normal cell line (NIH3T3). The chemotherapeutic potential of A. marina extracts was evaluated in a xenograft mouse model. The present data show that EtOAc extracts of A. marina leaves have the highest phenolic and flavonoid contents and anticancer activities and, following column chromatography, the EtOAc fractions F2-5, F3-2-9, and F3-2-10 showed higher cytotoxic effects than the other fractions. 1H-NMR and 13C-NMR profiles indicated that the F3-2-10 fraction contained avicennones D and E. EtOAc extracts of A. marina leaves also suppressed xenograft MDA-MB-231 tumor growth in nude mice, suggesting that EtOAc extracts of A. marina leaves may provide a useful treatment for breast cancer.

Naphtho[1,2-b]furan-4,5-dione is a potent anti-MRSA agent against planktonic, biofilm and intracellular bacteria

Aim: Naphtho[1,2-b]furan-4,5-dione (N12D) and naphtho[2,3-b]furan-4,9-dione (N23D) are furanonaphthoquinone derivatives from natural resources. We examined the antimicrobial activity of N12D and N23D against drug-resistant Staphylococcus aureus. Materials & methods: Minimum inhibitory concentration, minimum bactericidal concentration, bacterial viability and agar diffusion assay were conducted against methicillin-resistant S. aureus (MRSA) and clinical isolates of vancomycin-resistant S. aureus. Results & conclusion: The minimum inhibitory concentration of N12D and N23D against MRSA was 4.9–9.8 and 39 μM, respectively. With regard to the agar diffusion test, the inhibition zone of the quinone compounds was threefold larger than that of oxacillin. N12D was found to inhibit MRSA biofilm thickness from 24 to 16 μm as observed by confocal microscopy. N12D showed a significant reduction of the intracellular MRSA burden without decreasing the macrophage viability. The antibacterial mechanisms of N12D may be bacterial wall/membrane damage and disturbance of gluconeogenesis and the tricarboxylic acid cycle.

Chemical Composition, Antimicrobial and Antioxidant Activities of Essential Oils from Two Avicennia schaueriana Stapf & Leechm. Ex Moldenke (Acanthaceae) Populations

BACKGROUND

Avicennia schaueriana Stapf & Leechm. ex Moldenke (Acanthaceae) is a native species from the Brazilian mangroves presenting ecological and economic significance. This study compared the composition and the biological activities from the essential oils obtained from two A. schaueriana populations collected at Jureia-Itatins and Ilha do Cardoso.

METHODS

Essential oils were obtained by conventional means, and their compositions were analyzed by GC-MS. Screening assays for antimicrobial activity were carried out by the microdilution method and the antioxidant potential was assessed by the DPPH scavenging method.

RESULTS

The GC-MS analysis indicated that the Jureia oil (1) was composed mostly of the fatty acids palmitic (46.5%) and myristic (11.6%) acids, while the main components for the Ilha do Cardoso oil (2) were eugenol (19.7%), eugenol acetate (12.9%) and palmitic acid (15.1%). The oils showed an IC50 of 0.9 ± 0.011 mg/mL for 1 and 1.13 ± 0.028 mg/mL for 2 in the DPPH assay. The antimicrobial assay indicated MIC > 217 µg/mL for all tested microorganisms.

CONCLUSIONS

The different essential oil composition may indicate the presence of chemotypes for A. schaueriana. The antioxidant activity of the oils was weak if compared with flavonoids. Despite the high MIC values, these oils presented some antibacterial potential against Pseudomonas aeruginosa.