The essential oil of the leaves of Verbesina macrophylla (Cass.) S.F.Blake has antimicrobial, anti-inflammatory and antipyretic activities and is toxicologically safe

Potential Effects of Essential Oil from Plinia cauliflora (Mart.) Kausel on Leishmania: In Vivo, In Vitro, and In Silico Approaches

In the search for new chemotherapeutic alternatives for cutaneous leishmaniasis (CL), essential oils are promising due to their diverse biological potential. In this study, we aimed to investigate the chemical composition and leishmanicidal and anti-inflammatory potential of the essential oil isolated from the leaves of Plinia cauliflora (PCEO). The chemical composition of PCEO showed β-cis-Caryophyllene (24.4%), epi-γ-Eudesmol (8%), 2-Naphthalenemethanol[decahydro-alpha] (8%), and trans-Calamenene (6.6%) as its major constituents. Our results showed that the PCEO has moderate cytotoxicity (CC50) of 137.4 and 143.7 μg/mL on mice peritoneal exudate cells (mPEC) and Vero cells, respectively. The PCEO was able to significantly decrease mPEC infection by Leishmania amazonensis and Leishmania braziliensis. The value of the inhibitory concentration (IC50) on amastigote forms was about 7.3 µg/mL (L. amazonensis) and 7.2 µg/mL (L. braziliensis). We showed that PCEO induced drastic ultrastructural changes in both species of Leishmania and had a high selectivity index (SI) > 18. The in silico ADMET analysis pointed out that PCEO can be used for the development of oral and/or topical formulation in the treatment of CL. In addition, we also demonstrated the in vivo anti-inflammatory effect, with a 95% reduction in paw edema and a decrease by at least 21.4% in migration immune cells in animals treated with 50 mg/kg of PCEO. Taken together, our results demonstrate that PCEO is a promising topical therapeutic agent against CL.

Antinociceptive and anti-inflammatory activities of essential oil of the leaves of Amburana cearensis (Allemão) A.C. Smith. from the semi-arid region of Northeastern Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

Amburana cearensis (Allemão) A.C. Smith is a medicinal plant with wide distribution in South America, popularly known in Brazil as "cumaru" or "amburana de cheiro". In folk medicine, in the semi-arid region of Northeastern Brazil, infusions, teas and decoctions of leaves of Amburana cearensis have their practical use for treating fever, gastrointestinal disorders, inflammation, and inflammation pain. However, none of the ethnopharmacological properties has been scientifically evaluated using volatile compounds obtained from its leaves (essential oil).

AIM OF THE STUDY

This study investigated the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the essential oil from the leaves of A. cearensis.

MATERIAL AND METHODS

The acute toxicity of the essential oil was investigated in mice. The antinociceptive effect was evaluated using the formalin test and, abdominal writhing induced by acetic acid, being investigated the possible mechanisms of action involved in antinociception. The acute anti-inflammatory effect was investigated through models of carrageenan-induced peritonitis, yeast-induced pyrexia, and carrageenan- and histamine-induced paw inflammation.

RESULTS

No acute toxicity was observed at doses up to 2000 mg/kg; p.o. The antinociceptive effect was statistically equal to morphine. In the formalin assay, the oil showed analgesic activity in the neurogenic and inflammatory phases, having as mechanisms the cholinergic, adenosinergic system, and ATP-sensitive potassium channels (K-ATP). In peritonitis, a reduction in TNF-α and IL-1β levels and leukocyte migration were observed. The antipyretic effect was statistically superior to dipyrone. The reduction in paw edema was statistically superior to the standard in both models.

CONCLUSION

The results obtained not only support the traditional use of the species in inflammatory conditions and pain in folk medicine but also demonstrate that this is a rich source of phytocomponents such as germacrone, which can be used as a natural and sustainable therapeutic agent with industrial applications.

Application of Plant Surfactants as Cleaning Agents in Shampoo Formulations

With the increased demand for sustainable, hypoallergenic products, plant surfactants are a promising, eco-friendly option for cleaning products due to their low toxicity or even the absence of toxicity. In the present study, surfactant-rich extracts from Chenopodium quinoa, Glycine max, and Malpighia emarginata were assessed for their stability, antioxidant capacity, toxic potential, and cleaning potential in shampoo formulations. The surfactants in the extracts were isolated and characterized by NMR, UV-Vis, and FTIR spectroscopy. The results demonstrated that the extracts remained stable within the temperature and pH ranges tested. The antioxidant properties were also determined. In the analysis of irritation potential, G. max and C. quinoa exhibited low toxicity and no toxicity, respectively. The cleaning potential analysis confirmed that the extracts could be used as primary surfactants. Seven shampoo formulations were developed, which showed potential to reduce surface tension to the range of 27.1–31.7 mN/m and interfacial tension to the range of 5.4–7.3 mN/m. The wettability, percentage of solids, density, pH, and dirt dispersion of the formulas were within standard ranges, and the sebum removal capacity of the seven formulations was similar to or even better than that of a commercial shampoo.

Molecular mechanism of the anti-inflammatory effects of plant essential oils: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Plant essential oils (PEOs) extracted from aromatic compounds of the plant contain complex mixtures of volatile and lipophilic bioactive compounds. In ancient Egypt, Arabia, Greece, and China, PEOs were traditional used in aromatherapy for various health disorders, including pain and inflammation.

AIM OF THE STUDY

In this review, we provide an overview of the anti-inflammatory effects of PEOs and the underlying mechanisms associated with anti-inflammatory effects using in vitro and in vivo models. Further, clinical trials associated with PEOs were explored.

MATERIALS AND METHODS

The literature search was performed using various web-based tools and databases like Google Scholar, Web of Science, PubMed, CNKI and SCOPUS. The keywords used for conducting the literature review were general terms like "essential oils" followed by (AND) the subject of interest like "in vitro and/or in vivo anti-inflammatory models," "inflammatory response," "inflammatory indicators," "pro-inflammatory cytokines," "signaling pathway," "anti-inflammatory mechanism," "toxicology and side effects" and "clinical trials." The articles selected were published between 2017 and 2022. The articles prior to 2017 were only considered if they were associated with molecular mechanisms or signaling pathways involved in the inflammatory responses.

RESULTS

In vitro and in vivo inflammation models have been used to study the anti-inflammatory effects of 48 PEOs. Studies have reported that PEOs targets and inhibit multiple dysregulated signaling pathways associated with inflammation, including Toll-like receptors, nuclear transcription factor-κ B, mitogen-activated protein kinases, Nod-like receptor family pyrin domain containing 3, and auxiliary pathways like the nuclear factor erythroid 2-related factor 2/antioxidant response element and Janus kinase/signal transducers and activators of transcription) signaling pathways.

CONCLUSION

PEOs extracted from different plant materials had varied qualitative and quantitative compositions of biologically active compounds. Different anti-inflammatory potentials and different molecular signal transduction have been attributed to PEOs-derived bioactive compounds with different chemical structures. The data on therapeutic efficacy and the long-term side effects of PEOs as an anti-inflammatory drug are still unknown due to the lack of clinical trials on PEOs. There is still insufficient evidence to draw conclusions on anti-inflammatory properties of PEOs without promising outcomes from clinical trials.

Essential Oil Blends: The Potential of Combined Use for Respiratory Tract Infections

This study investigated the potential efficacy of 369 commercial essential oil combinations for antimicrobial, anti-toxic and anti-inflammatory activity with the aim of identifying synergy among essential oils commonly used in combination by aromatherapists for respiratory purposes. Essential oil combinations were assessed for their antimicrobial activities using a panel of Gram-positive, Gram-negative, and yeast strains associated with respiratory tract infections. The antimicrobial activity was measured by determining the minimal inhibitory concentration (MIC) of microbial growth. The fractional inhibitory concentration index (ΣFIC) was calculated to determine the antimicrobial interactions between the essential oils in the combination. The toxicity of the essential oil combinations was tested in vitro using the brine shrimp lethality assay, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on RAW 264.7 mouse macrophage cells and A549 lung cancer cell lines. In addition, an inflammatory response was evaluated measuring nitric oxide production. The essential oils, when in combination, demonstrated an increased antimicrobial effect, a reduction in toxicity and provided improved anti-inflammatory outcomes. Five distinct combinations [Cupressus sempervirens (cypress) in combination with Melaleuca alternifolia (tea tree), Hyssopus officinalis (hyssop) in combination with Rosmarinus officinalis (rosemary), Origanum marjorana (marjoram) in combination with M. alternifolia, Myrtus communis (myrtle) in combination with M. alternifolia and Origanum vulgare (origanum) in combination with M. alternifolia] were found to be the most promising, demonstrating antimicrobial activity, reduced cytotoxicity and improved anti-inflammatory effects. With the increased prevalence of respiratory tract infections and the growing antimicrobial resistance development associated with antimicrobial treatments, this study provides a promising complementary alternative for the appropriate use of a selection of essential oil combinations for use in the respiratory tract.

The Natural Compound Hydrophobic Usnic Acid and Hydrophilic Potassium Usnate Derivative: Applications and Comparisons

Usnic acid is the best-studied lichen metabolite, presenting several biological activities, such as antibacterial, immunostimulating, antiviral, antifungal, anti-inflammatory, and antiparasitic agents; despite these relevant properties, it is a hydrophobic and toxic molecule. In this context, scientific research has driven the development of innovative alternatives, considering usnic acid as a source of raw material in obtaining new molecules, allowing structural modifications (syntheses) from it. The purpose is to optimize biological activities and toxicity, with less concentration and/or response time. This work presents a literature review with an analogy of the hydrophobic molecule of usnic acid with its hydrophilic derivative of potassium usnate, emphasizing the elucidation and structural characteristics, biological activities, and toxicological aspects of both molecules, and the advantages of using the promising derivative hydrophilic in different in vitro and in vivo assays when compared to usnic acid.

Andrographis paniculata (Burm. f.) Wall. ex Nees: An Updated Review of Phytochemistry, Antimicrobial Pharmacology, and Clinical Safety and Efficacy

Infectious disease (ID) is one of the top-most serious threats to human health globally, further aggravated by antimicrobial resistance and lack of novel immunization options. Andrographis paniculata (Burm. f.) Wall. ex Nees and its metabolites have been long used to treat IDs. Andrographolide, derived from A. paniculata, can inhibit invasive microbes virulence factors and regulate the host immunity. Controlled clinical trials revealed that A. paniculata treatment is safe and efficacious for acute respiratory tract infections like common cold and sinusitis. Hence, A. paniculata, mainly andrographolide, could be considered as an excellent candidate for antimicrobial drug development. Considering the importance, medicinal values, and significant role as antimicrobial agents, this study critically evaluated the antimicrobial therapeutic potency of A. paniculata and its metabolites, focusing on the mechanism of action in inhibiting invasive microbes and biofilm formation. A critical evaluation of the secondary metabolites with the aim of identifying pure compounds that possess antimicrobial functions has further added significant values to this study. Notwithstanding that A. paniculata is a promising source of antimicrobial agents and safe treatment for IDs, further empirical research is warranted.

Quantitative Analysis of Rutin by HPTLC and In Vitro Antioxidant and Antibacterial Activities of Phenolic-Rich Extracts from Verbesina sphaerocephala

Verbesina sphaerocephala A. Gray, like other wild plants of the genus Verbesina, has been used in herbal medicine. There is information for other species of the genus related to their phenolic content, antioxidant capacity, and isolation of bioactive compounds with antimicrobial activity. However, there are no reports for V. sphaerocephala, although it has an important presence in the state of Michoacán, México. In this study, the phenolic composition, quantification of rutin, and in vitro antioxidant and antibacterial activities of methanolic extracts from V. sphaerocephala leaves and flowers were determined. The results showed that all the investigated extracts have high phenolic and flavonoid contents. The flavonoid rutin was identified in all the extracts from V. sphaerocephala by high-performance thin-layer chromatography (HPTLC). The V. sphaerocephala extracts showed scavenging activity against DPPH^• and ABTS^•+ radicals (IC₅₀ and 5.83 ± 0.50 and 0.93 ± 0.01 mg/mL, respectively) as well as relevant antioxidant capacity (51.05 ± 0.36 mg of ascorbic acid/g of dry tissue). The experimental results show that V. sphaerocephala extracts possessed a strong antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. This research indicates that V. sphaerocephala could be considered as a potential source of natural compounds from the point of ethnopharmacological usage.