Survey of plants popularly used for pain relief in Rio Grande do Sul, southern Brazil

Achyrocline satureioides infusion, popularly prepared and consumed, has an in vitro protective effect on human neural cells exposed to rotenone

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional harvest of Achyrocline satureioides (AS) occurs at dawn on Good Friday in some South American countries. Inflorescences are traditionally used as infusions for several disorders, including neuropsychiatric disorders. Pillows and cushions are popularly filled with AS to attenuate the symptoms of depression, anxiety, and sleep disturbances. However, evidence for the potential beneficial effects of AS on human neural cells remains unclear.

AIM OF THE STUDY

An in vitro model of SH-SY5Y human neural cells was applied to evaluate the effect of AS infusion, prepared as commonly used, on cells exposed to rotenone and to investigate its potential for neuropsychiatric disorders.

MATERIALS AND METHODS

A hot aqueous extract was obtained from a traditionally prepared AS inflorescence infusion and chemically characterized by high-resolution mass spectrometry and spectrophotometric quantification of total polyphenols, tannins, and flavonoids. The SH-SY5Y cell cultures were treated with AS extract at concentrations of 1, 3, 5, 10, 50, 100, and 300 μL/mL to determine the potential cyto- and genotoxic effects of AS on neural cells using MTT, Neutral Red, and GEMO assays. Apoptosis modulation was assessed using flow cytometry and apoptosis-modulating genes were evaluated by qRT-PCR. The protective effect of AS on the neurotoxicity triggered by rotenone exposure (30 nM) was determined by analyzing cellular viability and oxidative markers such as lipid peroxidation and protein carbonylation, and DNA damage was assessed by micronucleus assay.

RESULTS

The AS extract, as traditionally prepared, had estimated concentrations of 409.973 ± 31.107 μg/mL, 0.1041 ± 0.0246 mg GAE/mL, and 63.309 ± 3.178 mg QE/mL of total tannins, total polyphenols, and flavonoids, respectively. At concentrations of 30 and 100 μl/mL, AS decreased apoptotic events, whereas the highest concentration (300 μl/mL) increased apoptosis compared to that in the control (p < 0.05). In cells exposed to rotenone, AS treatment induced cell proliferation, reduced DNA damage (as evaluated by micronuclei), and reduced lipid and protein oxidation.

CONCLUSIONS

The data indicate the non-cytotoxic and beneficial effects of AS extract on human neural cells by reducing cellular mortality and oxidative stress in neural cells triggered by rotenone exposure.

Ethnobotanical knowledge on native Brazilian medicinal plants traditionally used as anthelmintic agents - A review

Intestinal helminthiasis is a neglected disease that affects a significant portion of the global population, specifically in developing countries, where medicinal plants are widely used for therapeutic purposes. With the purpose to identify the native species used in traditional Brazilian medicine for the management of helminthiasis, ethnopharmacological books edited in Brazil documenting the folk use of medicinal plants were analyzed. The native species cited in at least three studies were selected, and bibliographic research was performed using electronic databases to identify their scientifically validated anthelmintic properties. The search retrieved 133 native species belonging to 88 genera and 43 families from all six Brazilian biomes. Fabaceae (14 Genera and 25 Species) and Asteraceae (7 Genera and 8 Species) were the most frequently cited families. The most reported native species were Baccharis crispa Spreng., Hymenaea courbaril L., Senna occidentalis (L.) Link, Carapa guianensis Aubl., Stachytarpheta cayennensis (Rich.) Vahl, Annona glabra L., Hymenaea stigonocarpa Mart. ex Hayne, Spigelia anthelmia L., Simarouba versicolor A.St.-Hil. and Anacardium occidentale L. Bark (19%) and leaves (17%) were the most commonly used plant parts, and decoction (27%) was the most preferred method of preparation. Evidence of the anthelmintic properties of most species was confirmed using in vitro assays for key human and animal parasites, including Haemonchus contortus, Hymenolepis diminuta, Schistosoma mansoni and Trichostrongylus spp. The species S. alata, S. occidentalis, A. occidentale, and S. anthelmia have been the subject of many biological studies, supporting their use as vermicides. The overall results obtained in this review revealed that Brazil is rich in traditional herbal medicines used to manage helminthiasis; however pharmacological investigations are lacking to confirm their therapeutic properties. Thus, this study could serve as a baseline to validate their use and encourage further clinical investigation of their vermifuge potential.

Hepatoprotective Native Plants Documented in Brazilian Traditional Medicine Literature: Current Knowledge and Prospects

The native flora of Brazil covers a large biodiversity of plants, some of which have important pharmacological properties. Ethnobotanical studies have established that the folk use of plants for hepatobiliary disorders is very common in Brazil. This review aimed to compile, describe and discuss the main native Brazilian medicinal plants used as hepatoprotective agents listed on 25 books by authors from various regions in the country. Based on the 153 species found, a comprehensive analysis of the most relevant scientific studies is presented, including Piper umbellatum, Echinodorus macrophyllus, Fevillea trilobata and Achyrocline satureioides. Some medicinal plants share both a large number of citations and scientific evidence to corroborate their hepatoprotective effects, including Solanum paniculatum, Baccharis crispa and Phyllanthus niruri, which could be of interest to develop new phytomedicines. Additionally, some active ingredients are indicated as being responsible for the liver protective effects described, particularly phenolic compounds (flavonoids, coumestans and lignans).

Antinociceptive effects of a hydroethanolic stem bark extract of Burkea africana

Introduction

Pain is a major symptom of many clinical disorders and its relief has long been a concern for individuals across the globe. There is therefore an unmet need to search for new efficacious agents for the effective management of pain. The stem bark of the savanna tree Burkea africana (Hook) (Family: Leguminosae) is used in the Ghanaian traditional medicine for the treatment and management of various pain-related diseases.

Method

An acute oral toxicity study in mice was conducted by administering BAE (50–5000 mg kg⁻¹p.o.). Antinociceptive effect of BAE (50–1000 mg kg⁻¹p.o.) was evaluated using the acetic acid-induced abdominal constriction, acidic saline-induced muscle pain and formalin-induced pain models. The antinociceptive mechanism of BAE was also assessed using the formalin-induced pain model.

Results

The LD₅₀ of BAE was thus estimated to be above 5000 mg kg⁻¹ since none of the animals died in the acute toxicity study. Pretreatment with BAE (50–1000 mg kg⁻¹p.o.) significantly reduced the number of writhes after acetic-acid administration compared to the vehicle treated group. BAE also produced a significant and dose-dependent reversal of mechanical hyperalgesia induced by the injection of the acidic saline. Administration of BAE was able to significantly suppress both phases of the formalin test. This effect of the extract was however reversed by pretreatment with naloxone and granisetron.

Conclusions

BAE exhibits antinociceptive effects in rodent pain models with a possible involvement of 5-HT₃ receptors and opioidergic pathways.

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Burkea africana stem bark extract.

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Acetic acid-induced abdominal constriction.

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Acidic saline-induced muscle pain.

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Formalin-induced pain.

Topical hydrogel containing Achyrocline satureioides oily extract (free and nanocapsule) has anti-inflammatory effects and thereby minimizes irritant contact dermatitis

Inflammatory dermatoses are prevalent worldwide, with impacts on the quality of life of patients and their families. The aim of this study was to determine the anti-inflammatory effects of Achyrocline satureioides oily extracts and nanocapsules on the skin using a mouse model of irritant contact dermatitis induced by croton oil, and a skin inflammation model induced by ultraviolet B (UVB) radiation. The mice were treated with 15 mg/ear oily extract (HG-OLAS) or nanocapsules (HG-NCAS) of A. satureioides incorporated into Carbopol® 940 hydrogels. We found that HG-OLAS and HG-NCAS formulations reduced ear edema in croton oil-induced lesions with maximum inhibitions of 54±7% and 74±3%, respectively. HG-OLAS and HG-NCAS formulations decreased ear edema induced by UVB radiation (0.5 J/cm2), with maximum inhibitions of 68±6% and 76±2% compared to the UVB radiation group, respectively. HG-OLAS and HG-NCAS modulated myeloperoxidase (MPO) activity after croton oil induction. Furthermore, croton oil and UVB radiation for 6 and 24 h, respectively, stimulated polymorphonuclear cells infiltration. The topical treatments reduced inflammatory processes, as shown by histological analysis. Together, the data suggest that topical application of A. satureioides oily extracts and nanocapsules produced antiedematogenic and anti-inflammatory effects. They constitute a compelling alternative for treatment of skin injuries.

Antioxidant Effect of Nanoemulsions Containing Extract of Achyrocline satureioides (Lam) D.C.-Asteraceae

Ethanolic extracts of Achyrocline satureioides have pronounced antioxidant activity mainly due to the presence of the flavonoid quercetin. However, direct topical application of the extract is not possible due to the presence of high amounts of ethanol. In this sense, nanoemulsions arise as an alternative for topical formulation associating molecules with limited aqueous solubility. This article describes the development of topical nanoemulsions containing either A. satureioides extract or one of its most abundant flavonoid, quercetin. Nanoemulsions composed of octyldodecanol, egg lecithin, water and extract (NEE), or quercetin (NEQ) were prepared by spontaneous emulsification. This process led to monodisperse nanoemulsions presenting a mean droplet size of approximately 200-300 nm, negative zeta potential, and high association efficiency. A study of quercetin skin retention using porcine skin which was performed using a Franz diffusion cell revealed a higher accumulation of quercetin in skin for NEE when compared to NEQ. Finally, the antioxidant activity of formulations was measured by thiobarbituric acid-reactive species and the APPH model. A lower lipoperoxidation for the extract in respect to quercetin solution was observed. However, no difference between NEQ and NEE lipoperoxidation could be seen. The protection against lipoperoxidation by the formulations was also measured in the skin, where lower formation of reactive species was observed after treatment with NEE. In conclusion, this study shows the formulation effect on the physicochemical properties of nanoemulsions as well as on the skin retention and antioxidant activity of quercetin.