Toxicity study about a medicinal plant Casearia sylvestris: A contribution to the Brazilian Unified Health System (SUS)

Casearia sylvestris var. lingua (Càmbess.) Eichler leaves aqueous extract improves colon inflammation through mucogenic, antioxidant and anti-inflammatory actions in TNBS- induced IBD rats

ETHNOPHARMACOLOGICAL RELEVANCE

Casearia sylvestris var. lingua (Cambess.) Eichler, a member of the Salicaceae family, holds a prominent place in traditional medicine across various cultures due to its versatile therapeutic properties. Historically, indigenous communities have utilized different parts of the plant, including leaves, bark, and roots, to address a wide array of health conditions. Traditional uses of C. sylvestris var. lingua encompasses the treatment of gastrointestinal disorders, respiratory infections, wound healing, inflammation, and stomach ulcers. Pharmacological studies have demonstrated the plant's antimicrobial, anti-inflammatory, antioxidant, analgesic, gastroprotective, and immunomodulatory effects. This signifies the first scientific validation report for C. sylvestris var. lingua regarding its effectiveness against ulcerative colitis. The report aims to affirm the traditional use of this plant through pre-clinical experiments.

AIM OF THE RESEARCH

This work uses an aqueous extract from C. sylvestris var. lingua leaves (AECs) to evaluate the acute anti-ulcerative colitis efficacy in rat and HT-29 (human colorectal cancer cell line) models.

METHODS

To determine the secondary metabolites of AECs, liquid chromatography with a diode array detector (LC-DAD) study was carried out. 2,4,6-trinitrobenzenesulfonic acid (TNBS, 30 mg/0.25 mL EtOH 30% v/v) was used as an enema to cause acute colitis. Three days were spent giving the C. sylvestris var. lingua extract orally by gavage at dosages of 3, 30, and 300 mg/kg. The same route was used to deliver distilled water to the vehicle and naïve groups. After the animals were sacrificed on the fourth day, intestinal tissues were taken for histological examination and evaluation of biochemical tests such as those measuring superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT), malondialdehyde (MDA), nitrite/nitrate, myeloperoxidase (MPO) activity. Additionally, interleukin 1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and interleukin 10 (IL-10), were conducted on the intestinal tissues. Additionally, an MTT assay was used to evaluate the effect of AECs on the viability of HT-29 cells. Additionally, a molecular docking study was carried out to compare some potential target proteins with identified chemicals found in AECs.

RESULTS

LC-DAD analysis identified five compounds (caffeic acid, ellagic acid, ferulic acid, gallic acid, and quercetin) in AECs. Pre-administration of AECs (3; 30; 300 mg/kg) and mesalazine (500 mg/kg) reduced macroscopic scores (55%, 47%, 45%, and 52%, p < 0.001) and ulcerated areas (70.3%, 70.5%, 57%, and 56%, p < 0.001), respectively. It also increased SOD, GSH, and CAT activities (p < 0.01), while decreasing MDA (p < 0.001), nitrite/nitrate (p < 0.05), and MPO (p < 0.001) activities compared to the colitis group. Concerning inflammatory markers, significant modulations were observed: AECs (3, 30, and 300 mg/kg) lowered levels of IL-1β and TNF-α (p < 0.001) and increased IL-10 levels (p < 0.001) compared to the colitis groups. The viability of HT-29 cells was suppressed by AECs with an IC50 of 195.90 ± 0.01 μg/mL (48 h). During the molecular docking analysis, quercetin, gallic acid, ferulic acid, caffeic acid, and ellagic acid demonstrated consistent binding affinities, forming stable interactions with the 3w3l (TLR8) and the 3ds6 (MAPK14) complexes.

CONCLUSION

These results imply that the intestinal mucogenic, anti-inflammatory, and antioxidant properties of the C. sylvestris var. lingua leaf extract may be involved in its therapeutic actions for ulcerative colitis. The results of the in silico study point to the possibility of quercetin and ellagic acid interacting with P38 and TLR8, respectively, in a beneficial way.

Maternal-fetal safety evaluation of an aqueous extract of Casearia sylvestris leaves in rats

BACKGROUND

This study evaluated the maternal, embryotoxic, and teratogenic effects of the aqueous extract of Casearia sylvestris (AECS), a species listed in the Unique Health System of Brazil, and widely used for treating several conditions, such as diarrhea, wounds, pain, and ulcers.

METHODS

Pregnant rats were daily treated orally with 0, 175, 350, or 700 mg/kg/body weight of AECS, from gestational day (GD) 6 to 15 (organogenesis period). On GD 20, the pregnant rats were euthanized, and the litters submitted to an assessment of fetal development.

RESULTS

No clinical signs of toxicity were observed in the dams during the treatment. In the embryo-fetal development study, a significant increase in the basal zone height of the placenta was observed in the intermediate dose group. Furthermore, there was a significant increase in the relative anogenital distance measurement of female fetuses in the lowest and intermediate dose groups. Although no visceral abnormalities were observed in the treated-fetuses, skeletal anomalies evidenced by changes in the ossification of the sternum and the presence of supernumerary ribs were found in the intermediate and high dose groups.

CONCLUSION

In conclusion, the treatment with AECS during organogenesis at this dose level had detrimental effects on the normal development of fetuses.

Gastroprotective and gastric healing effects of the aqueous extract of Casearia sylvestris in rodents: Ultrasound, histological and biochemical analyzes

ETHNOPHARMACOLOGICAL IMPORTANCE

Casearia sylvestris Sw. (Salicaceae) is a native plant from the Americas, where it is also known as "guaçatonga" or "erva-de-bugre." Although its leaves have been commonly used to treat inflammation and gastrointestinal disorders in South America, the antiulcer effects of an aqueous extract from this medicinal plant, similar to popular use, have not to be investigated yet.

AIM OF THE STUDY

This study evaluated the hypothesis that the aqueous extract a of C. sylvestris (AEC) prevents the gastric ulcers and accelerates the healing of ulcers already installed, by assessing ultrasound imaging, histological and biochemical analyses.

MATERIALS AND METHODS

Rats (females) were treated with AEC (3, 30 or 300 mg/kg) prior to the ethanol or piroxicam-induced gastric ulcers. The healing effect of AEC (300 mg/kg) was examined in 80% acetic acid-induced ulcer in rats, whereas the quality of healing was evaluated in recurrent 10% acetic acid-induced ulcer in mice with recurrence induced by interleukin 1β. To assess the responses of the lesions, in addition to the classical methods used to analyze gastroprotection (ex vivo), we also measured the gastric wall thickness (in vivo) using ultrasonography. After euthanasia, the extent of ulcer was determined and the levels of reduced glutathione (GSH), lipid hydroperoxides (LOOH), nitrate, and the activities of myeloperoxidase (MPO), N-acetyl-β-D-glycosaminidase (NAG), superoxide dismutase (SOD), and glutathione S-transferase (GST) were measured. The antisecretory activity of AEC was also examined based on pylorus ligated rats. Furthermore, gastric tissue samples were analyzed histologically, and phytochemical analyses of the C. sylvestris extract were parallelly performed.

RESULTS

The AEC (30 or 300 mg/kg) prevented ulcers in the ethanol- and piroxicam-induced acute. Moreover, the AEC at a dose of 300 mg/kg also accelerated the gastric healing of acetic acid-induced ulcer in rats by 48% and the ultrasonography records shown a decrease in the wall thickness and the extent of edema of ulcerous lesions promoted by the extract. The gastric healing effect of AEC was also accompanied by reduced MPO and NAG activities at acetic acid-induced ulcer in rats; as well as was by the reduction in the nitrate and LOOH levels, the increase in mucin and SOD activity, and by a partial recovery of GSH levels. The AEC (300 mg/kg) minimized the ulcer recurrence in mice exposed to IL-1β, but the extract administration did not change pH or peptic activity of gastric juice in pylorus ligated rats.

CONCLUSION

The results of this study provide convincing evidence for the therapeutic efficacy of C. sylvestris with respect to gastroprotection and indicate that ultrasound examination would be a potentially promising approach for evaluating gastroprotective effects in vivo. Collectively, our findings indicate that the gastric the gastroprotective and healing effects of aqueous extract C. sylvestris involve a reduction in acid secretion, promotion of the antioxidant system, reductions in the migration of neutrophils and mast cells, with a consequent lower inflammatory response, and the preservation of mucin.

The potential of Brazilian native plant species used in the therapy for snakebites: A literature review

Snakebite envenoming is a potentially fatal disease categorized as a neglected public health issue for not receiving the appropriate attention from national and international health authorities. The most affected people by this problem usually live in poor rural communities, where medical resources are often sparse and, in some instances, there is even a scarcity of serum therapy. The administration of the appropriate antivenom is the only specific treatment available, however it has limited efficacy against venom-induced local effects. In this scenario, various plant species are used as local first aid for the treatment of snakebite accidents in Brazil, and some of them can effectively inhibit lethality, neurotoxicity, hemorrhage, and venom enzymes activities. This review compiles a list of plants used in the treatment of snakebites in Brazil, focusing on the native Brazilian species registered in the databases Pubmed, Scielo, Scopus and Google Scholar. All these searches were limited to peer-reviewed journals written in English, with the exception of a few articles written in Portuguese. The most cited native plant species were Casearia sylvestris Sw., Eclipta prostrata (L.) L., Mikania glomerata Spreng., Schizolobium parahyba (Vell.) S.F.Blake and Dipteryx alata Vogel, all used to decrease the severity of toxic signs, inhibit proteolytic and hemorrhagic activities, thus increasing survival time and neutralizing myotoxicity effects. Different active compounds showing important activity against the snake venoms and their toxins include flavonoids, alkaloids and tannins. Although some limitations to the experimental studies with medicinal plants were observed, including lack of comparison with control drugs and unknown active extracts compounds, species with anti-venom characteristics are effective and considered as candidates for the development of adjuvants in the treatment of snake envenomation. Further studies on the chemistry and pharmacology of traditionally used plant species will help to understand the role that snakebite herbal remedies may display in local medical health systems. It might also contribute to the development of alternative or complementary treatments to reduce the number of severe disabilities and deaths.

(-)-T-Cadinol-a Sesquiterpene Isolated From Casearia sylvestris (Salicaceae)-Displayed In Vitro Activity and Causes Hyperpolarization of the Membrane Potential of Trypanosoma cruzi

Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and affects 6-8 million people worldwide, mainly from developing countries. The treatment is limited to two approved nitro-derivatives, nifurtimox and benznidazole, with several side effects and reduced efficacy. Casearia sylvestris has been used in folk medicine as an antiseptic and cicatrizing in skin diseases. In the present work, the hexane phase from the MeOH extract from the leaves of Casearia sylvestris afforded a fraction composed by the sesquiterpene T-cadinol, which was chemically characterized by NMR and HRMS. The activity of T-cadinol was evaluated against T. cruzi, and IC₅₀ values of 18 (trypomastigotes) and 15 (amastigotes) µM were established. The relation between the mammalian toxicity and the antiparasitic activity resulted in a selectivity index >12. Based on this promising activity, the mechanism of action was investigated by different approaches using fluorescent-based techniques such as plasma membrane permeability, plasma membrane electric potential, mitochondrial membrane electric potential, reactive oxygen species, and the intracellular calcium (Ca²⁺) levels. The obtained results demonstrated that T-cadinol affected neither the parasite plasma membrane nor the electric potential of the membrane. Nevertheless, this compound induced a mitochondrial impairment, resulting in a hyperpolarization of the membrane potential, with decreased levels of reactive oxygen species. No alterations in Ca²⁺ levels were observed, suggesting that T-cadinol may affect the single mitochondria of the parasite. This is the first report about the occurrence of T-cadinol in C. sylvestris, and our data suggest this sesquiterpene as an interesting hit compound for future optimizations in drug discovery studies for Chagas disease.

Identification of flavonoid-3-O-glycosides from leaves of Casearia arborea (Salicaceae) by UHPLC-DAD-ESI-HRMS/MS combined with molecular networking and NMR

INTRODUCTION

Casearia is an essential source of cytotoxic highly oxidised clerodane diterpenes, in addition to phenolics, flavonoids, and glycoside derivatives. Here we identify flavonoid-3-O-glycoside derivatives in the ethyl acetate (EtOAc) fraction of the methanolic extract from leaves C. arborea leaves.

OBJECTIVE

To characterise the EtOAc phase from the methanolic extract of C. arborea leaves using ultra-high-performance liquid chromatography diode array detector high-resolution tandem mass spectrometry (UHPLC-DAD-HRMS/MS) and molecular networking-based dereplication. Methodology We identified compounds not annotated in the GNPS platform by co-injection of standards in HPLC-DAD or by isolation and characterisation of the metabolites using nuclear magnetic resonance (NMR) spectroscopy. A workflow on the GNPS platform aided the organisation of spectral data and dereplication by annotations. We subjected the EtOAc phase to HPLC-DAD analysis using standard compound co-injection to corroborate the GNPS annotations. We isolated unidentified compounds with semi-preparative HPLC-DAD for structural identification using NMR.

RESULTS

We annotated a molecular family of flavonoid-3-O-glycosides in the molecular networking created using the GNPS platform. These included avicularin, cacticin, isoquercitrin, quercitrin, rutin, and a quercetin-3-O-pentoside cluster. We confirmed the annotations with standard compounds using HPLC-DAD co-injection analysis, besides identifying quercetin-3-O-robinobioside and kaempferol. We isolated three flavonoid-3-O-pentosides and characterised them using one- and two-dimensional NMR; we identified them as reynoutrin, guaijaverin, and avicularin.

CONCLUSION

This work describes the isolation of kaempferol and nine known flavonoid-3-O-glycosides from the polar fraction of the methanolic extract (EtOAc) from C. arborea leaves using molecular networking to guide the chromatographic procedures. We identified eight compounds for the first time in Casearia that amplify and reinforce the genus' chemotaxonomy with the presence of glycosylated flavonoids.

Acute and Sub-chronic Toxicity Study of Recombinant Bovine Interferon Alpha in Rodents

Introduction

Recombinant bovine interferon alpha (rBoIFN-α) has been demonstrated to have antiviral activity. However, no conduct of acute or chronic toxicity tests has been reported.

Material and Methods

Specific pathogen-free Sprague Dawley rats were administered doses at different concentrations through intraperitoneal or intravenous injection. After the administration (single for an acute toxicity test over 14 days or daily for a sub-chronic toxicity test over 30 days), the rats’ behaviour and other indicators and the degree of toxic reaction were continuously monitored. Blood was collected for haematological and serum biochemical examinations. At the end of the experiments, the rats were sacrificed for necropsy and histopathological tissue analysis.

Results

The external performance, behaviour characteristics, and changes in body temperature and body weight of the rats in each subgroup were comparable to the normal control subgroup. Except for a few cases, there were no lesions in the viscera’s pathological structures, and the blood parameters and biochemical indicators were not noticeably different from those of the control subgroup.

Conclusion

This study suggests that rBoIFN-α seems to be safe for rats, and its use may foster the development of the cattle industry in China by protecting livestock health.

Antihyperalgesic effect of exercise is augmented by the oral pretreatment with extract of Casearia sylvestris in an animal model of osteoarthritis

Background/Purpose:

Osteoarthritis (OA) is the main orthopedic disease to cause pain and edema in humans. This study evaluated the influence of complementary medicine on the hyperalgesia and edema induced by exercise in an animal model of OA as well as possible role for interleukin (IL)-1β to these outcomes.

Methods:

Mice (25–35 g) were subjected to intraplantar injection of Freund’s complete adjuvant and were subjected to exercise and oral treatment with ethanolic crude extract of Casearia sylvestris (ECE-CS) or vehicle (alone or in combination) and evaluated through behavioral and biochemical tests.

Results:

At day 5, exercise and ECE-CS alone did not reduce hyperalgesia, while the combination of both enhanced this effect. In muscle and skin tissues from the treated paw of mice, both treatments alone or in combination reduced in similar extent the levels of IL-1β in relation to the control group.

Conclusion:

Association of both complementary therapies may bring benefits on pain associated with OA in humans.

Acute and subacute (28 days) toxicity of green coffee oil enriched with diterpenes cafestol and kahweol in rats

Green coffee oil enriched with cafestol and kahweol was obtained by supercritical fluid extraction using carbon dioxide while its safety and possible effects from acute and subacute treatment were evaluated in rats. For acute toxicity study, single dose of green coffee oil (2000 mg/kg) was administered by gavage in female rats. For subacute study (28 days), 32 male rats received different doses of green coffee oil extract (25, 50, and 75 mg/kg/day). In the acute toxicity study, main findings of this treatment indicated no mortality, body weight decrease, no changes in hematological and biochemical parameters, and relative weight increase in heart and thymus, without histopathological alterations in all assessed organs. All these findings suggest that LD₅₀ is higher than aforesaid dose. In the subacute toxicity, main findings showed body weight decrease mainly at the highest dose without food consumption change, serum glucose and tryglicerides levels decrease, and relative weight increase in liver. As evidenced in histopathological pictures, no changes were observed at all treated doses. Our study suggest that green coffee oil can be explored to clinically develop new hypocholesteromic and hypoglycemic agents. However, further studies evaluating long-term effects are needed in order to have sufficient safety evidence for its use in humans.

Toxicological findings about an anticancer fraction with casearins described by traditional and alternative techniques as support to the Brazilian Unified Health System (SUS)

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts, essential oils and molecules from Casearia sylvestris have popularly shown pharmacological actions against chronic diseases, as anxiety, inflammation, cancer and dyslipidemia. In the context of antitumoral therapy, we investigated in vitro, ex vivo and in vivo toxicological changes induced by a Fraction with Casearins (FC) and its component Casearin X isolated from C. sylvestris on animal and vegetal cells, and upon invertebrates and mammals.

MATERIAL AND METHODS

Cytotoxicity was carried out using normal lines and absorbance and flow cytometry techniques, Artemia salina nauplii, Danio rerio embryos and meristematic cells from Allium cepa roots. Acute and 30 days-mice analysis were done by behavioral, hematological and histological investigations and DNA/chromosomal damages detected by alkaline Cometa and micronucleus assays.

RESULTS

FC was cytotoxic against lung and fibroblasts cells and caused DNA breaks, loss of integrity and mitochondrial depolarization on ex vivo human leukocytes. It revealed 24 h-LC₅₀ values of 48.8 and 36.7 μg/mL on A. salina nauplii and D. rerio embryos, reduced mitotic index of A. cepa roots, leading to cell cycle arrest at metaphase and anaphase and micronuclei. FC showed i.p. and oral LD₅₀ values of 80.9 and 267.1 mg/kg body weight. Subacute i.p. injections induced loss of weight, swelling of hepatocytes and tubules, tubular and glomerular hemorrhage, microvesicular steatosis, lung inflammatory infiltration, augment of GPT, decrease of albumin, alkaline phosphatase, glucose, erythrocytes, and lymphocytes, and neutrophilia (p > 0.05). FC-treated animals at 10 mg/kg/day i.p. caused micronuclei in bone marrow and DNA strand breaks in peripheral leukocytes.

CONCLUSIONS

This research postulated suggestive side effects after use of FC-related drugs, demonstrating FC as antiproliferative and genotoxic on mammal and meristematic cells, including human leukocytes, teratogenicity upon zebrafish embryos, myelosuppression, clastogenicity, and morphological and biochemical markers indicating liver as main target for FC-induced systemic toxicity.

Plants used during maternity, menstrual cycle and other women's health conditions among Brazilian cultures

ETHNOPHARMACOLOGICAL RELEVANCE

For innumerous clinical cases related to women's health and precarious medical care in developing countries, a large repertoire of plants have been used as popular medicines in order to fill this gap, which in a certain way creates health risks to users, since pharmacological and toxicological tests are still insufficient to guarantee their efficacy and safety. Besides therapeutic use, abortive plants are broadly used in countries where abortion is prohibited, increasing that risk even more. In this way, ethnopharmacological studies that register plants used for women's health can contribute not only to the selection of potential bioactives, enriching the repertoire of drugs available to females, above all in public health systems, but also questioning the safety of products that are used without prescription.

AIMS AND OBJECTIVES

This review aims at determining plants applied by Brazilian cultures in the treatment of conditions related to maternity, menstrual cycle and other women's health particularities, and to supplement the lack of epidemiological data available to assess the health of indigenous, rural and other populations of Brazilian women.

MATERIALS AND METHODS

A literature review was conducted of the collection at the Ethnobotanical and Ethnopharmacological Center of the Federal University of São Paulo (period covered: 1965 to 2012). All of the 343 articles were consulted and 31 articles mentioning therapeutic uses of interest were selected. Relevant information was extracted to compose Table 1 - Maternity, Table 2 - Menstrual Cycle and Table 3 - Other Conditions. Data was statistically analyzed in order to generate the discussion about plants used in healing contexts by different Brazilian ethnicities. A bibliographic review was performed using the Scopus database to collect the following information about the most cited plants: ethnobotany/ethnopharmacology of non-Brazilian cultures for women's health conditions, pharmacology, toxicology, and adverse reactions.

RESULTS

A total of 319 species were cited for 22 indications related to women's health. Ninety-seven species were indicated for conditions related to maternity, 94 to the menstrual cycle and 232 to others. The same species could be present in more than one of these three categories. The most cited family was Fabaceae (13.5%), and the species were Ruta graveolens L. (1.76%) and Strychnos pseudoquina A. St.-Hil (1.76%). The most frequent part utilized, mode of preparation and route of administration were leaves (2.0%), tea (73.38%) and oral (87. 2%), respectively. The indications that showed the highest number of species were: to treat venereal diseases (69 species), abortive (54) and anti-inflammatory for the ovaries and/or uterus (54). According to our bibliographic survey, among the 19 most indicated species in this review, only four are also used by non-Brazilian cultures for conditions related to women's health; 25% of them were pharmacologically investigated and it was possible to validate their ethnopharmacological/ethnobotanical use, 10.5% have presented well-described adverse reactions and for 42.1% of these species toxicological studies were performed.

CONCLUSION

The survey raised important data about plants implemented in healing related to women's health conditions by Brazilian cultures and their practices. The compilation presented in this study enables the realization of further investigation regarding the development of herbal medicines and contributes to the incrementation of policies focused on these cultures. Further phytochemical, pharmacological and toxicological studies should be conducted, which will allow the discovery of pharmacological properties, bioactive constituents, and moreover, adequate posology, manner of use and adverse events.