Antibothropic action ofCasearia sylvestris Sw. (Flacourtiaceae) extracts

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.

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.

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.

Macroscopic, biochemical and hystological evaluation of topical anti-inflammatory activity of Casearia sylvestris (Flacourtiaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory skin diseases presents high prevalence and lack of alternatives that can be used for self-care by the population. Casearia sylvestris is a plant used topically in different communities in Brazil, to treat wounds or promote cutaneous healing. To evaluate the topical anti-inflammatory activity for the crude hydroalcoholic extract of Casearia sylvestris (HCE-CS) in the models of single or multiple administration of chroton oil to induce ear edema in mice.

MATERIALS AND METHODS

Experimental study using male Swiss mice (25-35g) kept under constant conditions in the Laboratory of Experimental Neuroscience (LaNEx)-UNISUL. Edema was induced in both models, respectively, by the single or multiple application of croton oil (CO, 2.5%, in 20 μl) on the external surface of the ear. The different groups of animals (n = 8) received different treatments: vehicle, dexamethasone (DEXA) or different doses of HCE-CS. Edema was evaluated macroscopically for 6 h (early edema) or 8 days (late edema) after the first application of the CO and immediately after the animals were submitted to euthanasia for the collection of the samples (treated ears). For early edema, the tissue was biochemically evaluated for myeloperoxidase activity (MPO) and levels of nitrite/nitrate. In the late edema model, the ears were histologically evaluated for general morphometry, degranulated and non-degranulated mast cells, as well as acanthosis.

RESULTS

Topic treatment with HCE-CS significantly reduced the early and late edema, as well as MPO activity and tissue levels of nitrite/nitrate. Finally, in the late edema model there was a lower density of degranulated mast cells in relation to the vehicle treated group and decreased thickness of the epidermis (acanthosis).

CONCLUSION

These results suggest a possible benefit of topical treatment with HCE-CS in inflammatory conditions of the skin.

Chemical Constituents and Pharmacological Activities of Family Flacourtiaceae: A Class of Important Phytomedicine

Flacourtiaceae plants are widely used as folk medicines in traditional medicine systems for its chemical diversity and pharmacological activities. In many different areas, Flacourtiaceae plants are used as traditional medicines for the treatment of ulcers, malaria, rheumatism. The Flacourtiaceae plants contain a very plentiful chemical composition, and phytochemical studies show that the Flacourtiaceae plants contained terpenoids, aromatic glycosides, flavnoids, phenylpropanoids, alkaloids, fatty hydrocarbon, and other compounds. In pharmacological studies, various extract and isolated individual compounds exhibited antitumor, anti-oxidation, and anti-inflammatory activities. In this review, the literature data on the chemical constituents and pharmacological investigations of the Flacourtiaceae plants are summarized, to provide information about a more comprehensive chemical composition and detailed pharmacological activities of Flacourtiaceae plants, with a view of further development of clinical medication. However, research on quantitative analysis, toxicity, and drug safety in vitro and in vivo is still insufficient, and further research is required.

Plants and Phytocompounds Active Against Bothrops Venoms

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Snakebite envenomation is an important health problem in tropical countries, with severe human and social consequences. In Latin America, the Bothrops species constitute the main threat to humans, and the envenomation caused by these species quickly develops into severe local tissue damage, including swelling, hemorrhaging, myonecrosis, skin ulceration, and pain. The systemic effects of envenomation are usually neutralized by antivenom serum therapy, despite its intrinsic risks. However, neutralization of local tissue damage remains a challenge. To improve actual therapy, two major alternatives are proposed: the rational design of new specific antibodies for most of the tissue damaging/ poor immunogenic toxins, or the search for new synthetic or natural compounds which are able to inhibit these toxins and complement the serum therapy. Natural compounds isolated from plants, mainly from those used in folk medicine to treat snakebite, are a good choice for finding new lead compounds to improve snakebite treatment and minimize its consequences for the victims. In this article, we reviewed the most promising plants and phytocompounds active against bothropic venoms.

In vitro and in vivo anti-Helicobacter pylori activity of Casearia sylvestris leaf derivatives

ETHNOPHARMACOLOGICAL RELEVANCE

The number of bacterial strains that are resistant to multiple conventional antimicrobial agents is increasing. In this context, natural products have been widely used as a strategy to treat diseases caused by bacteria. Infections by Helicobacter pylori have attracted attention because they are directly related to severe gastric medical conditions. Casearia sylvestris Swartz, popularly known as guaçatonga, is largely employed to treat gastric disorders in Brazilian folk medicine. This plant species has aroused much interest mainly because it displays anti-inflammatory activity and can act as an antiulcer agent.

AIM OF THE STUDY

To evaluate the in vitro and in vivo anti-H. pylori action of C. sylvestris leaf derivatives incorporated or not in a nanostructured drug delivery system.

MATERIALS AND METHODS

The essential oil (obtained by hydrodistillation) and ethanolic extract (obtained by maceration) were obtained from C. sylvestris leaves. The ethanolic extract was submitted to fractionation through solid phase extraction and column chromatography, to yield the ethanolic fractions. Hydrolyzed casearin J was achieved by submitting isolated casearin J to acid hydrolysis. The derivatives were chemically characterized by nuclear magnetic resonance (NMR), gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS) analyses. A nanostructured lipid system was used as drug delivery system. To assess the in vitro antibacterial activity of C. sylvestris leaf essential oil, ethanolic extract, and derivatives, microdilution, biofilm, and time-kill assays were performed against H. pylori ATCC 43504. Finally, the in vivo action was investigated by employing male Wistar rats experimentally infected with H. pylori.

RESULTS

Many C. sylvestris leaf derivatives presented significant in vitro activity against H. pylori. Among the derivatives, fraction 2 (F2) was the most effective. In vivo tests showed that both the ethanolic extract and F2 decreased the ulcerative lesion size, but only the ethanolic extract eradicated H. pylori from the gastric lesions. Incorporation of plant derivatives in nanostructured lipid system blunted the in vitro action, as demonstrated by the microdilution assay. However, this incorporation improved the ethanolic extract activity against biofilms.

CONCLUSION

C. sylvestris leaf derivatives are effective against H. pylori both in vitro and in vivo. According to phytochemical analyses, these derivatives are rich in terpenoids, which could be related to the anti-H. pylori action. Synergism could also underlie C. sylvestris efficacy judging from the fact that the sub-fractions and isolated compounds had lower activity than the extract. Incorporation in a nanostructured lipid system did not improve the activity of the compounds in our in vivo protocol.

Anti-ophidian activity of Bredemeyera floribunda Willd. (Polygalaceae) root extract on the local effects induced by Bothrops jararacussu venom

Bredemeyera floribunda roots are popularly used to treat snakebites in the semiarid region of Northeast Brazil, and previous studies indicate the anti-ophidian actions of triterpenoid saponins found in its roots. To assess B. floribunda root extract (BFRE) activity against the effects of Bothrops jararacussu venom (BjuV), antiphospholipasic, antiproteolytic, antihemorrhagic, antinecrotic, and anti-edematogenic activities were investigated in mice. Phytochemical analysis revealed the presence of saponins, flavonoids, and sugars, with rutin and saccharose being the major constituents of BFRE. Acute toxicity was determined and BFRE was nontoxic to mice. Phospholipase A2 and proteolytic activities induced by BjuV were inhibited in vitro by BFRE at all concentrations tested herein. BFRE (150 mg/kg) inhibited paw edema induced by BjuV (50 µg/animal), reducing total edema calculated by area under the curve, but carrageenan-induced paw edema was unchanged. Hemorrhagic and necrotizing actions of BjuV (50 µg/animal) were considerably decreased by BFRE treatment. Thus, BFRE blocked the toxic actions of B. jararacussu venom despite having no anti-inflammatory activity, which points to a direct inhibition of venom's toxins, as demonstrated in the in vitro assays. The larger amounts of rutin found in BFRE may play a role in this inhibition, since 3',4'-OH flavonoids are known inhibitors of phospholipases A2.

Medicinal Plants for the Treatment of Local Tissue Damage Induced by Snake Venoms: An Overview from Traditional Use to Pharmacological Evidence

Snakebites are a serious problem in public health due to their high morbimortality. Most of snake venoms produce intense local tissue damage, which could lead to temporary or permanent disability in victims. The available specific treatment is the antivenom serum therapy, whose effectiveness is reduced against these effects. Thus, the search for complementary alternatives for snakebite treatment is relevant. There are several reports of the popular use of medicinal plants against snakebites worldwide. In recent years, many studies have been published giving pharmacological evidence of benefits of several vegetal species against local effects induced by a broad range of snake venoms, including inhibitory potential against hyaluronidase, phospholipase, proteolytic, hemorrhagic, myotoxic, and edematogenic activities. In this context, this review aimed to provide an updated overview of medicinal plants used popularly as antiophidic agents and discuss the main species with pharmacological studies supporting the uses, with emphasis on plants inhibiting local effects of snake envenomation. The present review provides an updated scenario and insights into future research aiming at validation of medicinal plants as antiophidic agents and strengthens the potentiality of ethnopharmacology as a tool for design of potent inhibitors and/or development of herbal medicines against venom toxins, especially local tissue damage.

Anti-Inflammatory and Antibothropic Properties of Jatropha Elliptica, a Plant from Brazilian Cerrado Biome

Purpose: The aim of this study was to evaluate the antibothropic and anti-inflammatory properties of J. elliptica.Methods: Phytochemical screening and thin-layer chromatography (TLC) assays were performed on J. elliptica hydroalcoholic extract (TE) in order to observe its main constituents. The antibothropic activity of TE was evaluated by the in vitro neuromuscular blockade caused by Bothrops jararacussu venom (Bjssu), in a mouse phrenic nerve-diaphragm model (PND). A quantitative histological study was carried out to observe a possible protection of TE against the venom myotoxicity. The anti-inflammatory activity was also evaluated in two models, Bjssu-induced paw edema, and carrageenan-induced neutrophils migration in the peritoneal cavity. Results: TLC analysis revealed several compounds in TE, such as saponins, alkaloids, and phenolic constituents. TE was able to neutralize the blockade and the myotoxicity induced by venom, when it was pre-incubated for 30 min with venom. In addition, it showed anti-inflammatory activity, inducing less neutrophils migration and reducing paw edema. Conclusion:J. elliptica showed both antibothropic and anti-inflammatory properties.

Structural Basis for the Inhibition of a Phospholipase A2-Like Toxin by Caffeic and Aristolochic Acids

One of the main challenges in toxicology today is to develop therapeutic alternatives for the treatment of snake venom injuries that are not efficiently neutralized by conventional serum therapy. Venom phospholipases A2 (PLA2s) and PLA2-like proteins play a fundamental role in skeletal muscle necrosis, which can result in permanent sequelae and disability. This leads to economic and social problems, especially in developing countries. In this work, we performed structural and functional studies with Piratoxin-I, a Lys49-PLA2 from Bothropspirajai venom, complexed with two compounds present in several plants used in folk medicine against snakebites. These ligands partially neutralized the myotoxic activity of PrTX-I towards binding on the two independent sites of interaction between Lys49-PLA2 and muscle membrane. Our results corroborate the previously proposed mechanism of action of PLA2s-like and provide insights for the design of structure-based inhibitors that could prevent the permanent injuries caused by these proteins in snakebite victims.

Healing activity of Casearia sylvestris Sw. in second-degree scald burns in rodents

BACKGROUND

Every year thousands of people are victims of burns, mainly scald burns. Many of these victims have small size wounds and superficial partial thickness and do not seek specialized medical care. As in Brazil Casearia sylvestris Sw., popularly known as guaçatonga is widely used for its analgesic, antiseptic and anti-inflammatory activities, this study sought to evaluate the effects of its hydroalcoholic extract in healing process of burns injuries.

METHODS

The obtained extract was validated applying a thin layer chromatography and sophisticated validation method using Bothrops jararacussu snake venom that is necrotic and inflammatory, and by which guaçatonga extract was able to neutralize the irreversible neuromuscular blockade induced by the venom. After induction of the scald injury, the animals were treated daily with saline solution spray; spray containing extract; biofilm; or biofilm impregnated with extract.

RESULTS

Significant differences were observed between the four groups studied considering: extension of the healing area, neovascularization, fibroblast proliferation, and epithelialization.

CONCLUSION

The anti-inflammatory and bactericidal effects of C. sylvestris Sw. suggests a potential therapeutic benefit in the treatment of inflammatory conditions in second-degree scald burn injuries, as well as, counteracting against the in vitro paralysis induced by B. jararacussu venom.

Investigation of skin permeation, ex vivo inhibition of venom-induced tissue destruction, and wound healing of African plants used against snakebites

ETHNOPHARMACOLOGICAL RELEVANCE

Snakebite envenomation causes 5000-10,000 mortalities and results in more than 5-15,000 amputations in sub-Saharan Africa alone every year. The inaccessibility of antiserum therapy is a vast problem, and only about 2.5% of the actual need for antiserum in Africa is covered. Numerous plants have shown in vitro inhibitory activity against one or more of the hydrolytic enzymes involved in snakebite-induced necrosis. However, a more thorough examination of the plant species in ex vivo and in vitro cell assay models is needed to test their ability to inhibit necrosis.

MATERIALS AND METHODS

Extracts which had previously shown in vitro inhibitory activity against necrosis enzymes, were tested in an ex vivo air-liquid-interface model, and a wound healing scratch assay as well as for their ability to permeate the skin barrier and inhibit venom induced cell death.

RESULTS

Of the 14 water extracts and 16 ethanol extracts tested at a concentration of 10 μg/mL, only the ethanol extracts of Tamarindus indica and Paullinia pinnata resulted in a small but significant increase in cell migration of around 10% compared to treatment with buffer after 24h treatment. The remaining extracts showed no effect, or they even delayed the cell migration compared to the treatment with buffer. After 48 h treatment, 10 of the tested extracts showed a decreased cell migration compared to no treatment. At a 100 μg/mL concentration all the extracts inhibited cell migration and five extracts killed some of the cells, while four extracts killed all the cells. Ten of the thirty extracts were tested in a Franz cell set-up but none of the extracts tested did permeate the skin barrier over a 48 h period, and will therefore be of very limited use topically in the initial treatment of snakebites in its present form. None of the extracts were able to directly interact with the enzyme to lower the cell toxicity of the venom. Two extracts, Dichrostachys cinerea and Grewia mollis, were tested in the ex vivo model, but none of them inhibited the tissue destruction caused by venom.

CONCLUSION

On the basis of this study, topical treatment with plant extracts for snakebite-induced tissue necrosis cannot be recommended.

An isoflavone from Dipteryx alata Vogel is active against the in vitro neuromuscular paralysis of Bothrops jararacussu snake venom and bothropstoxin I, and prevents venom-induced myonecrosis

Snakebite is a neglected disease and serious health problem in Brazil, with most bites being caused by snakes of the genus Bothrops. Although serum therapy is the primary treatment for systemic envenomation, it is generally ineffective in neutralizing the local effects of these venoms. In this work, we examined the ability of 7,8,3'-trihydroxy-4'-methoxyisoflavone (TM), an isoflavone from Dipteryx alata, to neutralize the neurotoxicity (in mouse phrenic nerve-diaphragm preparations) and myotoxicity (assessed by light microscopy) of Bothrops jararacussu snake venom in vitro. The toxicity of TM was assessed using the Salmonella microsome assay (Ames test). Incubation with TM alone (200 μg/mL) did not alter the muscle twitch tension whereas incubation with venom (40 μg/mL) caused irreversible paralysis. Preincubation of TM (200 μg/mL) with venom attenuated the venom-induced neuromuscular blockade by 84% ± 5% (mean ± SEM; n = 4). The neuromuscular blockade caused by bothropstoxin-I (BthTX-I), the major myotoxic PLA₂ of this venom, was also attenuated by TM. Histological analysis of diaphragm muscle incubated with TM showed that most fibers were preserved (only 9.2% ± 1.7% were damaged; n = 4) compared to venom alone (50.3% ± 5.4% of fibers damaged; n = 3), and preincubation of TM with venom significantly attenuated the venom-induced damage (only 17% ± 3.4% of fibers damaged; n = 3; p < 0.05 compared to venom alone). TM showed no mutagenicity in the Ames test using Salmonella strains TA98 and TA97a with (+S9) and without (−S9) metabolic activation. These findings indicate that TM is a potentially useful compound for antagonizing the neuromuscular effects (neurotoxicity and myotoxicity) of B. jararacussu venom.

Vellozia flavicans Mart. ex Schult. hydroalcoholic extract inhibits the neuromuscular blockade induced by Bothrops jararacussu venom

Background

Snakebite is a significant public health issue in tropical countries. In Brazil, some of the most common snake envenomations are from Bothrops. Bothrops bites trigger local and systemic effects including edema, pain, erythema, cyanosis, infections, and necrosis. Vellozia flavicans is a plant from the Brazilian “cerrado” (savanna) that is popularly used as an anti-inflammatory medicine. Since inflammation develops quickly after Bothrops bites, which can lead to infection, the aim of the present study was to observe possible anti-snake venom and antimicrobial activities of V. flavicans (Vf).

Methods

The chromatographic profile of the main constituents from the Vf leaf hydroalcoholic extract was obtained by thin-layer chromatography (TLC). The anti-snake venom activity was measured by Vf’s ability to neutralize the in vitro neuromuscular blockade caused by Bothrops jararacussu venom (Bjssu) in a mouse phrenic nerve-diaphragm model (PND). After a 20 min incubation, preparations of PND were added to Tyrode’s solution (control); Vf (0.2, 0.5, 1, and 2 mg/mL); 40 μg/mL Bjssu; pre-incubation for 30 min with Bjssu and 1 mg/mL Vf; and a Bjssu pretreated preparation (for 10 min) followed by 1 mg/mL Vf. Myographic recording was performed, and the contractile responses were recorded. The antimicrobial activity (minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC]) was obtained for Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis, using gentamicin and vancomycin as positive controls.

Results

TLC analysis yielded several compounds from Vf, such as flavonoids (quercetin) and phenolic acids (chlorogenic acid). Bjssu completely blocked the contractile responses of PND preparations, while Vf preserved 97% (±10%) of the contractile responses when incubated with Bjssu. In the PND pretreated with Bjssu, Vf was able to inhibit the neuromuscular blockade progress. MIC and MBC of Vf ranged from 2.5 to 5.0 mg/mL for P. aeruginosa and S. aureus strains, while no antimicrobial activity was observed for E. coli and E. faecalis.

Conclusions

The hydroalcoholic extract from Vf leaves was able to neutralize and decrease the in vitro neuromuscular blockade caused by Bjssu. However, it did not show significant antimicrobial activity against the tested bacteria.

Cytotoxic clerodane diterpenoids from the leaves and twigs of Casearia balansae

Ten new clerodane diterpenoids (1-10), caseabalansins A-G, 18-epicaseabalansin A, 2-epicaseabalansin B, and 2-epicaseabalansin C, one new triterpenoid, balansinone (11), and seven known diterpenoids (12-18) were obtained from the leaves and twigs of Casearia balansae. Compounds 1 and 2 are the first examples of clerodane diterpenoids with an oxygen bridge between C-2 and C-19, and compounds 5-7 are three new diterpenoid artifacts presumably formed during the extraction process. The structures of the new compounds were established on the basis of extensive spectroscopic data, and that of 11 was verified by single-crystal X-ray crystallographic analysis. Compound 15 showed cytotoxic activity against the tumor cell lines PC3, DU145, SKOV3, and A549 with IC₅₀ values of 4.5, 4.3, 5.1, and 5.7 μM, respectively. Compounds 1a, 2a, and 4 showed selective activity against PC3 tumor cells.

Cytotoxic evaluation of Melia azedarach in comparison with, Azadirachta indica and its phytochemical investigation

BACKGROUND

Melia azedarach L. is an important medicinal plant that is used for variety of ailments in Iranian traditional medicine. Azadirachta indica A. Juss is its allied species and possesses similar properties and effects. The present study was undertaken to investigate anticancer activity of these M. azedarach in comparison with A. indica on cancer cell lines and also to evaluate their safety in humans by testing them on normal cell line. The study also aimed to determine the active components that are responsible for medicinal effects of M. azedarach in traditional usages.

METHODS

In this study, the cytotoxic activity of crude extracts from M. azedarach and A. indica leaves, pulps and seeds as well as three main fractions of their leaf extracts were assayed against HT-29, A-549, MCF-7 and HepG-2 and MDBK cell lines. MTT assay was used to evaluate their cytotoxic activities. Methanol leaf fraction of M. azedarach as the safest leaf fraction in terms of cytotoxicity was subjected for phytochemical study.

RESULTS

Results of the present study indicated that seed kernel extract of M. azedarach had the highest cytotoxic activity and selectivity to cancer cell lines (IC50 range of 8.18- 60.10 μg mL-1). In contrast to crude seed extract of A. indica, crude pulp and crude leaf extracts of this plant showed remarkably stronger anti-prolifrative activity (IC50 ranges of 83.45 - 212.16 μg mL-1 and 34.11- 95.51 μg mL-1 respectively) than those of M. azedarach (all IC50 values of both plants > 650 μg mL-1). The phytochemical analysis led to the isolation of four flavonol 3-O-glycosides including rutin, kaempferol-3-O-robinobioside, kaempferol-3-O-rutinoside and isoquercetin along with a purin nucleoside, β-adenosine.

CONCLUSIONS

The anti-prolifrative potentials of extracts from different parts of M. azedarach and A. indica were determined. By comparison, methanol leaf fraction of M. azedarach seems to be safer in terms of cytotoxicity. Our study shows that flavonols are abundant in the leaves of M. azedarach and these compounds seem to be responsible for many of medicinal effects exploited in the traditional uses.

Cross-cultural comparison of medicinal floras used against snakebites

ETHNOPHARMACOLOGICAL RELEVANCE

Envenomation causes an estimated 1.8-2.5 million incidences per year with a mortality level of 100-125,000 persons annually and more than 100,000 individuals suffer from severe complications, which may end in amputation of the attacked limb. The use of plants is a major part of the traditional practitioners' treatment of snakebites.

MATERIALS AND METHODS

A database was created for plants used to treat snakebites worldwide. From this database, we selected five countries with a high number of entries and representing different cultures, geography and floristic zones: Brazil, Nicaragua, Nepal, China and South Africa. The datasets were analysed by regression and binominal analysis to see if any family or genus used against snakebites was overrepresented in the respective traditional medicinal systems relative to the abundance in the local flora. The families from the different geographical areas were compared to ascertain whether the same plant families are preferred by different peoples.

RESULTS

Three 'hot' families (Apocynaceae, Lamiaceae and Rubiaceae) were recovered in at least two of the five compared countries in the regression analyses and one 'hot' family (Zingiberaceae) was recovered in two of the compared countries in the binomial analyses. Four out of five floras possess families identified as outliers in both regression and binomial analyses. Eight families were recovered by both the binomial and the regression analysis (40-62% of all highlighted families respectively). At the genus level, only Piper (Piperaceae) was recovered as a 'hot' genus in at least two floras. Seven genera were highlighted by both analyses (25-44% of the highlighted genera).

CONCLUSIONS

Cross-cultural comparison of medicinal floras used against snakebites appears to be useful for highlighting candidate families and genera for further studies.

Crystallization and preliminary X-ray diffraction analysis of a Lys49-phospholipase A2 complexed with caffeic acid, a molecule with inhibitory properties against snake venoms

Phospholipases A(2) (PLA(2)s) are one of the main components of bothropic venoms; in addition to their phospholipid hydrolysis action, they are involved in a wide spectrum of pharmacological activities, including neurotoxicity, myotoxicity and cardiotoxicity. Caffeic acid is an inhibitor that is present in several plants and is employed for the treatment of ophidian envenomations in the folk medicine of many developing countries; as bothropic snake bites are not efficiently neutralized by conventional serum therapy, it may be useful as an antivenom. In this work, the cocrystallization and preliminary X-ray diffraction analysis of the Lys49-PLA(2) piratoxin I from Bothrops pirajai venom in the presence of the inhibitor caffeic acid (CA) are reported. The crystals diffracted X-rays to 1.65 Å resolution and the structure was solved by molecular-replacement techniques. The electron-density map unambiguously indicated the presence of three CA molecules that interact with the C-terminus of the protein. This is the first time a ligand has been observed bound to this region and is in agreement with various experiments previously reported in the literature.

Chemical constituents of the bark of Dipteryx alata vogel, an active species against Bothrops jararacussu venom

The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The active CH₂Cl₂ sub-extract has been extensively analyzed for its chemical constituents, resulting in the isolation of four lupane-type triterpenoids: lupeol (1), lupenone (2), 28-hydroxylup-20(29)-en-3-one (3), betulin (4), nine isoflavonoids: 8-O-methylretusin (5), 7-hydroxy-5,6,4’-trimethoxyisoflavone (6), afrormosin (8), 7-hydroxy-8,3’,4’-trimethoxyisoflavone (9), 7,3’-dihydroxy-8,4’-dimethoxyisoflavone (10), odoratin (11), 7,8,3’-trihydroxy-4’-methoxyisoflavone (13), 7,8,3’-trihydroxy-6,4’-dimethoxyisoflavone (15), dipteryxin (17), one chalcone: isoliquiritigenin (7), one aurone: sulfuretin (14) and three phenolic compounds: vanillic acid (12), vanillin (16), and protocatechuic acid (18). Their chemical structures were elucidated on the basis of spectroscopic analysis, including HRMS, 1D- and 2D-NMR techniques.

In vitro antiophidian properties of Dipteryx alata Vogel bark extracts

Extracts from Dipteryx alata bark obtained with different solvents (hexane, dichloromethane, ethyl acetate and methanol) were mixed in vitro with Bothrops jararacussu (Bjssu, 40 μg/mL) and Crotalus durissus terrificus (Cdt, 15 μg/mL) snake venoms, and applied to a mouse phrenic nerve-diaphragm preparation to evaluate the possible neutralization of venom effects. Cdt venom neurotoxic effect was not inhibited by any of the extracts, while the neurotoxic and myotoxic actions of Bjssu venom were decreased by the methanolic extract. This inhibition appears to be augmented by tannins. Dichloromethane bark extract inhibited ~40% of Bjssu venom effects and delayed blockade induced by Cdt. The methodology used to determine which extract was active allows inferring that: (i) phenolic acids and flavonoids contained in the methanolic extract plus tannins were responsible mostly for neutralization of Bjssu effects; (ii) terpenoids from the dichloromethane extract may participate in the anti-Cdt and anti-Bjssu venom effects; (iii) a given extract could not inhibit venoms from different species even if those belong to the same family, so it is improper to generalize a certain plant as antiophidian; (iv) different polarity extracts do not present the same inhibitory capability, thus demonstrating the need for characterizing both venom pharmacology and the phytochemistry of medicinal plant compounds.