Antinociceptive and Anti-Inflammatory Activities of the Ethanolic Extract from Synadenium umbellatum Pax. (Euphorbiaceae) Leaves and Its Fractions

Anti-inflammatory and antinociceptive effects of a pectinolide-enriched fraction from Mesosphaerum pectinatum (L.) Kuntze

ETHNOPHARMACOLOGICAL RELEVANCE

Mesosphaerum pectinatum (L.) Kuntze (Lamiaceae), also known as sambacaitá, is a medicinal plant widely used in northeastern Brazil for the treatment of inflammatory and painful conditions, bacterial infections and cancer. Hence, the medicinal use of this species is quite meaningful to the search for bioactive compounds.

AIM OF THE STUDY

To evaluate the antinociceptive and anti-inflammatory activities of the pectinolide-enriched fraction of Mesosphaerum pectinatum (PEF) in animal models.

MATERIALS AND METHODS

The PEF was analyzed with HPLC-DAD and ¹H and ¹³C NMR. After the analysis, compounds of the pectinolide class were detected as major constituents in this fraction. The PEF (50, 100 and 200 mg/kg, p.o.) and the reference drugs - morphine (3.0 mg/kg, p.o.) and dexamethasone (2.0 mg/kg, p.o.) - were evaluated using models for nociception (hot plate, formalin-induced licking response) or inflammation (carrageenan-induced peritonitis and ear edema model).

RESULTS

The PEF significantly decreased the licking time of the animals treated when compared to the control group (second phase). In the carrageenan-induced peritonitis model, PEF (100 and 200 mg/kg) significantly decreased total and differential leukocyte counts. The PEF (0.3, 1.0 and 3.0 mg/ear) significantly reduced mice ear edema at the same extent and like the results obtained with the standard drug (dexamethasone). The MPO activity was reduced in mice ear at doses of 1 and 3 mg/ear. Antinociceptive effect on the hot plate test was not observed, demonstrating that there is no analgesic activity.

CONCLUSION

Our results suggest that the pectinolide-enriched fraction exhibits anti-inflammatory effects and that it is involved with inhibiting the release of the inflammatory mediators.

Bioactive Secondary Plant Metabolites from Euphorbia umbellata (PAX) BRUYNS (Euphorbiaceae)

The species Euphorbia umbellata has been used to treat inflammatory diseases, cancer, and ulcers. Biological activities reported in the literature, including antiproliferative, cytotoxic and anti-inflammatory, are attributed to the chemical constituents present in its composition as terpenes and polyphenolic compounds. The most recurrently verified metabolites in the Euphorbiaceae family plant species are terpenes, of which euphol is a major constituent with broadly reported cytotoxic, antinociceptive and anti-inflammatory effects; it frequently appears in various extracts obtained from the plant. Euphol has a documented inhibitory effect on neutrophil chemotaxis and can modulate the complement system. Since complement system activation is intimately intertwined with autoimmune and inflammatory diseases, tumor growth promotion and metastasis, plant metabolites from Euphorbia umbellata might influence the outcomes of inflammatory processes. We believe that this is the first review presenting the current knowledge on Euphorbia umbellata secondary metabolites and their biological activities.

In vivo antinociceptive and anti-inflammatory potential of hesperidin and its cyclodextrin inclusion compounds

Introduction. This study aims to evaluate the antinociceptive activity on inflammatory and non-inflammatory nociception models, as well as the anti-inflammatory action of hesperidin and its inclusion compounds with beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin. Material and method. For these experiments, we employed nociception models using thermal, chemical and pressure stimuli and an inflammation model for the evaluation of inflammatory edema by plethysmometer test. Results and discussions. The obtained results demonstrate that the HES-βCD inclusion compounds exhibited antinociceptive action predominantly on experimental non-inflammatory nociception models, while HES-HP-βCD exhibited anti-inflammatory and antinociceptive activities predominantly in inflammatory nociception models. Conclusions. This research may be the starting point for future studies regarding the improvement of biopharmaceutical qualities of HES by encapsulation in cyclodextrins. Keywords: hesperidin, cyclodextrin inclusion compunds, antinociceptive, anti-inflammatory activity,

Toxicological and anti-inflammatory profile of Synadenium grantii Hook. f. in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Synadenium grantii Hook. f., popularly known as "janaúba" or "leiterinha", is used in the folk medicine to treat gastric disorders, some types of neoplasias and inflammatory diseases.

AIM OF THE STUDY

The aim of this study was to show the anti-inflammatory activity of the methanol extract obtained from S. grantii stems and also certify the safety of the extract performing toxicological analysis.

MATERIAL AND METHODS

The anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice orally pre-treated with the S. grantii extract (1, 3 or 10 mg/kg). The leukocyte influx (optical microscopy) and secretion of chemical mediators (TNF, IL-6 and IL-1β, by enzyme-linked immunosorbent assay) were quantified in the inflamed exudate. The toxicity was investigated using the dose-fixed procedure (acute toxicity) and repeated dose 28-day (subacute toxicity) in mice orally treated with S. grantii extract. The open field and rota-rod test were used to evaluate possible interference of adverse effect of S. grantii on motor coordination, locomotor and exploratory activity.

RESULTS

The analysis of the inflammatory exudate of S. grantii-treated mice demonstrated reduction in the polymorphonuclear cells (PMN) migration to the inflamed tissue, as well as the reduction of the pro-inflammatory cytokines TNF and IL-1β. Furthermore, the acute and sub-acute toxicity studies did not show significant changes in body weight, general behaviour, biochemical parameters, organ weight and liver and kidney histopathological analysis. However, animals acutely treated with S. grantii presented reduction in the number of crosses in relation to the vehicle group, without significant difference in the number of elevations and latency time between the groups in rota-rod test. The obtained results allow to set the NOAEL (Non-observed-adverse-effect level) in 100 mg/kg for this specie of rodent.

CONCLUSIONS

Together, the results herein obtained show that S. grantii extract presented anti-inflammatory activity by decreasing the influx of PMN to the inflamed tissue, as well as the cytokines TNF and IL-1β levels. In addition, S. grantii extract seemed not to present significant acute or subacute toxicity when administered to mice, demonstrating for the first time the safety of this extract, when orally administered.

A new isoquinoline and ceramide from the stem barks of Discoglypremna caloneura (Pax) Prain (Euphorbiaceae) with antiproteinase and cytotoxic activities

Two new compounds, an isoquinoline (1) and caloneuramide (2), a ceramide were isolated from the stem bark of Discoglypremna caloneura together with seven known compounds namely aurantiamide acetate (3), acetylaleuritolic acid (4), 3α-hydroxylaleuritolic acid 2α-p-hydroxybenzoate (5), mixture of stigmasterol (6) and β-sitosterol (7), mixture of 7-oxo-stigmasterol (8) and 7-oxo-β-sitosterol (9). Their structures were determined based on data from literature and spectroscopic methods. Derivatization reactions on the isoquinoline led to two new compounds, the methylated (10) and acetylated (11) derivatives. Some compounds and extracts were evaluated for their cytotoxic and antiproteinase activity. Antiproteinase effect of compounds 1, 10 and 11 exhibited IC₅₀ values of 10.77, 1.19 and 3.61 μg/mL respectively; significantly low compared to the standard drug, acetyl salicylic acid (IC₅₀ = 20.28 μg/mL). Ethyl acetate and methanol extract exhibited moderate cytotoxicity activity on Chang liver cells with CC₅₀ values of 167.90 ± 2.20 and 106.30 ± 2.03 μg/mL compared to the reference drug cucurmin (CC₅₀ = 11.05 ± 1.04 μg/mL).

Acute Oral Toxicity and Anti-inflammatory and Analgesic Effects of Aqueous and Methanolic Stem Bark Extracts of Piliostigma thonningii (Schumach.)

Inflammation and pain are devastating conditions characterizing many diseases. Their manifestation ranges from mild body discomfort, to a debilitating experience, which may culminate in organ failure or death. In conventional medicine, corticosteroids, nonsteroidal anti-inflammatory drugs, opioids, and adjuvants are utilized to manage symptoms related to pain and inflammation. Despite their reported successes, these agents are only palliative, debatably inaccessible, unaffordable, and cause many undesirable side effects. As a result, the search for alternative and complementary therapies is warranted. Medicinal plants have been intensively utilized by humans for a long time to treat various ailments. In spite of their reported efficacies, empirical scientific data supporting their healing claims is scanty. P. thonningii (Schumach.) has been used in African traditional medicine, especially by traditional herbalists in Nigeria and Kenya, to treat conditions associated with inflammation. Even though analgesic, anti-inflammatory, and toxicity studies have been performed on leaf extracts, and some of their isolated compounds in Nigeria, there is scanty data supporting the use of stem bark extracts, which are commonly utilized in Kenya for pain, and inflammation management. Moreover, scientific data regarding safety and toxicity of the stem bark extracts of P. thonningii utilized in Kenya by traditional herbalists are inadequate. Based on this background, acute oral toxicity evaluation of the aqueous and methanolic stem bark extracts of P. thonningii, in Swiss albino mice, was performed according to the OECD/OCDE (2008) guidelines. Anti-inflammatory activities were investigated using the xylene-induced ear oedema in mice, whereas analgesic activities were examined following the acetic acid-induced writhing technique. The acute oral toxicity data was analyzed, and interpreted according to the OECDE (2008) guidelines. Anti-inflammatory and analgesic activities data were tabulated on MS Excel, and exported to GraphPad Prism (v8.3). Descriptive statistics were computed, and expressed as mean ± SEM. Thereafter, One-Way ANOVA followed by Tukey's test was performed. p < 0.05 was considered statistically significant. All the studied plant extracts had LD50 values > 2000 mg/kg bw, and were hence deemed to be nontoxic according to OECD/OCDE document no. 425. The results showed that the acetic acid-induced writhing frequency in mice administered the aqueous stem bark extract of P. thonningii, at a dose of 500 mg/kg bw, was not significantly different from that recorded for mice which received the reference drug (acetylsalicylic acid 75 mg) (p > 0.05). Additionally, at all the studied extract doses, significantly lower acetic acid-induced writhing frequencies were recorded in mice that received the aqueous stem bark extract of P. thonningii, compared with the writhing frequencies in mice that received the methanolic extract of the same plant (p < 0.05). On the other hand, the aqueous stem bark extract of P. thonningii, at doses of 100 mg/kg bw and 500 mg/kg bw, and the methanolic stem bark extract of the same plant, at a dose level of 500 mg/kg bw, exhibited significantly higher percentage inhibitions of xylene-induced oedema than the percentage inhibitions shown by the reference drug (dexamethasone 1 mg/kg bw) (p < 0.05). Generally, the aqueous stem bark extract of P. thonningii, at all the studied dose levels, caused significantly higher inhibitions of xylene-induced ear oedema in mice, compared with the percentage inhibitions shown by methanolic stem bark (p < 0.05). Therefore, the aqueous, and methanolic stem bark extracts of P. thonningii, grown in Kenya, possess peripheral analgesic and anti-inflammatory activities in Swiss albino mice. Hence, they have a potential of offering safe analgesic, and anti-inflammatory compounds. Further studies aimed at isolating, elucidating, and characterizing bioactive components from the studied extracts are recommended. Moreover, specific mode(s) through which these extracts exert the reported bioactivities should be established. Further toxicological investigations involving the studied plant extracts are encouraged to fully establish their safety.

Anti-ulcer mechanisms of polyphenols extract of Euphorbia umbellata (Pax) Bruyns (Euphorbiaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia umbellata (leitosinha) is used in southern Brazilian folk medicine to treat gastric problems, as well as for its analgesic and anti-inflammatory properties.

AIM OF STUDY

To evaluate the anti-ulcer effects of methanolic bark fraction (MF) against in vivo and in vitro assays, as well as an antioxidant, antibacterial and chromatographic study of this fraction.

MATERIALS AND METHODS

In vivo anti-ulcer activity was performed using ethanol and indomethacin models with different MF concentrations (50, 100 or 200mg/Kg). The stomachs of the animals were applied to histological evaluation, and the serum to evaluate the ABTS(•+) radical capture. The 200mg/Kg dose was used to analyze the mechanisms involved in antiulcerogenic properties of methanolic fraction. The in vitro activity was performed using several different antioxidant assays, in addition to anti-Helicobacter pylori and anti-urease experiments. The chromatographic study was carried out by LC-MS analysis.

RESULTS

Pharmacological investigation of the MF showed an anti-ulcer potential in ethanol and indomethacin in vivo assays. The material presented a high antioxidant activity for several oxidant in vitro systems (DPPH(•), ABTS(•+), O2(•-), HOCl, TauCl and HRP), as well as an ABTS(•+) capture increasing (7.5%) by the treated animals serum (when compared to the negative control). Prostaglandins, nitric oxide/ cyclic guanosine monophosphate pathway and involvement of the protein components of the glutathione complex are some of the mechanisms related with this potential anti-ulcer action. The histological examination of the stomachs of the animals showed that the MF also prevents local action of offensive agents. Chemical analysis using LC-QTOF-MS revealed the presence of ellagic and gallic acid derivatives and flavonols.

CONCLUSION

The findings provide scientific basis to the ethnopharmacological purpose of the studied plant and the biological activities of MF of E. umbellata stem bark may be due to the presence of phenolic compounds.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.