Inhibition of Carrageenan-Induced Acute Inflammation in Mice by the Microgramma vacciniifolia Frond Lectin (MvFL).

Most anti-inflammatory drugs used nowadays have an excessive cost and their prolonged use has been connected with several injurious effects. Thus, the search for new anti-inflammatory agents is increasing. Lectins are carbohydrate-interacting proteins that can modulate immune response and the release of inflammation mediators. The Microgramma vacciniifolia frond lectin (MvFL) was previously reported to be an immunomodulatory agent in vitro. This work aimed to evaluate the effects of MvFL on the in vivo inflammatory status in the carrageenan-induced peritonitis and paw edema, using female Swiss mice. The animals were pretreated intraperitoneally with MvFL (5 and 10 mg/kg). In the peritonitis assay, the total and differential migration of white blood cells was evaluated, as well as the levels of cytokines, nitric oxide (NO), and total proteins in the peritoneal fluid. In the paw edema evaluation, the paw volume was measured in the early (from 30 min-2 h) and late (3-4 h) phases of edema formation. MvFL (5 and 10 mg/kg) was efficient in reducing neutrophil infiltration, pro-inflammatory cytokines (IL-6, IL-17, and TNF-α), NO, and protein content in the peritoneal fluid. It also repressed the edema formation in the late phase of the assay. In conclusion, MvFL showed inhibitory effects in in vivo acute inflammation, which encouraged future studies exploiting its immunomodulatory ability.

Antinociceptive activity of Schinus terebinthifolia leaf lectin (SteLL) in sarcoma 180-bearing mice.

ETHNOPHARMACOLOGY RELEVANCE: Schinus terebinthifolia Raddi leaves have been used in folk medicine due to several properties, including antitumor and analgesic effects. The variable efficacy and adverse effects of analgesic drugs have motivated the search for novel antinociceptive agents. It has been reported that the S. terebinthifolia leaf lectin (SteLL) has antitumor activity against sarcoma 180 in mice. AIM OF THE STUDY: This work aimed to evaluate whether SteLL would reduce cancer pain using an orthotopic tumor model. MATERIALS AND METHODS: A sarcoma 180 cell suspension was inoculated into the right hind paws of mice, and the treatments (150 mM NaCl, negative control; 10 mg/kg morphine, positive control; or SteLL at 1 and 2 mg/kg) were administered intraperitoneally 24 h after cell inoculation up to 14 days. Spontaneous nociception, mechanical hyperalgesia, and hot-plate tests were performed. Further, the volume and weight of the tumor-bearing paws were measured. RESULTS: SteLL (2 mg/kg) improved limb use during ambulation. The lectin (1 and 2 mg/kg) also inhibited mechanical hyperalgesia and increased the latency time during the hot-plate test. Naloxone was found to reverse this effect, indicating the involvement of opioid receptors. The tumor-bearing paws of mice treated with SteLL exhibited lower volume and weight. CONCLUSION: SteLL reduced hyperalgesia due to sarcoma 180 in the paws of mice, and this effect can be related to its antitumor action.

Characterization of 3-aminospirostane alkaloids from roots of Solanum paniculatum L. with hepatoprotective activity.

RATIONALE: Solanum paniculatum L., popularly known as jurubeba, has traditionally been used in Brazilian folk medicine for liver diseases. However, there is a lack of knowledge about the chemical characterization of 3-aminospirostane alkaloids, an important class related to pharmacological activities. This work aimed to characterize the alkaloids using liquid chromatography with tandem mass spectrometry (LC/MS/MS) supported by molecular networking and theoretical calculations as well as to evaluate the contribution to hepatoprotective activity. METHODS: S. paniculatum roots were collected and macerated with MeOH/H2 O (8:2) obtaining the crude extract (SP-CE). From this, partition using EtOAc with pH variation yielded the alkaloidic fraction (SP-AF). Both were evaluated in an acute liver injury model (100 and 200 mg/kg), after intraperitoneal administration of carbon tetrachloride (CCl4 ) in mice. AST (aspartate transaminase) and ALT (alanine transaminase) serum levels were investigated, as well as the histopathological characteristics. The SP-CE and SP-AF were analyzed by LC/MS/MS, using quadrupole/time-of-flight and ion-trap systems. The alkaloids annotated by the GNPS molecular network had their structures defined using gas-phase ionization and fragmentation reaction supported by theoretical calculations. RESULTS: The SP-CE and SP-AF decreased the ALT serum levels compared with the negative control. The group treated with the SP-CE (at the highest dose) demonstrated a significant decrease of ALT. Hepatic cell degeneration decrease was observed mainly at the highest dose of the treatment. Detailed electrospray ionization MS/MS data allowed us to identify alkaloids not previously reported, to propose their gas-phase reactions and to redefine the initial open ring fragmentation mechanism of the steroidal alkaloids with the jurubidine moiety. CONCLUSIONS: The results allowed us to identify seven steroidal alkaloids from jurubeba and redefine the initial mechanism of fragmentation. A significant hepatoprotective effect was also demonstrated, corroborating its traditional use.

Evaluation of antitumor activity and toxicity of Schinus terebinthifolia leaf extract and lectin (SteLL) in sarcoma 180-bearing mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Schinus terebinthifolia Raddi is a plant broadly used in folk medicine and the use of its leaf extract as an antitumor agent has been reported. AIM OF THE STUDY: To evaluate the antitumor potential and the toxicity of saline extract (SE) and lectin (SteLL) from S. terebinthifolia leaves in sarcoma 180-bearing mice. MATERIALS AND METHODS: Cytotoxicity to sarcoma 180 cells was tested in vitro, and antitumor assay was performed using Swiss female mice. The treatments (0.15 M NaCl, negative control; methotrexate 1.5 mg/kg, positive control; SE 100 mg/kg; SteLL 1 and 5 mg/kg) by intraperitoneal injections started on the 8th day after tumor inoculation and lasted 7 days. It was analyzed: tumor weight; number and gauge of tumor vessels; hematological and biochemical parameters; histopathological changes; and occurrence of micronuclei in bone marrow cells. RESULTS: SE and SteLL showed IC50 values (concentrations that reduced cell viability to 50%) of 301.65 and 8.30 µg/mL, respectively. The lectin was able to induce apoptosis. Treatments with the extract and lectin caused a 57.6-73.6% reduction in tumor weight, which was not significantly different from the reduction in the methotrexate group. Tumors of animals treated with SteLL at 5 mg/kg showed reduced number of secondary vessels while the gauge was lower in all treated groups. In the groups treated with SteLL, tumors showed reduced and slightly vascularized parenchyma, with necrosis in the center and at the periphery. No alterations in the blood levels of urea, creatine, and glucose were detected while serum AST level was moderately increased in the SE group. Histopathological analysis revealed vacuolization and steatosis in the liver of animals treated with the extract and lectin. In addition, the treatments with SE and SteLL resulted in the reduction of filtration space and alterations in tubular architecture in kidneys. In respect to hematological parameters, it was only detected increase in the number of monocytes in SE group. The extract and lectin did not induce the formation of micronuclei in the bone marrow cells. CONCLUSIONS: SE and SteLL had antitumor effect against sarcoma 180 without inducing hematological changes and genotoxic effects in mice; however, some degree of hepatic and renal toxicity was observed, suggesting the evaluation of drug delivery strategies in the future.

Antinociceptive Effect of the Essential Oil from Croton conduplicatus Kunth (Euphorbiaceae).

Medicinal plants have been widely used in the treatment of chronic pain. In this study, we describe the antinociceptive effect of the essential oil from Croton conduplicatus (the EO 25, 50, and 100 mg/kg, i.p.), a medicinal plant native to Brazil. Antinociceptive activity was investigated by measuring the nociception induced by acetic acid, formalin, hot plate and carrageenan. A docking study was performed with the major constituents of the EO (E-caryophyllene, caryophyllene oxide, and camphor). The EO reduced nociceptive behavior at all doses tested in the acetic acid-induced nociception test (p < 0.05). The same was observed in both phases (neurogenic and inflammatory) of the formalin test. When the hot-plate test was conducted, the EO (50 mg/kg) extended the latency time after 60 min of treatment. The EO also reduced leukocyte migration at all doses, suggesting that its antinociceptive effect involves both central and peripheral mechanisms. Pretreatment with glibenclamide and atropine reversed the antinociceptive effect of the EO on the formalin test, suggesting the involvement of KATP channels and muscarinic receptors. The docking study revealed a satisfactory interaction profile between the major components of the EO and the different muscarinic receptor subtypes (M2, M3, and M4). These results corroborate the medicinal use of C. conduplicatus in folk medicine.