Solid lipid nanoparticles improve octyl gallate antimetastatic activity and ameliorate its renal and hepatic toxic effects.

Metastasis is the main cause of cancer-related death and requires the development of effective treatments with reduced toxicity and effective anticancer activity. Gallic acid derivatives have shown significant biological properties including antitumoral activity as shown in a previous study with octyl gallate (G8) in vitro. Thus, the aim of this work was to evaluate the antimetastatic effect of free and solid lipid nanoparticle-loaded G8 in mice in a lung metastasis model. Animals inoculated with melanoma cells presented metastasis in lungs, which was significantly inhibited by treatment with G8 and solid lipid nanoparticle-loaded G8, named G8-NVM. However, G8-treated mice showed an increase in several toxicological parameters, which were almost completely circumvented by G8-NVM treatment. This study supports the need for pharmacological studies on new potential medicinal plants to treat cancer and can provide new perspectives on using nanotechnology to improve biological activities while decreasing the chemotherapy toxicological effects of anticancer drugs.

Pyrazolines as potential anti-Alzheimer's agents: DFT, molecular docking, enzyme inhibition and pharmacokinetic studies.

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized as the main dementia in the elderly. Eighteen pyrazolines were synthesized and evaluated for their inhibitory effects against acetylcholinesterase (AChE) in vitro. Possible interactions between pyrazolines and the enzyme were explored by in silico experiments. Compound 2B of the series was the most active pyrazoline with an IC50 value of 58 nM. Molecular docking studies revealed two important π-π interactions with residues Trp 286 and Tyr 341. A correlation between the HOMO-1 surface and AChE inhibition was observed. ADMET assays demonstrated a good profile for compound 2B. From the abovementioned findings, a new avenue of compound 2B analogues could be explored to develop anti-AD agents.

Ester derivatives of gallic acid with potential toxicity toward L1210 leukemia cells.

Gallic acid and gallates with the same number of hydroxyl groups and varying the length of the side carbon chain, with respective lipophilicity being defined through the ClogP values, were examined for their ability to induce apoptosis (through the DNA ladder fragmentation pattern), mitochondrial and cytoplasmic GSH depletion and NF-kappaB activation in murine lymphoblastic L1210 leukemia cells. A relationship between cytotoxic effect and a limited degree of lipophilicity was observed.

Antiproliferative effects of a series of cyclic imides on primary endothelial cells and a leukemia cell line.

The present study describes the cytotoxic properties of a series of 15 cyclic imides observed against different endothelial cells and K562 leukemic cells. Initially, eight structurally unrelated compounds were evaluated against cultured bone marrow endothelial cells (BMEC) and human umbilical vein endothelial cells (HUVEC). Only two imides showed cytotoxic activity at 10 microM. In continuation of our screening, eight compounds, structurally related to the compound with the higher cytotoxic activity, were assayed against endothelial cells and the K562 leukemic cell line. All of these new compounds except two exhibited cytotoxic and antiproliferative activities at concentrations below 10 microM against BMEC and HUVEC, respectively. The K562 leukemia cell line was only affected by concentrations of 100 microM. Preliminary SAR analysis indicated that the cytotoxic activity of these compounds was related to the presence of a planar imide ring directly bound to an aromatic ring.

Non-peptide antagonists for kinin B1 receptors: new insights into their therapeutic potential for the management of inflammation and pain.

Kinin B1 and B2 receptors are central to the aetiology of pain and inflammation. Constitutive B2 receptors are commonly associated with the acute phase of inflammation and nociception, whereas the inducible B1 receptors are mostly linked to the chronic or persistent phase (or both). Therefore, selective, orally active kinin B1 receptor antagonists could be potentially therapeutic. B1 receptor antagonists have long been exclusively peptides, but recently a few non-peptide representatives have been identified. The clinical potential of these non-peptide molecules has not yet been evaluated, but they might have a role in treating persistent inflammation and pain, especially when no satisfactory therapy is available. This review summarizes recent advances in the identification and the potential therapeutic properties of these molecules.

Antibacterial activity of extract, fractions and four compounds extracted from Piper solmsianum C. DC. VAR. solmsianum (Piperaceae).

Piper solmsianum C. DC. var. solmsianum (Piperaceae) is a shrub commonly found in areas with wet tropical soils. Other Piper species have been used in folk medicine as antitumoral and antiseptic agents. We studied the crude methanolic extract, some organic fractions and compounds isolated from this plant for possible antimicrobial activity against Gram-positive and Gram-negative bacteria. The bioautographic assays disclosed three inhibition zones. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined showing excellent activity, particularly against the Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus, Staphylococcus saprophyticus and Streptococcus agalactiae). It appears that the antimicrobial activity of Piper solmsianum is related mainly to the presence of conocarpan and eupomatenoid-5 (neolignans). However another, as yet unidentified, active compound could also be extracted from the plant.

Pharmacological characterisation of the plant sesquiterpenes polygodial and drimanial as vanilloid receptor agonists.

This study was designed to assess the participation of transient receptor potential vanilloid 1 (TRPV1) in the biological effects induced by the plant-derived sesquiterpenes polygodial and drimanial. In rat isolated urinary bladder, polygodial and drimanial produced a tachykinin-mediated contraction that was inhibited by combination of NK(1) and NK(2) tachykinin receptor antagonists, SR 140333 and SR 48968. Furthermore, two different TRPV1 antagonists, capsazepine and ruthenium red prevented the contraction induced by both compounds. In addition, capsaicin, polygodial and drimanial displaced in a concentration-dependent manner the specific binding sites of [(3)H]-resiniferatoxin to rat spinal cord membranes, with a IC(50) values of 0.48, 4.2 and 3.2 microM, respectively. Likewise, capsaicin, polygodial and drimanial promoted an increase of [(45)Ca(2+)] uptake in rat spinal cord synaptosomes. In cultured rat trigeminal neurons, polygodial, drimanial and capsaicin were also able to significantly increase the intracellular Ca(2+) levels, effect that was significantly prevented by capsazepine. Together, the present results strongly suggest that the pharmacological actions of plant-derived sesquiterpenes polygodial and drimanial, seem to be partially mediated by activation of TRPV1. Additional investigations are needed to completely define the pharmacodynamic properties of these sesquiterpenes.

Anti-edematogenic effects of velutinol A isolated from Mandevilla velutina: evidence for a selective inhibition of kinin B1 receptor-mediated responses.

This study assesses the effects of compound velutinol A obtained from M. velutina in the rat paw edema induced by several phlogistic agents. Attempts were made to analyze how velutinol A is able to inhibit kinin B(1) receptor-mediated inflammatory responses. Velutinol A (100 nmol/paw) partially reduced (about 30%) the edema evoked by carrageenan (300 microg/paw). However, velutinol A (100 nmol/paw) failed to affect the edema induced by histamine (200 nmol/paw), substance P (30 nmol/paw), PAF (10 nmol/paw) or BK (3 nmol/paw). Interestingly, the edema caused by the selective kinin B(1) receptor agonist des-Arg(9)-BK (100 nmol/paw) in animals pre-treated with PAF or LPS was significantly inhibited by velutinol A (100 nmol/paw) (48 and 46%, respectively). A similar inhibition of des-Arg(9)-BK-induced edema after pre-treatment with PAF was obtained with the non-peptidic and selective B(1) receptor antagonist SSR 240612 (60 nmol/paw) (46%). In addition, the systemic administration of velutinol A (10 mg/kg, i.p.) or SSR 240612 (1 mg/kg, i.p.) also caused a significant reduction of des-Arg(9)-BK (100 nmol/paw)-induced edema in PAF-treated rats (51 and 43%, respectively). The results provide convincing evidence that velutinol A selectively blocks the edema responses mediated by B(1) receptor activation in vivo. This compound might represent a new non-peptidic and selective antagonist for kinin B(1) receptors.

Antinociceptive properties produced by the pregnane compound velutinol A isolated from Mandevilla velutina.

Velutinol A is a pregnane compound isolated from the rhizomes of the Brazilian plant Mandevilla velutina that interferes with kinin actions and possesses anti-inflammatory action. Here, we investigate the effect produced by velutinol A in different models of inflammatory nociception. The nociceptive effect caused by the intraplantar injection of phorbol myristate acetate (PMA, 50 pmol/paw) in mice was practically abolished by coadministration of velutinol A (1-10 nmol/paw). In contrast, the coadministration of velutinol A (10 nmol/paw) failed to affect the nociceptive response elicited by either bradykinin (BK, 10 nmol/paw) or prostaglandin E(2) (PGE(2), 10 nmol/paw). Of note, velutinol A (10 nmol/paw) partially inhibited the nociceptive response caused by capsaicin (1 nmol/paw). However, velutinol A (10 microM) did not significantly interfere with the specific binding sites of [(3)H]resiniferatoxin or [(3)H]BK in vitro. Our data also suggest that these effects are related with its ability to interact with kinin B(1) receptor-mediated mechanisms, as the cotreatment of mice with velutinol A (10 nmol/paw) consistently blocked the nociceptive response induced by the selective B(1) receptor agonist des-Arg(9)-BK. Finally, the persistent hyperalgesia produced by intraplantar injection of carrageenan (300 microg/paw) was completely reversed by the coadministration of velutinol A (10 nmol/paw). Collectively, the present results show that the pregnane compound velutinol A produces peripheral antinociceptive action in some models of acute and persistent inflammatory pain by interacting with kinin B(1)-receptor mediated effects. Thus, velutinol A or its derivatives could constitute an attractive molecule of interest for the development of new analgesic drugs. Additional studies are now in progress in order to further explore its precise mechanism of action on B(1) receptor pathways.

Evaluation of antiviral activity of phenolic compounds and derivatives against rabies virus.

Human rabies is a viral disease with a great impact on public health, mainly on account of its fatal course in the majority of cases. Despite the well-established prophylaxis by immunization, rabies is believed to be responsible for 40,000-70,000 human deaths per year, mostly in endemic areas. Palliative support and experimental protocols to avoid death have been employed with no expressive results, with the exception of a recent human case of recovery from rabies. No antiviral drugs are currently available to fight against this infection. In combination with the prophylaxis, an antiviral drug would be useful for human rabies treatment, providing enhanced protection against the encephalitis caused by the virus. Phenolic compounds are derived from the secondary plant metabolism, although they can also be obtained by synthetic processes. Many studies have shown a great range of pharmacological effects for these substances, including vasodilatation, antiallergenic, antiinflammatory and antiviral properties, among others. In this study, the potential in-vitro anti-rabies activity of 24 synthetic phenolic compounds was evaluated using McCoy cells and PV rabies strain. The cytotoxicity (CC50) was assayed by the MTT method and the antiviral activity (IC50) was estimated by the inhibition of viral cytopathic effects. Isoprinosine and ketamine were used as positive controls. The tested compounds showed selectivity indices (SI=CC50/IC50) ranging from 1.0 to 3.9. Six phenolic compounds failed to inhibit the cytopathic effect to any degree, and four showed SI > or = 3.0. According to these results, some probable structure-activity relationships are suggested. It was observed that the presence of free hydroxyl and ether groups influenced the anti-rabies activity. However, additional studies are required to establish these relationships.

Evaluation of the anti-proliferative effect the extracts of Allamanda blanchetti and A. schottii on the growth of leukemic and endothelial cells.

PURPOSE: To investigate the anti-proliferative effect of A. blanchetti and A. schottii extracts. METHODS: The anti-proliferative effect of A. blanchetti and A. schottii ethanolic extracts on K562 leukemic cells as well as on BMEC and HUVEC were evaluated. Phytochemical analysis to identify the possible active components was carried out. RESULTS: The root extract of A. schottii was the most active of them. At 80 microg/mL, the root extracts showed a cytostatic effect on K562, whereas at 400 microg/mL, there was a strong cytotoxic effect. Similar cytostatic and cytotoxic effects were seen in the endothelial cells, but at lower doses. The effect of A. schottii root extract on endothelial cells was seen at concentrations ten times lower (8 microg/mL) than the effect of the A. blanchetti root extract (80 microg/mL). Phytochemical investigation of different fractions and parts of the plant led to the isolation of several known compounds, some of which are described for the first time in the genus Allamanda, and with previous evidence of anticancer and antitumoral properties. CONCLUSIONS: Our results suggest that both plants studied exhibit cytostatic and cytotoxic activity, but the most active compounds are located in the roots.

A new triterpene with antinociceptive activity from Maytenus robusta.

A new triterpene 3,15-dioxo-21alpha-hydroxy friedelane has been isolated from methanol extract of Maytenus robusta and its structure elucidated on the basis of spectral analysis. Stigmasterol, friedelin, friedelanol and 3,15-dioxo friedelane were also obtained. 3,15-dioxo-21alpha-hydroxy friedelane was analyzed against the writhing test in mice and exhibited potent dose-dependent effects with an ID50 value of 12.5 +/- 2.1 micromol kg(-1) and a maximal inhibition of 85.90%. It was about 10-fold more active than aspirin and paracetamol, used as reference drugs.

Assessment of In Vitro Biological Activities of Anthocyanins-Rich Plant Species Based on Plinia cauliflora Study Model.

Plinia cauliflora (jaboticaba) is a native fruit tree from Brazilian rainforest widely used in popular medicine to prevent diarrhea, asthma, and infections. Studies have shown that the major therapeutic potential of jaboticaba fruits is on its peel, a rich source of anthocyanins. These secondary metabolites have well-known antioxidant and anti-inflammatory activities and have been claimed to be effective to treat diabetes, cancer, cardiovascular diseases, and stroke. This chapter describes a series of methodologies to evaluate important in vitro biological activities like cytotoxicity, proliferation, and migration of a hydroalcoholic extract of jaboticaba peel on mouse fibroblast L929 line. Assays to assess total phenolic, flavonoid, and anthocyanin contents and antioxidant activities are described as well.

Topical antiinflammatory effects of the ether extract from Protium kleinii and alpha-amyrin pentacyclic triterpene.

Protium kleinii (Burseraceae), a native Brazilian medicinal plant is claimed to be useful to treat some inflammatory states. Now we reported that topical application of either the ether extract or the main active constituent from P. kleinii the pentacyclic triterpene alpha-amyrin, all caused a dose-related inhibition of both ear oedema (ID50 values are 0.55 and 0.31 mg/ear, respectively) and influx of polymorphonuclear cells (ID50 values are 0.72 and 0.45 mg/ear, respectively) in response to topical application of 12-O-tetradecanoylphorbol-acetate (TPA) in the of mice ear. In terms of the efficacy, the maximal obtained inhibition for both ear oedema and neutrophil influx was very similar to that produced by the topical application of the steroidal antiinflammatory drug dexamethasone (DE; with inhibition of 70+/-5%, 66+/-3%, and 87+/-4% for oedema and 83+/-6%, 73+/-5%, and 91+/-3% for neutrophil influx, for the ether extract, alpha-amyrin, and dexamethasone, respectively). Likewise, both the ether extract and alpha-amyrin given topically dose-dependently prevented the increase of the proinflammatory cytokine interleukin-1beta levels in response to topical application of TPA. The calculated mean ID50 values are 1.81 and 0.53 mg/ear, respectively. Again, the efficacy of the extract and alpha-amyrin was very similar to that produced by dexamethasone (63+/-6%, 61+/-5%, and 74+/-5%, respectively). In marked contrast to phenidone, a lipo and cyclooxygenase inhibitor, neither the ether extract nor the alpha-amyrin inhibited arachidonic acid-mediated ear oedema in mice. Collectively, these results indicate that the active constituents present in the ether extract of P. kleinii including the pentacyclic triterpene alpha-amyrin are good candidates to develop a skin permeable antiinflammatory drug.

Antifungal activity of drimane sesquiterpenes from Drimys brasiliensis using bioassay-guided fractionation.

PURPOSE: This study describes the antifungal effect of extracts and compounds isolated from Drimys brasiliensis acting against dermatophytes. METHODS: The activities were evaluated by using the microbroth dilution method. RESULTS: Bioassay-guided fractionation of the most active extract from the bark (CHCl3) led to the isolation of the sesquiterpene drimanes polygodial, 1-beta-(p-methoxycinnamoyl)-polygodial, drimanial and 1-beta-(p-cumaroyloxy)-polygodial, which were selectively active against Epidermophyton floccosum and Tricophyton rubrum. CONCLUSIONS: The selective antifungal activity reported in this paper for drimanes isolated from D. brasiliensis opens the possibility that they could be helpful for the developing of new antifungal agents for treating the difficult to eradicate dermatomycoses produced by E. floccosum.

SB225002 Induces Cell Death and Cell Cycle Arrest in Acute Lymphoblastic Leukemia Cells through the Activation of GLIPR1.

Acute Lymphoblastic Leukemia (ALL) is the most frequent childhood malignancy. In the effort to find new anti-leukemic agents, we evaluated the small drug SB225002 (N-(2-hydroxy-4-nitrophenyl)-N'-(2-bromophenyl)urea). Although initially described as a selective antagonist of CXCR2, later studies have identified other cellular targets for SB225002, with potential medicinal use in cancer. We found that SB225002 has a significant pro-apoptotic effect against both B- and T-ALL cell lines. Cell cycle analysis demonstrated that treatment with SB225002 induces G2-M cell cycle arrest. Transcriptional profiling revealed that SB225002-mediated apoptosis triggered a transcriptional program typical of tubulin binding agents. Network analysis revealed the activation of genes linked to the JUN and p53 pathways and inhibition of genes linked to the TNF pathway. Early cellular effects activated by SB225002 included the up-regulation of GLIPR1, a p53-target gene shown to have pro-apoptotic activities in prostate and bladder cancer. Silencing of GLIPR1 in B- and T-ALL cell lines resulted in increased resistance to SB225002. Although SB225002 promoted ROS increase in ALL cells, antioxidant N-Acetyl Cysteine pre-treatment only modestly attenuated cell death, implying that the pro-apoptotic effects of SB225002 are not exclusively mediated by ROS. Moreover, GLIPR1 silencing resulted in increased ROS levels both in untreated and SB225002-treated cells. In conclusion, SB225002 induces cell cycle arrest and apoptosis in different B- and T-ALL cell lines. Inhibition of tubulin function with concurrent activation of the p53 pathway, in particular, its downstream target GLIPR1, seems to underlie the anti-leukemic effect of SB225002.

N-(1'-naphthyl)-3,4,5-trimethoxybenzohydrazide as microtubule destabilizer: Synthesis, cytotoxicity, inhibition of cell migration and in vivo activity against acute lymphoblastic leukemia.

Tubulin-interacting agents, like vinca alkaloid and taxanes, play a fundamental role in cancer chemotherapy, making cellular microtubules (MT), one of the few validated anticancer targets. Cancer resistance to classical MT inhibitors has motivated the development of novel molecules with increased efficacy and lower toxicity. Aiming at designing structurally-simple inhibitors of MT assembly, we synthesized a series of thirty-one 3,4,5-trimethoxy-hydrazones and twenty-five derivatives or analogs. Docking simulations suggested that a representative N-acylhydrazone could adopt an appropriate stereochemistry inside the colchicine-binding domain of tubulin. Several of these compounds showed anti-leukemia effects in the nanomolar concentration range. Interference with MT polymerization was validated by the compounds' ability to inhibit MT assembly at the biochemical and cellular level. Selective toxicity investigations done with the most potent compound, a 3,4,5-trimethoxy-hydrazone with a 1-naphthyl group, showed remarkably selective toxicity against leukemia cells in comparison with stimulated normal lymphocytes, and no acute toxicity in vivo. Finally, this molecule was as active as vincristine in a murine model of human acute lymphoblastic leukemia at a weekly dose of 1 mg/kg.

Evidence for the involvement of vanilloid receptor in the antinociception produced by the dialdeydes unsaturated sesquiterpenes polygodial and drimanial in rats.

This study investigated whether or not the neonatal treatment of rats with the sesquiterpenes polygodial or drimanial could cause persistent antinociception similar to that induced by capsaicin. Rats were injected subcutaneously 48 h after birth with capsaicin (50 mg/kg), polygodial (150 mg/kg), drimanial (150 mg/kg) or vehicle (1ml/kg). Six to eight weeks later, rats were tested in models of nociception. Treatment of rats with capsaicin, polygodial or drimanial produced significant inhibition of the first phase and, to a lesser extent, the second phase of formalin-induced nociception. A significant reduction in Complete Freund's Adjuvant and capsaicin-induced hyperalgesia was observed in the animals neonatally treated with capsaicin, polygodial or drimanial compared with vehicle-treated rats. Moreover, both sesquiterpenes caused inhibition of plasma extravasation induced by injection of capsaicin. The neonatal treatment with capsaicin, polygodial or drimanial significantly decreased [3H]-resiniferatoxin binding sites in the rat spinal cord, but only capsaicin neonatal treatment significantly reduced the expression of TRPV1 in dorsal root ganglia (DRG) when assessed by Western blot. These results extend our previous findings demonstrating that the neonatal treatment of rats with polygodial or drimanial, similar to that reported for capsaicin, produced persistent antinociception in adult animals associated with TRPV1 down-regulation in the spinal cord, but not TRPV1 expression in DRG.

Mechanisms involved in the antinociception caused by compound MV8612 isolated from Mandevilla velutina in mice.

The pregnane compound MV8612 isolated from the rhizome of the plant Mandevilla velutina administered by intraperitoneal (i.p.), intrathecal (i.t.) or by intracerebroventricular (i.c.v.) routes caused graded and complete inhibition of the thermal hyperalgesia caused by i.t. injection of bradykinin (BK) in mice with mean ID(50) values of 7.8 micromol/kg, 33.6 and 4.6 nmol/site, respectively. Compound MV8612 (i.p.) also inhibited both the neurogenic and inflammatory pain responses to formalin with mean ID(50) values of 5.6 and 10.6 micromol/kg, respectively. Given i.t., MV8612 produced significant inhibition of both phases of the formalin-induced licking (inhibition of 34+/-5 and 36+/-4%, respectively). Given by i.c.v. route MV8612 inhibited both phases of formalin-induced pain (32+/-6 and 63+/-5%) with mean ID(50) of 8.4 nmol/site against the late phase. MV8612, given by i.p., i.c.v. or i.t. routes, also inhibited capsaicin-induced pain (51+/-4, 25+/-8 and 39+/-6%, respectively). The i.t. injection of potassium (K(+)) channel blockers, apamin and charybdotoxin given 15 min before, markedly prevented the antinociception of MV8612 against both phases of formalin-induced nociception. In contrast, tetraethylammonium (TEA) or glibenclamide had no effect. The i.c.v. treatment with pertussis toxin resulted in a significant inhibition of both MV8612- and morphine-induced antinociception against both phases of formalin-induced pain. Taken together these results confirm and also extend our previous data by demonstrating that the greater part of the antinociception caused by MV8612 seems to be associated with its ability to interfere with BK action. Finally, both the low and high conductance calcium (Ca(2+))-activated K(+) channels and the activation of G(i/o) pertussis sensitive G-proteins take part in the mechanism by which compound MV8612 produces antinociception.

Anti-allodynic action of the tormentic acid, a triterpene isolated from plant, against neuropathic and inflammatory persistent pain in mice.

Experiments were designed to address whether the pentacyclic triterpene tormentic acid isolated from the stem bark of the plant Vochysia divergens exerts oral anti-allodynic properties in two models of chronic pain in mice: neuropathic pain caused by partial ligation of the sciatic nerve and inflammatory pain produced by intraplantar injection of Complete Freund's Adjuvant. Oral administration of tormentic acid (30 mg/kg) twice a day for several consecutive days produced time-dependent and pronounced anti-allodynia effect in both ispsilateral and contralateral paws after plantar injection of Complete Freund's Adjuvant. The inhibition observed was 82+/-9% and 100+/-11%, respectively. Interestingly, tormentic acid did not inhibit paw oedema formation following Complete Freund's Adjuvant plantar injection. Tormentic acid (30 mg/kg, p.o.) and gabapentin (70 mg/kg, p.o.), given twice a day, inhibited markedly the neuropathic allodynia induced by partial ligation of the sciatic nerve, with inhibition of 91+/-19% and 71+/-16%, respectively. The anti-allodynic action of tormentic acid was not associated with impairment of the motor activity of the animals. Together, the present results indicate that tormentic acid or its derivatives might be of potential interest in the development of new clinically relevant drugs for the management of persistent neuropathic and inflammatory allodynia.