Chronic diseases such as cancer, diabetes, neurodegenerative and cardiovascular diseases are characterized by an enhanced state of oxidative stress, which may result from the overproduction of ...reactive species and/or a decrease in antioxidant defenses. The search for new chemical entities with antioxidant profile is still thus an emerging field on ongoing interest. Due to the lack of reviews concerning the antioxidant activity of lichen-derived natural compounds, we performed a review of the antioxidant potential and mechanisms of action of natural compounds isolated from lichens. The search terms "lichens", "antioxidants" and "antioxidant response elements" were used to retrieve articles in LILACS, PubMed and Web of Science published until February 2014. From a total of 319 articles surveyed, 32 met the established inclusion and exclusion criteria. It was observed that the most common isolated compound studied was usnic acid, cited in 14 out of the 32 articles. The most often described antioxidant assays for the study of in vitro antioxidant activity were mainly DPPH, LPO and SOD. The most suggested mechanisms of action were scavenging of reactive species, enzymatic activation and inhibition of iNOS. Thus, compounds isolated from lichens are possible candidates for the management of oxidative stress, and may be useful in the treatment of chronic diseases.
Chronic pain conditions, such as neuropathic pain, are a common problem that poses a major challenge to health‐care providers due to its complex natural history, unclear aetiology and poor response ...towards therapy. Despite the large number of drugs available, the adherence is limited by the large range of side effects and pharmacological ineffectiveness. Thus, the search for new chemical entities that can act as promising molecules to treat chronic pain conditions has emerged. The natural products remain as the most promising sources of new chemical entities with applicability for the medical approach. Hence, we performed a systematic review analysing pre‐clinical studies shown to be promising in a possible applicability in neuropathic pain. The search terms neuropathic pain, phytotherapy and medicinal plants were used to retrieve English language articles in LILACS, PUBMED and EMBASE published until 10 April 2013. From a total of 1529 articles surveyed, 28 met the inclusion and exclusion criteria established. The main chemical compounds studied were flavonoids (28%), terpenes (17%), alkaloids (14%), phenols (10%), carotenoids (10%) and others (21%). The mostly described animal models for the study of neuropathic pain included were chronic constriction injury (CCI – 32%), partial sciatic nerve ligation (PSNL – 28%), streptozotocin – induced diabetic (28%), alcoholic neuropathy (3.5%), sodium monoiodoacetate (MIA – 3.5%) and neuropathic pain induced by paclitaxel (3.5%). The opioids, serotonergic and cannabinoid systems are suggested as the most promising targets for the natural products described. Therefore, the data reviewed here suggest that these compounds are possible candidates for the treatment of chronic painful conditions, such as neuropathic pain.
Peripheral nerve injury (PNI) is a serious public health problem that is linked with motor, sensory and autonomic deficits. Given the fact that this type of disorder leads to a decreased quality of ...life in most patients and adherence of available drugs is limited and have adverse effects, we investigated the efficacy of natural products in a PNI model. The search terms plants, medicinal, nerve regeneration, nerve crush, sciatic nerve as well as MeSH terms or free-text words were used to retrieve English language articles in PubMed, Scopus, Web of Science and LILACS published until July 2015. After sciatic nerve crush, natural products have improved significantly motor performance, sensory function and electrical conductance measured over weeks. Among the pharmacological targets suggested by the action of natural products, there were citations on the activation of the antiapoptotic signaling pathway, modulation in the expression of pro-inflammatory cytokines and neurotrophic factors. The systematic review provides scientific evidence that natural products are pharmacologically effective in the treatment of PNI such as sciatic nerve crush.
Pain is one of the most prevalent and difficult to manage symptoms in cancer patients, and conventional drugs present a range of adverse reactions. The development of β-cyclodextrins (β-CD) complexes ...has been used to avoid physicochemical and pharmacological limitations due to the lipophilicity of compounds such as p-Cymene (PC), a monoterpene with antinociceptive effects. Our aim was to obtain, characterize, and measure the effect of the complex of p-cymene and β-cyclodextrin (PC/β-CD) in a cancer pain model. Initially, molecular docking was performed to predict the viability of complex formation. Afterward, PC/β-CD was obtained by slurry complexation, characterized by HPLC and NMR. Finally, PC/β-CD was tested in a Sarcoma 180 (S180)-induced pain model. Molecular docking indicated that the occurrence of interaction between PC and β-CD is favorable. PC/β-CD showed complexation efficiency of 82.61%, and NMR demonstrated PC complexation in the β-CD cavity. In the S180 cancer pain model, PC/β-CD significantly reduced the mechanical hyperalgesia, spontaneous nociception, and nociception induced by non-noxious palpation at the doses tested (
< 0.05) when compared to vehicle differently from free PC (
> 0.05). Therefore, the complexation of PC in β-CD was shown to improve the pharmacological effect of the drug as well as reducing the required dose.
Many diseases, such as inflammatory and central nervous system disorders, currently have a limited number of effective side-effect free treatments. Citronellol (CT) is a monoterpene alcohol present ...in the essential oil of several plants used in cooking and traditional medicine, such as those of the genus Cymbopogon and Citrus, with pharmacological activities already described in the literature. The aim of this review was to summarize the pharmacological activities already attributed to CT that could be used in treatments for humans. The databases PubMed, MedLine, Scopus, Lilacs and Scielo were searched using the terms “Citronellol” and “Drug effect”. 32 articles were identified and used in the study. Twenty-one articles demonstrated CT activities, including antibiotic and antifungal effects in vitro, and 11 properties including analgesic and anticonvulsant effects in vivo, besides presenting low toxicity. In view of the need to discover new drugs and the activities reported for CT, it can be stated that CT is a promising molecule to target in future pharmacological studies.
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•Several diseases do not yet have effective treatment without side effects, demonstrating the need for new drug discovery.•Natural products, especially terpenes, have been presented as promising alternatives for the discovery of new drugs.•Citronellol is a monoterpene present in the essential oil of several medicinal plants used in food.•Citronellol has several pharmacological activities, such as anti-inflammatory and analgesic that can be better investigated.•Citronellol presents low toxicological activity, making it an alternative in the search for new drugs.
The use of natural products is crucial to suppress the development of these micro-organisms and to reduce the concentration necessary to inhibit these microrganisms, reducing the toxicity risks also. ...In this study, the essential oil from Chenopodium ambrosioides Leaves and its main constituent α-Terpinene were used in the antibacterial and potentiating activity of antibiotics and ethidium bromide assays, against the bacterial strains Staphylococcus aureus IS-58, carriers of efflux pumps. The Minimum Inhibitory Concentration (MIC) was determined using a microdilution method. The capacity of the aforementioned was also tested in combination with tetracycline and ethidium bromide, with the aim of improving the activity of the antibacterials. The MIC of the C. ambrosioides L. essential oil and of α-Terpinene were above 1024 μg/mL, comprising a clinically irrelevant value. However, when associated with the antibiotics, the C. ambrosioides L. essential oil, significantly decreased the MIC of tetracycline and ethidium bromide. The efflux pump is the only mechanism the bacteria possesses to reduce the toxicity of ethidium bromide, and thus this reduction in the MIC demonstrates that the C. ambrosioides L. essential oil is an effective option in the inhibition of the efflux pump present in these micro-organisms.
The anti-hyperalgesic effect of the complex containing α-terpineol (αTPN) and β-cyclodextrin (βCD) was analyzed in a non-inflammatory chronic muscle pain model, as well as its mechanism of action ...through docking study for a possible interaction with receptors. The αTPN-βCD complex was prepared and characterized through the thermogravimetry/derivate thermogravimetry (TG/DTG), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The model of chronic muscle pain was induced by two injections of pH 4.0 saline (20 μl) into the left gastrocnemius 5 days apart. After confirming hyperalgesia, male mice were treated with αTPN-βCD (25, 50 or 100 mg/kg; p.o.) or vehicle (saline 0.9%, p.o.) daily for 10 days. 1 h after the mechanical hyperalgesia, motor performance was evaluated. In addition, the systemic administration of naloxone and ondansetron tested the analgesic effect on the active opioid and serotonin receptors, respectively. The characterization tests indicated that αTPN was efficiently incorporated into βCD. The oral treatment with αTPN-βCD, at all doses tested, produced a significant (p < 0.001) decrease in the mechanical hyperalgesia, without causing any alteration in the force and in motor performance. This analgesic effect was reversed by the systemic administration of naloxone or ondansetron. These findings are corroborated by the docking study described in the present study, which verified a possible interaction of αTPN-βCD with opioid (MU, Kappa, Delta) and 5-HT receptors. Thus, it can be concluded that αTPN-βCD reduced the hyperalgesia followed by the chronic muscle pain model, probably evoked by the descending inhibitory pain system, specifically by opioid and serotoninergic receptors.
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•β-Cyclodextrin (βCD) improves anti-hyperalgesic effect of α-terpineol (αTPN).•αTPN-βCD producied a longer lasting analgesic profile when compared to αTPN.•Docking study suggested that αTPN-βCD seems to implies the opioid and serotoninergic receptors.
S. aureus
are among the main bacteria causing problems related to multidrug resistance in nosocomial infections. Therefore, it is necessary to carry out a reliable and rapid diagnosis for the ...identification of the bacteria and characterization of its susceptibility profile, especially vancomycin, which is an alternative treatment against multidrug-resistant (MDR)
S. aureus
. Thus, the goal of this study was to characterize isolates of
S. aureus
regarding the resistance and virulence and to check the susceptibility to vancomycin, through different methods, for comparative purposes. Seventeen antimicrobials were tested to assess the susceptibility profile. It was evaluated the presence of identification (
nuc
), resistance (
mecA
and
blaZ
), biofilm (
icaA
and
icaD
) and siderophore (
sfaD
and
sbnD
) genes. The susceptibility to vancomycin was evaluated by Minimum Inhibitory Concentration (MIC) by broth microdilution (BMD), E-test, commercial panel (Kit), and Phoenix equipment. Most
S. aureus
(93,33%) was classified as MDR. These isolates were 100% positive for
nuc, mecA
,
icaA
,
icaD,
and
sfaD
genes; 96.67% for
sbnD
and 33.33% for
blaZ
. In relation to BMD, all methods correctly classified the susceptibility of the isolates; however, regarding the exact MIC value for vancomycin, Phoenix showed agreement of 63.33%, E-test (33.33%) and Kit (26.66%). In conclusion, most of
S. aureus
was considered MDR. Also, they presented resistance, biofilm production, and siderophores genes, showing the pathogenic potential of these bacteria. Besides, the Phoenix test was considered the most effective, as it presents advantages, such as identification of the microorganism and a greater number of antimicrobials tested at a time.
In addition to seven known alkaloids (2, 6–11) and 1,2,4-trimethoxybenzene (1), three isoquinoline-derived alkaloids (3–5), namely, duguetinine (3), a compound based on an unprecedented ...oxahomoaporphine scaffold, and two new 8-oxohomoaporphine alkaloids, duguesuramine (4) and 11-methoxyduguesuramine (5), and a new asarone-derived phenylpropanoid (10) were isolated from the bark of Duguetia surinamensis. The isolation workflow was guided by HPLC-HRESIMS/MS and molecular networking-based analyses. Twenty-four known alkaloids were dereplicated from the D. surinamensis alkaloid-rich fraction network and were assigned by manual MS/MS interpretation. Their cytotoxic potential was evaluated.
Many plants produce (−)‐linalool, a plant‐derived monoterpene alcohol, including members of the Lamiaceae (mints) and Lauraceae family (laurels, cinnamon, rosewood). The anti‐inflammatory and ...analgesic effects of (−)‐linalool have been widely suggested for various studies. Poor chemical stability and short half‐life restrain the clinical applications of some essential oil and monoterpenes, including (−)‐linalool. However, β‐cyclodextrin (β‐CD) has been used to increase solubility and stability of lipophilic compounds and also to improve the pharmacological effects. In this study, the antinociceptive effect of (−)‐linalool and (−)‐linalool/β‐CD was examined using the acetic acid writhing reflex, formalin and hotplate tests in rodents. (−)‐Linalool and (−)‐linalool/β‐CD demonstrated strong antinociceptive activity in all the chemical‐ and heat‐induced mice models (p < 0.01 or p < 0.001). These findings imply the involvement of both peripheral and central antinociceptive mechanisms. In peritonitis induced by carrageenan, isolated monoterpene or β‐CD complex also reduced total leucocyte migration and TNF‐α levels in peritoneal fluid. The inclusion complexes, (−)‐linalool/β‐CD, revealed that the antinociceptive effect was significantly (p < 0.01) improved when compared with (−)‐linalool alone. Such results were unlikely to be provoked by any motor abnormality. Together, our results suggest that β‐CD might represent an important tool for improvement of analgesic and anti‐inflammatory profiles of (−)‐linalool and other water‐insoluble compounds, such as lipophilic monoterpenes or essential oils.
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