Mairim Russo Serafini

Collagen-Based Films Containing Liposome-Loaded Usnic Acid as Dressing for Dermal Burn Healing

The aim of this study was assess the effect of collagen-based films containing usnic acid as a wound dressing for dermal burn healing. Second-degree burn wounds were performed in forty-five Wistar rats, assigned into nine groups: COL—animals treated with collagen-based films; PHO—animals treated with collagen films containing empty liposomes; UAL—animals treated with collagen-based films containing usnic acid incorporated into liposomes. After 7, 14, and 21 days the animals were euthanized. On 7th day there was a moderate infiltration of neutrophils, in UAL, distributed throughout the burn wounds, whereas in COL and PHO, the severity of the reaction was slighter and still limited to the margins of the burn wounds. On the 14th day, the inflammatory reaction was less intense in UAL, with remarkable plasma cells infiltration. On the 21st day, there was reduction of the inflammation, which was predominantly composed of plasma cells in all groups, particularly in UAL. The use of the usnic acid provided more rapid substitution of type-III for type-I collagen on the 14th day, and improved the collagenization density on the 21st day. It was concluded that the use of reconstituted bovine type-I collagen-based films containing usnic acid improved burn healing process in rats.

Encapsulation of carvacrol, a monoterpene present in the essential oil of oregano, with β-cyclodextrin, improves the pharmacological response on cancer pain experimental protocols

Cancer pain is a major public health problem worldwide due to the strong impact on the quality of life of patients and side effects of the existing therapeutic options. Monoterpenes, as carvacrol (CARV), have been extensively studied about their therapeutic properties, especially their importance in the control of painful conditions and inflammation, which can be improved through the use of inclusion complexes of β-cyclodextrin (β-CD). We evaluated the effect of encapsulation of CARV in β-CD (CARV/β-CD) on the nociception induced by tumor cells (Sarcoma 180) in rodents. Inclusion complexes were prepared in two different procedures and characterized through thermal analysis and scanning electron microscopy. CARV/β-CD complex was administered (50 mg/kg, p.o.) in mice with tumor on the hind paw and was able to reduce the hyperalgesia (von Frey) during 24 h, unlike the free CARV (100 mg/kg, p.o.), which promoted effects until 9 h. Administration on alternate days of complex of CARV/β-CD (12.5-50 mg/kg, p.o.) reduced hyperalgesia, as well as spontaneous and palpation-induced nociception. However, pure CARV (50 mg/kg) did not cause significant changes in nociceptive responses. Together, these results produced evidence that the encapsulation of carvacrol in β-cyclodextrin can be useful for the development of new options for pain management.

Terpenes and derivatives as a new perspective for pain treatment: a patent review

Introduction: Terpenes are natural compounds found in several organisms belonging to the animal and plant kingdoms. They constitute the largest class of natural products with > 55,000 known compounds structurally diversified. Several studies have attributed to this big family of compounds a range of pharmacological properties, such as anticancer, antimicrobial, antifungal, antiviral, antihyperglycemic, analgesic, anti-inflammatory and antiparasitic. Areas covered: In this review, the authors summarize therapeutic patent applications concerning the employment of terpenes for pain relief, focusing on the perspective for these compounds to become candidates for new drugs intended to control painful syndromes. Expert opinion: Over years of tremendous academic and industrial investment in the characterization of the analgesic action of terpenes, there was the development of a successful product that has been well-accepted clinically. Furthermore, there is still hope that new therapeutic options for the control of painful syndromes will be developed from terpenes, which have been shown to be great candidates for this purpose because of the range of pharmacological mechanisms in important target sites.

Redox properties and cytoprotective actions of atranorin, a lichen secondary metabolite.

Atranorin (ATR) is a lichenic secondary metabolite with potential uses in pharmacology. Antinociceptive and antiinflammatory actions have been reported, and the use of atranorin-enriched lichen extracts in folk medicine is widespread. Nonetheless, very few data on ATR biological actions are available. Here, we evaluated free radical scavenging activities and antioxidant potential of ATR using various in vitro assays for scavenging activity against hydroxyl radicals, hydrogen peroxide, superoxide radicals, and nitric oxide. The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) indexes and in vitro lipoperoxidation were also evaluated. Besides, we determined the cytoprotective effect of ATR on H(2)O(2)-challenged SH-SY5Y cells by the MTT assay. ATR exerts differential effects towards reactive species production, enhancing hydrogen peroxide and nitric oxide production and acting as a superoxide scavenger; no activity toward hydroxyl radical production/scavenging was observed. Besides, TRAP/TAR analysis indicated that atranorin acts as a general antioxidant, although it demonstrated to enhance peroxyl radical-induced lipoperoxidation in vitro. ATR was not cytotoxic, and also protected SH-SY5Y cells against H(2)O(2)-induced cell viability impairment. Our results suggest that ATR has a relevant redox-active action, acting as a pro-oxidant or antioxidant agent depending on the radical. Also, it will exert cytoprotective effects on cells under oxidative stress induced by H(2)O(2).

Antioxidant Activity and Mechanisms of Action of Natural Compounds Isolated from Lichens: A Systematic Review

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.

Review of the biological properties and toxicity of usnic acid

Since its first isolation in 1844, usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione] has become the most extensively studied lichen metabolite and one of the few that are commercially available. Lichens belonging to usnic acid-containing genera have been used as crude drugs throughout the world. There are indications of usnic acid being a potentially interesting candidate for such activities as anti-inflammatory, analgesic, healing, antioxidant, antimicrobial, antiprotozoal, antiviral, larvicidal and UV protection. However, some studies reported the liver toxicity and contact allergy. Thus, further studies are needed to establish the efficacy and safety of usnic acid

Sida cordifolia Leaf Extract Reduces the Orofacial Nociceptive Response in Mice

In this study, we describe the antinociceptive activity of the ethanol extract (EE), chloroform (CF) and methanol (MF) fractions obtained from Sida cordifolia, popularly known in Brazil as “malva branca” or “malva branca sedosa”. Leaves of S. cordifolia were used to produce the crude ethanol extract and after CF and MF. Experiments were conducted on Swiss mice using the glutamate and formalin‐induced orofacial nociception. In the formalin test, all doses of EE, CF and MF significantly reduced the orofacial nociception in the first (p < 0.001) and second phase (p < 0.001), which was also naloxone‐sensitive. In the glutamate‐induced nociception test, only CF and MF significantly reduced the orofacial nociceptive behavior with inhibition percentage values of 48.1% (100 mg/kg, CF), 56.1% (200 mg/kg, CF), 66.4% (400 mg/kg, CF), 48.2 (200 mg/kg, MF) and 60.1 (400 mg/kg, MF). Furthermore, treatment of the animals with EE, CF and MF was not able to promote motor activity changes. These data demonstrate that S. cordifolia has a pronounced antinociceptive activity on orofacial nociception. However, pharmacological and chemical studies are necessary in order to characterize the responsible mechanisms for this antinociceptive action and also to identify other bioactive compounds present in S. cordifolia. Copyright

Cyclodextrin-Complexed Ocimum basilicum Leaves Essential Oil Increases Fos Protein Expression in the Central Nervous System and Produce an Antihyperalgesic Effect in Animal Models for Fibromyalgia

O. basilicum leaves produce essential oils (LEO) rich in monoterpenes. The short half-life and water insolubility are limitations for LEO medical uses. β-Cyclodextrin (β-CD) has been employed to improve the pharmacological properties of LEO. We assessed the antihyperalgesic profile of LEO, isolated or complexed in β-CD (LEO/β-CD), on an animal model for fibromyalgia. Behavioral tests: mice were treated every day with either LEO/β-CD (25, 50 or 100 mg/kg, p.o.), LEO (25 mg/kg, p.o.), tramadol (TRM 4 mg/kg, i.p.) or vehicle (saline), and 60 min after treatment behavioral parameters were assessed. Therefore, mice were evaluated for mechanical hyperalgesia (von Frey), motor coordination (Rota-rod) and muscle strength (Grip Strength Metter) in a mice fibromyalgia model. After 27 days, we evaluated the central nervous system (CNS) pathways involved in the effect induced by experimental drugs through immunofluorescence protocol to Fos protein. The differential scanning analysis (DSC), thermogravimetry/derivate thermogravimetry (TG/DTG) and infrared absorption spectroscopy (FTIR) curves indicated that the products prepared were able to incorporate the LEO efficiently. Oral treatment with LEO or LEO-βCD, at all doses tested, produced a significant reduction of mechanical hyperalgesia and we were able to significantly increase Fos protein expression. Together, our results provide evidence that LEO, isolated or complexed with β-CD, produces analgesic effects on chronic non-inflammatory pain as fibromyalgia.

Evaluation of the anti-inflammatory and antinociceptive properties of p-cymene in mice.

We attempted to identify the antinociceptive and anti-inflammatory actions of the monoterpene p-cymene. Firstly, behavioural screening was carried out to verify the influence of p-cymene [25, 50, and 100 mg/kg intraperitoneal (i.p.)] on the central nervous system (CNS) activity. The antinociceptive activity of p-cymene was evaluated by the acetic acidinduced writhing response, formalin, and hot-plate test, respectively. The leukocyte migration induced by injection of carrageenan was used to assess the anti-inflammatory activity. p-Cymene showed depressant activity on CNS after 4 h of treatment and also a possible action on the autonomous nervous system (ANS), mainly at the dose of 100 mg/kg (i.p.). It was found that p-cymene (50 and 100 mg/kg, i.p.) significantly (p < 0.05) reduced the writhing responses induced by acetic acid. p-Cymene also decreased the licking time in the first and second phase, respectively, of the formalin test. The results of the hot-plate test showed that all doses of p-cymene increased significantly the latency time of the response to the thermal stimulus in both licking and jumping parameters. In addition, there was a significantly (p < 0.05) decreased leukocyte migration at all doses of p-cymene. The experimental data demonstrate that p-cymene possesses antinociceptive and anti-inflammatory activities

β-caryophyllene, a dietary cannabinoid, complexed with β-cyclodextrin produced anti-hyperalgesic effect involving the inhibition of Fos expression in superficial dorsal horn

AIMS Evaluate the anti-hyperalgesic effect of the complex containing β-caryophyllene (βCP) and β-cyclodextrin (βCD) in a non-inflammatory chronic muscle pain mice model and investigated its action on superficial dorsal horn of the lumbar spinal cord. MAIN METHODS The βCP-βCD complex were prepared and characterized through the DSC, TG/DTG, FTIR, XRD and SEM. The model of chronic muscle pain was induced by two injections of pH4.0 saline (20μL) into left gastrocnemius 5days apart. After confirming hyperalgesia, male mice were treated with βCP-βCD (10 or 20mg/kg; p.o.) or vehicle (saline 0.9%, p.o.) daily for 9days. 1h after, the mechanical hyperalgesia, muscle withdrawal thresholds and motor performance were evaluated. To evaluate the βCP-βCD action on spinal cord, animals induced with chronic muscle pain were treated with βCP-βCD (20mg/kg; p.o.) or vehicle (saline 0.9%, p.o.) and 90min. after, were perfused, the lumbar spinal cord collected, crioprotected, cut and submitted in an immunofluorescence protocol for Fos protein. KEY FINDINGS The characterization tests indicated that βCP were efficiently incorporated into βCD. The oral treatment with βCP-βCD, at all doses tested, produced a significant (p<0.05) reduction on mechanical hyperalgesia and a significant (p<0.05) increase in muscle withdrawal thresholds, without produce any alteration in force. In addition, βCP-βCD was able to significantly (p<0.05) decrease Fos expression in the superficial dorsal horn. SIGNIFICANCE Thus, βCP-βCD attenuates the non-inflammatory chronic muscle pain in mice and inhibits the Fos expression in the lumbar spinal cord.