In vivo and in silico anti-inflammatory properties of the sesquiterpene valencene.

Valencene (VLN) is a sesquiterpene found in juices and essential oils of citrus species such as Cyperus rotundus. Considering the evidence that this species has anti-inflammatory effects, the present study aims to evaluate the anti-inflammatory activity of VLN in vivo and in silico. Swiss mice (n = 6) were orally treated according to their treatment groups as follows: VLN (10, 100 or 300 mg/kg), negative control (0.9% saline), and positive controls (indomethacin 25 mg/kg or promethazine 6 mg/kg). The anti-inflammatory activity was evaluated in murine models of acute and chronic inflammation. The inhibition of acute inflammation was evaluated in models of paw edema induced by different inflammatory agents (carrageenan, dextran, histamine, and arachidonic acid (AA)) and carrageenan-induced pleurisy and peritonitis. The modulation of chronic inflammation was evaluated in a granuloma model induced cotton pellets implantation. The interaction with inflammatory targets was evaluated in silico using molecular docking analysis. The administration of VLN to challenged mice significantly inhibited paw edema formation with no significant difference between the administered doses. The compound also reduced albumin extravasation, leukocyte recruitment, and the production of myeloperoxidase (MPO), IL-1ß, and TNF-α in both pleural and peritoneal lavages. According to the mathematical-statistical model observed in silico analysis, this compound has favorable energy to interact with the cyclooxygenase enzyme (COX-2) and the histamine 1 (H1) receptor. Finally, animals treated with the sesquiterpene showed a reduction in both granuloma weight and concentration of total proteins in a chronic inflammation model. Given these findings, it is concluded that NLV presents promising pharmacological activity in murine models of acute and chronic inflammation.

Limonene, a citrus monoterpene, non-complexed and complexed with hydroxypropyl-ß-cyclodextrin attenuates acute and chronic orofacial nociception in rodents: Evidence for involvement of the PKA and PKC pathway.

BACKGROUND: Chronic orofacial pain is a serious public health problem with a prevalence of 7-11% in the population. This disorder has different etiologies and characteristics that make pharmacological treatment difficult. Natural products have been shown to be a promising source of treatments for the management of chronic pain, as an example the terpenes. PURPOSE: The aim of this study was to evaluate the anti-nociceptive and anti-inflammatory effects of one of these terpenes, d-limonene (LIM - a common monoterpene found in citrus fruits) alone and complexed with hydroxypropyl-ß-cyclodextrin (LIM/HPßCD) in preclinical animal models. METHODS: Orofacial pain was induced by the administration of hypertonic saline on the corneal surface, the injection of formalin into the temporomandibular joint (TMJ), or chronic constriction injury of the infraorbital nerve (CCI-IoN). The study used male Wistar rats and Swiss mice treated with LIM (50 mg/kg), LIM/HPßCD (50 mg/kg), vehicle (control), gabapentin or morphine, and eyes wiping (induced by hypertonic saline), face rubbing (formalin-induced in TMJ) or mechanical hyperalgesia (provoked by CCI-IoN) were assessed. Additionally, ELISA was used to measure TNF-α, and western blot analysis to assess levels of PKAcα, NFκB, p38MAPK and phosphorylated PKC substrates. Serum levels of aspartate aminotransferase (AST) and alanine transferase (ALT) were also evaluated. RESULTS: LIM and LIM/HPßCD significantly reduced (p < 0.001) corneal nociception and formalin-induced TMJ nociception. In addition, both substances attenuated (p < 0.001) mechanical hyperalgesia in the CCI-IoN model. The antinociceptive effect induced by LIM and HPßCD/LIM was associated with decreased TNF-α levels, downregulation of the NFκB and p38MAPK signalling pathways and reduced PKC substrate phosphorylation and PKA immunocontent. Moreover, the results demonstrated that complexation with HPßCD was able to decrease the therapeutic dose of LIM. CONCLUSION: LIM was found to be a promising molecule for the treatment of orofacial pain due to its capacity to modulate some important mediators essential to the establishment of pain, and HPßCD can be a key tool to improve the profile of LIM.

HPLC-DAD-UV analysis, anti-inflammatory and anti-neuropathic effects of methanolic extract of Sideritis bilgeriana (lamiaceae) by NF-κB, TNF-α, IL-1ß and IL-6 involvement.

Medicinal plants remain an invaluable source for therapeutics of diseases that affect humanity. Sideritis bilgeriana (Lamiaceae) is medicinal plant used in Turkey folk medicine to reduce inflammation and pain, but few studies scientific corroborates its medicinal use so creating a gap between popular use and scientific evidence. Thus, we aimed to evaluate the pharmacological effects of the methanolic extract of S. bilgeriana (MESB) in rodents nociception models and also performed its phytochemical analysis. Firstly, a screening was carried out that enabled the identification of the presence of phenolic compounds and flavonoids. In view of this, a chromatographic method by HPLC-DAD-UV was developed that made it possible to identify chlorogenic acid and its quantification in MESB. MESB-treated mice (MESB 50, 100 and 200 mg/kg, p.o.) reduced mechanical hyperalgesia and myeloperoxidase activity (p < 0.01), and also showed a reduced pain behavior in capsaicin test. In the carrageenan-induced pleurisy test, MESB (100 mg/kg p.o.) significantly reduced the leukocyte (polymorphonuclear) count in the pleural cavity and equally decreased the TNF-α and IL-1ß levels (p < 0.001). In the PSNL model, mechanical hyperalgesia was reduced on the first evaluation day and during the 7 days of evaluation compared to the vehicle group (p < 0.001). Thermal hyperalgesia was also reduced 1 h after treatment compared to the vehicle group (p < 0.001) and reversed the loss of force initially displayed by the animals, thus inferring an analgesic effect in the muscle strength test. Analysis of the marrow of these animals showed a decrease in the level of pro-inflammatory cytokine IL-6 (p < 0.001) and factor NF-κB, in relation to the control group (p < 0.05). Moreover, the MESB treatment produced no noticeable side effects, no disturb in motor performance and no signs of gastric or hepatic injury. Together, the results suggests that MESB could be useful to management of inflammation and neuropathic pain mainly by the management of pro-inflammatory mediators (NF-κB, TNF-α, IL-1ß and IL-6), so reinforcing its use in popular medicine and corroborating the need for further chemical and pharmacological studies for the species.

Evidence for the involvement of IL-1ß and TNF-α in anti-inflammatory effect and antioxidative stress profile of the standardized dried extract from Miconia albicans Sw. (Triana) Leaves (Melastomataceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Miconia albicans (Melastomataceae), commonly known in Brazil as "canela-de-velho", is used in folk medicine for treating rheumatoid arthritis and reducing pain and inflammation. THE AIM OF THE CURRENT WORK WAS: to provide data on physicochemical characterization of the drug plant and dried extract from M. albicans leaves, as well as investigate the anti-inflammatory effect and antioxidant stress profile from the standardized dried extract of this species employing different model systems. MATERIALS AND METHODS: plant material (dried crushed leaves) was extracted by turboextraction using 50% ethanol (v/v). Different pharmacological techniques were performed to establish quality control parameters of the plant drug, and dried extract of M. albicans (DEMA) was chemically characterized by HPLC-PDA to selection of the chemical marker. Total phenolic and flavonoid contents were determined by the Folin-Ciocalteu and AlCl3 colorimetric methods, respectively. Antioxidant potential of the DEMA was investigated by employing different in vitro antioxidant assays, including DPPH and ABTS radical scavenging assays, ferric reducing antioxidant assay, NO scavenging assay, metal ion (Fe2+) chelating activity and antioxidant capacity by inhibition of lipid peroxidation (TBARS). Finally, anti-inflammatory activity of the DEMA was evaluated using two models of acute inflammation: carrageenan induced inflammation and mechanical hyperalgesia. RESULTS AND DISCUSSION: M. albicans leaves, after drying in forced air circulation chamber at ±40 °C for 48 h and crushing in knife mill, presented a moisture content below the maximum allowed for plant drugs (6.4%). The powder of M. albicans was classified as moderately coarse and total ash content was found to be 6.27%. Preliminary phytochemical screening of DEMA revealed the presence of flavonoids, tannins, saponins, leucoanthocyanins and steroids. DEMA had significant higher total phenolic (551.3 mg gallic acid equivalent/g of dried extract) and flavonoid contents (367.19 mg catechin equivalent/g of dried extract). Two major compounds (λ = 340 nm) were identified in DEMA by HPLC-PDA: the flavonoids rutin and quercetin. Rutin content, selected as chemical marker, was determined and found to be 1.16 mg/g dried extract (r = 0.9941). Regarding to antioxidant activity, our results revealed the DEMA exhibited good antioxidant activity on different models. M. albicans treatment also reduced the levels of TNF-α e IL-1ß and consequently inflammatory nociception and edema caused by carrageenan injection. Based on previous studies and our results, is possible to suggest a positive correlation between the flavonoids rutin and quercetin and the antioxidant and anti-inflammatory capacities. CONCLUSION: Together, these data suggest that M. albicans has the possibility of use in conditions such as arthritis or other joint pain, even needing other work to better consolidate this profile.

Involvement of the PKA pathway and inhibition of voltage gated Ca2+ channels in antihyperalgesic activity of Lippia grata/ß-cyclodextrin.

Neuropathic pain (NP) is a difficult condition to treat because of the modest efficacy of available drugs. New treatments are required. In the study we aimed to investigate the effects of the essential oil from Lippia grata alone or complexed in ß-cyclodextrin (LG or LG-ßCD) on persistent inflammatory and neuropathic pain in a mouse model. We also investigated Ca2+ currents in rat dorsal root ganglion (DRG) neurons. Male Swiss mice were treated with LG or LG/ß-CD (24 mg/kg, i.g.) and their effect was evaluated using an acute inflammatory pleurisy model and nociception triggered by intraplantar injection of an agonist of the TRPs channels. We also tested their effect in chronic pain models: injection of Freund's Complete Adjuvant and partial sciatic nerve ligation (PSNL). In the pleurisy model, LG reduced the number of leukocytes and the levels of TNF-α and IL-1ß. It also inhibited cinnamaldehyde and menthol-induced nociceptive behavior. The pain threshold in mechanical and thermal hyperalgesia was increased and paw edema was decreased in models of inflammatory and neuropathic pain. PSNL increased inflammatory protein contents and LG and LG-ßCD restored the protein contents of TNF-α, NF-κB, and PKA, but not IL-1ß and IL-10. LG inhibited voltage gated Ca2+ channels from DRG neurons. Our results suggested that LG or LG-ßCD produce anti-hyperalgesic effect in chronic pain models through reductions in TNF-α levels and PKA, and inhibited voltage-gated calcium channels and may be innovative therapeutic agents for the management of NP.

Central nervous system and analgesic profiles of Lippia genus

Abstract Many people use medicinal plants to relieve disorders related to the central nervous system, such as depression, epilepsy, anxiety and pain, even though the effectiveness of most of them has not yet been proven through scientific studies. Plants of the Lippia genus, Verbenaceae, are widely used in ethnobotany as a food, for seasoning and in antiseptic remedies. They are also marketed and used for the treatment of different types of pain, including stomach ache, abdominal pain and headache, as well as being used as sedatives, anxiolytics and anticonvulsants. Despite their widespread use, there are no reviews on the central nervous system profile of plants of this genus. Therefore, the databases Medline-PubMed, Embase, Scopus and Web of Science were searched using the terms Lippia and biologic activity. Thirty-five papers were found. Eleven species of Lippia showed central nervous system activity, with leaves and the aerial parts of plants being the most commonly used, especially in aqueous and ethanol extracts or volatile oil. The species are composed mainly of terpenoids and phenylpropanoids, including polyketides, flavonoids and in less quantity some alkaloids. Although several species of Lippia present analgesic activity, most studies have not explored the mechanisms responsible for this effect, however, there is some evidence that volatile oils and constituents of the extracts may be responsible for the relief of some CNS disorders, but the effects on pain modulation seem to be the most exploited so far.