Samples of the expressed fixed oil from different sources of Nigella sativa seeds were examined by thin-layer and gas chromatography for content of fixed oils and thymoquinone, and these substances were tested as possible inhibitors of eicosanoid generation and membrane lipid peroxidation. The crude fixed oil and pure thymoquinone both inhibited the cyclooxygenase and 5-lipoxygenase pathways of arachidonate metabolism in rat peritoneal leukocytes stimulated with calcium ionophore A23187, as shown by dose-dependent inhibition of thromboxane B2 and leukotriene B4, respectively. Thymoquinone was very potent, with approximate IC50 values against 5-lipoxygenase and cyclo-oxygenase of < 1 microgram/ml and 3.5 micrograms/ml, respectively. Both substances also inhibited non-enzymatic peroxidation in ox brain phospholipid liposomes, but thymoquinone was about ten times more potent. However, the inhibition of eicosanoid generation and lipid peroxidation by the fixed oil of N. sativa is greater than is expected from its content of thymoquinone (ca. 0.2% w/v), and it is possible that other components such as the unusual C20:2 unsaturated fatty acids may contribute also to its anti-eicosanoid and antioxidant activity. These pharmacological properties of the oil support the traditional use of N. sativa and its derived products as a treatment for rheumatism and related inflammatory diseases.

The pentacyclic triterpene lupeol has been studied for its inhibitory effects on murine models of inflammation and peritoneal macrophage functions in-vitro. Lupeol (0.5 and 1 mg/ear) administered topically suppressed the mouse ear oedema induced by 12-0-tetradecanoyl-phorbol acetate (TPA), being less effective on ear oedema induced by arachidonic acid. Quantitation of the neutrophil specific marker myeloperoxidase demonstrated that its topical activity was associated with reduction in cell infiltration into inflamed tissues. When tested in-vitro, lupeol significantly reduced prostaglandin E2 (PGE2) production from A23187-stimulated macrophages, but failed to affect leukotriene C4 release. It was a weak inhibitor of nitrite release, but dose-dependently suppressed PGE2. Cytokine production (tumour necrosis factor-alpha and interleukin-1beta) was inhibited in the range 10-100 microM in lipopolysaccharide-treated macrophages. This study demonstrated that lupeol possessed anti-inflammatory activity which was likely to depend on its ability to prevent the production of some pro-inflammatory mediators.

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Interest in the phytochemical study of species of the Sideritis genus (Lamiaceae) has been stimulated by their pharmacological activity and their wide range of medicinal folk uses in Spain such as vulnerary, anti-infectious, anti-inflammatory, anti-rheumatic and anti-ulcerous applications. Various flavonoids and terpenoids have been isolated from this genus. 1,2) We have recently reported the anti-inflammatory properties of a lipid fraction obtained from Sideritis javalambrensis and those of the diterpenoid (ent-13(16),14-labdadiene-6a,8a,18triol-andalusol-) isolated from the acetone extract of Sideritis foetens, an endemic plant of Southern Spain. 3,4,5) Inflammation is normally a localized protective response which serves to destroy, dilute, or wall-off both the injurious agent and the injured tissue. The inflammatory response is coordinated by cells such as macrophages, lymphocytes, leukocytes and mast cells. A large number of mediators produced by these cells play a key role, for example, arachidonic acid metabolites such as prostaglandins and leukotrienes, reactive oxygen species, hydrolytic enzymes, histamine, nitric oxide, cytokines, etc. [6][7][8] Acute inflammation is associated with a rapid, early infiltration of polymorphonuclear leukocytes and increased vascular permeability at the site of injury.In this paper, we have evaluated the in vivo anti-inflammatory properties of a sterol fraction obtained from S. foetens on different inflammatory responses in mice. In addition, the interaction of this fraction with the functional properties of leukocytes and mast cells was analyzed in vitro. Immunomodulating activity through interaction with complement activation was also investigated. MATERIALS AND METHODS Plant MaterialThe aerial parts of Sideritis foetens were collected in Sierra de Gádor, Almería province (Spain). A voucher specimen has been deposited in the Department of Botany, Faculty of Pharmacy, Complutense University, Madrid (Spain). Extraction and IdentificationThe carrageenan-induced mouse paw oedema model was used for a bioassay guidedfractionation based on the anti-inflammatory activity.Dried aerial parts of Sideritis foetens (3 kg) were macerated with 99.5% acetone (12 l) at room temperature. The acetone extract was evaporated in vacuo to yield 84.8 g of residue. This extract (11.8 g) was fractionated by flash column chromatography over a silica gel (450 g, 230-400 mesh) column (6ϫ80 cm) using cyclohexane: acetone 70/30 to yield nine fractions. The most active fraction (subfraction B) (1.5 g) was chromatographed over a silica gel column (80 g, 230-400 mesh) using cyclohexane/ethyl acetate 70/30 as solvent, yielding the sterol fraction as white needles (800 mg).Sterol identification was performed by GC analysis [Perkin Elmer Sigma 3B equipped with a SE-30 Sobrechromosob WHP 3/100 column (lenght 2 m, i.d. 0.32 mm). Experimental conditions were: injector temp., 295°C; oven temp., 270°C (isotherm); detection temp., 285°C)]. The relative retention times were compared to standard samples. Campester...

Poly(L-valine-L-proline-L-alanine-L-valine-L-glycine) (VPAVG) is a new kind of proteinaceous polymer belonging to the Elastin-like family. These polymers are based on the recurrence of certain short peptide monomers that are considered as "building blocks" in the natural elastin. This smart thermoresponsive polymer has the ability to self-associate at physiological temperature to form aggregates with about 60% in water. This ability can be harnessed to prepare microparticles loaded with an active substance. The aim of this report is to evaluate, from the results of the experiment conducted, the biocompatibility of microparticles prepared from poly(VPAVG). We have studied the cytotoxic effects of microparticles, edema formation after subcutaneous injection (1 and 2.5 mg) in rats (n = 6), and also intraocular tolerance after the intravitreal injection of 2.5 mg of poly(VPAVG) microparticles into pigmented rabbits (n = 12). The polymer did not induce any cytotoxicity or nonspecific depression of cellular respiration on macrophages under the range of polymer concentrations investigated in this study (20, 30, 40, and 60 mg/mL). We observed no inflammatory response to microparticles after subcutaneous injection in the hind-paw of rats, with no significant differences between the control group (PBS) and experimental groups. Anterior and posterior segment signs were evaluated after intraocular injection of poly(VPAVG) microparticles. Only a few eyes (2/11) of the experimental group presented inflammation signs at day 28 postinjection. Nevertheless, 45% (5/11) of the eyes receiving microparticles showed tractional retinal detachment. The results observed in this work suggested certain fibroblastic activity induced by poly(VPAVG) microparticles after their intraocular injection.

Natural products play a significant role in human health in relation to the prevention and treatment of inflammatory conditions. Among them, terpenoids (also referred to as terpenes), are the largest and most widespread class of secondary metabolites. They are found in higher plants, mosses, liverworts, algae and lichens, and also in insects, microbes or marine organisms. Some terpenoids have been used for therapeutic purposes for centuries as antibacterial, anti-inflammatory, antitumoral agents, and in recent decades research activity into the clinical potential of this class of compounds has increased continuously as a source of pharmacologically interesting agents. In the present review, molecular basis of the anti-inflammatory action of diterpenoids is presented with special emphasis on their ability to modulate critical cell signaling pathways involved in the inflammatory response of the body such as nuclear transcription factor-kappaB (NF-kappaB) activation. NF-kappaB plays an important role in the regulation of immune and inflammatory responses. Indeed, deregulated NF-kappaB expression is a characteristic phenomenon in several inflammatory diseases and NF-kappaB has become a major target in drug discovery. Hence, this article also introduces our recently elucidated findings about the potential of labdane diterpenoids as anti-inflammatory agents due to their ability to inhibit NF-kappaB. The future development of this class of compounds as anti-inflammatory drugs requires the introduction of novel molecular targets of therapeutic relevance in addition to biotechnological approaches for the production of these molecules.

The anti-inflammatory activity of abietic acid, a diterpene isolated from Pimenta racemosa var. grissea (Myrtaceae), was evaluated in-vivo and in-vitro. This compound significantly inhibited rat paw oedema induced by carrageenan in a time- and dose-dependent manner, and mouse ear oedema induced by 12-O-tetradecanoylphorbol acetate, after oral or topical administration. The inhibition of myeloperoxidase enzyme showed that its topical activity was influenced by neutrophil infiltration into the inflamed tissues (ears). In addition, the effect of abietic acid on some macrophage functions was analysed in-vitro. Non-toxic concentrations of abietic acid inhibited prostaglandin E2 (PGE2) production in lipopolysaccharide-treated macrophages, whereas nitrite, tumour necrosis factor alpha and interleukin-1beta production were only weakly affected by this diterpene. PGE2 production from A23187-stimulated macrophages was only inhibited at high doses (100 microM) and it failed to modify leukotriene C4 production. These results indicate that abietic acid exerts in-vivo anti-inflammatory activity after oral or topical administration and has partial ability to prevent the production of some inflammatory mediators.

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