Topically applied diterpenoids from Egletes viscosa (Asteraceae) attenuate the dermal inflammation in mouse ear induced by tetradecanoylphorbol 13-acetate- and oxazolone

UPLC-QTOF-MS/MS-based metabolomic approach and gastroprotective effect of two chemotypes of Egletes viscosa (L.) less. against ethanol-induced gastric ulcer in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Egletes viscosa (L.) (macela) is a native wild herb that can be found in different states of northeastern Brazil. The infusions of its flower buds are traditionally used for the treatment of gastrointestinal disorders. E. viscosa possesses two chemotypes (named A and B), distinguishable by the composition of the essential oil from the flower buds. Although there are previous studies of the gastroprotective effect of the isolated constituents of E. viscosa, its infusions have not been investigated yet.

AIM OF THE STUDY

The present study aimed to evaluate and compare the chemical composition and the gastroprotective effect of flower bud infusions of E. viscosa from chemotype A (EVCA) and chemotype B (EVCB).

MATERIALS AND METHODS

Sixteen infusions were brewed with flower buds according to the traditional preparation mode and were analyzed through a UPLC-QTOF-MS/MS based metabolomic approach for determination of their metabolic fingerprints and quantification of bioactive compounds. Afterward, these data were analyzed by chemometric methods (OPLS-DA) for discrimination of the two chemotypes. Additionally, infusions of EVCA and EVCB (50, 100 and 200 mg/kg, p.o.) were evaluated on gastric ulcers induced by absolute ethanol (96%, 0.2 mL, p.o.) in mice. To elucidate the gastroprotective mechanisms, the effect of EVCA and EVCB on gastric acid secretion and gastric wall mucus was determined and the role of TRPV1 channels, prostaglandins, nitric oxide and K_ATP channels were assessed. Moreover, the oxidative stress-related parameters and the histological aspects of the stomach tissue were analyzed.

RESULTS

The chemotypes can be discriminated from each other using UPLC-QTOF-MS/MS chemical fingerprints. Both chemotypes presented similar chemical compositions, consisting basically of caffeic acid derivatives, flavonoids and diterpenes. The quantification of bioactive compounds demonstrated that chemotype A possesses more ternatin, tanabalin and centipedic than chemotype B. EVCA and EVCB (50, 100 and 200 mg/kg, p.o.) significantly decreased the severity of ethanol-induced gastric lesions, as shown by a reduction in histological alterations and leucocyte infiltration in gastric tissue. The gastroprotective mechanism of both infusions involves an antioxidant effect, maintenance of gastric mucus and reduction gastric secretion. Stimulation of endogenous prostaglandins and nitric oxide release, activation of TRPV1 channels, and K_ATP channels are also involved in the gastroprotection of the infusions.

CONCLUSION

The gastroprotective effect of EVCA and EVCB was equivalent and mediated through antioxidant and antisecretory actions, including the activation of TRPV1 receptors, stimulation of endogenous prostaglandins and nitric oxide, and opening of K_ATP channels. The presence of caffeic acid derivatives, flavonoids and diterpenes in both infusions is involved in mediating this protective effect. Our findings support the traditional use of infusions of E. viscosa for gastric disorders regardless of the chemotype.

Effects of centipedic acid on acute lung injury: A dose-response study in a murine model

Centipedic Acid (CPA), a natural diterpene from Egletes viscosa, an endemic species of the Caatinga biome, has shown antioxidant and anti-inflammatory properties. However, no report on the CPA on respiratory system mechanics has been so far advanced. We aimed to investigate the dose-response behavior of CPA on E. coli lipopolysaccharide (LPS)-triggered acute lung injury (ALI). Forty-eight C57BL/6 mice were randomly divided into six groups: control (SS), induced to ALI (LPS), 4 groups induced to ALI pre-treated with 12.5, 25, 50 and 100 mg/kg of CPA (CPA12.5, CPA25, CPA50 and CPA100 groups). CPA 100 mg/kg could prevent inflammatory cell infiltration, alveolar collapse, changes in tissue micromechanics and lung function (airway resistance, tissue elastance, tissue resistance and Static compliance). These results indicate preventive potential of this compound in the installation of ALI.

Efficacy of essential oils of Egletes viscosa and Lippia schaueriana on the reproductive biology of Rhipicephalus sanguineus sensu lato engorged females

The study analyzed the chemical composition and the acaricide effect of Egletes viscosa Less (macela-da-terra) and Lippia schaueriana Mart. (lipia-da-serra) essential oils (EOs) on Rhipicephalus sanguineus s. l. (Acari: Ixodidae) engorged females. The chemical analysis (GC-MS and GC-FID) identified 27 components in E. viscosa EO and 18 in L. schaueriana EO, which comprise more than 98% of its constituents. The effects of the oils on the reproductive biology of R. sanguineus ticks were assessed by adult immersion test. Both EOs significantly reduced (p < 0.05) the egg production index when the females were exposed to 25 and 50 mg/mL, also affecting the egg viability. During the laying process, the eggs produced by the females exposed to the EO showed several morphological alterations such as dehydrated, darkened, and disaggregated, and these alterations were more severe as the concentrations increased. The mortality percentages were 58.9%, 70.8% and 92.7% when the ticks were exposed to 12.5, 25 and 50 mg/mL of E. viscosa oil, respectively. In the same concentrations, the efficacy of L. schaueriana was 39.3%, 53.4%, and 84.6%. Therefore, it can be concluded that the essential oils of E. viscosa and L. schaueriana have acaricidal effect in females of R. sanguineus s.l ticks.

Using HPLC-DAD and GC-MS Analysis Isolation and Identification of Anticandida Compounds from Gui Zhen Cao Herbs (Genus Bidens): An Important Chinese Medicinal Formulation

Gui Zhen Cao is an herbal formulation that has been documented in Chinese traditional medicine as a remedy for diarrhea, dysentery, inflammation, and toxicity. The sources of this formulation (Bidens pilosa L., Bidens biternata (Lour.) Merr. & Sherff, Bidens bipinnata L.) are also listed in ethnomedicinal reports all over the world. In this study, all these plants are tested for in vitro anticandida activity. A quantitative evaluation of the phytochemicals in all these plants indicated that their vegetative parts are rich in tannins, saponins, oxalates, cyanogenic glycoside and lipids; moreover, the roots have high percentages of alkaloids, flavonoids, and phenols. The results indicated significant anticandida activity, especially for the hexane extract of B. bipinnata leaves which inhibited C. albicans (42.54%), C. glabrata (46.98%), C. tropicalis (50.89%), C. krusei (40.56%), and C. orthopsilosis (50.24%). The extract was subjected to silica gel chromatography and 220 fractions were obtained. Purification by High Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) and Gas Chromatography tandem Mass Spectrometry (GC-MS/MS) analysis led to the identification of two anticandida compounds: dehydroabietic and linoleic acid having an inhibition of 85 and 92%, respectively.

Baccharis dracunculifolia (Asteraceae) essential oil displays anti-inflammatory activity in models of skin inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Baccharis dracunculifolia (Asteraceae) is a commonly used plant in traditional medicine known as "alecrim-do-campo". Popularly it has been used as an immunostimulant, antibiotic, anti-inflammatory among other applications. So far, only a few studies have investigated the B. dracunculifolia anti-inflammatory effect and none has investigated the effectiveness of essential oil on skin diseases.

AIM OF THE STUDY

The study aimed at evaluating the topical anti-inflammatory activity of B. dracunculifolia essential oil (BdEO) in mice models of acute and chronic skin inflammation.

MATERIALS AND METHODS

BdEO was obtained from leaves and it was analyzed with Gas Chromatograph. Topical anti-inflammatory activity of BdEO (0.1, 0.3 and 1.0 mg/ear) was evaluated in Arachidonic Acid or TPA-induced acute and chronic skin inflammation in mice. Parameters such edema, cell migration and keratinocytes proliferation were evaluated. In addition, safety and a possible mechanism of action for BdEO essential oil were also investigated.

RESULTS

Our results indicate that mainly terpenoids compounds compose BdEO. In addition, topical treatment with BdEO inhibited inflammatory parameters in both acute and chronic models of skin inflammation. This protective effect was associated with reduced edema formation, smaller cellular influx into the inflamed tissue and reduction of keratinocytes hyperproliferation. Although BdEO appears to exert its anti-inflammatory effect through a corticosteroid pathway, no local or systemic side effects were observed.

CONCLUSION

Taken together, the present results showed that the essential oil obtained by hydrodistillation from B. dracunculifolia leaf samples exhibit remarkable topical anti-inflammatory properties. Therefore, our study demonstrated evidence for BdEO topical anti-inflammatory efficacy and safety, suggesting that it could be considered for developing of a new phytotherapeutic formulation as treatment for skin diseases.

In vivo Anti-inflammatory Activity of Lipidated Peptidomimetics Pam-(Lys-βNspe)6-NH2 and Lau-(Lys-βNspe)6-NH2 Against PMA-Induced Acute Inflammation

Host Defense Peptides (HDPs) are key components of innate immunity that exert antimicrobial, antibiofilm, and immunomodulatory activities in all higher organisms. Synthetic peptidomimetic analogs were designed to retain the desirable pharmacological properties of HDPs while having improved stability toward enzymatic degradation, providing enhanced potential for therapeutic applications. Lipidated peptide/β-peptoid hybrids [e.g., Pam-(Lys-βNspe)₆-NH₂ (PM1) and Lau-(Lys-βNspe)₆-NH₂ (PM2)] are proteolytically stable HDP mimetics displaying anti-inflammatory activity and formyl peptide receptor 2 antagonism in human and mouse immune cells in vitro. Here PM1 and PM2 were investigated for their in vivo anti-inflammatory activity in a phorbol 12-myristate 13-acetate (PMA)-induced acute mouse ear inflammation model. Topical administration of PM1 or PM2 led to attenuated PMA-induced ear edema, reduced local production of the pro-inflammatory chemokines MCP-1 and CXCL-1 as well as the cytokine IL-6. In addition, diminished neutrophil infiltration into PMA-inflamed ear tissue and suppressed local release of reactive oxygen and nitrogen species were observed upon treatment. The obtained results show that these two peptidomimetics exhibit anti-inflammatory effects comparable to that of the non-steroidal anti-inflammatory drug indomethacin, and hence possess a potential for treatment of inflammatory skin conditions.

Luteolin-phospholipid complex: preparation, characterization and biological evaluation

OBJECTIVES

This study aims to develop novel carrier system incorporating luteolin, a poorly soluble biologically active plant active.

METHODS

We investigated a lipid-based drug delivery system to enhance dissolution and absorption profile of luteolin. Luteolin was complexed with phospholipids, and the preparation was characterized. The formulation was evaluated for physicochemical properties, in-vitro solubility or release studies. In vivo anti-inflammatory action of luteolin and its phospholipid complex was evaluated by using carrageenan and 12-O-tetradecanoylphorbol-13-acetate as inducers.

KEY FINDINGS

The prepared luteolin-phospholipid complex (LPC) showed drug loading of about 72.64% with average particle size of 152.6 nm. The Fourier transform infrared spectroscopy and thermal studies confirm formation of complex. The solubility of luteolin as LPC was about 2.5 times higher than the solubility of pure luteolin in water. In the diffusion study, LPC showed 95.12% of drug release at the end of 2 h. Animal studies demonstrated significant differences in response of LPC and luteolin.

CONCLUSION

LPC was successfully prepared by optimizing the process parameters. The resultant delivery system improved bioavailability and efficacy of luteolin and in the future may become an efficient tool for administration of luteolin.

Polyandric acid A, a clerodane diterpenoid from the Australian medicinal plant Dodonaea polyandra, attenuates pro-inflammatory cytokine secretion in vitro and in vivo

Dodonaea polyandra is a medicinal plant used traditionally by the Kuuku I'yu (Northern Kaanju) indigenous people of Cape York Peninsula, Australia. The most potent of the diterpenoids previously identified from this plant, polyandric acid A (1), has been examined for inhibition of pro-inflammatory cytokine production and other inflammatory mediators using well-established acute and chronic mouse ear edema models and in vitro cellular models. Topical application of 1 significantly inhibited interleukin-1β production in mouse ear tissue in an acute model. In a chronic skin inflammation model, a marked reduction in ear thickness, associated with significant reduction in myeloperoxidase accumulation, was observed. Treatment of primary neonatal human keratinocytes with 1 followed by activation with phorbol ester/ionomycin showed a significant reduction in IL-6 secretion. The present study provides evidence that the anti-inflammatory properties of 1 are due to inhibition of pro-inflammatory cytokines associated with skin inflammation and may be useful in applications for skin inflammatory conditions including psoriasis and dermatitis.

Anti-inflammatory activity of hautriwaic acid isolated from Dodonaea viscosa leaves

The aim of this study was to identify an anti-inflammatory compound from D. viscosa leaves. The structure of this bioactive substance was elucidated by IR and NMR studies, which indicated that this natural product corresponds to hautriwaic acid (HA). This diterpene exhibited good anti-inflammatory activity in 12-O-tetradecanoylphorbol 13-acetate (TPA) mice ear edema models by applications at doses of 0.25, 0.5 and 1.0 mg/ear (60.2, 70.2 and 87.1% inhibition, respectively); additionally Dodonaea viscosa dichloro-methane extract (DvDE) displays a 97.8% anti-inflammatory effect at 3 mg/kg. Multiple applications of DvDE at doses of 100 mg/kg on TPA mice ear edema inhibited the edema-associated inflammation by 71.8%, while HA at doses of 15 mg/kg, reduced edema to 64% and indomethacin 40%.

Systematic review of herbals as potential anti-inflammatory agents: Recent advances, current clinical status and future perspectives

Many synthetic drugs reported to be used for the treatment of inflammatory disorders are of least interest now a days due to their potential side effects and serious adverse effects and as they are found to be highly unsafe for human assistance. Since the last few decades, herbal drugs have regained their popularity in treatment against several human ailments. Herbals containing anti-inflammatory activity (AIA) are topics of immense interest due to the absence of several problems in them, which are associated with synthetic preparations. The primary objective of this review is to provide a deep overview of the recently explored anti-inflammatory agents belonging to various classes of phytoconstituents like alkaloids, glycosides, terpenoids, steroids, polyphenolic compounds, and also the compounds isolated from plants of marine origin, algae and fungi. Also, it enlists a distended view on potential interactions between herbals and synthetic preparations, related adverse effects and clinical trials done on herbals for exploring their AIA. The basic aim of this review is to give updated knowledge regarding plants which will be valuable for the scientists working in the field of anti-inflammatory natural chemistry.

In vivo activity of benzoyl ester clerodane diterpenoid derivatives from Dodonaea polyandra

Four new benzoyl ester clerodane diterpenoids, 15,16-epoxy-8α-(benzoyloxy)methylcleroda-3,13(16),14-trien-18-oic acid (1), 15,16-epoxy-8α-(benzoyloxy)methyl-2α-hydroxycleroda-3,13(16),14-trien-18-oic acid (2), 15,16-epoxy-8α-(benzoyloxy)methyl-2-oxocleroda-3,13(16),14-trien-18-oic acid (3), and 15,16-epoxy-2α-benzoyloxycleroda-3,13(16),14-trien-18-oic acid (4), have been isolated from the leaves and stems of Dodonaea polyandra. The anti-inflammatory activities of compounds 1, 2, and 4 were evaluated by means of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema. Compounds 2 and 4 exhibited maximum inhibition of inflammation (70-76%) at doses of 0.22 and 0.9 μmol/ear, respectively. Modest activity (~45% inhibition) was maintained at nanomole/ear doses.

Anti-Frostbite Effects of Prunus Tomentosa Thunb Total Flavone

The aim of this study is to assess the influence of Prunus Tomentosa Thunb Total Flavone (PTTTF) on rabbits' frostbitten ears and on expressions of Matrix Metalloproteinase (MMP-9) in mouse frostbitten tissues and IL-1β in mouse Peripheral Blood Mononuclear Cells (PBMCs). Twelve New Zealand rabbits were randomly divided into two groups, both ears of each rabbit were frostbitten by liquid nitrogen. PTTTF and triamcinolone acetonide acetate ointment (TAAO) were spread on the left ear for 7 days, and the right ear was not treated as control. Therapeutic effects of the drugs and the pathological changes were observed. Drugs (PTTTF and TAAO) were prophylactically spread on the skin of the paws of mice for 5 days. After paw frostbitten models were established, the agents were consecutively spread for another 2 days. Expressions of MMP-9 in frostbitten tissues and IL-1β in PBMCs were respectively detected by the immunohistochemical method and RT-PCR. Compared with controls, four days later, the swelling inhibiting rate of PTTTF was 26.84%, and was 32.52% seven days later. The therapeutic effect of PTTTF was better than that of TAAO. Pathological changes of PTTTF group showed the effusion of a small quantity of neutrophil granulocytes and the tissue dropsy was not obvious. Expressions of both MMP-9 and IL-1β were significantly decreased in PTTTF group compared with those in model control group. There was no significant difference in expressions of MMP-9 and IL-1β between PTTTF group and TAAO group. We concluded that PTTTF produced a significant therapeutic effect on the frostbite of the rabbits' ears. PTTTF could inhibit expressions of MMP-9 in frostbite tissues and IL-1β in PBMCs to relieve the frostbite inflammation.