Tabebuia avellanedae extracts inhibit IL-2-independent T-lymphocyte activation and proliferation

Tabebuia impetiginosa: A Comprehensive Review on Traditional Uses, Phytochemistry, and Immunopharmacological Properties

Tabebuia impetiginosa, a plant native to the Amazon rainforest and other parts of Latin America, is traditionally used for treating fever, malaria, bacterial and fungal infections, and skin diseases. Additionally, several categories of phytochemicals and extracts isolated from T. impetiginosa have been studied via various models and displayed pharmacological activities. This review aims to uncover and summarize the research concerning T. impetiginosa, particularly its traditional uses, phytochemistry, and immunopharmacological activity, as well as to provide guidance for future research. A comprehensive search of the published literature was conducted to locate original publications pertaining to T. impetiginosa up to June 2020. The main inquiry used the following keywords in various combinations in titles and abstracts: T. impetiginosa, Taheebo, traditional uses, phytochemistry, immunopharmacological, anti-inflammatory activity. Immunopharmacological activity described in this paper includes its anti-inflammatory, anti-allergic, anti-autoimmune, and anti-cancer properties. Particularly, T. impetiginosa has a strong effect on anti-inflammatory activity. This paper also describes the target pathway underlying how T. impetiginosa inhibits the inflammatory response. The need for further investigation to identify other pharmacological activities as well as the exact target proteins of T. impetiginosa was also highlighted. T. impetiginosa may provide a new strategy for prevention and treatment of many immunological disorders that foster extensive research to identify potential anti-inflammatory and immunomodulatory compounds and fractions as well as to explore the underlying mechanisms of this herb. Further scientific evidence is required for clinical trials on its immunopharmacological effects and safety.

Endophytic fungi isolated from medicinal plants: future prospects of bioactive natural products from Tabebuia/Handroanthus endophytes

Medicinal plants are a rich source of natural products used to treat many diseases; therefore, they are the basis for a new drug discovery. Plants are capable of generating different bioactive secondary metabolites, but a large amount of botanical material is often necessary to obtain small amounts of the target substance. Nowadays, many medicinal plants are becoming rather scarce. For this reason, it is important to point out the interactions between endophytic microorganisms and the host plant, because endophytes are able to produce highly diverse compounds, including those from host plants that have important biological activities. Thence, this review aims at presenting the richness in bioactive compounds of the medicinal plants from Tabebuia and Handroanthus genera, as well as important aspects about endophyte-plant interactions, with emphasis on the production of bioactive compounds by endophytic fungi, which has been isolated from various medicinal plants for such a purpose. Furthermore, bio-prospection of natural products synthesized by endophytes isolated from the aforementioned genera used in traditional medicine could be used to treat illnesses.

Tabetri™ (Tabebuia avellanedae Ethanol Extract) Ameliorates Atopic Dermatitis Symptoms in Mice

Tabebuia avellanedae has been traditionally used as an herbal remedy to alleviate various diseases. However, the plant's pharmacological activity in allergic and inflammatory diseases and its underlying mechanism are not fully understood. Therefore, we investigated the pharmacological activity of Tabetri (T. avellanedae ethanol extract (Ta-EE)) in the pathogenesis of AD. Its underlying mechanism was explored using an AD mouse model and splenocytes isolated from this model. Ta-EE ameliorated the AD symptoms without any toxicity and protected the skin of 2,4-dinitrochlorobenzene- (DNCB-) induced AD mice from damage and epidermal thickness. Ta-EE reduced the secreted levels of allergic and proinflammatory cytokines, including histamine, immunoglobulin E (IgE), interleukin- (IL-) 4, and interferon-gamma (IFN-γ) in the DNCB-induced AD mice. Ta-EE suppressed the mRNA expression of T helper 2-specific cytokines, IL-4 and IL-5, and the proinflammatory cytokine IFN-γ in the atopic dermatitis skin lesions of AD mice. Moreover, Ta-EE suppressed the mRNA expression of IL-4, IL-5, IFN-γ, and another proinflammatory cytokine, IL-12, in the Con A-stimulated splenocytes. It also suppressed IL-12 and IFN-γ in the LPS-stimulated splenocytes. Taken together, these results suggest that Ta-EE protects against the development of AD through the inhibition of mRNA expression of T helper 2-specific cytokines and other proinflammatory cytokines.

Tabetri™ (Tabebuia avellanedae Ethanol Extract) Ameliorates Osteoarthritis Symptoms Induced by Monoiodoacetate through Its Anti-Inflammatory and Chondroprotective Activities

Although osteoarthritis (OA), a degenerative joint disease characterized by the degradation of joint articular cartilage and subchondral bones, is generally regarded as a degenerative rather than inflammatory disease, recent studies have indicated the involvement of inflammation in OA pathogenesis. Tabebuia avellanedae has long been used to treat various diseases; however, its role in inflammatory response and the underlying molecular mechanisms remain poorly understood. In this study, the pharmacological effects of Tabetri (Tabebuia avellanedae ethanol extract (Ta-EE)) on OA pathogenesis induced by monoiodoacetate (MIA) and the underlying mechanisms were investigated using experiments with a rat model and in vitro cellular models. In the animal model, Ta-EE significantly ameliorated OA symptoms and reduced the serum levels of inflammatory mediators and proinflammatory cytokines without any toxicity. The anti-inflammatory activity of Ta-EE was further confirmed in a macrophage-like cell line (RAW264.7). Ta-EE dramatically suppressed the production and mRNA expressions of inflammatory mediators and proinflammatory cytokines in lipopolysaccharide-stimulated RAW264.7 cells without any cytotoxicity. Finally, the chondroprotective effect of Ta-EE was examined in a chondrosarcoma cell line (SW1353). Ta-EE markedly suppressed the mRNA expression of matrix metalloproteinase genes. The anti-inflammatory and chondroprotective activities of Ta-EE were attributed to the targeting of the nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) signaling pathways in macrophages and chondrocytes.

Anti-inflammatory cyclopentene derivatives from the inner bark of Tabebuia avellanedae

Six new cyclopentenyl esters, avellaneine A-F (1-4, 7, 8), two new cyclopentyl esters, avellaneine G, H (9, 10), along with two known cyclopentenyl esters were obtained from water extract of the inner bark of Tabebuia avellanedae Lorentz ex Griseb. The chemical structures of the new compounds were elucidated by spectroscopic techniques. The anti-inflammatory effects of these compounds were determined on LPS-stimulated RAW 264.7 cell line. Some of the tested compounds (2, 3, 4, 6, 7) reduced the NO production in a dose-dependent manner, while 6 and 7 decreased PGE2 production in a dose-dependent manner, without altering cell viability. Data presented in this research indicated that Tabebuia avellanedae's ethnopharmacological action of treating inflammatory diseases was based on the constituents which exert a significant anti-inflammatory effect on inflammatory responses.

Analgesic and anti-inflammatory effects in animal models of an ethanolic extract of Taheebo, the inner bark of Tabebuia avellanedae

Taheebo, the purple inner bark of the Bignoniaceae tree Tabebuia avellanedae Lorentz ex Griseb, which is found in tropical rain forests in northeastern Brazil, has been used as a traditional medicine for various diseases for more than 1,500 years. In the current study, various animal models were used to demonstrate the analgesic and anti-inflammatory properties of its ethanolic extract, thereby investigating its potential as a therapeutic treatment for diseases with pain and inflammation. In the hot plate and writhing tests for the in vivo analgesic effect test of Taheebo, a 200 mg/kg dose of the extract induced a significant anti-nociceptive effect and increased the pain threshold by approximately 30% compared with the control. In vascular permeability and tetradecanoylphorbol acetate (TPA)‑, arachidonic acid- and carrageenan-induced paw edema tests for anti-inflammatory effects, treatment with 200 mg/kg Taheebo led to significant anti-inflammatory effects and inhibited inflammation by 30-50% compared with the control. At 100 mg/kg, the extract decreased the levels of pain and inflammation in all tested models, but the degree of inhibition was not statistically significant. The results suggest that the ethanolic extract of the inner bark of Tabebuia avellanedae has the potential to be developed as a therapeutic or supportive drug against diseases with accompanying pain and inflammation, including osteoarthritis.

Comparative characteristic of the inflammatory diterpenes in the roots of Euphorbia fischeriana with different preparation method using HPLC-ELSD

A rapid and simple method was established for the simultaneous determination of ten diterpenes by reversed phase HPLC coupled with evaporative light scattering detection. Chromatographic separation was carried out in gradient mode by using a WondaSil™ C(18) column (250mm×4.6mm, 5μm) with mobile phases of methanol and water at 1mL/min. The drift tube temperature of evaporative light scattering detector was set to 65°C and nitrogen flow-rate was 2.7L/min. The method validated was shown to be specific, precise, accurate and linear. Moreover, it was applied to investigate four samples of E. fischeriana with different extracting methods. Contrast to the dried roots, the fresh roots had much higher content of prostratin which represented much higher inflammatory effects than other diterpenes. The results demonstrated that the dried roots were suitable for the ordinary therapy to avoid intense stimulatory, while the fresh roots could be used in the anticancer treatment. All of the results suggested that comparative analysis of chemical components as biomarker and connecting toxic effects of an herb was helpful for revealing the mechanism of its toxicity, and for guiding safer and better application of the herb in TCM clinic.

Bioassay-guided separation of the proinflammatory constituents from the roots of Euphorbia kansui

In view of the toxic inflammatory reaction induced by Euphorbia kansui roots, a traditional Chinese medicine used for the treatment of edema, ascites, and asthma, the 95% ethanol extract was found to have a significant stimulating effect on inflammatory cells. Bioassay-guided separation of the 95% ethanol extract from the roots of E. kansui led to the isolation of five diterpenoids whose structures were identified by (1)H, (13)C NMR spectroscopy and HR-ESI-MS as kansuinine B (1), kansuinine A (2), kansuiphorin C (3), 3-O-benzoyl-20-deoxyingenol (4), and 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (5). The proinflammatory effect of compounds 1-5 was evaluated in vitro in models of inflammation using exoteric mice splenic lymphocytes (SPL) and rat peritoneal macrophages (PMphi). Compounds 1, 2, and 5 markedly promoted SPL proliferation and NO production by PMphi at concentrations from 0.78 to 12.50 microg/mL. Hence the three compounds are believed to be important proinflammatory components of the roots of E. kansui.

In vitro and in vivo anti-inflammatory effects of taheebo, a water extract from the inner bark of Tabebuia avellanedae

AIM OF STUDY

Tabebuia spp. (Bignoniaceae) are native to tropical rain forests throughout Central and South America and have long been used as a folk medicine to treat bacterial infection, blood coagulation, cancer and inflammatory diseases. In this study, we aimed to demonstrate the ethnopharmacological activity of Tabebuia avellanedae in various in vitro and in vivo inflammatory conditions.

MATERIALS AND METHODS

To do this, LPS-stimulated macrophages and arachidonic acid or croton oil-induced mouse ear edema models were employed.

RESULTS

The water extract (taheebo) of Tabebuia avellanedae significantly suppressed the production of prostaglandin (PG) E(2) and nitric oxide (NO), and blocked the mRNA expression of their catalyzing enzymes (cyclooxygenase [COX)-II] and inducible NO synthase [iNOS], respectively), in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The blockade of inflammatory mediators by taheebo seemed to be the result of the interruption of extracellular signal-related kinase (ERK) activation, according to immunoblotting analysis and the NO assay, where LPS strongly induced the phosphorylation (a hallmark of activation) of ERK, and U0126, a selective ERK inhibitor, was found to strongly inhibit PGE(2) production. Similarly, oral administration of taheebo (100mg/kg) for 1 week completely diminished mouse ear edema induced by arachidonic acid, an activator of COX-II, but not croton oil, an activator of lipoxygenase.

CONCLUSIONS

These data suggest that the ethnopharmacological action of taheebo may be due to its negative modulation of macrophage-mediated inflammatory responses by suppressing PGE(2) production. Thus, this water extract may be developed as a new therapeutic remedy for various inflammatory diseases such as arthritis and atherosclerosis.