0000000000234730
AUTHOR
José M. Escandell
Bcl-2 is a negative regulator of interleukin-1β secretion in murine macrophages in pharmacological-induced apoptosis
BACKGROUND AND PURPOSE Cucurbitacin R, a natural anti-inflammatory product, has been shown to exhibit activity against both adjuvant-induced arthritis and delayed-type hypersensitivity reactions induced by various agents. Previous studies have demonstrated that the effects of cucurbitacin R stem from its inhibition of both cytokine production and lymphocyte proliferation. EXPERIMENTAL APPROACHES Effects of cucurbitacin R were investigated on lipopolysaccharide-stimulated RAW 264.7 cells. Cell cycle evolution was analysed by flow cytometry, detection of apoptosis by DNA ladder, Bcl-2, p21, p53, Bax, cleaved caspase-1 (p10), caspase-9, and caspase-3, cleaved caspase (p17) and interleukin-1β d…
Inhibition of Delayed-Type Hypersensitivity by Cucurbitacin R through the Curbing of Lymphocyte Proliferation and Cytokine Expression by Means of Nuclear Factor AT Translocation to the Nucleus
Cucurbitacin R is known to exhibit an anti-inflammatory effect in different experimental models of inflammation. In this article, we outline the effect of cucurbitacin R on T lymphocyte proliferation, cytokine production, and nuclear factor activation, as well as its influence on various experimental models of delayed-type hypersensitivity (DTH) in mice. Cucurbitacin R reduced the proliferation of phytohemagglutinin A-stimulated human T lymphocytes (IC(50), 18 microM), modifying the cell cycle, as well as the production of cytokines [interleukin (IL)-2, IL-4, IL-10, and especially interferon-gamma] and the induction of the principal cyclins implicated in the cell cycle (A(1), B(1), D(2), an…
New insight into the inhibition of the inflammatory response to experimental delayed-type hypersensitivity reactions in mice by scropolioside A.
Scropolioside A, an iridoid isolated from Scrophularia auriculata ssp. pseudoauriculata, showed anti-inflammatory properties against different experimental models of delayed-type hypersensitivity. This iridoid reduced the oedema induced by oxazolone by 79% (72 h) at 0.5 mg/ear while reducing that induced by sheep red blood cells by 47% (18 h), 45% (24 h) and 36% (48 h) at 10 mg/kg. In vivo it reduced both oedema formation and cell infiltration whereas in vitro it reduced the proliferation of activated T-lymphocytes (IC50 of 67.74 microM). Treatment with scropolioside A (100 microM) 18 and 24 h after phytohemagglutinin stimulation increased the number of cells arrested in the subG(0) phase w…
Dihydrocucurbitacin B Inhibits Delayed Type Hypersensitivity Reactions by Suppressing Lymphocyte Proliferation
We have studied the effects of dihydrocucurbitacin B, a triterpene isolated from Cayaponia tayuya roots, on different models of delayed type hypersensitivity (DTH) in mice, as well as on T-lymphocyte proliferation and the mediators involved. In experiments with mice, dihydrocucurbitacin B inhibited the inflammatory reactions induced by oxazolone, dinitrofluorobenzene, and sheep red blood cells, reducing both the edema and cell infiltration. Moreover, the analysis of inflamed tissues showed that dihydrocucurbitacin B reduced the presence of the most relevant cytokines implicated in these processes, including interleukin-1 beta, interleukin-4, and tumor necrosis factor-alpha. Dihydrocucurbita…
Cucurbitacin R Reduces the Inflammation and Bone Damage Associated with Adjuvant Arthritis in Lewis Rats by Suppression of Tumor Necrosis Factor-α in T Lymphocytes and Macrophages
The aim of this study was to investigate the effects of cucurbitacin R on an experimental model of adjuvant-induced arthritis in rats. The treatment of arthritic rats with cucurbitacin R (1 mg/kg p.o. daily) modified the evolution of the clinical symptoms, whereas the histopathology of paws demonstrated a reduction in the signs of arthritis. Compared with the control group, radiography of the tibiotarsal joints of cucurbitacin R-treated rats showed a decrease in joint damage and soft tissue swelling of the footpad. The in vivo study of the expression of proinflammatory enzymes (nitric-oxide synthase-2 and cyclooxygenase-2) with the aid of the Western blot technique, and that of tumor necros…
Inhibition of Transcription Factors by Plant-Derived Compounds and their Implications in Inflammation and Cancer
Inflammation is a general term used to describe various pathological processes with diverse causes that can include infection, trauma, or an autoimmune response. Due to its many causes, the inflammatory response involves multiple and varied mediators, including vasoactive amines, free radicals, and both lipidic and peptidic mediators. Medicinal plants and the compounds derived from them are a good source of new and specific inhibitors of the inflammatory process. The past decade has witnessed many important discoveries in this field, with new findings challenging the more traditional views of pharmacologists. Various studies, for example, have demonstrated the positive effects of plant-deri…
Activated kRas protects colon cancer cells from cucurbitacin-induced apoptosis: The role of p53 and p21
Cucurbitacins have been shown to inhibit proliferation in a variety of cancer cell lines. The aim of this study was to determine their biological activity in colon cancer cell lines that do not harbor activated STAT3, the key target of cucurbitacin. In order to establish the role of activated kRas in the responsiveness of cells to cucurbitacins, we performed experiments in isogenic colon cancer cell lines, HCT116 and Hke-3, which differ only by the presence of an activated kRas allele. We compared the activity of 23, 24-dihydrocucurbitacin B (DHCB) and cucurbitacin R (CCR), two cucurbitacins that we recently isolated, with cucurbitacin I (CCI), a cucurbitacin with established antitumorigeni…
Dihydrocucurbitacin B, isolated from Cayaponia tayuya, reduces damage in adjuvant-induced arthritis
23,24-Dihydrocucurbitacin B, from the anti-rheumatic plant Cayaponia tayuya, was tested on arthritis induced by adjuvant to corroborate the anti-inflammatory properties of this plant. Arthritis was induced in Lewis rats; the resulting arthritic rats were then treated with dihydrocucurbitacin B (1 mg/kg orally, daily, 1 week). The effect of dihydrocucurbitacin B on the synthesis, release, and activity of pro-inflammatory enzymes (elastase, cyclooxygenase-2, and nitric oxide synthase-2) as well as its effect on different mediators (tumor necrosis factor-alpha and interleukin-1beta) were determined. Dihydrocucurbitacin B modified the evolution of the clinical symptoms, reducing the swelling an…
Cucurbitacins as inducers of cell death and a rich source of potential anticancer compounds.
Triterpenes have been reported to induce cell death. One relevant group of this family of compounds is cucurbitacins, which have been studied as inducers of apoptosis in various cancer cell lines. The most significant mechanisms with regard to the apoptotic effects of cucurbitacins are their ability to modify transcriptional activities via nuclear factors or genes and their capability to activate or inhibit pro- or anti-apoptotic proteins. Still, while the majority of studies on these compounds have dealt with their apoptotic effects on cancer cell lines, several research groups have also explored their anti-inflammatory activities. In general, cucurbitacins are considered to be selective i…
New insights into the bioactivity of cucurbitacins
The cucurbitacins are a group of tetracyclic triterpenoids derived from the cucurbitane skeleton and found primarily in the Cucurbitaceae family. These triterpenoids, present in free or glycosidic form, are generally responsible for the bitter taste of the plants that contain them and are probably the principal cause of the antifeedant effects observed for such plants. Several plants used in traditional medicine to treat both inflammatory diseases as well as various types of tumors are rich in cucurbitacins, a fact which has given rise to several studies concerning their potential use as anti-inflammatory and anticancer agents. Nevertheless, since many cucurbitacins are extremely toxic, rel…