Anti-inflammatory effects of the products from Wilbrandia ebracteata on carrageenan-induced pleurisy in mice

Opuntia monacantha: Validation of the anti-inflammatory and anti-arthritic activity of its polyphenolic rich extract in silico and in vivo via assessment of pro- and anti-inflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Opuntia monacantha belongs to the cactus family Cactaceae and is also known by cochineal prickly pear, Barbary fig or drooping prickly pear. It was traditionally used to treat pain and inflammation. O. monacantha cladodes showed pharmacological effects such as antioxidant potential owing to the presence of certain polysaccharides, flavonoids, and phenols.

AIM OF THE STUDY

This research aimed to evaluate the anti-inflammatory as well as the anti-arthritic potential of ethanol extract of Opuntia monacantha (E-OM).

MATERIALS AND METHODS

In vivo edema in rat paw was triggered by carrageenan and used to evaluate anti-inflammatory activity, while induction of arthritis by Complete Freund's Adjuvant (CFA) rat model was done to measure anti-arthritic potential. In silico studies of the previously High performance liquid chromatography (HPLC) characterized metabolites of ethanol extract was performed by using Discovery Studio 4.5 (Accelrys Inc., San Diego, CA, USA) within active pocket of glutaminase 1 (GLS1) (PDB code: 3VP1; 2.30 Å).

RESULTS

EOM, particularly at 750 mg/kg, caused a reduction in the paw edema significantly and decreased arthritic score by 80.58% compared to the diseased group. It revealed significant results when histopathology of ankle joint was examined at 28th day as it reduced inflammation by 18.06%, bone erosion by 15.50%, and pannus formation by 24.65% with respect to the diseased group. It restored the altered blood parameters by 7.56%, 18.47%, and 3.37% for hemoglobin (Hb), white blood count (WBC), and platelets, respectively. It also reduced rheumatoid factor RF by 13.70% with concomitant amelioration in catalase (CAT) and superoxide dismutase (SOD) levels by 19%, and 34.16%, respectively, in comparison to the diseased group. It notably decreased mRNA expression levels of COX-2, IL-6, TNF-α, IL-1, NF-κβ and augmented the levels of IL-4 and IL-10 in real time PCR with respect to the diseased group and piroxicam. HPLC analysis previously performed showed that phenolic acids and flavonoids are present in E-OM. Molecular docking studies displayed pronounced inhibitory potential of these compounds towards glutaminase 1 (GLS1), approaching and even exceeding piroxicam.

CONCLUSIONS

Thus, Opuntia monacantha could be a promising agent to manage inflammation and arthritis and could be incorporated into pharmaceuticals.

Cucurbitacin B: A review of its pharmacology, toxicity, and pharmacokinetics

Cucurbitacin B (CuB, C₃₂H₄₆O₈), the most abundant and active member of cucurbitacins, which are highly oxidized tetracyclic triterpenoids. Cucurbitacins are widely distributed in a variety of plants and mainly isolated from plants in the Cucurbitaceae family. CuB is mostly obtained from the pedicel of Cucumis melo L. Modern pharmacological studies have confirmed that CuB has a broad range of pharmacological activities, with significant therapeutic effects on a variety of diseases including inflammatory diseases, neurodegenerative diseases, diabetes mellitus, and cancers. In this study the PubMed, Web of Science, Science Direct, and China National Knowledge Infrastructure (CNKI) databases were searched from 1986 to 2022. After inclusion and exclusion criteria were applied, 98 out of 2484 articles were selected for a systematic review to comprehensively summarize the pharmacological activity, toxicity, and pharmacokinetic properties of CuB. The results showed that CuB exhibits potent anti-inflammatory, antioxidant, antiviral, hypoglycemic, hepatoprotective, neuroprotective, and anti-cancer activities mainly via regulating various signaling pathways, such as the Janus kinase/signal transducer and activator of transcription-3 (JAK/STAT3), nuclear factor erythroid 2-related factor-2/antioxidant responsive element (Nrf2/ARE), nuclear factor (NF)-κB, AMP-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K)/Akt, cancerous inhibitor of protein phosphatase-2A/protein phosphatase-2A (CIP2A/PP2A), Wnt, focal adhesion kinase (FAK), Notch, and Hippo-Yes-associated protein (YAP) pathways. Studies of its toxicity and pharmacokinetic properties showed that CuB has non-specific toxicity and low bioavailability. In addition, derivatives and clinical applications of CuB are discussed in this paper.

Cucurbitacins: Nature’s Wonder Molecules

Abstract:

Over the past decades, several natural constituents belonging to different classes have been isolated from plants for medicinal purposes. Cucurbitacins is one such type of natural compound. Cucurbitacin is any of a class of biochemical compounds that some plants notably members of the pumpkin and gourd family, Cucurbitaceae produce and which function as a defense against herbivores. They and their derivatives have been found in many plant families (including Brassicaceae, Cucurbitaceae, Scrophulariaceae, Begoniaceae, Elaeocarpaceae, Datiscaceae, Desfontainiaceae, Polemoniaceae, Primulaceae, Rubiaceae, Sterculiaceae, Rosaceae, and Thymelaeaceae), in some mushrooms (including Russula and Hebeloma) and even in some marine mollusks. They have been isolated from various plant species, chiefly belonging to the Cucurbitaceae family which comprises around 130 genera and 800 species. Cucurbitacins are a group of tetracyclic triterpenoid substances that are highly oxygenated and contain a cucurbitane skeleton characterized by 9β-methyl−19-norlanosta-5-ene. Cucurbitacins can be categorized into twelve main groups according to variations in their side-chains. Cucurbitacins A, B, C, D, E, F, I, J, K, L, O, P, Q, R, S, and their glycosides are mainly found in Cucurbitaceae family members. These plants have been used as folk medicines in some countries because of their broad spectrum of crucial pharmacological activities such as anti-inflammatory, anti-cancer, anti-diabetic, and anti-atherosclerotic effects. The present review explores the possibility of a correlation between the chemistry of various Cucurbitacins and the uses of the plants which contain them, thereby opening avenues for further phytochemical, ethnomedicinal, and modern pharmacological research on these important molecules.

KOTMIN13, a Korean herbal medicine alleviates allergic inflammation in vivo and in vitro

Background

The ethanol extract of KOTMIN13, composed of Inula japonica Flowers, Trichosanthes kirilowii Semen, Peucedanum praeruptorum Radix, and Allium macrostemon Bulbs, was investigated for its anti-asthmatic and anti-allergic activities.

Methods

The anti-asthmatic effects of KOTMIN13 were evaluated on ovalbumin (OVA)-induced murine asthma model. Anti-allergic properties of KOTMIN13 in bone-marrow derived mast cells (BMMC) and passive cutaneous anaphylaxis (PCA) in vivo were also examined.

Results

In asthma model, KOTMIN13 effectively suppressed airway hyperresponsiveness induced by aerosolized methacholine when compared to the levels of OVA-induced mice. KOTMIN13 treatment reduced the total leukocytes, eosinophil percentage, and Th2 cytokines in the bronchoalveolar lavage fluids in OVA-induced mice. The increased levels of eotaxin and Th2 cytokines in the lung as well as serum IgE were decreased by KOTMIN13. The histological analysis shows that the increased inflammatory cell infiltration and mucus secretion were also reduced. In addition, the degranulation and leukotriene C₄ production were inhibited in BMMC with IC₅₀ values of 3.9 μg/ml and 1.7 μg/ml, respectively. Furthermore, KOTMIN13 treatment attenuated mast-mediated PCA reaction.

Conclusions

These results demonstrate that KOTMIN13 has anti-asthmatic and anti-allergic effects in vivo and in vitro models.

Cucurbitacin I Attenuates Cardiomyocyte Hypertrophy via Inhibition of Connective Tissue Growth Factor (CCN2) and TGF- β/Smads Signalings

Cucurbitacin I is a naturally occurring triterpenoid derived from Cucurbitaceae family plants that exhibits a number of potentially useful pharmacological and biological activities. However, the therapeutic impact of cucurbitacin I on the heart has not heretofore been reported. To evaluate the functional role of cucurbitacin I in an in vitro model of cardiac hypertrophy, phenylephrine (PE)-stimulated cardiomyocytes were treated with a sub-cytotoxic concentration of the compound, and the effects on cell size and mRNA expression levels of ANF and β-MHC were investigated. Consequently, PE-induced cell enlargement and upregulation of ANF and β-MHC were significantly suppressed by pretreatment of the cardiomyocytes with cucurbitacin I. Notably, cucurbitacin I also impaired connective tissue growth factor (CTGF) and MAPK signaling, pro-hypertrophic factors, as well as TGF-β/Smad signaling, the important contributing factors to fibrosis. The protective impact of cucurbitacin I was significantly blunted in CTGF-silenced or TGF-β1-silenced hypertrophic cardiomyocytes, indicating that the compound exerts its beneficial actions through CTGF. Taken together, these findings signify that cucurbitacin I protects the heart against cardiac hypertrophy via inhibition of CTGF/MAPK, and TGF- β/Smad-facilitated events. Accordingly, the present study provides new insights into the defensive capacity of cucurbitacin I against cardiac hypertrophy, and further suggesting cucurbitacin I's utility as a novel therapeutic agent for the management of heart diseases.

Application of spray granulation for conversion of mixed phospholipid-bile salt micelles to dry powder form: influence of drug hydrophobicity on nanoparticle reagglomeration

The aim of this study was to investigate the feasibility of using spray granulation as a drying method to convert phospholipid (PL)-sodium deoxycholate (SDC)-mixed micelles (MMs) containing a water-insoluble drug to a solid dosage form and to evaluate how drugs with significantly different physicochemical properties affect the spray granulation process and subsequent in vitro and in vivo processes. Cucurbitacin B (Cu B) and glycyrrhizin (GL) were used as the model drugs. After spray granulation, the dried Cu B-PL/SDC-MM powder was completely redispersible within 15 minutes in vitro. Meanwhile, the area under the curve during 24 hours (AUC_0–24) and peak serum concentration from the dried powder were significantly (P<0.05) lower than the values from Cu B-PL/SDC-MMs in vivo. However, a better result was obtained for GL, ie, the drug was redispersed completely within 5 minutes in vitro. Further, absorption from the dried GL-PL/SDC-MM powder was increased to the same level as that for GL-PL/SDC-MMs in vivo compared with the control group. The difference in these results can be found in Cu B and GL. Cu B nanoparticles reagglomerated when released, resulting in slower redispersibility and less absorption compared with the original PL-SDC-MMs. However, no agglomeration or delay was observed for GL. A possible explanation is the difference in surface hydrophobicity between Cu B and GL. The results of this study not only show that spray granulation is an effective drying technique that can complement spray-drying and freeze-drying, but also confirm that the physicochemical properties of a drug have a significant influence on the in vitro and in vivo performance of the dried powder obtained after spray granulation.

Aspirin and indomethacin reduce lung inflammation of mice exposed to cigarette smoke

Neutrophil accumulation response to cigarette smoke (CS) in humans and animal models is believed to play an important role in pathogenesis of many tobacco-related lung diseases. Here we evaluated the lung anti-inflammatory effect of aspirin and indomethacin in mice exposed to CS. C57BL/6 mice were exposed to four cigarettes per day during 4 days and were treated i.p. with aspirin or indomethacin, administered each day 1h before CS exposure. Twenty four hours after the last exposure, cells and inflammatory mediators were assessed in bronchoalveolar lavage (BAL) fluid and the lungs used for evaluation of lipid peroxidation, p38 mitogen-activated protein kinase (MAPK) phosphorylation and nuclear transcription factor kappaB (NF-kappaB) activation. Exposure to CS resulted in a marked lung neutrophilia. Moreover, the levels of oxidative stress-related lipid peroxidation, prostaglandin E(2) (PGE(2)), interleukin 1beta (IL-1beta), monocyte chemotactic protein 1 (MCP-1), and activated NF-kappaB and p38 MAPK were greatly increased in CS group. Aspirin or indomethacin treatment led to a significant reduction of neutrophil influx, but only aspirin resulted in dramatic decrease of inflammatory mediators. Moreover, both drugs reduced lung p38 MAPK and NF-kappaB activation induced by CS. These results demonstrate that short-term CS exposure has profound airway inflammatory effects counteracted by the anti-inflammatory agents aspirin and indomethacin, probably through COX-dependent and -independent mechanisms.

Gastric anti-ulcer activity of leaf fractions obtained of polar extract from Wilbrandia ebracteata in mice

Leaf fractions of Wilbrandia ebracteata were investigated for anti-ulcerogenic effects in ethanol and indomethacin-induced gastric ulcer assays in mice. Protective anti-ulcer effects were detected only in the ethanol-induced ulcer assay effects after pre-treatment with MeOH extract, MeOH chlorophyll-free, chlorophyll residue, HEX, DCM, aqueous MeOH fraction, ethyl acetate (EtOAc) and aqueous fractions. A potent anti-ulcerogenic effect was determined after pre-treatment of animals with EtOAc fraction, which was fractionated for isolation of active constituents. Seven flavonoids, 3',4',5,6,7,8-hexahydroxyflavonol, orientin, isoorientin, vitexin, isovitexin, luteolin, 6-methoxi-luteolin were isolated from the leaves of W. ebracteata (Cucurbitaceae) by chromatographic methods and identified by their spectral data. The data suggest that flavonoids are active anti-ulcerogenic compounds from leaves of W. ebracteata. The ability of scavenging free radicals was evaluated by DPPH reduction assay by TLC of flavonoids isolated.

Cucurbitacin B has a potent antiproliferative effect on breast cancer cells in vitro and in vivo

Cucurbitacins are a group of diverse triterpenoid substances isolated from plants with medicinal properties. One particularly potent family member is cucurbitacin B (CuB). The antiproliferative effects of CuB against human breast cancer cells were tested. Six human breast cancer cell lines were examined because they represent a diverse mix of breast cancer subtypes varying in expression of estrogen receptor (ER), Her2/neu, and p53 mutation. The antiproliferative effect of CuB were also studied in vivo. The effective dose inhibiting 50% growth (ED(50)) was between 10(-8) M and 10(-7) M for this collection of breast cancer cell lines. These cells underwent rapid morphologic changes after 15-20 min exposure to CuB (5 x 10(-7) M), which was associated with disruption of the microtubules and F-actin, as observed by confocal microscopy. Human MDA-MB-231 (ER-, p53 mutated) breast cancer cells were orthotopically implanted into the breasts of nude mice who intraperitoneally received either CuB 1.0 mg/kg or vehicle. Tumor volume was reduced by 55% in the group that received CuB for 6 weeks compared with vehicle controls. No apparent organ tissue damage was observed by pathological assessment. Interestingly, the experimental mice had lower serum glucose levels, consistent with use of CuB as an antidiabetic drug in China. This drug appears to be a third in a family of drugs targeting the microtubules (taxanes [e.g. taxol], vinca alkaloid [e.g. vincristine], and now CuB). Our in vitro and in vivo results suggest that CuB may be an effective, new approach for the treatment of ER-, Her2/neu amplified, and p53 mutant breast cancers.

Anti-inflammatory effects of a triterpenoid isolated from Wilbrandia ebracteata Cogn

Wilbrandia ebracteata (WE), a Brazilian medicinal plant used in folk medicine for the treatment of rheumatic diseases, displays anti-inflammatory properties and constitutes a rich source of cucurbitacins and cucurbitacin-related compounds. The current study investigated the potential anti-inflammatory properties of Dihydrocucurbitacin B (DHCB), a cucurbitacin-derived compound isolated from roots of WE, in some in vivo and in vitro experimental models. Intraperitoneal treatment of mice with DHCB reduced both carrageenan-induced paw edema (0.3, 1 and 3 mg/kg caused inhibitions of 26, 44 and 56 % at 2 h after stimulation, respectively) and pleurisy (10 mg/kg inhibited leukocyte numbers and LTB(4) levels in the pleural fluid by 51 and 75% at 6 h after cavity challenge, respectively). In vitro, DHCB (up to 10 microg/mL) failed to modify LTB(4) production by human neutrophils or PGE(2) production by COS-7 cells transfected with COX-1, but PGE(2) production by COX-2 transfected COS-7 cells was markedly inhibited (by 72%). The levels of COX-1 or COX-2 proteins in IL-1alpha-stimulated NIH3T3 cells were unaffected by DHCB. The results corroborate the potential anti-inflammatory properties ascribed to W. ebracteata Cogn. in folk medicine and suggest that they might be attributed, at least in part, to the capacity of one of this plants main constituents, DHCB, to inhibit COX-2 activity (but not its expression) during inflammation.

Growth inhibitory activity of cucurbitacin glucosides isolated from Citrullus colocynthis on human breast cancer cells

Our aim was to study the effects of cucurbitacin glucosides extracted from Citrullus colocynthis leaves on human breast cancer cell growth. Leaves were extracted, resulting in the identification of cucurbitacin B/E glucosides. The cucurbitacin glucoside combination (1:1) inhibited growth of ER(+) MCF-7 and ER(-) MDA-MB-231 human breast cancer cell lines. Cell-cycle analysis showed that treatment with isolated cucurbitacin glucoside combination resulted in accumulation of cells at the G(2)/M phase of the cell cycle. Treated cells showed rapid reduction in the level of the key protein complex necessary to the regulation of G(2) exit and initiation of mitosis, namely the p34(CDC2)/cyclin B1 complex. cucurbitacin glucoside treatment also caused changes in the overall cell morphology from an elongated form to a round-shaped cell, which indicates that cucurbitacin treatment caused impairment of actin filament organization. This profound morphological change might also influence intracellular signaling by molecules such as PKB, resulting in inhibition in the transmission of survival signals. Reduction in PKB phosphorylation and inhibition of survivin, an anti-apoptosis family member, was observed. The treatment caused elevation in p-STAT3 and in p21(WAF), proven to be a STAT3 positive target in absence of survival signals. Cucurbitacin glucoside treatment also induced apoptosis, as measured by Annexin V/propidium iodide staining and by changes in mitochondrial membrane potential (DeltaPsi) using a fluorescent dye, JC-1. We suggest that cucurbitacin glucosides exhibit pleiotropic effects on cells, causing both cell cycle arrest and apoptosis. These results suggest that cucurbitacin glucosides might have therapeutic value against breast cancer cells.

Effect of cucurbitacins on bilirubin-albumin binding in human plasma

The aim of this study is to investigate the effect of three cucurbitacins (Cuc) E, D and I on the bilirubin-albumin binding, both in human serum albumin (HSA) and in plasma. Bilirubin-HSA solution and plasma free of cucurbitacins were prepared as well as others containing serial concentrations of cucurbitacins. The concentration of unbound bilirubin was determined in bilirubin-HSA solution and the direct and total bilirubin concentrations were measured in plasma (with normal or elevated bilirubinemia) by Jendrassik and Grof method. In the conditions we adopted Cuc E and D (to a lesser extent), decreased the levels of unbound bilirubin in bilirubin-HSA solution and decreased direct bilirubin concentration and total bilirubin concentration in plasma in a dose-dependent manner while Cuc I had no effect. The effect of Cuc is related to the presence of native HSA. Thus, when albumin was absent or has been denatured by heating or by urea, Cuc E did not modify bilirubin levels, suggesting that the native structure of albumin is essential for such activity. The interaction of HSA with Cuc E was investigated by fluorescence spectroscopy. Cuc E increased the intrinsic fluorescence of the protein and the magnitude of fluorescence intensity of bilirubin-albumin complex. We concluded that Cuc E and D produced a rearrangement in the structure of albumin, particularly in the domain-II, resulting in an increase in the binding of bilirubin to albumin regardless to whether it's conjugated to glucuronic acid or unconjugated.

Anti-inflammatory effect of Houttuynia cordata injection

Houttuynia cordata (Saururaceae) injection (HCI) is a traditional Chinese medicine used in China. It was chosen as one of eight types of traditional Chinese medicine that play a unique role in severe acute respiratory syndrome (SARS) owing to the effect of curbing inflammation. In order to validate this plausible anti-inflammatory property, the chemical composition of HCI has been analysed by GC/MS, 22 components were identified, and the inflammation induced by carrageenan in the rat pleurisy model and by xylene in the mice ear edema model was adopted to study the anti-inflammatory activity of HCI. Injection of carrageenan into the pleural cavity elicited an acute inflammatory response characterized by protein rich fluid accumulation and leukocyte infiltration in the pleural cavity. The peak inflammatory response was obtained at 24 h when the fluid volume, protein concentration, C-reactive protein and cell infiltration were maximums. The results showed that these parameters were attenuated by HCI at any dose and touched bottom at dose of 0.54 ml/100 g, although less strong than dexamethasone. This drug was also effective in inhibiting xylene induced ear edema, and the percentage of inhibition came to 50% at dose of 80 microl/20 g. The results clearly indicate that HCI have anti-inflammatory activity.

Antinociceptive activity of 3-O-β-d-glucopyranosyl-23,24-dihydrocucurbitacin F from Hintonia standleyana (Rubiaceae)

Oral administration of a MeOH-CH(2)Cl(2) (1:1) extract of the stem bark of Hintonia standleyana (HSE) produced a dose-dependent antinociceptive effect when tested in mice using the writhing (150-750 mg/kg) and the hot-plate (150-600 mg/kg) models. From the active extract 3-O-beta-d-glucopyranosyl-23,24-dihydrocucurbitacin F (GDHCF), 5-O-[beta-d-apiofuranosyl-(1-->6)-beta-d-glucopyranosyl]-7-methoxy-3',4'-dihydroxy-4-phenylcoumarin (AG4-PC) and desoxycordifolinic acid (DCA) were isolated. GDHCF (10-100 mg/kg, p.o.) significantly reduced acetic acid-induced abdominal contortions and increased the hot-plate latency in comparison to vehicle-treated mice. Metamizol (50-100 mg/kg) and morphine (2.5-5 mg/kg) were used as positive controls, respectively. GDHCF-induced antinociception was partially blocked by naloxone (1 mg/kg, i.p.), l-NAME (150 mg/kg, i.p.) and glibenclamide (10mg/kg, i.p.) suggesting that its pharmacological effect could be due to the activation of the nitric oxide pathway, followed by the opening of the ATP-sensitive K(+) channels, as well as an activation of the opioid receptors.

Tentative Fingerprint-Efficacy Study of Houttuynia cordata Injection in Quality Control of Traditional Chinese Medicine

To establish potent fingerprint for quality control of traditional Chinese medicine, Houttuynia cordata (Saururaceae) injection (HCI), the attempt on fingerprint-efficacy was developed in this study. HCI from ten different factories were determined by gas chromatography-mass spectrum (GC-MS) and classified by hierarchical clustering. The anti-inflammatory effect of HCI was characterized with the rat pleurisy model induced by carrageenin and the mice ear edema model by xylene. The results showed that anti-inflammatory effect of the injections from most of factories on the two models was significant. There was corresponding relationship between the fingerprint of HCI and efficacy to certain extent. The main common constitutes in injection from the factories that possess anti-inflammatory activity were analysed with GC-MS and identified using the NIST Mass Spectral Database. This common pattern of HCI based on the efficacy was helpful for the purpose of quality control.

Cucurbitacins and cucurbitane glycosides: structures and biological activities

The natural cucurbitacins constitute a group of triterpenoid substances which are well-known for their bitterness and toxicity. Structurally, they are characterized by the tetracyclic cucurbitane nucleus skeleton, namely, 19-(10-->9beta)-abeo-10alpha-lanost-5-ene (also known as 9beta-methyl-19-norlanosta-5-ene), with a variety of oxygen substitutions at different positions. According to the characteristics of their structures, cucurbitacins are divided into twelve categories. The biological effects of the cucurbitacins are also covered.

Inhibition of nitric oxide generation by 23,24-dihydrocucurbitacin D in mouse peritoneal macrophages

Nitric oxide (NO) has various physiological functions. However, uncontrolled overproduction of NO can be toxic in many pathologic conditions involving inflammatory tissue damage. In the present study, we examined effects of 23,24-dihydrocucurbitacin D (DHCD) isolated from the root of Bryonia alba L. on macrophage NO generation. DHCD (<80 microM) effectively abolished NO generation from macrophages activated with lipopolysaccharide and interferon-gamma. DHCD decreased the levels of protein and mRNA for inducible NO synthase (iNOS). DHCD potently blocked nuclear factor-kappaB (NF-kappaB) activation, a process necessary for transcriptional activation of iNOS. These results suggested that DHCD inhibited NO generation by blocking NF-kappaB activation and iNOS gene transcription. Because NF-kappaB activation is necessary not only for NO generation but also for many inflammatory processes, DHCD and its derivatives could be developed as anti-inflammatory drugs.

A New Cucurbitacin D Related 16,23-Epoxy Derivative and Its Isomerization Products

[reaction: see text] A new (23S,24Z)-16,23-epoxy cucurbitacin derivative was isolated from Ecballium elaterium L. (Cucurbitaceae) fruit juice along with known cucurbitacin derivatives. Structure elucidation of these derivatives was accomplished by NMR spectroscopy and mass spectrometry from HPLC-MS data. Isomerization of the epoxy derivative was monitored by 1D and 2D NMR experiments. The configuration of the reaction products was elucidated as (23R,24E) and (23R,24Z), and a mechanism for the acid-catalyzed rearrangement process is proposed.

Nitric oxide and cyclooxygenase may participate in the analgesic and anti-inflammatory effect of the cucurbitacins fraction from Wilbrandia ebracteata

Wilbrandia ebracteata is a medicinal plant from South America used in folk medicine for the treatment of chronic rheumatic diseases. We have shown that the high performance liquid chromatography-characterized (HPLC) dichloromethane fraction isolated from Wilbrandia ebracteata (WEDC) inhibits the parameters observed in experimental models of inflammation in vivo and in vitro. In the present study, we extend our previous observations on the analgesic effects of WEDC by investigating its actions using the hot plate test and zymosan-induced writhing test in mice, as well as zymosan-induced arthritis in rats evaluating articular inflammatory pain, cell migration and determination of NO release into the joint exudate. The effect of WEDC on the activity of COX-1 and COX-2 in vitro and its ulcerogenic capacity in vivo were also investigated. The oral treatment of the animals with WEDC (1-10 mg/kg) produced a significant, dose-dependent reduction of articular incapacitation and abdominal contortions in the writhing test. The same effect was not observed in the hot plate and rota-rod tests. WEDC also reduced nitrite release into the zymosan-inflamed joints. In the evaluation of COX activity, we observed that WEDC was able to selectively inhibit COX-2 but not COX-1 activity in COS-7 cells. Moreover, WEDC treatment did not show gastrointestinal toxicity. Our data confirm the anti-nociceptive activities of the WEDC and indicate that this effect could be associated with inhibition of cyclooxygenase-2 (COX-2) and nitric oxide release. The effects could be attributed to cucurbitacins since several of these were isolated from the WEDC.

Anti-ulcerogenic and analgesic activities of the leaves of Wilbrandia ebracteata in mice

Wilbrandia ebracteata (Cogn.) Cogn. is a medicinal plant belonging to the Cucurbitaceae family used popularly as an antiulcer and analgesic medicine. The hydromethanol extract of leaves was investigated to determine its anti-ulcerogenic (ethanol and indomethacin induced gastric damage) and analgesic (writhing and tail-flick tests) activities in mice (efficacy), its acute toxicity (safety), and its phytochemistry (quality control). Oral administration of leaf extract at a dose of 1000 mg/kg body wt. significantly reduced 73.3% of the total area of lesion in ethanol-induced gastric damage, but was inactive in an indomethacin-induced gastric damage test. The hydromethanol extract was also inactive in both analgesic tests. Oral administration of the leaf extract did not produce mortality in mice, while the LD50 value of the roots was 22.10 mg/kg body wt. in female mice and 58.31 mg/kg body wt. in male mice. Leaves of W. ebracteata reacted positively for steroids, flavonols, flavanones, saponins, tannins and xanthones and negative for other compounds, including cucurbitacins. Leaf extract of W. ebracteata was active as an anti-ulcerogenic, probably through increasing gastric defensive factors, and flavonoids might be the main constituent responsible for this activity.

Chromatographic procedures for the isolation of plant steroids

In this review, we consider the general principles and specific methods for the purification of different classes of phytosteroids which have been isolated from plant sources: brassinosteroids, bufadienolides, cardenolides, cucurbitacins, ecdysteroids, steroidal saponins, steroidal alkaloids, vertebrate-type steroids and withanolides. For each class we give a brief summary of the characteristic structural features, their distribution in the plant world and their biological effects and applications. Most classes are associated with one or a few plant families, e.g., the withanolides with the Solanaceae, but others, e.g., the saponins, are very widespread. Where a compound class has been extensively studied, a large number of analogues are present across a range of species. We discuss the general principles for the isolation of plant steroids. The predominant methods for isolation are solvent extraction/partition followed by column chromatography and thin-layer chromatography/HPLC.