Inhibition of the DHT-induced PSA secretion by Verbascum xanthophoeniceum and Serenoa repens extracts in human LNCaP prostate epithelial cells

Ethnopharmacological relevance

Verbascum xanthophoeniceum is a mullein plant, typical of Balkan region and some parts of Turkey, traditionally used as phytotherapeutic agent due to its anti-inflammatory properties. It is rich in phenylethanoid and iridoid metabolites whose anti-inflammatory properties are under characterization.

Materials and methods

The role of Verbascum xanthophoeniceum crude methanolic extract and its isolated phenylethanoid glycoside verbascoside have been evaluated, in comparison to a saw palmetto extract, on a human in vitro model of androgen-regulated prostate epithelium, the LNCaP cell line. Cytotoxicity and DHT-induced free and total PSA secretion have been thoroughly studied.

Results

We have found that similar to saw palmetto, Verbascum xanthophoeniceum extract and its isolated phenylethanoid glycoside verbascoside have no cytotoxicity in human LNCaP prostate epithelial cells, whereas an inhibitory effect on the DHT-induced free and total PSA secretion, a recognized anti-androgen like activity, has been shown in case of both Verbascum xanthophoeniceum extract and pure verbascoside. Furthermore, in the absence of the endogenous androgen DHT, an androgen-like activity in Verbascum xanthophoeniceum is detectable as it is for saw palmetto, suggesting that a mixed androgen-antiandrogen activity is present.

Conclusions

For the first time, Serenoa repens and Verbascum xanthophoeniceum extracts have shown an absence of cytotoxicity and an inhibitory effect on DHT-induced PSA secretion in an in vitro model of human prostate epithelium, whereas the phenylethanoid glycoside verbascoside appeared to explain only part of the Verbascum xanthophoeniceum inhibitory activity on PSA secretion.     

Pharmacokinetics of 8-O-acetylharpagide and harpagide after oral administration of Ajuga decumbens Thunb extract in rats

Ethnopharmacological relevance

Ajuga decumbens Thunb is a medicinal plant native to China popularly used to treat chronic pelvic inflammation and hysteromyoma. Its main bioactive components are iridoid glycosides, such as 8-O-acetylharpagide and harpagide that had presented antibacterial, anti-inflammatory, and antiviral activities.

Aim of the study

To establish a sensitive LC–MS/MS method and compare the pharmacokinetics of 8-O-acetylharpagide and harpagide in rats after oral administration of their pure forms and from compounds obtained from Ajuga decumbens extract.

Materials and methods

Rats received orally 15 mg/kg (equivalent of 6 mg/kg 8-O-acetylharpagide and 1.5 mg/kg harpagide), 30 mg/kg and 60 mg/kg of Ajuga decumbens Thunb extract and were compared to animals that received 12 mg/kg of 8-O-acetylharpagide or 3 mg/kg of harpagide p.o. Concentrations of 8-O-acetylharpagide and harpagide in plasma were determined by LC–MS/MS method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis.

Results

Results showed that the iridoid glycosides were quickly absorbed by oral route and showed a dose-dependence profile. Pharmacokinetic parameters of both glycosides were essentially the same except Tmax when dosed as the extract or pure forms.

Conclusion

8-O-acetylharpagide was metabolized to harpagide, which affected the pharmacokinetic profiles of harpagide when dosed as the extract. This pharmacokinetic study seems to be useful for a further clinical study of Ajuga decumbens Thunb extract.     

Immunomodulatory effects of crude phenylethanoid glycosides from Ligustrum purpurascens

Ethnopharmacological relevance

Ligustrum purpurascens, named as “Ku ding cha”, has been used as a kind of functional tea in southern China for about two thousand years, which has the effects on diuresis, anti-hypertension, weight-loss and anti-inflammation.

The aim of the study

This study was aimed to investigate the immune enhancement effects of the crude phenylethanoid glycosides (CPGs) from Ligustrum. Purpurascens on mice and analyze the chemical profiles of phenylethanoid glycosides in the CPGs.

Materials and methods

The immune functions enhancing potential of CPGs was determined using serum hemolysin antibody, phagocytosis, splenocyte antibody production, and NK cells activity assays. The contents of five major constituents in the crude glycosides of Ligustrum purpurascens were determined by using liquid chromatography, other five glycosides were deduced according to their UV and MS spectra compared with the literature as well.

Results

In the immunizing experiment, mice treated with different doses of CPGs showed an increase (p<0.01) in the haemagglutination titre compared with the control group. The increases (p<0.05) were found to be significant at doses of 440 mg/kg and 1.32 g/kg in the experiments of antibody production of spleen cells, MΦ phagocytosis of chicken RBCs and NK cell activity. Further chemical characterization yielded 10 constituents from CPGs, five glycosides were quantified by HPLC and the structures of other five compounds were speculated according to their UV and MS spectra.

Conclusion

The results suggested that phenylethanoid glycosides from Ligustrum purpurascens have immunomodulatory effects on mice.     

Bioassay-guided isolation of anti-inflammatory, antinociceptive and wound healer glycosides from the flowers of Verbascum mucronatum Lam.

Ethnopharmacological relevance

The leaves, flowers and whole aerial parts of Verbascum L. species have been used to treat respiratory problems, haemorrhoids and other types of inflammatory conditions in traditional Turkish medicine.

Aim of the study

In order to evaluate this traditional information, the anti-inflammatory, antinociceptive and wound healing activities of Verbascum mucronatum Lam. which is used as haemostatic in Turkish folk medicine were investigated.

Materials and methods

In vivo inhibitory effect of the extracts on the carrageenan-induced hind paw edema model in mice was studied for the assessment of anti-inflammatory activity. Moreover, the wound healing potential of the plant were evaluated by using in vivo wound healing experimental models, i.e. incision and excision models on mice and rats, were comparatively assessed with a reference ointment Madecassol^®. Skin samples were also evaluated histopathologically.

Results

The results of these experimental studies exhibited that Verbascum mucronatum displays anti-inflammatory, antinociceptive and wound healing activities. Through bioassay-guided fractionation and isolation procedures four iridoid glucosides, ajugol (1), aucubin (2), lasianthoside I (3), catalpol (4), two saponins, ilwensisaponin A (5) and C (6) and a phenylethanoid glycoside, verbascoside (7) were isolated and their structures were elucidated by spectral techniques. Verbascoside (7) was found to possess significant wound healing activity as well as antinociceptive and anti-inflammatory potentials, per os without inducing any apparent acute toxicity or gastric damage.

Conclusion

The experimental study revealed that Verbascum mucronatum displays remarkable antinociceptive, anti-inflammatory and wound healing activities.     

In vivo anti-inflammatory and anti-ulcerogenic activities of extracts from wild growing and in vitro plants of Castilleja tenuiflora Benth. (Orobanchaceae)

Ethnopharmacological relevance

Castilleja tenuiflora Benth. (Orobanchaceae) is a perennial shrub used since the 16^th century in Mexican traditional medicine for the treatment of a number of health disorders including inflammation, stomach pain and tumors. The aim of the present study was to evaluate the cytotoxic, anti-inflammatory and anti-ulcerogenic activities of ethyl acetate (EaE), methanol (ME) and aqueous extracts (AE) of Castilleja tenuiflora wild grown (CtW) and in vitro plants (CtIv).

Material and method

Phytochemical analysis of the phenylethanoid glycoside (PhG) and iridoid glycoside (IG) components was carried out by chromatographic methods. In vitro cytotoxic activity of the extracts was evaluated in the following four carcinoma cell lines: colon (HF-6), breast (MCF-7), prostate (PC-3), and nasopharyngeal (KB). The topical anti-inflammatory activity was evaluated in mouse ear edema induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Anti-ulcerogenic activity was evaluated in rats using an absolute ethanol-induced acute gastric ulcer model.

Results

The main compounds in the extracts were isoverbascoside, verbascoside and aucubin and their concentration depended both on the solvent used and on the plant material origin. None of the extracts showed cytotoxicity against the tested cell lines. In contrast, CtWEaE, CtWAE and CtIvEaE (1.6 mg/ear) showed moderate anti-inflammatory activity similar to dexamethasone (1 mg/ear) with a 38.2, 39.3 and 49.1% decrease of inflammation, respectively. CtWEaE and CtIvEaE (100 mg/kg) showed high anti-ulcerogenic activity with 88.3 and 83.1% inhibition, respectively, compared to famotidine (20 mg/kg, 32.8% inhibition).

Conclusion

Castilleja tenuiflora extracts provided significant gastric protection in an acute ulcer induction model and topical anti-inflammatory activity in a mouse ear edema model. These activities are related to verbascoside and may explain the traditional use of Castilleja tenuiflora in the treatment of anti-inflammatory and gastrointestinal disorders. Cultured Castilleja tenuiflora plants (in vitro) exhibited pharmacological activities and also have the potential to produce bioactive compounds.     

Traditionally used Veronica officinalis inhibits proinflammatory mediators via the NF-κB signalling pathway in a human lung cell line

Ethnopharmacological relevance

Extracts from Veronica officinalis L. are traditionally used for the treatment of lung diseases; however, the effective compounds and the mode of action are still unknown.

Aim of the study

Here we analyzed the effects of a standardized Veronica extract on genes expression and signalling protein production associated with the development of inflammatory lung diseases.

Material and methods

The degranulation capacity of primary mast cells, as well as gene expression and release of inflammatory mediators from human lung epithelial cells (A549 cells) were analyzed in relation to the synthetic drugs azelastine and dexamethasone. Gene and protein expression of cyclooxygenase-2 were investigated by semi-quantitative RT-PCR and western blotting, respectively. The involvement of phosphorylated mitogen-activated protein kinases and NF-κB signaling in regulation of these molecules were characterized by western blotting and electrophoretic mobility shift assays. Characteristic extract components were identified by LC–MS and verminoside was quantified by HPLC analysis.

Results

We demonstrated that Veronica officinalis has a small influence on the degranulation capacity of mast cells but rather inhibits gene and protein expression of the chemokine eotaxin in A549 lung epithelial cells, which is essential for recruitment of inflammatory-associated cells in lung diseases. Furthermore, release of the inflammatory mediator PGE₂ was diminished through inhibition of COX-2 expression via the NF-κB signaling pathway in TNF-α-activated A549 cells. Phytochemical analysis identified verproside and verminoside as the most abundant iridoid glycosides.

Conclusion

Our results are a contribution to explaining the observed anti-inflammatory effects of Veronica offcinalis extract on a molecular level. However, its clinical potency has at first to be proven in animals and subsequently in clinical trials.     

Antiinflammatory Properties of Extracts and Compounds Isolated from Verbascum xanthophoeniceum Griseb

Verbascum xanthophoeniceum Griseb. is an endemic plant of the Balkan region, a representative of the genus Verbascum used in traditional medicine for respiratory and inflammatory disorders. The objective of this study was to evaluate in vivo and in vitro the antiinflammatory action of crude extract, different fractions and pure compounds obtained from V. xanthophoeniceum Griseb. Bioactive metabolites were isolated by the use of low‐pressure chromatographic separation. Crude methanol extract (CME) was applied in a model of paw oedema and different fractions and substances were tested in vitro for their effect on NO and cytokine production by peritoneal macrophages, and on the COX‐1 and COX‐2 expression. The CME exerted inhibition on cobra venom factor (CVF)‐induced oedema in mice, in correlation with reduced alternative pathway (AP) complement activity. A highly suppressive effect was expressed by nigroside VI on IL‐6 and NO production and by forsythoside B on TNF‐α production. Leucosceptoside B lowered NO release and COX‐1 expression in macrophages. Verbascum xanthophoeniceum could serve as a promising source of active compounds with antiinflammatory action, particularly in complement‐mediated disorders. Copyright © 2012 John Wiley & Sons, Ltd.     

Iridoid glycosides extracted from Zhizi (Fructus Gardeniae) decrease collagen-induced platelet aggregation and reduce carotid artery thrombosis in an in vivo rat model

Objective

To investigate the anti-platelet aggregation and antithrombotic effects in rats of iridoid glycosides extracted from Zhizi (Fructus Gardeniae).

Methods

The present study evaluated the antithrombotic activity of iridoid glycosides (IGs) in a rat model of carotid artery thrombosis. The effects on coagulation, such as thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT), and the effect on collagen-induced platelet aggregation in vivo were investigated. Rats were intragastrically administered IGs (50, 100 or 200 mg/kg) twice daily for 3 days.

Results

IGs were shown for the first time to have an antithrombotic action through the inhibition of platelet aggregation, with little effect on the coagulation time of peripheral blood. Our results also showed that IGs may significantly and dose-dependently reduce arterial thrombus load in a model of carotid artery thrombosis and inhibit collagen-induced platelet aggregation in rats. IGs (100 or 200 mg/kg) had no significant effect on APTT and PT, but did lengthen TT at a higher dose.

Conclusion

These data, together with the previously reported neuroprotective effects of IGs in rats with cerebral ischemia, suggest that the antithrombotic action of IGs may potentially contribute to the treatment of cerebral ischemic diseases, including cerebral apoplexy.     

Direct inhibition of calcineurin by caffeoyl phenylethanoid glycosides from Teucrium chamaedrys and Nepeta cataria

Ethnopharmacological relevance

Teucrium chamaedrys L. and Nepeta cataria L. (Lamiaceae) are species with traditional uses that relate to the treatment of inflammation. Extracts of both species were found to inhibit calcineurin; an important regulator of T-cell mediated inflammation that has received little attention in ethnopharmacological research.

Materials and methods

Extracts and isolated compounds were tested against calcineurin in its calmodulin-activated and basal un-activated state. Active compounds were isolated using Sephadex LH-20 gel filtration and HPLC then identified using NMR spectroscopy.

Results and conclusions

Activity-guided fractionation of Teucrium chamaedrys and Nepeta cataria led to the isolation of the caffeoyl phenylethanoid glycosides teucrioside, verbascoside and lamiuside A (teupolioside). The three compounds inhibited calcineurin both in the presence and absence of calmodulin, suggesting a direct interaction with calcineurin. Calcineurin inhibition should be considered as a potential mode of action when investigating the immunomodulatory activity of caffeoyl phenylethanoid glycoside containing plants.     

Anti-inflammatory compounds of “Qin-Jiao”, the roots of Gentiana dahurica (Gentianaceae)

Ethnopharmacological relevance

“Qin-Jiao” is a well-known traditional Chinese medicinal (TCM) herb having been used generally for fighting rheumatoid arthritis (RA) since ancient times. The root of Gentiana dahurica Fisch (Gentianaceae) is one of the four officially validated “Qin-Jiao” as listed in the Chinese Pharmacopoeia. In addition, it is a common Tibetan medicinal herb used for the treatment of tonsillitis, urticaria, and RA, while the flowers have been used as a Mongolian herb for curing cough sore throat and eliminating the phlegm due to its anti-inflammatory effect.

Aim of the study

The aim of the study was to characterize the anti-inflammatory compounds in “Qin-Jiao”, on the basis of detailed investigation on not only the phytochemical study of Gentiana dahurica, but also the bioactive evaluation on compounds obtained presently and previously from different “Qin-Jiao” origins and Gentiana species.

Materials and methods

The ethanol extract of air-dried roots of Gentiana dahurica was suspended into H₂O and extracted with EtOAc and n-BuOH, successively. Repeated column chromatography (CC) and semi-preparative HPLC were carried out on each of the fractions. The isolated compounds were determined by detailed spectroscopic analysis and acidic hydrolysis. Anti-inflammatory activities of 18 isolates, together with 12 typical compounds obtained previously by our group from the other “Qin-Jiao” origins (Gentiana crassicaulis, Gentiana straminea) and Gentiana rigescens, were tested by inhibitory effects on LPS-induced NO production in macrophage RAW264.7 cells and TPA-induced cyclooxygenases-2 and -1 (COXs-2/1) production on zebrafish model.

Results

A new lignan glycoside (1) was identified, together with 20 known compounds, including 10 iridoid glycosides (2–11), three steroids (12–14), four lignans (15–18), one phenylpropanoid (19) and two triterpenes (20–21). Anti-inflammatory bioassay showed that only compound 21 displayed potential inhibitory effect on NO production (IC₅₀=16.85 μM), while 20 tested compounds had inhibitory activities on COXs-2/1. Among them, the triterpenoid 21 was the most active compound with an inhibitory value of 78% at a concentration of 30 μM. All the tested compounds showed no cytotoxicity on five human cancer cell lines (40 μM) and zebrafish (30 μM), except for 21 displaying weak cytotoxicity on human myeloid leukemia HL-60 (IC₅₀=16.43 μM).

Conclusion

Most of compounds particularly iridoid glycosides from “Qin-Jiao” display potential inhibitory effect on COXs-2/1. The results support the historical importance of the well-known TCM herb, “Qin-Jiao”, having been commonly used for fighting RA. As major components, the bioactive iridoid glycosides should play important role in the anti-inflammatory effect of “Qin-Jiao”. Although further research will be required to evaluate the selective activities of the COXs-2/1 inhibitors, this work validates the medicinal use of “Qin-Jiao” and provides information for different “Qin-Jiao” origins having different treating effects on RA.     

Picea mariana polyphenolic extract inhibits phlogogenic mediators produced by TNF-α-activated psoriatic keratinocytes: Impact on NF-κB pathway

Ethnopharmacological relevance

Picea mariana ((Miller) Britton, Sterns, and Poggenburg; Pinaceae) bark has been traditionally used by North American natives for treating topical inflammations. It has been also suggested to improve various inflammatory skin disorders like Psoriasis vulgaris. Extracts from this bark storage protein contain polyphenolic compounds which have well-known antiinflammatory activities. Based on the capacity of polyphenolic compounds to modulate functions of normal human keratinocytes, this study was set up to decipher the mechanisms of action of a chemically characterized polyphenolic extract from Picea mariana bark (BS-EAc_f) on lesional keratinocytes of skin with psoriasis vulgaris, a disease driven by the immune system in which TNF-α plays a significant role.

Materials and methods

BS-EAc_f corresponds to the ethyl acetate soluble fraction from the hot water extract of Picea mariana bark. BS-EAc_f effects were evaluated in normal human (NHK) and psoriatic (PK) keratinocytes stimulated by TNF-α. Cell viability was assessed by lactate deshydrogenase release and propidium iodide (PI) staining. The mechanisms of action of BS-EAc_f in keratinocytes were investigated by flow cytometry, ELISAs, RT-PCR and western blot analyses.

Results

PK exhibited a higher response to TNF-α than NHK regarding the ICAM-1 expression and the production of NO, IL-6, IL-8, fractalkine and PGE₂, whereas BS-EAc_f significantly inhibited this TNF-α-induced increase at concentrations without causing keratinocyte toxicity. Additionally, this extract significantly inhibited the TNF-α-induced release of elafin and VEGF by PK and NHK. Since TNF-α activation of most of these factors is dependent on the NF-κB pathway, this latter was studied in TNF-α-activated PK. BS-EAc_f inhibited the TNF-α-induced phosphorylation and degradation of total IκBα as well as phosphorylation of NF-κB p65.

Conclusions

The ethyl acetate fraction from Picea mariana bark extract showed inhibitory effects of cytokines, chemokines, adhesion molecules, nitric oxide and prostaglandins produced by keratinocytes under TNF-α activation through down-regulating the NF-κB pathway. This study demontrated that this extract could be a potential antiinflammatory agent capable of improving psoriatic skin.     

Depressant effects of Clinopodium mexicanum Benth. Govaerts (Lamiaceae) on the central nervous system

Ethnopharmacological relevance

The decoction of leaves of Clinopodium mexicanum Benth. Goaverts (Lamiaceae), commonly known as “Toronjil de Monte”, is used in the Mexican traditional medicine to induce sleep, as well as sedative and analgesic remedy.

Aim of the study

To evaluate the putative depressant effects of an aqueous extract of the medicinal plant Clinopodium mexicanum on the central nervous system (CNS).

Materials and methods

The effects of the extract (AECM) on mice were tested in several animal paradigms, including sodium pentobarbital-induced sleep, open field tests, and hole-board tests. The effects of AECM on pentylenetetrazole- and picrotoxin-induced convulsions in mice and on the antithermonociceptive response in the hot-plate paradigm were also tested. Additionally, the active extract (AECM) was analyzed with HPLC–ESI-MS techniques.

Results

Mice acutely treated with AECM at 100, 200, 500 and 1000 mg/kg doses prolonged the sleeping time induced by sodium pentobarbital (42 mg/kg). This extract, at 100 and 200 mg/kg doses, showed a sedative effect in the hole-board paradigm and decreased spontaneous activity in mice. AECM at 10, 100 and 200 mg/kg prolonged the onset of seizures induced by pentylenetetrazole (90 mg/kg) and antagonized tonic convulsions induced by picrotoxin (10 mg/kg). Additionally, AECM inhibited the response to a thermonociceptive stimulus. The intraperitoneal AECM treatment produced mortality with an LD₅₀ = 2154 mg/kg. Chemical analysis showed that the flavanone glycosides neoponcirin, poncirin, and isonaringenin are the main compounds of the active extract.

Conclusions

This study demonstrates that an acutely administered single dose of an aqueous extract of Clinopodium mexicanum can exert depressant effects on the CNS. These findings are in agreement with the traditional use of Clinopodium mexicanum to induce sleep as well as sedative and analgesic remedy. The chemical analysis of AECM revealed the presence of the flavanone glycosides neoponcirin, poncirin, and isonaringin.     

An ethnopharmacological study on Verbascum species: From conventional wound healing use to scientific verification

Aim of the study

The leaves, flowers, and whole aerial parts of Verbascum L. (Scrophulariaceae) species are used to treat eczema and other types of inflammatory skin conditions and as a desiccant for wounds in Turkish traditional medicine. In the present study, the methanolic extracts of 13 Verbascum species growing in Turkey, including Verbascum chionophyllum Hub.-Mor., Verbascum cilicicum Boiss., Verbascum dudleyanum (Hub.-Mor.) Hub.-Mor., Verbascum lasianthum Boiss., Verbascum latisepalum Hub.-Mor., Verbascum mucronatum Lam., Verbascum olympicum Boiss., Verbascum pterocalycinum var. mutense Hub.-Mor., Verbascum pycnostachyum Boiss. & Heldr., Verbascum salviifolium Boiss., Verbascum splendidum Boiss., Verbascum stachydifolium Boiss. & Heldr and Verbascum uschackense (Murb.) Hub.-Mor. were assessed for their in vivo wound healing activity.

Material and methods

In vivo wound healing activity of the plants were evaluated by linear incision and circular excision experimental models subsequently histopathological analysis. The healing potential was comparatively assessed with a reference ointment Madecassol^®, which contains 1% extract of Centella asiatica.

Results

The methanolic extracts of Verbascum olympicum, Verbascum stachydifolium and Verbascum uschackense demonstrated the highest activities on the both wound models. Moreover, the methanolic extracts of Verbascum latisepalum, Verbascum mucronatum, and Verbascum pterocalycinum var. mutense were found generally highly effective. On the other hand, the rest of the species did not show any remarkable wound healing effect. Results of the present study support the continued and expanded utilization of these plant species employed in Turkish folk medicine.

Conclusion

The experimental study revealed that Verbascum species display remarkable wound healing activity.     

In vivo analgesic activity,toxicity and phytochemical screening of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine

Ethnopharmacological relevance

Psidium cattleianum Sabine is extensively used in Brazilian traditional medicine to treat several diseases including painful disorders. Aim of the study to investigate the toxicity and the possible analgesic activities of the hydroalcoholic extract from the leaves of Psidium cattleianum Sabine (ELPCS), to support its use in folk medicine. To screen the major phytochemical constituents of this extract and evaluate their antioxidant activity.

Materials and methods

ELPCS was assessed for its antioxidant activity using the DPPH model. Its analgesic activity was examined using mouse models of acetic acid-induced writhing and hot plate paw licking models. The major phytochemical constituents of the extract were screened; their toxicity on LLC-MK2 mammalian cells was evaluated.

Results

ELPCS exhibited significant peripheral analgesic activity at doses of 60, 80, 100, 200 and 400 mg/kg in mice, but it did not display central analgesic activity and not was toxic to LLC-MK2 cell (LD₅₀>400 µg/mL). The extract exhibited free radical scavenging activity as evidenced by IC₅₀ values (15.9 µg/mL) obtained by the DPPH method. Phytochemical screening detected flavonoids, saponins, cardiac glycosides, anthraquinones, and tannins.

Conclusions

The results of the experimental studies proved the analgesic activity of ELPCS and supported the traditional use of this plant.     

Inhibition of angiotensin convertin enzyme (ACE) activity by the anthocyanins delphinidin- and cyanidin-3-O-sambubiosides from Hibiscus sabdariffa

Ethnopharmacological relevance

The beverages of Hibiscus sabdariffa calyces are widely used in Mexico as diuretic, for treating gastrointestinal disorders, liver diseases, fever, hypercholesterolemia and hypertension. Different works have demonstrated that Hibiscus sabdariffa extracts reduce blood pressure in humans, and recently, we demonstrated that this effect is due to angiotensin converting enzyme (ACE) inhibitor activity.

Aim of the study

The aim of the current study was to isolate and characterizer the constituents responsible of the ACE activity of the aqueous extract of Hibiscus sabdariffa.

Materials and methods

Bioassay-guided fractionation of the aqueous extract of dried calyces of Hibiscus sabdariffa using preparative reversed-phase HPLC, and the in vitro ACE Inhibition assay, as biological monitor model, were used for the isolation. The isolated compounds were characterized by spectroscopic methods.

Results

The anthocyanins delphinidin-3-O-sambubioside (1) and cyanidin-3-O-sambubioside (2) were isolated by bioassay-guided purification. These compounds showed IC₅₀ values (84.5 and 68.4 μg/mL, respectively), which are similar to those obtained by related flavonoid glycosides. Kinetic determinations suggested that these compounds inhibit the enzyme activity by competing with the substrate for the active site.

Conclusions

The competitive ACE inhibitor activity of the anthocyanins 1 and 2 is reported for the first time. This activity is in good agreement with the folk medicinal use of Hibiscus sabdariffa calyces as antihypertensive.     

Anti-inflammatory activity of roots of Ecbolium viride (Forsk) Merrill

Ethnopharmacological relevance

Traditionally the aqueous extracts of dried roots of the plant Ecbolium viride are used for menorrhagia, rheumatism and jaundice.

Aim of the study

The aim was to evaluate the anti-inflammatory activity of Ecbolium viride extract in an in vivo model.

Materials and methods

The ethyl acetate fraction of Ecbolium viride root extract was prepared and administered orally to rats. The anti-inflammatory activity of Ecbolium viride was determined by carrageenan-induced paw edema and cotton pellet granuloma models.

Results

Oral administration of Ecbolium viride extract reduced inflammation significantly (P < 0.01) in both the carageenan paw edema and the cotton pellet granuloma models.

Conclusions

The results of the study supported the traditional use of Ecbolium viride in the treatment for inflammatory disease.     

Muscarinic-dependent inhibition of gastric emptying and intestinal motility by fractions of Maytenus ilicifolia Mart ex. Reissek

Ethnopharmacological relevance

Maytenus ilicifolia Mart. ex. Reissek (Celastraceae) is widely used in Brazilian folk medicine to treat gastric disturbances.

Aim of the study

This work intended to characterize the effects of Maytenus ilicifolia on gastrointestinal motility.

Materials and methods

Gastric emptying and intestinal transit were measured in the same animal. Mice received a semisolid marked with phenol red, half an hour after treatment with extracts. The amount of marker in the stomach and the distance reached in the intestine after 15 min were measured as index of gastrointestinal emptying and intestinal transit, respectively.

Results

Intraperitoneal administration of a flavonoid-rich extract potently reduced the gastric emptying (ED₅₀ = 89 mg/kg) and the intestinal transit (ED₅₀ = 31 mg/kg) of mice. Bio-guided purification of the flavonoid-rich extract by chemical partition with solvents of decreasing polarity yielded fraction insF with about 12–14 times higher activity than the initial flavonoid extract in both the gastric emptying and the intestinal transit. The inhibitory effects of the insF (9.7 mg/kg, i.p.) on gastric emptying and intestinal transit were reversed by co-administration of bethanechol (10 mg/kg, s.c.) but not by co-administration of metoclopramide (30 mg/kg, p.o.) indicating muscarinic but not dopaminergic interaction of the compounds of Maytenus.Chemical investigation of the insF fraction by HPLC–MS allowed the identification of 4 free flavonoids (catechin, epicatechin, quercetin and kaempferol), 29 flavonol glycosides and 8 tannins. The flavonol glycosides ranged from 1 to 4 monosaccharide units, having mainly quercetin and kaempferol as aglycone moieties, and the tannins were composed by catechin/epicatechin and/or afzelechin/epiafzelechin.

Conclusions

Overall, the results indicate that the components of Maytenus ilicifolia have a potential use in the treatment of gastrointestinal motility disturbances such as diarrhea.     

Anti-histamine effect of Rubia tibetica, used to treat anaphylaxis caused by tick bites in the Pamir Mountains, Afghanistan

Ethnopharmacological relevance

The roots of Rubia tibetica are chewed as an antidote to anaphylaxis caused by bites of the tick Ornithodoros lahorensis by the Wakhi people in Afghanistan.

Aims of the study

To test whether Rubia tibetica possess anti-histamine effect.

Materials and methods

Water and ethanol extracts of roots of Rubia tibetica were tested for anti-histamine effect on the H₁-receptor in the guinea pig ileum assay. Fixed concentrations of plant extract with increasing concentrations of histamine were examined. Mepyramine was used as control.

Results and conclusion

The ethanol extract of Rubia tibetica showed dose-dependent anti-histamine effect, whereas the water extract had little activity. The chewing of Rubia tibetica roots may alleviate the fatal swelling of the tongue during anaphylaxis.     

Antimicrobial,anti-inflammatory activities and toxicology of phenylethanoid glycosides from Monochasma savatieri Franch. ex Maxim

Ethnopharmacological relevance

Monochasma savatieri Franch. ex Maxim is used for treating many diseases in Traditional Chinese Medicine.

Aim of the study

The present study was designed to evaluate antibacterial, anti-inflammatory activities and toxicity of the total phenylethanoid glycosides from Monochasma savatieri Franch. ex Maxim (TPG).

Materials and methods

The antibacterial activity of TPG was checked by MIC and MBC in vitro; survival of mice with Pseudomonas aeruginosa or Staphylococcus aureus infection-induced sepsis was investigated to evaluate antibacterial activity of TPG in vivo. Additionally, antibacterial activities of TPG were also investigated in a Pseudomonas aeruginosa infection-induced pneumonia in the mice model. Cotton pellet induced granuloma and xylene induced ear swelling in mice models were used to quantify the anti-inflammatory activity.

Results

TPG showed a significant possess bacteriostatic properties against five bacteria strains at a concentration between 0.0625 and 16 mg/ml. Moreover, TPG has bactericidal activity against Pseudomonas aeruginosa, Streptococcus pneumoniae or Escherichia coli. TPG (60, 120, and 180 mg/kg) prolonged survival rate of mice with Pseudomonas aeruginosa or Staphylococcus aureus infection-induced sepsis. In addition, TPG (180 mg/kg) could reduce the bacterial colony-forming units in lung tissue. Furthermore, TPG (60–180 mg/kg) had significantly reduced xylene-induced ear edema and granulomat formation induced by cotton pellet at a dose-dependent manner. In addition, administration of TPG (1.5 g/kg) for 15 days did not result in toxicities in liver, kidney, spleen and thymus tissue in rats.

Conclusion

These results indicated that TPG might be useful for the development of a novel treatment for respiratory infections or pneumonia caused by Pseudomonas aeruginosa or Staphylococcus aureus.     

Anti-ulcerogenic activity and isolation of the active principles from Sambucus ebulus L. leaves

Ethnopharmacological relevance

Sambucus ebulus L. has a very prominent place in Turkish folk medicine. Leaves of the plant are practiced externally to relieve rheumatic pain, to treat abscess, for wound healing and internally against hemorrhoids and stomachache. In a previous work, aqueous extract of the leaves was shown to possess potent antiulcerogenic activity on water immersion and immobilization-induced stress ulcer model in rats. This study aims to investigate the antiulcerogenic activity profile of the plant on various in vivo peptic ulcer models and gastric biochemical parameters and through bioassay-guided processing to isolate the active constituent (s) and to elucidate its structure.

Materials and methods

Among the subextracts obtained by successive solvent extractions from the MeOH extract of the leaves, the butanol subextract exerted significant antiulcerogenic activity against water-immersion and immobilization-induced stress ulcer model in rats as the bioassay model. This subextract was then subjected to successive chemical separation techniques (precipitation, column chromatography based on ion-exchange, silica gel and sephadex) and the activity of each fraction/subfraction was tested using the same bioassay model. After determination of active principles, further studies were performed on the active subextract by using various in vivo test models (ethanol-, serotonin-, pyloric ligation-induced ulcerogenesis) in rats as well as biochemical methods for the evaluation of antiulcerogenic potential.

Results

Bioassay-guided fractionation procedures yielded two flavonol glycosides as the active antiulcerogenic principles. The structures of these compounds were elucidated as isorhamnetin-3-O-monoglycoside and quercetin-3-O-monoglycoside by using ¹H, ¹³C-NMR, and FAB-MS techniques.

Conclusion

This study has proven the folkloric use of Sambucus ebulus leaves for the treatment of gastric ailments in Turkish folk medicine. The antiulcerogenic activity of the two flavonol glycosides isolated in the present study was not previously reported elsewhere.