Gastrointestinal and uterine smooth muscles relaxant and anti-inflammatory effects of corchorus olitorius leaf extract in laboratory animal models

ETHNO-PHARMACOLOGICAL RELEVANCE

Corchorus olitorius is reportedly used in ethno-medicine to arrest threatened miscarriage and other conditions associated with excessive uterine contractions. The plant is also used as a purgative, demulscent and an anti-inflammatory agent.

AIM OF THE STUDY

Against the background of ethno-medicinal use, this current work was designed to evaluate the gastrointestinal and uterine smooth muscles relaxant and anti-inflammatory effects of Corchorus olitorius leaf extract (COLE).

MATERIALS AND METHODS

Pieces of uterine and gastrointestinal tissues were suspended separately in organ baths containing ideal physiological salt solutions bubbled with air and were tested for responses to standard drugs and COLE, then repeated in the presence of antagonists. Anti-inflammatory study was carried out via the egg albumin-induced paw edema model in rats.

RESULTS

The application of COLE to pieces of uterine tissue significantly decreased the amplitudes of contractions in a dose dependent manner such that the highest dose applied (666.67 μg/ml) achieved a 100% inhibitory effect. Oxytocin induced contractions were also significantly inhibited by both salbutamol and COLE. On the isolated rabbit jejunum, the effect of COLE was also inhibitory and like atropine, significantly inhibited acetylcholine induced contractions. In the in vivo study, the extract inhibited charcoal meal movement in test rats when compared with control. Anti-inflammatory effect of COLE was significant and compared favourably with that of aspirin following in vivo trials.

CONCLUSIONS

COLE therefore, may be a good tocolytic, anti-diarrheal and anti-inflammatory agent and offers hope of new drug discovery for such uses.

Screening a small molecule library to identify inhibitors of NF-κB inducing kinase and pro-labor genes in human placenta

The non-canonical NF-κB signaling (RelB/p52) pathway drives pro-labor genes in the human placenta, including corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2), making this a potential therapeutic target to delay onset of labor. Here we sought to identify small molecule compounds from a pre-existing chemical library of orally active drugs that can inhibit this NF-κB signaling, and in turn, human placental CRH and COX-2 production. We used a cell-based assay coupled with a dual-luciferase reporter system to perform an in vitro screening of a small molecule library of 1,120 compounds for inhibition of the non-canonical NF-κB pathway. Cell toxicity studies and drug efflux transport MRP1 assays were used to further characterize the lead compounds. We have found that 14 drugs have selective inhibitory activity against lymphotoxin beta complex-induced activation of RelB/p52 in HEK293T cells, several of which also inhibited expression of CRH and COX-2 in human term trophoblast. We identified sulfapyridine and propranolol with activity against CRH and COX-2 that deserve further study. These drugs could serve as the basis for development of orally active drugs to affect length of gestation, first in an animal model, and then in clinical trials to prevent preterm birth during human pregnancy.

A Systematic Review of the Uterine Relaxant Effect of Herbal Sources

BACKGROUND

Preterm birth is a worldwide tragedy with a high incidence. Several medications are used to inhibit acute preterm labor, but tocolysis by these medicines do not extend pregnancy beyond 1-2 days.

OBJECTIVES

The purpose of this study was to discover new medications from plant extracts or their active compounds which inhibit the uterine contractions in order to treat preterm labor.

DATA SOURCES

PubMed, Google Scholar, Scopus and IranMedex databases were searched up to 1st February 2012 with the most relevant keywords.

STUDY SELECTION

All studies in which plant extracts or their active compounds inhibited the uterine contractions both in vivo and in vitro were included.

THE RESULTS

Of initial search, 259 records were reviewed and finally 72 were included among which only 31 studies isolated an active compound from the plants extract belonging mostly to classes of flavonoids and terpenes classes. Flavonoids have been known as a phosphodiesterase (PDE) and a protein kinase C (PKC) inhibitor. It seems that the uterolytic activity of reviewed flavonoids such as naringenin, kaempferol and quercetin, especially in a calcium free solution, was via these inhibitory pathways.

CONCLUSION

Laboring uterus response to dissimilar tocolytics differs from that of non-laboring uterus. In order to find a treatment for preterm labor, future studies should focus on the laboring uterus and also determine the structure activity relationship of the different tocolytics. This systematic review was registered to the PROSPERO with code number CRD42015027551.

Chemical composition and pharmacological properties of the essential oils obtained seasonally from Lippia thymoides

CONTEXT

Lippia thymoides Mart. & Schauer (Verbenaceae) is used in folk medicine to treat wounds, fever, bronchitis, rheumatism, headaches, and weakness.

OBJECTIVE

This study determinates the chemical composition of essential oils from L. thymoides, obtained at during each of the four seasons and correlates with pharmacological properties.

MATERIALS AND METHODS

Essential oils were obtained by hydrodistillation and analyzed by gas chromatography coupled to mass spectroscopy (GC-MS). Antioxidant activity was determined by DPPH free radical scavenging and β-carotene bleaching methods. The antimicrobial assays were performed by minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) methods. Isolated rat aorta and uterus, and guinea-pig trachea were utilized to evaluate relaxant potential in pre-contracted smooth muscle.

RESULTS AND DISCUSSION

Essential oils from leaves of L. thymoides had the sesquiterpene β-caryophyllene (17.22-26.27%) as the major constituent followed by borneol (4.45-7.36%), camphor (3.22-8.61%), camphene (2.64-5.66%), and germacrene D (4.72-6.18%). In vitro assays showed that these essential oils do not have antioxidant activity, have antimicrobial selectivity to Gram-positive bacteria Staphylococcus aureus (MIC = 0.004 mg/mL and MMC = 0.26-10.19 mg/mL) and Micrococcus luteus (MIC = 0.03 mg/mL and MMC = 8.43 mg/mL), relax isolated rat aorta (EC50 = 305-544 μg/mL, with endothelium; and EC50 = 150-283 μg/mL, without endothelium), and uterus (EC50 = 74-257 μg/mL), and minor potency, isolated guinea-pig trachea.

CONCLUSIONS

Lippia thymoides is a source of natural products of pharmaceutical interest, being necessary additional studies to determine the substances involved in the biological activities.

The leaves of Ficus exasperata Vahl (Moraceae) generates uterine active chemical constituents

ETHNOPHARMACOLOGICAL RELEVANCE

In the search for new, safe and efficacious uterine active agents, the plant Ficus exasperata was subjected to phytochemical screening and pharmacological analysis.

MATERIALS AND METHODS

Ethyl acetate and methanolic leaf extracts of Ficus exasperata were fractionated and purified by a series of chromatographic techniques. The isolation process was guided by in vitro functional uterine assays involving the use of C57Bl/6 female mice. Identification of the active chemical constituents was performed by several spectroscopic techniques which included 1D and 2D nuclear magnetic resonance (NMR) and high resolution mass spectrometry (HRMS). The uterine effects of these compounds were investigated on spontaneous, oxytocin-induced and high KCl-induced contractions using isolated uterine segments of non-pregnant female mice. The activity of different compounds on the amplitude (maximum tension above basal force) and frequency of uterine contractions were simultaneously measured and then statistically analysed. The structure-activity relationships were also examined where possible.

RESULTS

These studies led to the identification of some new phytochemical derivatives. Pharmacological assay revealed the presence of both uterine stimulatory and inhibitory constituents. The new pheophytin/pheophorbide derivatives, flavonoids, fatty acids and glycerol derivatives significantly reduced the frequency and amplitude of uterine contraction, while KCl salt, pyrimidine and pheophorbide-b derivatives significantly augmented both spontaneous and agonist-induced contractions.

CONCLUSION

This study has demonstrated that Ficus exasperata generates secondary metabolites which have proven effective in the significant inhibition of uterine contractions and thus a potential source of new tocolytic agents. Additionally, uterine stimulatory constituents were also generated some of which may be potential drugs for contraception and/or labour facilitation. Lead compounds generated from this study are the pheophytin/pheophorbide derivatives, pyrimidine derivatives and flavonoid derivatives.

Oxytocin inhibiting effect of the aqueous leaf extract of Ficus exasperata (Moraceae) on the isolated rat uterus

The leaves of Ficus exasperata Vahl Enum. Pl. vahl (Moraceae) are used by traditional healers in Southern Nigeria and some parts of Africa to avoid preterm births. However, previous reports showed that the plant also exhibited uterine contractions at specific concentrations. This study is therefore aimed at investigating the purported uterine inhibitory aspect of the plant on the isolated rat uterus. The aqueous extract (AET) was tested on rhythmic spontaneous uterine contractions. Concentration-response relationships were obtained for oxytocin (OT), acetylcholine (ACh) and ergometrine (EGM), in the presence or absence of fixed concentrations of AET. Salbutamol (SBL) and verapamil (VER) were used as positive controls. AET, at 1.0 x 10(-2) mg/mL, significantly increased (p < 0.05) the EC50 of oxytocin-induced contractions but had no significant effect on ACh, EGM and spontaneous uterine contractions. However, SBL and VER significantly increased (p < 0.01) the EC50, of OT, ACh and EGM and significantly inhibited (p < 0.01) the frequency and amplitude of spontaneous uterine contractions. The aqueous leaf extract of F. exasperata inhibits oxytocin-induced uterine contractions at the concentration shown in this study. This observation may explain its folkloric use in counteracting preterm contractions and alleviating dysmenorrhoea.

Evaluation of tocolytic activity of ethanol extract of the stem bark of Ficus capensis Thunb. (Moraceae)

Ficus capensis, a wild fig tree is used in herbal medicines to treat pregnancy related ailment and most especially as a remedy for threatened abortion. The purpose of this study was to investigate this claim with view to validating scientifically the ethno-medicinal usage. The ethanolic extract obtained by maceration technique was subjected to pharmacological testing in vitro on a piece of isolated rat uterus previously pretreated with stilbestrol, suspended in De Jalon at 37 degrees C. Concentrations used were 40 mg/mL and 80 mg/mL. The higher concentration (80 mg/mL) significantly (p < 0.05) exerted smooth muscle relaxant activity on the uterus (a reduction of oxytocin, ergometrin and acetylcholine induced contractions as well as an increase of the EC50 was observed for all the agonists tested in the presence of the extract). Evaluation of the data also indicated that the effect of the 40 mg/mL concentration was statistically insignificant, although a lowering of the dose response curve was observed for oxytocin, acetylcholine and ergometrin. Its relaxant activity at 80 mg/mL was 40 and 50% of the inhibitory effects produced by salbutamol (0.002 microg/mL) and atropine (0.02 microg/mL) on oxytocin and acetylcholine induced contractions, respectively. The results indicate the presence of active principles in the bark extract of Ficus capensis which may be responsible for some of the applications in traditional medicines as an anti-abortifacient and as a remedy against threatened abortion.