Evaluation of anti-migraine potential of Areca catechu to prevent nitroglycerin-induced delayed inflammation in rat meninges: possible involvement of NOS inhibition

Ethnopharmacological relevance

Areca catechu nut extract is a popular folk remedy for the treatment of migraine in Kerala and Tamil Nadu states of India.

Aim of the study

In order to prove the claimed utilization of plant, the effect of hydroalcoholic extract of Areca catechu nut (ANE) was investigated in nitroglycerine induced inflammation in rat meninges. In these models infusion of nitric oxide donor glyceryl trinitrate (GTN) produces augmented plasma protein extravasation (PPE) in dura mater, provides an important substrate for the development of migraine in rats.

Materials and methods

The effect on plasma protein extravasation was assessed in both the models of intravenous and topical GTN application following oral administration of ANE (250 mg/kg and 500 mg/kg) in both curative and preventive treatment and compared with that of control positive. The l-NAME (15 mg/kg, i.v.) was used as reference standard. Plasma protein extravasation was measured using fluorescein as marker and was measured using a Perkin-Elmer LS-30 luminescence spectrometer.

Results

Expression of iNOS in the spleen after intravenous injection produced PPE into the dura mater in control positive group was significantly (P < 0.01) reduced to 1.553 ± 0.02499 and 1.398 ± 0.01887 by preventive treatment with ANE at the dose of 250 and 500 mg/kg, orally, respectively. The extravasation produced by topical GTN due to expression of iNOS in dural macrophages was also reduced to 1.555 ± 0.03384 and 1.425 ± 0.01204 by preventive treatment with ANE at the dose of 250 and 500 mg/kg, orally, respectively. While ANE do not showed any significant results in curative treatment in both the models of i.v. and topical GTN application.

Conclusion

These findings collectively indicate that the extract exhibited significant inhibition of iNOS, which may be the probable mechanism for its anti-migraine activity, providing evidence, at least in part, for its folkloric use.     

Indigofera suffruticosa Mill as new source of healing agent: involvement of prostaglandin and mucus and heat shock proteins

Ethnopharmacological relevance

Indigofera suffruticosa is specie typical of the “Cerrado” or Brazilian savannah; it is a member of the Fabaceae family - in folkmedicine is used for gastric disorders, infection and inflammation.

Aim of the study

Ethyl acetate fraction (AcF) and aqueous fraction (AqF) of the methanolic extract of I. suffruticosa leaves were evaluated against acute gastric ulcer. The AcF fraction was selected to assess its activity in ulcer healing and its gastroprotective effects via mucus and gastric secretion.

Materials and methods

The gastroprotective action of AcF and AqF fractions were evaluated in a rodent experimental model. The action mechanisms, involvements of the antisecretory action, mucus and prostaglandin production, toxicological and healing activity of the AcF (100 mg/kg, p.o.) were evaluated. We also used histological analysis (HE and PAS) and immunohistochemical (PCNA and HSP-70) assays to evaluate the effects of I. suffruticosa.

Results

AcF significantly inhibited the gastric mucosal damage caused by ethanol. This effect was statistically significant in 100 mg/kg group compared vehicle. AcF did not interfered with gastric secretion, significantly increased the PGE₂ and mucus production (validated in PAS technique). The gastroprotection was attenuated by pretreatment with N-ethylmaleimide, but not L-NAME. In acid-acetic-induced ulcer model AcF accelerated ulcer healing. Immunohistochemistry analysis showed induction of proliferating cell (PCNA) and heat shock protein (HSP 70).

Conclusions

These results showed that AcF acted as gastroprotective agent stimulating prostaglandin, mucus and HSP70.     

Identification and pharmacological characterization of the anti-inflammatory principal of the leaves of dwarf elder (Sambucus ebulus L.)

Aim of the study

The performed investigations aimed on the identification of the anti-inflammatory principal of extracts of leaves of Sambucus ebulus L. (dwarf elder) in order to rationalize the traditional use of this plant for the treatment of chronically inflammatory diseases.

Materials and methods

Dwarf elder leaf extract was subjected to activity guided fractionation using inhibition of TNFα induced expression of vascular cell adhesion molecule 1 (VCAM-1) on the surface of human umbilical vein endothelial cells (HUVECs) as monitoring tool (positive control: parthenolide 10 μM, VCAM-1 expression (% of control): 5.35 ± 0.38%).

Results

Bio-guided isolation resulted in identification of ursolic acid as anti-inflammatory principal. Besides its inhibitory effects against TNFα induced expression of VCAM-1 (IC₅₀ 6.25 μM), ursolic acid inhibits also TNFα induced expression of ICAM-1 (IC₅₀ value between 3.13 and 6.25 μM) (positive control: parthenolide 10 μM, ICAM-1 expression (% of control): 38.89 ± 16.6%). Toxic effects of ursolic acid on HUVECs can be drastically reduced using an enriched extract instead of the pure compound.

Conclusions

Our findings suggest an additional mechanism of the anti-inflammatory activity of ursolic acid by demonstrating its ability to inhibit TNFα-stimulated expression of VCAM-1 and ICAM-1 and support the traditional use of extracts and preparations of Sambucus ebulus L., rich in ursolic acid, for the treatment of chronically inflammatory processes.     

Pharmacological characterization of the diuretic effect of Hibiscus sabdariffa Linn (Malvaceae) extract

Ethnopharmacological relevance

Hibiscus sabdariffa L. (Malvaceae) populary known in Mexico as “Jamaica”, “flor de Jamaica”, has widely used in Mexican Traditional Medicine as antihypertensive and diuretic, although the latter activity has been reported the present work show evidence about the diuretic, natriuretic and potassium-sparing effects.

Aim of the study

To evaluate the diuretic activity of Hibiscus sabdariffa aqueous extract on in vivo and in situ models.

Materials and methods

The Hibiscus sabdariffa aqueous extract was administrated in increasing doses and evaluated the diuresis produced and disposal of electrolytes. Moreover, in isolated kidney was determined the renal filtration rate with plant extract, furosemide and amiloride.

Results

The yield of Hibiscus sabdariffa aqueous extraction was 28.3% and the chemical standardization from 1 g of extract was: 56.5 mg delphinidin-3-O-sambubioside, 20.8 mg/g cyanidin-3-O-sambubioside, 3.2 mg/g quercetin, 2.1 mg/g rutin and 2.7 mg/g chlorogenic acid. The diuretic and natriuretic effect of Hibiscus sabdariffa aqueous extract showed a dose-dependent behavior. The pharmacological constants of natriuretic effect was ED50 = 86 mg/kg and Emax = 0.9 mEq/100 g/5 h. In the model of kidney in situ was observed that renal filtration increased 48% with the aqueous extract of Hibiscus sabdariffa and an additive effect when was perfuse with furosemide.

Conclusion

The compound presents in Hibiscus sabdariffa as quercetin had effect on the vascular endothelium causing oxide nitric release, increasing renal vasorelaxation by increasing kidney filtration. Therefore, the diuretic effect of Hibiscus sabdariffa may be mediated by nitric oxide release.     

Typhonium flagelliforme induces apoptosis in CEMss cells via activation of caspase-9, PARP cleavage and cytochrome c release: Its activation coupled with G0/G1 phase cell cycle arrest

Ethnopharmacological relevance

The plant Typhonium flagelliforme (TF), commonly known as ‘rodent tuber’ in Malaysia, is often used as traditional remedy for cancer, including leukemia.

Aim of the study

We had previously identified morphologically that the linoleic acid rich fraction (DCM/F7) from the tubers of this plant induces selective anti-proliferative effects and apoptosis in CEMss cells. In this present study, we subjected the same DCM/F7 fraction to cell based activity analyses in order to determine the possible mechanism of cell death in leukemic CEMss cells in vitro.

Materials and methods

Extraction of Typhonium flagelliforme tuber has done and fractionation has been done by vacuum liquid column chromatography. The anti-proliferative activity was assayed using MTT and the apoptosis detection was done by Annexin V and DNA laddering assay. Colorimetric caspase assay and immunoblot analysis were employed to detect the expression of protein associated with cell death. Cell cycle analysis was done using flow cytometry.

Results

We found that the cancer inhibitory effect of the DCM/F7 fraction in CEMss cells was 3 ± 0.08 μg/ml (IC₅₀). An early apoptotic induction in CEMss cells was observed by Annexin V assay, which showed a clear dose-dependent DNA fragmentation being observed in gel electrophoresis at 10 and 20 μg/ml. The DCM/F7 fraction at 3 μg/ml significantly arrested CEMss cells at G0/G1 phase (p < 0.05). A constant but increasing pattern-related Sub-G0/G1 index was observed between 12 and 72 h treatment. In relation to this, we further investigated the biochemical events leading to cell death and found that the DCM/F7 fraction increased the cellular levels of caspase-3 and -9 on treated cells. Our results indicated that cytochrome c from mitochondria into the cytosol increased gradually as the DCM/F7 concentration increases, which later lead to the subsequent cleavage of PARP in to 85 kDa fragments. On the contrary, Bcl-2 protein was found to decrease concomitantly during treatment.

Conclusions

Collectively, results presented in this study demonstrated that the DCM/F7 fraction inhibited the proliferation of leukemia cells, leading to the programmed cell death, which was confirmed to be through the mitochondrial pathway.     

Antimalarial activity and toxicity evaluation of a quantified Nauclea pobeguinii extract

Aim of the study

To evaluate the in vitro and in vivo antiplasmodial activity and toxicity of the aqueous and 80% EtOH extract of the stem bark of Nauclea pobeguinii (Pob. Ex. Pell.) Petit (Rubiaceae), a plant used in traditional medicine in DR Congo against malaria.

Materials and methods

The aqueous and 80% EtOH extract from N. pobeguinii stem bark, and its constituents (5S)-5-carboxystrictosidine, 19-O-methylangustoline, 3-O-β-fucosylquinovic acid, 3-ketoquinovic acid and strictosamide, were evaluated for their in vitro activity against Plasmodium falciparum (chloroquine-sensitive Ghana-strain). The 80% EtOH extract, containing 5.6% strictosamide, was evaluated in vivo in the 4-day P. berghei mouse model, and in the P. yoelii N67 model.

Results

All compounds were inactive or only moderately active in vitro. The aqueous and 80% EtOH extract displayed moderate in vitro activity with IC₅₀ values of 44 and 32 μg/mL, respectively, without apparent cytotoxicity on MRC-5 cells (CC50 > 64 μg/mL). Daily oral dosing of the 80% EtOH extract, at 300 mg/kg, resulted in 86% reduction of parasitaemia in the 4-day P. berghei mouse model, and 75% reduction in the P. yoelii N67 model. Prolonging oral dosing to 2 × 5 days, with an interval of 2 days, and oral administration of the 80% EtOH extract at 300 mg/kg induced 92% reduction of parasitaemia, and a mean survival time of 17 days. Strictosamide, the putative active constituent, may be metabolically activated in the gastrointestinal tract after oral administration. Levels of creatinin, urea, ALAT and ASAT remained unchanged after treatment. No acute toxicity was observed in mice after a single 2 g/kg oral dose, nor after 4 weekly doses. No significant macroscopic or microscopic lesions were observed in heart, lung, spleen, kidney, liver, large intestine and brain.

Conclusions

These results can partly support and justify the use of N. pobeguinii in traditional medicine in the DR Congo for the treatment of uncomplicated malaria.     

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

Aim of the study

In order to evaluate the antimalarial potential of traditional remedies used in Peru, Indigenous and Mestizo populations from the river Nanay in Loreto were interviewed about traditional medication for the treatment of malaria.

Materials and methods

The survey took place on six villages and led to the collection of 59 plants. 35 hydro-alcoholic extractions were performed on the 21 most cited plants. The extracts were then tested for antiplasmodial activity in vitro on Plasmodium falciparum chloroquine resistant strain (FCR-3), and ferriprotoporphyrin inhibition test was also performed in order to assume pharmacological properties.

Results

Extracts from 9 plants on twenty-one tested (Abuta rufescens, Ayapana lanceolata, Capsiandra angustifolia, Citrus limon, Citrus paradise, Minquartia guianensis, Potalia resinífera, Scoparia dulcis, and Physalis angulata) displayed an interesting antiplasmodial activity (IC₅₀ < 10 μg/ml) and 16 remedies were active on the ferriprotoporphyrin inhibition test.

Conclusions

The results give scientific validation to the traditional medical knowledge of the Amerindian and Mestizo populations from Loreto and exhibit a source of potentially active plants.     

Realgar and realgar-containing Liu-Shen-Wan are less acutely toxic than arsenite and arsenate

Ethnopharmacological relevance

Liu-Shen-Wan (LSW) is a widely-used traditional Chinese medicine containing realgar (As₄S₄).

Aim of the Study

Realgar has been included in many traditional medicines, and is often taken as arsenite for risk assessment in realgar-containing traditional remedies. Is realgar toxicologically similar to arsenite?

Materials and Method

Mice were orally given LSW (60 and 200 mg/kg; 200 mg LSW contains 27 mg realgar), realgar (30 mg/kg, equivalent to 21 mg As/kg), and the equivalent As dose as sodium arsenite (NaAsO₂), or as arsenate (Na₂HAsO₄). Acute toxicity and tissue As accumulation were determined 8 h later.

Results

Arsenite and arsenate increased serum alanine aminotransferase (ALT) levels, indicative of liver injury; blood urea nitrogen (BUN) was also increased by arsenite and arsenate, indicative of nephrotoxicity. No elevations of ALT and BUN were observed in LSW and realgar groups. Histopathology showed more damage in arsenite- and arsenate-treated liver and kidneys, while in realgar- and LSW- treated animals, only mild alterations were seen. Hepatic and renal As contents were dramatically increased to 6200 and 3350 ng/g, respectively, after arsenite, but only increased to 260 and 180 ng/g after LSW. The expressions of arsenic-sensitive stress genes, namely metallothionein-1 and heme oxygenase-1, were increased after arsenite or arsenate by 3-10-folds, but were unaltered after LWS and realgar.

Conclusions

Realgar and LSW are much less toxic than arsenite and arenate. The use of total As content to evaluate the safety of realgar-containing traditional medicines is not scientifically sound.     

Activation of M3 muscarinic receptor and Ca²⁺ influx by crude fraction from Crotonis Fructus in isolated rabbit jejunum

Ethnopharmacological relevance

Crotonis Fructus is the mature fruit of Croton tiglium L. (Euphorbiaceae), which has been used in traditional Chinese medicine for the treatment of gastrointestinal (GI) diseases, such as constipation, abdominal pain, peptic ulcer, and intestinal inflammation for thousands of years. The aim of this study was to investigate the pharmacological effect of extracts and fractions from Crotonis Fructus on GI tract.

Materials and methods

The activities of methanol extract and fractions from Crotonis Fructus on the smooth muscle contractions were evaluated using isolated rabbit jejunum model.

Results

The results suggest that the n-BuOH and H₂O fractions showed spasmolytic activity, while the MeOH extract, PE and EtOAc fractions exerted spasmogenic effect. Moreover, bioassay-guided fractionation verified that the EtOAc fraction was more potent than others, followed by PE fraction and methanol extract. Additionally, atropine (10 μM), 4-DAMP (10 μM) and verapamil (0.1 μM) produced a significant inhibition of contractions caused by EtOAc fraction, while either hexamethonium (10 μM) or methoctramine (10 μM) was inactive. Additionally, a HPLC fingerprint of EtOAc fraction was appraised to ensure its chemical consistency and the main component has been identified as phorbol 12-acetate-13-tiglate.

Conclusions

These data indicate that the regulatory effect of EtOAc fraction on GI motility are medicated via the activation of M3 muscarinic receptor and Ca²⁺ influx through L-type Ca²⁺ channel. These provide a scientific basis for the traditional use of Crotonis Fructus in GI disorders.     

Acute and sub-chronic oral toxicity studies of an aqueous stem bark extract of Pterocarpus soyauxii Taub (Papilionaceae) in rodents

Pterocarpus soyauxii Taub (Papilionaceae) is used in Cameroonian traditional medicine and pharmacopoeia to treat hypertension, diabetes, gastrointestinal parasitizes and cutaneous diseases.

Aim of the study

The present investigation was carried out to evaluate the safety of an aqueous stem bark extract of Pterocarpus soyauxii by determining toxicity after acute and sub-chronic oral administration in male and female rodents.

Materials and methods

The acute toxicity test was conducted in mice. An aqueous extract of barks was administrated by gavage in single doses of 2.5-12.5 g/kg. General behaviour and mortality were examined for up to 7 days. The sub-chronic toxicity test was performed in rats. The plant extract was administered by daily gavage of 150-600 mg/kg for 42 days. Body weight, food and water intakes were followed weekly. Haematological, biochemical and organ parameters were determined at the end of the 42-day administration.

Results

In the acute study in mice, oral administration of the aqueous extract of Pterocarpus soyauxii caused dose-dependent general behaviour adverse effects and mortality. The no-observed adverse effect level (NOAEL) of the extract was 5.0 g/kg. The lowest-observed adverse effect level (LOAEL) was 7.5 mg/kg. Mortality increased with the dose, LD₅₀ was > 10.75 g/kg for the mouse. In the sub-chronic study in rats, daily oral administration of the aqueous extract of Pterocarpus soyauxii did not result in death or significant changes in haematological or biochemical parameters, excepted increased hepatic catalase activity (P < 0.05) at the dose of 600 mg/kg. No alteration was observed in body weight, food and water intake. Liver, kidney, lung and pancreas histopathology did not reveal morphological alteration.

Conclusions

The results showed that the aqueous stem bark extract of Pterocarpus soyauxii Taub had very low toxicity in oral acute high dose administration and no toxicity in oral sub-chronic low dose administration and indicate that the plant could be considered safe for oral medication.     

Evaluation of antinociceptive effect of Aegiceras corniculatum stems extracts and its possible mechanism of action in rodents

Ethnopharmacological relevance

Aegiceras corniculatum (Linn.) Blanco is used in various traditional medicinal system(s) for the treatment of rheumatism, painful arthritis and inflammation. Therefore, the pharmacological studies of its antinociceptive effect was undertaken to validate its traditional use.

Materials and methods

n-Hexane, ethyl acetate and methanol extract(s) derived from Aegiceras corniculatum (stems) were studied using various nociceptive model(s) induced chemically or thermally in mice including acetic acid-induced writhing, formalin-induced paw licking and hot plate test.

Results

In acetic acid-induced writhing test, plant extracts dose dependently decreased the writhing numbers. The methanolic extract (1-10 mg/kg, i.p. in mice) of the plant was more potent than acetaminophen and acetyl salicylic acid, with an IC₅₀ of 4.2 ± 0.99 mg/kg. Moreover, the time of nociceptive behaviors induced by intraplantar formalin injection was also suppressed during 1st and 2nd phases in the presence of ethyl acetate extract whereas, n-hexane and methanolic extracts inhibited the paw licking in mice during the 1st (IC₅₀ 12 ± 0.76 mg/kg) and 2nd phases (IC₅₀ 3.8 ± 0.55 mg/kg). Naloxone, β-funaltrexamine, and naltrindole antagonized the n-hexane extract-induced antinociception in the first phase of formalin test indicating its non-selective analgesic response via opioid receptor(s). However, ethyl acetate extract was devoid of any opioid action. Additionally, these extracts significantly inhibited the pain stimulation in hot plate test. Withdrawal syndrome of morphine dependence was also diminished in the presence of plant extracts via potentiation of GABAergic system.

Conclusion

These results suggested that Aegiceras corniculatum extract(s) possesses analgesic properties and acts on the central nervous system, thereby suppressing the inflammatory pain justifying its folklore use.     

Renaissance remedies: Antiplasmodial protostane triterpenoids from Alisma plantago-aquatica L. (Alismataceae)

Aim of the study

In a preliminary screen of extracts from plants used as antimalarial remedies used in Europe in the 16th and 17th, the ethyl acetate extract of Alisma plantago-aquatica L. (Alismataceae) was active against Plasmodium falciparum K1 strain with 77% growth inhibition at 4.9 μg/ml. The aim of this study was to isolate and identify the substances responsible for this antiplasmodial activity.

Materials and methods

With HPLC-based activity profiling in combination with HPLC hyphenated methods (HPLC-PDA, -MSn, HR-MS, and off-line microprobe NMR) the activity was assigned to time windows, and the substances contained therein were characterised chemically. The active compounds were isolated with semi-preparative HPLC and structures were elucidated with high resolution mass spectrometry, and 1D and 2D NMR spectroscopy.

Results

Four compounds were isolated and identified as protostane triterpenoids alisol A, alisol B 11-monoacetate, alisol B 23-monoacetate, and alisol G. Their IC₅₀s against Plasmodium falciparum ranged from 5.4 to 13.8 μM.

Conclusions

This is the first report of antiplasmodial activity from protostanes triterpenoids, and the first result of our ongoing project of screening for antiprotozoal natural products from remedies used in European renaissance medicine.     

Antidiabetic potential of unripe Carissa carandas Linn. fruit extract

Ethnopharmacological relevance

Carissa carandas commonly known as Karanda have a long history of use in traditional system of medicine. It is used by tribal healers of Western Ghat region of Karnataka as hepatoprotective and antihyperglycemic. However, no scientific data is available to validate the folklore claim. The present study has been designed to evaluate its unripe fruit for the antidiabetic activity.

Aim

In the present study, methanol extract of unripe fruits and its fractions were studied for its antidiabetic potential.

Materials and methods

The methanol extract and its fractions were screened for antidiabetic activity in alloxan induced diabetic rats. The polyphenolic, flavonoid and flavanone contents of methanolic extract and its fractions were also determined and correlated with its antidiabetic activity.

Results

The experimental data indicated that the methanol extract and its ethyl acetate soluble fraction has significantly lowered the elevated blood glucose levels by 48% (p < 0.001) and 64.5% (p < 0.001) respectively at dose level of 400 mg/kg per oral after 24 h as compared to diabetic control. In order to assess the role of polyphenolic components in the relevant activity, polyphenolic and flavonoid contents were determined. The polyphenolic and flavonoid content of methanol extract and its ethyl acetate soluble fraction were found to be 15.8 ± 1.2 mg and 18.55 ± 0.34 mg (gallic acid equivalent/g extract) and flavonoid content 2.92 ± 0.03 mg and 1.534 ± 0.30 mg (rutin equivalent/g extract) respectively.

Conclusion

The increased antidiabetic potential of ethyl acetate fraction over methanol extract is due to its partial purification achieved by fractionation which resulted in increase in degree of polymerization and segregation of secondary metabolites.     

Hypoglycemic and antihyperglycemic effect of Witheringia solanacea in normal and alloxan-induced hyperglycemic rats

Aim of the study

Witheringia solanacea is a small shrub that belongs to the Solanaceae family. The plant is used as an antidiabetic in Costa Rican herbal medicine. The aim of this study was to evaluate the hypoglycemic and antihyperglycemic activity of the aqueous extract of W. solanacea leaves in rodent models.

Materials and methods

A crude extract of W. solanacea leaves was prepared in boiling water and the aqueous filtrate was lyophilized. A single oral dose of 250, 500 and 1000 mg/kg of the extract was evaluated for hypoglycemic activity in a glucose tolerance test in normal rats and for antihyperglycemic activity in alloxan-induced (140 mg/kg) diabetic rats. The blood glucose level was determined at different times by the glucose oxidase method.

Results

Dosage of 500 and 1000 mg/kg of the extract significantly decreased (p < 0.05) blood glucose levels in the glucose tolerance test in normal rats after 1 h, there was no significant difference observed at 250 mg/kg. Dose of 500 mg/kg of the extract significantly reduced (p < 0.05) blood glucose levels in alloxan induced hyperglycemic rats at 4 and 5 h.

Conclusions

In the present study, the hypoglycemic and antihyperglycemic potential of the W. solanacea was demonstrated in rats. These results give support to the traditional use of W. solanacea as antidiabetic herbal medicine.     

Dual protective effect of Passiflora incarnata in epilepsy and associated post-ictal depression

Ethnopharmacological relevance

Passiflora incarnata L. (Passifloraceae) has been used for the treatment of epilepsy in several traditional systems of medicine.

Aim of the study

The aerial parts of Passiflora incarnata contain multiple bioactive metabolites such as, flavonoids (like, chrysin that show CNS depressant activity by agonizing GABA-benzodiazepine receptor), amino acids (like, GABA), harmala alkaloids (reversible monoamine oxidase-A inhibitor), etc. In view of this, the present study was designed to investigate dual protective effect of the hydroethanolic extract of Passiflora incarnata in pentylenetetrazol (PTZ)-induced seizure and associated post-ictal depression.

Materials and methods

Different groups of mice were administered with repeated subconvulsive doses of PTZ (50 mg/kg; i.p.) at an interval of 5 days for 15 days. From 5th to 15th day the animals in different groups were administered daily with varying doses of hydroethanolic extract of Passiflora incarnata (150, 300, and 600 mg/kg; i.p.), diazepam (2 mg/kg; i.p.) and vehicle. On every 5th day, after PTZ treatment, seizure severity (score) was noted. Following convulsive episodes the locomotor activity (using actophotometer) and immobility period (using forced swim test) were also determined. On 15th day after behavioral assessment, the brain serotonin and noradrenaline levels were determined using spectrofluorometric methods.

Results

Treatment with the extract significantly (p < 0.05) reduced the seizure severity and immobility period as compared to vehicle control, in a dose and time-dependent manner. Moreover, the extract treatment retained the serotonin and noradrenaline levels of the brain.

Conclusions

The results of present study concluded that the hydroethanolic extract of Passiflora incarnata suppress PTZ-induced seizures, and ameliorates its associated post-ictal depression, which has been found to be get worsened with the standard antiepileptic drug, diazepam.     

Toxicological evaluation of the aqueous leaf extract of Moringa oleifera Lam. (Moringaceae)

Ethnopharmacological relevance

The rapid increase in consumption of herbal remedies worldwide has been stimulated by several factors, including the notion that all herbal products are safe and effective. However, over the past decade, several news-catching episodes in developed communities indicated adverse effects, sometimes life-threatening, allegedly arising as a consequence to taking herbal products or traditional medicines from various ethnic groups. Despite the popular use of Moringa oleifera for treating various disorders, there is limited or no scientific data available regarding safety aspects of this remedy, nor are there any documented toxicological studies that can be used to ascertain the safety index of its herbal preparation. Therefore, this present study aimed to carry out extensive toxicological evaluation of the aqueous leaf extract of Moringa oleifera.

Materials and Methods

In an acute toxicity test, male Wistar albino mice were orally administered an aqueous extract up to 6400 mg/kg and intraperitoneally up to 2000 mg/kg. A sub-chronic toxicity test was performed by daily administration with the extract at 250, 500 and 1500 mg/kg orally for 60 days. Control rats received distilled water. Sperm quality was analyzed, haematological and biochemical (liver enzymes, urea and creatinine) parameters were determined and a histopathological examination was carried out.

Results

The LD₅₀ was estimated to be 1585 mg/kg. The extract did not elicit any significant difference (P ≥ 0.05) in sperm quality, haematological and biochemical parameters in the treated rats compared to the control. Moreover, there was no significant difference in weight gain of the control and treated animals although there was a dose-dependent reduction in food consumption of the animals treated with 250 to 1500 mg/kg extract.

Conclusions

Results obtained in this study suggest that the aqueous leaf extract of Moringa oleifera is relatively safe when administered orally.     

Antinociceptive and gastroprotective actions of ethanolic extract from Pluchea sagittalis (Lam.) Cabrera

Ethnopharmacological relevance

Pluchea sagittalis, an herbaceous plant widely distributed in South America, is used in folk medicine for the treatment of digestive diseases and inflammation.

Aim of the study

This study was designed to investigate the antinociceptive and gastroprotective effects of the ethanolic extract (EE) of aerial parts from Pluchea sagittalis in rodents.

Materials and methods

The antinociceptive effects of EE was evaluated in mice after oral administration in chemical tests (acetic-acid, glutamate and formalin) or by biting behavior following intrathecal administration of cytokines such as interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in mice. Furthermore, rats were treated with EE and subsequently exposed to acute gastric lesions induced by 80% ethanol. Afterwards the gastric lesion extension and the mucus levels of gastric mucosa were measured.

Results

The oral administration of EE showed a dose-dependent inhibition of acetic acid-induced abdominal constrictions and glutamate-induced pain in mice, with ID₅₀ values of 624.0 (523.0-746.0) mg/kg and 368.0 (216.0-628.0) mg/kg, respectively. In the formalin test, the EE also produced significant inhibition of the inflammatory phase, with an ID₅₀ value of 411.0 (183.0-721.0) mg/kg; however, it was ineffective in the neurogenic phase caused by formalin. In addition, oral treatment with EE caused a significant inhibition of biting behavior induced by i.t. injection of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). The antinociception caused by the EE (300 mg/kg, p.o.) was not reversed by naloxone (1 mg/kg, i.p.) when assessed in the acetic acid writhing test. The EE (300-1000 mg/kg, p.o.) did not affect the motor coordination of animals in an open-field model. Oral treatment with the EE protected rats against gastric lesions induced by ethanol, with an ID₅₀ value of 55.0 (46.6-64.9) mg/kg, and increased the mucus levels of gastric mucosa to levels found in the non-lesioned group.

Conclusions

The mechanism by which the extract produced antinociception still remains unclear, but this effect seems to be primarily related to the modulation or inhibition of the action of pro-inflammatory mediators. Furthermore, these data support, at least in part, the ethnomedical use of Pluchea sagittalis.     

Anti-hyperglycemic activity of the leaves of Tetracera scandens Linn. Merr. (Dilleniaceae) in alloxan induced diabetic rats

Aim of the study

The present study was aimed to investigate the anti-diabetic potential of the leaves of Tetracera scandens Linn. Merr. (Dilleniaceae) in vivo with regard to prove its efficacy by local herbalists in the treatment of diabetes frailties.

Materials and methods

Crude aqueous (AQ) and methanol (MEOH) extracts of the leaves of T. scandens L. were administered to both normal and alloxan induced diabetic male albino rats (Wistar strain). The blood glucose levels were measured at 0, 2, 4, 6 and 8 h after oral administration of AQ and MEOH extracts.

Results

Significant reduction in glucose was observed in fasting blood glucose levels in the treated diabetic rats without causing any hypoglycemic effect compared to normal rats. Both polar extracts of the leaves of T. scandens L. exhibited significant anti-hyperglycemic activity at different doses and intervals. The highest anti-hyperglycemic effect (62.5%) was observed by the AQ extract at 0.25 g/kg body weight (b.w.) and MEOH extract (36.5%) at 0.5 g/kg b.w. after 8 h. The significant anti-hyperglycemic activity was found to be comparable with a known oral synthetic hypoglycemic drug, glibenclamide 0.25 mg/kg b.w.

Conclusion

This study provides scientific evidence that the leaves of T. scandens L. have anti-diabetic efficacy and justifies its utility by local herbalists. However, more experiments at the clinical levels are required to confirm the utility of this plant by traditional practitioners in the management of diabetes mellitus.     

In vitro antitrypanosomal and antileishmanial activity of plants used in Benin in traditional medicine and bio-guided fractionation of the most active extract

Ethnopharmacological relevance

The aim of the study was to evaluate the in vitro antitrypanosomal and antileishmanial activity of crude extracts of 10 plant species traditionally used in Benin to treat parasitic infections.

Materials and methods

For each species, dichloromethane, methanol and aqueous extracts were tested. Their antitrypanosomal and antileishmanial activities were evaluated in vitro on Trypanosoma brucei brucei (strain 427) (Tbb) and on promastigotes of Leishmania mexicana mexicana (MHOM/BZ/84/BEL46) (Lmm).

Results

The best growth inhibition was observed with the dichloromethane extracts of aerial parts of Acanthospermum hispidum DC. (Asteraceae) (IC₅₀ = 14.5 μg/ml on Tbb and 11.1 μg/ml on Lmm), twigs of Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (IC₅₀ = 5.8 μg/ml on Tbb), aerial parts of Byrsocarpus coccineus Schumach. & Thonn (syn. Rourea coccinea (Schumach. & Thonn.) Hook.f.) (IC₅₀ = 14.7 μg/ml on Tbb) and aerial parts of Carpolobia lutea G.Don. (IC₅₀ = 18.3 μg/ml on Tbb). All these extracts had a low cytotoxicity. It is not the case for the methanolic and water extracts of roots of Anchomanes difformis (Blume) Engl. (IC₅₀ = 14.7 and 13.8 μg/ml on Tbb) which were toxic at the same concentration range on WI38, human cells. A bio-guided fractionation of the most active extract of Keetia leucantha allowed to identify oleanolic acid and ursolic acid as responsible for the observed activities.

Conclusion

Our study gives some justification for antiparasitic activity of some investigated plants.     

Antibacterial, antioxidant and fibroblast growth stimulation activity of crude extracts of Bridelia ferruginea leaf, a wound-healing plant of Nigeria

Aim of the study

Determination of pharmacological activity relevant to wound healing of Bridelia ferruginea leaf, a traditional medicine used to treat wounds in rural Nigeria.

Materials and methods

Aqueous and ethanolic leaf extracts were tested against bacterial species of relevance to wound infections: Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ethanolic extracts were assessed for their ability to stimulate the growth of human dermal fibroblasts (FS5) and protect against damage induced by hydrogen peroxide. Antioxidant activity was also assessed using the DPPH assay.

Results

Both aqueous and ethanolic extracts had weak antibacterial activity (MIC > 470 μg/ml). A significant effect (p < 0.001) on the growth of FS5 fibroblasts was observed only at a concentration of 5 μg/ml (28% increase), above which the extracts appeared toxic to the cells. The ethanolic extract offered the highest protection against H₂O₂ damage to FS5 cells, comparable with catalase (82% at 250 μg/ml). The DPPH assay revealed antioxidant activity of the ethanolic leaf extract with IC₅₀ 12.5 ± 0.3 μg/ml comparable to l-ascorbic acid (7.3 ± 0.1 μg/ml).

Conclusion

The antibacterial, modest fibroblast stimulation activity and relatively strong antioxidant activity lend some support to the topical use of Bridelia ferruginea leaf for wound-healing in the traditional medicine of South-western Nigeria.