Anti-nociceptive activity of Pereskia bleo Kunth. (Cactaceae) leaves extracts

Ethnopharmacological relevance

Local communities in Malaysia consume Pereskia bleo Kunth. (Cactaceae) leaves as raw vegetables or as a concoction and drink as a tea to treat diabetes, hypertension, rheumatism, cancer-related diseases, inflammation, gastric pain, ulcers, and for revitalizing the body.

Aim of the study

To evaluate anti-nociceptive activity of the extracts and vitexin, isolated for the first time in this species, in two analgesic models; formalin-induced licking and acetic acid-induced abdominal writhing.

Materials and methods

Three and a half kilos of P. bleo leaves were extracted using Soxhlet apparatus with ethanol for 72 h. The crude ethanol extract was treated with activated charcoal overnight and subjected to a liquid–liquid partition yielding hexane, dichloromethane, ethyl acetate and butanol extracts. All extracts, including the crude ethanol and vitexin isolated from the ethyl acetate partition were tested for peripheral anti-nociceptive activity using formalin test and acetic acid-induced abdominal writhing, besides having their acute toxicity assays performed.

Results

The phytochemical analyses resulted in the isolation of vitexin (1), β-sitosterol glucoside (2) and β-sitosterol (3) isolated from the ethyl acetate, dichloromethane and hexane extracts, respectively. This is the first time vitexin and β-sitosterol glucoside are isolated from this species. The anti-nociceptive activities for all extracts were only moderate. Vitexin, which was isolated from the ethyl acetate extract did not show any activity in all models tested when used alone at the same concentration as it appears in the extract.

Conclusion

This study showed that all the extracts possess moderate anti-nociceptive activity. Vitexin is not the compound responsible for the anti-nociceptive effect in the ethyl acetate extract. Further investigations are needed to identify the compound(s) that might be responsible for the anti-nociceptive activity in this plant.     

Mutagenic and antimutagenic activities of aqueous and methanol extracts of Euphorbia hirta

Euphorbia hirta (E. hirta) is a weed commonly found in tropical countries and has been used traditionally for asthma, bronchitis and conjunctivitis. However, one of the constituents in this plant, quercetin, was previously reported to be mutagenic. This work aimed to determine the level of quercetin in the aqueous and methanol plant extracts and to investigate the mutagenic effects of quercetin and the extracts in the Ames test utilising the mutant Salmonella typhimurium TA98 and TA100 strains. The antimutagenic activity of Euphorbia hirta aqueous and methanol extracts was also studied in Salmonella typhimurium TA98. HPLC analyses showed that quercetin and rutin, a glycosidic form of quercetin, were present in the acid-hydrolysed methanol extract and non-hydrolysed methanol extract respectively. The quercetin concentration was negligible in both non-hydrolysed and acid-hydrolysed aqueous extracts. The total phenolic contents in Euphorbia hirta were determined to be 268 and 93 mg gallic acid equivalent (GAE) per gram of aqueous and methanol extracts, respectively. Quercetin (25 μg/mL) was found to be strongly mutagenic in Salmonella typhimurium TA98 in the absence and presence of S-9 metabolic activation. However, both the aqueous and methanol extracts did not demonstrate any mutagenic properties when tested with Salmonella typhimurium TA98 and TA100 strains at concentrations up to 100 μg/mL in the absence and presence of S-9 metabolic activation. In the absence of S-9 metabolic activation, both the extracts were unable to inhibit the mutagenicity of the known mutagen, 2-nitrofluorene, in Salmonella typhimurium TA98. On the other hand, the aqueous extracts at 100 μg/mL and methanol extracts at 10 and 100 μg/mL exhibited strong antimutagenic activity against the mutagenicity of 2-aminoanthracene, a known mutagen, in the presence of S-9 metabolic activating enzymes. The results indicated that these extracts could modulate the xenobiotic metabolising enzymes in the liver at the higher concentrations.     

Involvement of arginine-vasopressin in the diuretic and hypotensive effects of Pereskia grandifolia Haw. (Cactaceae)

Ethnopharmacological relevance

Pereskia grandifolia Haw. (Cactaceae), popularly known as “ora-pro-nobis” is well recognized in Brazilian traditional medicine as a diuretic agent, although no scientific data have been published to support this effect. The aim of this work is to evaluate the diuretic and hypotensive activities of the infusion (INFPG) and the ethanol extract (HEPG) of Pereskia grandifolia and possible mechanism of action.

Materials and methods

The infusions (2.5–10%) and the HEPG (3–100 mg/kg) were orally administered in a single dose or daily (for seven days) to rats. The urine excretion rate, pH, density, conductivity and content of Na⁺, K⁺, Cl⁻ and HCO₃⁻ were measured in the urine of saline-loaded animals. In collected serum samples the concentration of electrolytes, urea, creatinine, aldosterone, vasopressin and angiotensin converting enzyme (ACE) activity were evaluated. The involvement of V₂ vasopressin receptor in the diuretic activity and the hypotensive effect of HEPG were also determined.

Results

Water excretion rate was significantly increased by HEPG, while the urinary K⁺ and Cl⁻ excretion was significantly reduced in acute and prolonged treatment. The oral administration of the HEPG (30 mg/kg) significantly reduced serum levels of vasopressin and the mean arterial pressure (MAP) in normotensive rats. All other evaluated parameters have not been affected by any treatment.

Conclusion

The results showed that HEPG could present compound(s) responsible for aquaretic activities with no signs of toxicity, and this effect could involve a reduction in the arginine-vasopressin release.     

Anti-ulcerogenic properties of the aqueous and methanol extracts from the leaves of Solanum torvum Swartz (Solanaceae) in rats

ETHNOPHARMACOLOGICAL RELEVANCE: Solanum torvum (Solanaceae) is a plant currently used in Cameroon ethnomedicine for the treatment of stomach ailments. AIM OF THE STUDY: The present study was undertaken to determine the anti-ulcer potential of the aqueous and methanol extracts from the leaves of Solanum torvum. MATERIALS AND METHODS: The aqueous and methanol extracts from the leaves of Solanum torvum were tested orally at the doses of 250, 500 and 750mg/kg, on gastric ulcerations experimentally induced by HCl/ethanol, indomethacin, pylorus ligation and stress. The fractionation of the methanol extract through silica gel column chromatography produced seven different fractions (A-G) which were tested orally at the dose of 100mg/kg against HCl/ethanol-induced ulceration. RESULTS: The methanol extract at the dose of 750mg/kg produced 98.12, 99.16, 98.70 and 96.03% inhibition when gastric ulcerations were induced by HCl/ethanol, indomethacin, pylorus ligation and stress, respectively. The aqueous extract at the same dose produced 96.55, 96.86, 98.63 and 98.63% inhibition on ulcerations induced respectively by HCl/ethanol, indomethacin, pylorus ligation and stress. All the fractions of the methanol extract significantly inhibited ulcer formation. Fraction F which contains flavonoids and triterpens was the most active and exhibited an inhibitory percentage of 84.74. Both extracts significantly increased mucus production and reduced gastric acid secretion. CONCLUSIONS: The aqueous and methanol extracts of the leaves of Solanum turvum possess anti-ulcerogenic properties that may be due to cytoprotective mechanism. These results support the ethnomedical uses of the plant in the treatment of gastric ulcer.     

Acute toxicity, antinociceptive activity and indole alkaloids of aqueous extract from bark of Aspidosperma cuspa (Kunth) Blake

Etnopharmacological relevance

Aspidosperma cuspa (Kunth) Blake (Apocynaceae) is popularly known as “amargosa” or “cuspa”, and its bark is used in folk medicine primarily for pain.

Aim of the study

In the present study the acute toxicity, antinociceptive effect and alkaloids of the aqueous decoction extract of the Aspidosperma cuspa bark in mice was investigated.

Materials and methods

Acute toxicity was tested using a variation of the method described by Lichfield and Wilcoxon. The antinociceptive activity was evaluated using the acetic acid induced writhing and tail-flick tests. The phytochemical analysis was performed.

Results and conclusion

Oral administration of the extract did not cause animal death (LD₅₀>4 g/kg), and the histological analysis showed an absence of alterations in all organs examined. TD₅₀ of the extract was 0.5521 g/kg for male mice and 1.1565 g/kg for females. The aqueous extract at doses 276 mg/kg (p.o.) did not produce a significant inhibition of acetic acid-induced writhes, but showed a significant effect in tail-flick test. Naloxone, an opioid receptor antagonist, pretreatment inhibited significantly the antinociceptive activity of the extract. It is suggested that the aqueous decoction extract of the bark of Aspidosperma cuspa has an antinociceptive effect, and this may be mediated by opioid receptors. Three indole alkaloids (aspidocarpine, 11-methoxytubotaiwine and picraline) were isolated from the aqueous extract. The antinociceptive activity of the extract is presumed to be due to these compounds.     

Prophylactic and curative activities of extracts from Warburgia ugandensis Sprague (Canellaceae) and Zanthoxylum usambarense (Engl.) Kokwaro (Rutaceae) against Plasmodium knowlesi and Plasmodium berghei

Ethnopharmacological relevance

This work reports the anti-plasmodial activities of Warburgia ugandensis and Zanthoxylum usambarense commonly used as phytomedicines against malaria by some Kenyan communities.

Aim of study

To determine the anti-plasmodial activities of extracts from Warburgia ugandensis and Zanthoxylum usambarense against Plasmodium knowlesi and Plasmodium berghei.

Materials and methods

Eight plant extracts were screened for in vitro anti-plasmodial activity against Plasmodium knowlesi, in a 96-well plate incubated at 37 °C on a RPMI culture medium supplemented with baboon serum. Of the eight, three were investigated for prophylactic and curative activities in BALB/c mice against drug-sensitive Plasmodium berghei in a 4-day test at a dose rate of 200 mg/kg/day.

Results

Inhibitory concentrations (IC₅₀) values of between 3.14 and 75 μg/ml, up to 69% chemosuppression of parasites growth and over 80% survivorship of treated mice were observed.

Conclusion

The two medicinal plants, Warburgia ugandensis and Zanthoxylum usambarense possess bioactive compounds against malaria parasites and could be exploited for further development into malaria therapy.     

In vivo anti-nociceptive and anti-inflammatory activities of the aqueous extract of the leaves of Piper sarmentosum

Ethnopharmacological relevance

Piper sarmentosum (Piperaceae) is a medicinal plant traditionally used by the Malays to treat headaches, toothaches, coughs, asthma and fever.

Aim of the study

In order to establish the pharmacological properties of the leaf of this plant, studies were performed on anti-nociceptive and anti-inflammatory activities.

Materials and methods

The aqueous extract of Piper sarmentosum (AEPS) was prepared in the doses of 30, 100 and 300 mg/kg. Anti-nociceptive activity of AEPS was evaluated by abdominal constriction and hot-plate tests. AEPS was also pre-challenged with 5 mg/kg naloxone to determine the involvement of opioid receptors. Anti-inflammatory activity was evaluated using carrageenan-induced paw edema assay.

Results

Subcutaneous administration of AEPS exhibited anti-nociceptive activity (P < 0.05) in a dose-dependent manner in the abdominal constriction and hot-plate tests. Pre-treatment with naloxone completely (P < 0.05) diminished the extract anti-nociceptive activity in both tests. The AEPS, at all doses used, exerted significant (P < 0.05) anti-inflammatory activity in a dose-dependent manner.

Conclusions

The AEPS exhibits opioid-mediated anti-nociceptive activity at the peripheral and central levels, as well as anti-inflammatory activity, which confirmed the traditional uses of the plant in the treatment of pain- and inflammatory-related ailments.     

Acute and subchronic oral toxicity assessment of the aqueous extract from the stem bark of Erythrina senegalensis DC (Fabaceae) in rodents

Aim of the study

The decoction of the stem bark of Erythrina senegalensis (EAES) is traditionally used in the Western region of Cameroon against liver disorders. The present study evaluated the potential toxicity of this decoction after acute and sub-chronic administration in rodents.

Materials and methods

In acute study, a single administration of EAES was given orally to mice at doses ranging from 1.25 to 12.5 g/kg. General behaviour, adverse effects and mortality were determined for up to 14 days post treatment. In the sub-chronic study, EAES was given orally as a single administration to Wistar rats at doses of 300, 600 and 1200 mg/kg/day for 28 days. Animal body weight was observed throughout the experimental period while haematological and biochemical parameters of blood and urine, as well as kidney and liver tissues histology were evaluated at the end of the experiment.

Results

In the acute study in mice, none of the doses used induced mortality or significant behavioural changes. In the sub-chronic study in rats, daily oral administration of EAES at the dose of 600 mg/kg resulted in a significant increase in the relative body weight at the last week of treatment. The relative weights of organs were not affected by the treatment. No haematological changes were observed a part of a significant increase in WBC count at the dose of 600 mg/kg. Serum AST, ALT, ALP, total protein, total cholesterol and triglycerides decreased significantly while total and conjugated bilirubin significantly increased. Renal function indices assay in blood showed significant modification in all the treated groups compared to control while, in urine, only urea excretion markedly reduced at a dose of 1200 mg/kg. Histological analysis did no show any liver or kidney alteration.

Conclusion

These results demonstrated that there is a wide margin of safety for the therapeutic use of EAES and further corroborated the traditional use of this extract as a hepatoprotective agent.     

三七水浸液对不同玉米品种的化感作用

利用不同浓度三七茎叶、根水浸液对三七产区常见作物玉米的3个不同类型品种进行化感作用生物测定,结果表明：①三七茎叶对玉米的化感作用强于根部;②玉米幼苗生长阶段比种子萌发阶段更易受到化感物质的影响,玉米的地下部分比地上部分更为敏感;③常规品种白糯1号对三七化感作用的敏感性最强,杂交种云瑞1号和鲁三3号的敏感性较弱,更适合与三七轮作。     

Anti-inflammatory and analgesic effects of ethanol and aqueous extracts of Pterocephalus hookeri (C.B. Clarke) Höeck

Aim of the study

This study evaluates the anti-inflammatory and analgesic activities of the ethanol and aqueous extracts of a Tibetan herb Pterocephalus hookeri (C.B. Clarke) Höeck to provide experimental evidence for its traditional use such as cold, flu and rheumatoid arthritis.

Materials and methods

Investigations on the analgesic effects of P. hookeri (C.B. Clarke) Höeck were carried out, including hot-plate test and acetic acid-induced writhing. The anti-inflammatory activities were observed by utilizing the following models: carrageenin-induced edema of the hind paw of rats, cotton pellet-induced granuloma formation in rats, acetic acid-induced permeability, and xylene-induced ear edema in mice. The effects of the administration of indomethacin were also studied.

Results

It has been shown that the ethanol and aqueous extracts significantly increased the hot-plate pain threshold and reduced acetic acid-induced writhing response in mice. The ethanol and aqueous extracts remarkably inhibited the increase in vascular permeability induced by acetic acid and ear edema induced by xylene. The ethanol extract also significantly decreased the carrageenin-induced rat paw edema perimeter and inhibited the increase of granuloma weight.

Conclusion

The results show that the ethanol and aqueous extracts have both central and peripheral analgesic activities and as anti-inflammatory effects, supporting the traditional application of this herb in treating various diseases associated with inflammation and pain.     

in vitro genotoxic and mutagenic evaluation of the aqueous extract of Codiaeum variegatum and its amoebicidal sub-fraction

Ethnopharmacological relevance

Codiaeum variegatum, grown in many varieties, has been widely used as a houseplant based on its brightly decorative foliage. In addition, a variety of this plant has been used for a long time against bloody diarrhea by the local population in Cameroon.

Aim of the study

In our previous study, the aqueous extract of this plant and an isolated sub-fraction exhibited significant anti-amoebic activity on axenic culture of Entamoeba histolytica. Due to the medicinal value of these extracts, we promptly initiated to investigate their genotoxic and mutagenic potential in order to assure their safe and rationale usage in traditional healthcare system.

Material and methods

Both extracts were incubated with L5178Y mouse lymphoma cells, primary hepatic cells and HepG2 human hepatocellular carcinoma cells and their genotoxicity and mutagenicity were evaluated by quantifying DNA damage and chromosomal aberrations through comet assay, micronucleus assay and mouse lymphoma mutation assay.

Results

The aqueous extract of Codiaeum variegatum is not cytotoxic up to 2000 µg/mL while the amoebicidal fraction is significantly cytotoxic (≤ 40–55%) on L5178Y mouse lymphoma and HepG2 cells at concentrations higher than 500 µg/mL. Besides, no significant DNA damage and induction of micronucleus formation were identified at concentrations up to 2000 µg/mL. Moreover, the mutagenic potential of these extracts after short (4 h) and long term (24 h) treatment, revealed no significant gene mutation induction.

Conclusion

The aqueous extract of Codiaeum variegatum and the amoebicidal fraction SF9B are neither genotoxic on non-competent or metabolic competent cell lines, nor mutagenic in mouse lymphoma mutation assay and therefore they could be safely used at lower doses for medicinal purpose.     

Evidence of the mechanism of action of Erythrina velutina Willd (Fabaceae) leaves aqueous extract

Ethnopharmacological relevance

Erythrina velutina is traditionally used for sleepiness, convulsions and nervous system excitation in Brazil. Although central effects have been reported for Erythrina velutina, little is known about its mechanism of action.

Aim of the study

To investigate the pharmacological evidences of mechanism of action of Erythrina velutina leaves aqueous extract (AE).

Materials and methods

Terminal segments of the guinea-pig ileum (n = 5–8) were mounted in an organ bath and isotonic contractions were recorded. Phytochemical screening was carried out on AE.

Results

AE (0.025–2.50 mg/ml) produced contractile response in the guinea-pig ileum, yielding typical concentration–response curves (EC₅₀ = 0.63 mg/ml). Electrically evoked contractions were significantly increased in the presence of AE. AE-elicited contractions were significantly reduced by bicuculline, tetrodotoxin, atropine, verapamil or incubation in low calcium–high potassium solution. Atropine along with verapamil abolished AE contractile response. Alkaloids, catechins, steroids, flavonols, flavononols, flavonoids, phenols, saponins, tannins, triterpenoids, and xanthones were detected in AE.

Conclusions

AE contains important constituents for pharmacological activities. AE-induced contractions seem to involve GABA_A receptor activation, acetylcholine release, muscarinic receptor activation, augmentation of Ca²⁺ entry through L-type calcium channels, and calcium release from the intracellular stores. These findings provide further support for Erythrina velutina traditional uses.     

HPLC-ELSD测定不同产地吉祥草中凯提皂苷元的含量

 目的 建立吉祥草中凯提皂苷元的含测定方法。方法 采用高效液相色谱（HPLC）-蒸发光散射检测器(ELSD ),Agilent Ecplise XDB-C₁₈ (4.6 mm×150 mm , 5 μm)柱,甲醇-水(50∶50)为流动相,流速为1.0 mL · min-1,柱温25 ℃,载气压力0.33 MPa,漂移管温度65 ℃。结果 凯提皂苷元质量浓度在0.1~1.5 mg·mL-1之间线性关系良好,r=0.999 5,平均回收率 98.4%, RSD=1.5% (n=3)。结论 该方法分离效果好,操作简便,稳定性好,重复性好,可用于吉祥草中凯提皂苷元的含测定,为吉祥草药材的开发利用奠定基础。     

Anti-diarrhoeal activity of the aqueous extract of Mezoneuron benthamianum Baill (Caesalpiniaceae)

The effect of the aqueous extract of Mezoneuron benthamianum (MB) on experimentally induced diarrhoea, intestinal propulsive movement (IPM) and intestinal fluid accumulation (enteropooling) were investigated in rats and mice. The extract (400, 800 and 1600 mg/kg, orally) produced a significant (p<0.05) and dose-dependent reduction in propulsion in the castor oil-induced intestinal transit in mice. The mean peristaltic index (%) for these doses of extract, control, (distilled water, 10 ml/kg, p.o.) and morphine, (10 mg/kg, s.c.) were 73.48, 69.34, 57.27, 89.93 and 31.56, respectively. The effect of the extract at the highest dose was significantly (p<0.05) lower than that of the standard drug. This effect was antagonised by yohimbine (1mg/kg, s.c.). In a dose-dependent manner, the extract delayed the onset of diarrhoea, produced a significant decrease in the frequency of defaecation, severity of diarrhoea and protected the mice treated with castor oil. Total diarrhoea scores were 12.0+/-0.63, 10.3+/-2.06, 8.5+/-2.15, 7.1+/-0.91 and 5.8+/-0.79 for control, extract (400, 800 and 1600 mg/kg) and morphine, respectively. The extract significantly decreased the volume (ml) of intestinal fluid secretion induced by castor oil (1.75+/-0.02 to 0.93+/-0.04) compared with 1.90+/-0.05 for control. The inhibitory effect on fluid accumulation by the extract was also attenuated by yohimbine (1.0 mg/kg). Preliminary phytochemical screening revealed the presence of flavonoids, tannins, cardiac glycosides, anthraquinones and saponins. Administration of the extract up to 2 g/kg (orally) did not produce any toxic effect in the acute toxicity studies in mice. The LD(50) of the extract when given intraperitoneally was 1021.31 mg/kg. The results obtained show that MB possesses anti-diarrhoeal activity due to its inhibitory effects on gastrointestinal propulsion and intestinal fluid accumulation. The antagonistic actions of yohimbine in the experiments suggest a role for the a(2)-adrenergic receptor system.     

Antioxidant and anti-inflammatory activities of the phenolic extracts of Sapium sebiferum (L.) Roxb. leaves

Ethnopharmacological relevance

The leaves of Sapium sebiferum have long been used in Traditional Chinese Medicine (TCM) for the treatment of eczema, shingles, edema, swelling, ascites, scabs, and snakebites, among other maladies.

Aim of this study

The present study aimed to investigate the antioxidant and anti-inflammatory effects of the phenolic extracts of Sapium sebiferum leaves using in vitro and in vivo models.

Materials and methods

The in vitro antioxidant activities of the extracts were measured using common chemical methods (total phenolic content; total flavonoid content; scavenging of DPPH·, ABTS+·, superoxide, and nitrite radicals; reducing power; β-carotene bleaching; and FTC assays). The in vivo topical anti-inflammatory activities were tested using the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced dermatitis animal model. The SOD and CAT activities and the GSH content of ear tissue were also determined using test kits.

Results

The extracts of Sapium sebiferum leaves exhibited strong in vitro antioxidant activities. They also showed significant (P<0.001) and dose-dependent anti-inflammatory activities in an acute dermatitis model at the doses of 0.03 mg/ear, 0.1 mg/ear, and 0.3 mg/ear. The application of Sapium sebiferum leaf extracts increased the SOD and CAT activities and the GSH content relative to those of the TPA treatment group. The anti-inflammatory effect of the Sapium sebiferum leaf extract was positively correlated with its antioxidant activity.

Conclusion

These results demonstrate that Sapium sebiferum leaf extract is an effective anti-inflammatory agent in the TPA-induced dermatitis model, and its anti-inflammatory effect is related, at least in part, to its antioxidant activity.     

Comparison between ethanolic and aqueous extracts from Chinese juniper berries for hypoglycaemic and hypolipidemic effects in alloxan-induced diabetic rats

AIM OF THE STUDY: Hypoglycaemic and hypolipidemic properties of the ethanolic and aqueous extracts, respectively, from Chinese juniper (Juniperus chinensis L.) berries were investigated in alloxan-induced diabetic rats. MATERIALS AND METHODS: After oral administration of each extract singly or repeatedly to alloxan-induced diabetic rats, the blood glucose, glutamate-pyruvate transferase (GPT), glutamate-oxaloacetate transaminase (GOT), total cholesterol (TC) and triglyceride (TG) levels were assayed. RESULTS: The blood glucose levels after a single oral administration of the ethanolic extract significantly reduced in a time-dependent manner, which is much faster and more than that of glibenclamide. The blood glucose levels of alloxan-induced diabetic rats treated with the ethanolic extract were reduced to 94, 81%, 66%, 45% and 40% at 1, 3, 5, 7 and 9h, respectively (p<0.05), while the aqueous extract had no effect at all. Repeated oral administration of the ethanolic extract also effectively reduced the GPT value to 58% of the diabetic rats, but slightly reduced the GOT value to 87% of the diabetic rats (p<0.05). On the other hand, the repeated oral administration of aqueous extract effectively reduced the GOT value to 43% of the diabetic rats, without affecting the GPT level. Effects of both extracts on the TC and TG levels were different. There was no significant difference in the TC and TG levels between diabetic control and diabetic groups when repeatedly administered orally with ethanolic extract. On the other hand, the aqueous extract brought down the TC value to 57% and the TG value to 37% of the diabetic control rats (p<0.05). CONCLUSIONS: The results suggested that the ethanolic extract of Chinese juniper berries possesses a potential hypoglycaemic effect while the aqueous extract has a potential hypolipidemic effect.     

Antidiarrhoeal and antimicrobial activities of Emilia coccinea (Sims) G. Don extracts

Emilia coccinea (Sims) G. Don is reported to possess a number of medicinal properties including antidiarrhoeal and antimicrobial activities. The antidiarrhoeal effects of both methanol and aqueous extracts of the leaves of Emilia coccinea were studied in rats against castor oil-induced diarrhoea at the doses of 200, 400 and 600 mg/kg body weight. The methanol extract, and to a lesser extent the aqueous extract, significantly prolonged the time for diarrhoeal induction; it reduced the frequency of diarrhoea episodes and decreased the propulsion of charcoal meal through the gastrointestinal tract in a dose dependent manner. The aqueous extract did not have any antimicrobial activity at the tested concentration (5 mg/ml), but the methanol extract was most active on Escherichia coli. These results may support the fact that this plant is used traditionally to cure diarrhoea.     

Transdermal behaviour of the N-alkylamide spilanthol (affinin) from Spilanthes acmella (Compositae) extracts

Aim of the study

N-Alkylamides are a large group of bioactive molecules found in several plants from the genera Echinacea, Xanthoxylum and Spilanthes. Extracts and formulations derived from these plants are not only orally used, but also applied on the skin as well. However, there is currently no specific information available about the intrinsic local pharmacokinetics of N-alkylamides after topical application on human skin, questioning the role of this mode of administration.The present study investigates the transdermal behaviour of spilanthol, a prominent N-alkylamide.

Materials and methods

Two pharmaceutically accepted dose solutions (ethanol and propylene glycol based aqueous donor vehicles), combined with three different receptor fluids (PBS, PBS + 0.5% HPβCD, EtOH/H₂O (30:70, v/v)), were applied on split-thickness human skin in a Franz diffusion cell (FDC) system. Fundamental permeation characteristics of spilanthol in a solvent-independent way (100% aqueous dose solution) were also obtained using an extrapolation approach with different organic solvent/H₂O ratios.

Results and conclusions

We demonstrated for the first time that spilanthol permeates the skin. The following aqueous-extrapolated primary transdermal parameters were obtained (mean ± SEM): K_p,aq = 3.31 (±0.29) × 10⁻³ cm/h, D_m,aq = 1.86 (±0.09) × 10⁻⁴ cm²/h and K_m,aq = 7.28 (±1.59) × 10⁻¹. Partitioning (K_m) was strongly dependent on the donor solution composition, while diffusion (D_m) was mainly influenced by the receptor fluid composition.     

Anti-inflammatory and anti-nociceptive activities of the stem bark extracts from Allanblackia monticola STANER L.C. (Guttiferae)

THE AIM OF THIS STUDY: was to assess the anti-inflammatory and mechanism of action of Allanblackia monticola (Guttiferae). The anti-inflammatory activity "in vivo" of the methylene chloride/methanol extract, methanol and methylene chloride fractions of stem barks of Allanblackia monticola, administered orally at doses of 37.5; 75; 150 and 300 mg/kg, was evaluated on carrageenan-induced oedema in rats to determine the most active fraction. Indomethacin, inhibitor of cyclo-oxygenase was used as reference drug. The effects of the most active fraction were then examined on the rat paw oedema caused by histamine, serotonin, arachidonic acid and dextran followed by its ulcerogenic effect. The results showed that the methylene chloride fraction of Allanblackia monticola was more effective on the oedema caused by the carrageenan. The anti-nociceptive activity of the methylene chloride fraction was assessed using the acetic acid-induced abdominal constriction model, formalin test and hot plate test. At 150 mg/kg, Allanblackia monticola caused maximum inhibitions of inflammation induced by carrageenan (83.33%), by histamine (42.10%), by dextran (40.29%) and by arachidonic acid (64.28%). Allanblackia monticola (75-300 mg/kg) did not cause significant modification of the oedema induced by serotonin. Concerning the anti-nociceptive properties of the plant, the methylene chloride fraction (75-300 mg/kg) caused a dose-dependent inhibition on abdominal contractions induced by acetic acid (32.34-77.37%) and significantly inhibited the inflammatory pain caused by formalin (40.71-64.78%). Allanblackia monticola did not increase the latency time in the hot plate test. Like indomethacin (10mg/kg), the fraction at the dose of 150 mg/kg caused ulceration of the gastric mucous membrane in treated rats. These results show that Allanblackia monticola has an anti-inflammatory and analgesic activities with gastric ulcerative side effects.     

Antioxidant and hepatoprotective activity of ethanolic and aqueous extracts of Momordica dioica Roxb. leaves

In present study, the hepatoprotective activity of ethanolic and aqueous extracts of Momordica dioica Roxb. leaves were evaluated against carbon tetrachloride (CCl4) induced hepatic damage in rats. The extracts at dose of 200mg/kg were administered orally once daily. The substantially elevated serum enzymatic levels of serum glutamate oxaloacetate transaminase (AST), serum glutamate pyruvate transaminase (ALT), serum alkaline phosphatase (SALP) and total bilirubin were restored towards normalization significantly by the extracts. Silymarin was used as standard reference and exhibited significant hepatoprotective activity against carbon tetrachloride induced haptotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that Momordica dioica Roxb. leaves have potent hepatoprotective action against carbon tetrachloride induced hepatic damage in rats. Ethanolic extract was found more potent hepatoprotective. Meanwhile, in vivo antioxidant and free radical scavenging activities were also screened which were positive for both ethanolic and aqueous extracts. This study suggests that possible mechanism of this activity may be due to free radical-scavenging and antioxidant activities which may be due to the presence of flavonoids in the extracts.