Antinociceptive effect and acute toxicity of the Hyptis suaveolens leaves aqueous extract on mice

The aqueous extract of Hyptis suaveolens leaves was studied for their antinociceptive property in chemical and thermal models of nociception in mice. Oral administration of the aqueous extract (100, 200, and 400 mg/kg) dose-dependently reduced the number of writhings induced by acetic acid, decreased the licking activity of the early phase in formalin test and increased the reaction time in hot-plate test. The antinociceptive effect was significantly antagonized by naloxone (3 mg/kg; i.p.). Preliminary acute toxicity study showed that no animal death with doses up to 5 g/kg (p.o.).     

Anti-diabetic activity of flowers of Hibiscus rosasinensis

The ethanol extract of flowers of Hibiscus rosasinensis at doses of 250 mg/kg and 500 mg/kg significantly reduced the blood glucose level in both acute (1, 3, 5 h) and sub acute (1, 3, 5, 7 days) treatments.     

Cytotoxic activity of lignans from Hibiscus cannabinus

The antimicrobial and cytotoxic activities of six lignans isolated from the core and bark acetone extracts of Hibiscus cannabinus have been investigated. Two compounds (2 and 3) showed strong cytotoxic activity against HeLa, Hep-2 and A-549 cell lines while compound 5 showed moderate activity on HeLa cells when they were in advanced stage of cellular division. The compounds did not exhibit antimicrobial activity.     

Relaxant effect of aqueous extract of Cistus ladaniferus on rodent intestinal contractions

The effects of the aqueous extract of Cistus ladaniferus leaves and stems were studied on the rodent isolated jejunum. The extract produced a reversible concentration dose-dependent (0.1-3 mg/ml) inhibition of the spontaneous motility of the rabbit jejunum. The inhibitory effects of the extract were not affected by pretreatment with the inhibitors of the alpha and beta adrenergic receptors yohimbine, prazosin or propranolol. The extract also inhibited K(+)-induced contractions in rabbit and rat jejunum at a similar concentration range. This result suggests that the antispasmodic action of the extract is mediated through calcium channel blockade. The results confirm the traditional use of C. ladaniferus in treating intestinal ache.     

Contractile effect of the aqueous extract of Psidium guajava leaves on aortic rings in rat

Aqueous leaves extract of Psidium guajava significantly and dose-dependently (0.25-2 mg/ml) contracted aorta rings. The effect was evaluated also in presence of nifedipine and phentolamine. The sensitivity of the aortic rings to cumulative doses of P. guajava was significantly enhanced in the presence of phentolamine suggesting that the effect of P. guajava was to a large extent mediated by activation of alpha-adrenoceptor and to a lesser extent by acting via calcium ion channel.     

Antiinflammatory activity of the aqueous leaf extract of Byrsocarpus coccineus

The antiinflammatory effect of the aqueous leaf extract of Byrsocarpus coccineus was evaluated using the carrageenan and egg albumin induced rat paw edema, xylene induced mouse ear edema and formaldehyde induced arthritis inflammation tests. The extract administered orally at doses of 50, 100, 200 and 400 mg/kg b.w produced a significant (P<0.05) dose dependent inhibition of edema formation in all four methods used. The results obtained suggest that the aqueous leaf extract of B. coccineus is endowed with effective antiinflammatory activity mediated via either inhibition of phospholipase A(2) (PLA(2)) activity or cyclooxygenase cascade and by blocking the release of vasoactive substances (histamine, serotonin and kinins). These findings seem to justify the use of the plant in traditional African medicine in the treatment of inflammation, including arthritic conditions.     

Free radical-scavenging activity of aqueous extract of Pteris multifida Poiret

Aqueous extract of Pteris multifida showed scavenging activities on DPPH, hydroxyl radicals and reducing power.     

Toxicity and anthelmintic efficacy of crude aqueous of extract of the bark of Sacoglottis gabonensis

The water extract of the stem bark of Sacoglottis gabonensis was evaluated for its preliminary acute toxicity and anthelmintic efficacy against gastro-intestinal nematodes of small ruminants and mice in both in vitro and in vivo studies. Intra-peritoneal administration of doses ranging from 400 to 3200 mg/kg of the aqueous stem bark extract produced varying degrees of toxicity manifested as depression, drowsiness and unsteady gait, paralysis of the hind limbs, dyspnoea, coma and death. The pathological lesions noted at necropsy were mainly congestion and edema of the lungs, bronchi and bronchioles and hepatomegally with focal necrosis of liver cells. The severity of the clinical symptoms and pathological lesions were dose-related. In the in vitro study, the extract significantly (P<0.05) reduced the hatching of strongyline nematode eggs from naturally infected small ruminants. The 100 mg/ml concentration of the extract produced the highest (94.4%) inhibition on nematode egg hatch and the result was comparable to similar effect produced by either levamisole (100% at 15 mg/ml) or albendazole (99.7% at 6.25 mg/ml). In rats experimentally infected with Heligmosomoides polygyrus, treatment with the S. gabonensis stem bark aqueous extract significantly (P<0.05) reduced adult worm burden and completely inhibited faecal egg output 5 days post treatment.     

Triterpenoidal constituents of an aqueous extract from neem kernels

A quantitative HPLC analysis of the major triterpenoids present in an aqueous extract of powdered neem kernels prepared in the traditional manner was undertaken. The study shows that water extracts contain all the principal triterpenoids in neem kernel though the quantities extracted are much less than in the subsequent extraction with methanol.     

Effect of Mitragyna speciosa aqueous extract on ethanol withdrawal symptoms in mice

Administration of the aqueous extract of Mitragyna speciosa at a dose of 300 mg/kg significantly inhibited ethanol withdrawal-induced behaviors that included rearing, displacement and head weaving. The results also showed that at doses of 100, 300 and 500 mg/kg M. speciosa showed antidepressant activity without effect on the spontaneous motor activity.     

Antidiabetic properties of aqueous barks extract of Parinari excelsa in alloxan-induced diabetic rats

The aqueous extract of the Parinari excelsa barks at doses of 100 and 300 mg/kg/day for 7 days has a significant antihyperglycemic effect on alloxan-induced diabetic rats. At the same dose the acute oral administration of aqueous extract of the P. excelsa barks (100 and 300 mg/kg) induced a significant decrease of blood glucose on glucose-loaded normoglycaemic rats. Our results seem to confirm the rational bases for its use in traditional medicine.     

Effect of aqueous Euphorbia hirta leaf extract on gastrointestinal motility

The aqueous leaf extract of Euphorbia hirta decreased the gastrointestinal motility in normal rats and decreased the effect of castor oil-induced diarrhoea in mice.     

Inhibition of viral adsorption and penetration by an aqueous extract from Rhododendron ferrugineum L. as antiviral principle against herpes simplex virus type-1

The polyphenol-enriched aqueous extract RF from the aerial parts of Rhododendron ferrugineum exhibited strong antiviral activity against herpes simplex virus type-1 while adenovirus 3 was not affected. RF exhibited an IC₅₀ of 7.4 μg/mL and a selectivity index of 64 when added to the virus inoculum prior to infection. RF abolished virus entry into the host cell by blocking attachment to the cell surface. When added after attachment at a concentration of > 25 μg/mL, RF inhibited also penetration of HSV-1 into the host cell. RF directly interacts with viral envelope proteins as demonstrated for the viral glycoprotein gD.     

Anti-TB activity of Evodia elleryana bark extract

An ethyl acetate extract of bark from Evodia elleryana produced significant growth inhibition of Mycobacterium tuberculosis at concentrations only minimally inhibitory to human T cells. The crude extract yielded 95% inhibition of TB at 50 microg/ml. The crude extract yielded 29% growth inhibition of human T-cells in culture at that concentration.     

Analgesic properties of Capraria biflora leaves aqueous extract

The analgesic properties of dried leaves of Capraria biflora were investigated. The aqueous extract (50-200 mg kg(-1)) produced moderate inhibition of acetic acid-induced writhing in mice. At the same doses, a better analgesic effect was observed on the hot plate test.     

Vasorelaxation and antispasmodic effects of Kaempferia parviflora ethanolic extract in isolated rat organ studies

The ethanolic extract of Kaempferia parviflora (KP) rhizomes dose-dependently relaxed both aortic rings and ileum precontracted with phenylephrine and acethylcholine, respectively.     

Anti-nociceptive activity of the aqueous extract of Erythrina velutina leaves

Anti-nociceptive and anti-oedematogenic effects of the aqueous extract from the leaves of Erythrina velutina were tested through experimental models of nociception in mice and paw oedema induced by carrageenin in rats. The extract (300 and 600 mg/kg) did not change the carrageenin-induced paw oedema. In the hot plate test the extract also did not alter the latency time for mice liking the rear paws. Moreover, the extract (600 mg/kg) decreased by 96.5% the paw liking time in the second phase of the formalin test. This effect was antagonized by naloxone (5 mg/kg). In the acetic acid-induced writhing test, the extract (300 and 600 mg/kg) reduced the number of writhing by 88.8% and 96.4%, respectively. Our present results demonstrated that the crude extract from the leaves of E. velutina has anti-nociceptive but not anti-oedematogenic properties.     

Hypoglycemic effect of Bauhinia cheilandra in rats

The extract of the methanolic leaves of Bauhinia cheilandra (BC) was tested on glucose loaded and alloxan-induced diabetic rats. In both tests, the methanolic extract at doses of 300, 600, and 900 mg/kg, has shown a statistically significant and considerable hypoglycemic activity.     

Antihyperglycemic activity of the aqueous extract of Urtica dioica

When administered 30 min before glucose loading, the aqueous extract of Urtica dioica (nettle) (250 mg/kg) showed a strong glucose lowering effect. The decrease of glycemia has reached to 33+/-3.4% of the control value 1 h after glucose loading. This effect was persistent during 3 h. In contrast, nettle did not show hypoglycemic effect in alloxan-induced diabetic rats. The amount of glucose absorbed in a segment jejunum in situ was 8.05+/-0.68 mg in presence of nettle extract vs. 11.11+/-0.75 mg in control rats during 2 h (P<0.05). The results indicate that nettle has a significant antihyperglycemic effect in OGTT model. This effect may be caused in part by the reduction of intestinal glucose absorption. LD(50) is 3.5 g/kg (i.p.).     

Arthropod repellency, especially tick (Ixodes ricinus), exerted by extract from Artemisia abrotanum and essential oil from flowers of Dianthus caryophyllum

A toluene extract of southernwood (Artemisia abrotanum) and the essential oil from flowers of carnation (Dianthus caryophyllum ) exerted pronounced a repellent effect both against ticks (nymphs of Ixodes ricinus) and yellow fever mosquitoes (Aedes aegypti). The most potent repellents found were coumarin and thujyl alcohol from A. abrotanum and phenylethanol from D. caryophyllum where coumarin and thujyl alcohol were also detected.