Fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats

Ethnopharmacological relevance

The aerial parts of Coccinia cordifolia L. are used to treat female infertility in West Bengal state of India.

Aim of the study

The present study was undertaken to evaluate the fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats.

Materials and methods

The effect of aqueous extract of Coccinia cordifolia L. on hyperprolactinemia induced infertility, endometriosis induced infertility and androgen-induced infertility was studied. The effect on serum estrogen level, serum progesterone level and reproductive tract was also evaluated in normal healthy female rats. The extract was administered orally at two different doses of 500 mg/kg and 1000 mg/kg.

Results

In hyperprolactinemia induced infertility model, the numbers of uterine implants were almost 10 times more in the extract treated groups as compared to control. The high dose of extract also produced a significant increase in serum estrogen levels (p < 0.01) and number of corpus luteum (p < 0.05) in healthy female rats. The extract at both doses was effective in reducing the weight of endometrial implants by 70–80%, but failed to induce fertility in rats with endometriosis. The extract was ineffective in inducing fertility in androgen-induced infertility model.

Conclusions

The aqueous extract of Coccinia cordifolia L. induces fertility in hyperprolactinemia induced infertility model in female rats.     

Anticonvulsant activity of Benkara malabarica (Linn.) root extract: In vitro and in vivo investigation

Aim of the study

To systematically investigate the anticonvulsant activity of methanol extract of Benkara malabarica roots and to provide a biochemical basis elucidating its mode of action.

Methods

The median lethal dose (LD₅₀) of Benkara malabarica extract was determined. The anticonvulsant activity of the extract was assessed in strychnine-induced and isoniazide-induced convulsion models; phenytoin (20 mg/kg) and diazepam (1 mg/kg) were used as standards, respectively. Percentage protection provided by the drug was accounted as decrease in the number of convulsions within 8 h of observation. Mechanism of action was studied by performing GABA transaminase (GABA-T) assay, isolated from rat brain. Active constituent was isolated and characterized from the plant extract.

Results

The median lethal dose (LD50) of Benkara malabarica was found to be more than 500 mg/kg. It demonstrated 30% and 35% protection against strychnine-induced convulsions and 60% and 80% protection against isoniazide-induced convulsions, at doses of 25 mg/kg and 50 mg/kg, respectively. Enzyme assay results revealed that Benkara malabarica extract possesses GABA-T inhibitory activity (IC50 = 0.721 mg/ml). Scopoletin which was identified as the major constituent of the extract was found to be an inhibitor of GABA-T (IC50 = 10.57 μM).

Conclusions

The anticonvulsant activity of the plant extract is predominantly GABA mediated and may be due to the action of scopoletin alone or is a result of synergy of different compounds in the extract in which scopoletin is the major constituent.     

Antidepressant-like effect of Lafoensia pacari A. St.-Hil. ethanolic extract and fractions in mice

Ethnopharmacological relevance

Lafoensia pacari A. St.-Hil. (Lythraceae) has been referred in Brazilian traditional medicine for the treatment of different diseases, among them depression. Nevertheless, there are not studies about this possible effect on the central nervous system (CNS).

Aim of the study

To evaluate the antidepressant-like effects of the ethanolic extract of Lafoensia pacari (PEtExt) and its fractions on the performance of male mice.

Materials and methods

Antidepressant activity was studied using forced swimming (FST) and tail suspension (TST) tests, and motor activity in the open-field test. The ethanolic extract of Lafoensia pacari (PEtExt) were administered acutely (1.0 g/kg, p.o.), for 21 days (100, 300 mg, and 1.0 g/(kg day), p.o.), three administration in a 24-h period (1.0 g/kg, p.o.), and the fractions for 21 days. Imipramine (15 mg/(kg day), p.o.) was used as the control positive.

Results

The PEtExt significantly reduced immobility time in FST and TST, without affecting the motor activity. Only the chloroformic fraction (50 mg/(kg day), p.o.) increase the latency to immobility and decrease the immobility time in the FST.

Conclusions

These data indicate that the extract of Lafoensia pacari A. St.-Hil. possesses antidepressant-like properties in mice.     

Role of Sida cordifolia L. leaves on biochemical and antioxidant profile during myocardial injury

Ethnopharmacological relevance

The Sida cordifolia L. (Family: Malvaceae) is a widely allocated herb by folk tribes of Gujarat state of India for the treatment of coronary manifestations. However, no published data relevant to use of the plant is available.

Aim of the study

The aim of the present study was to evaluate the antioxidant and biochemical profile of hydroalcoholic extract of Sida cordifolia L. (HESC) leaves against myocardial infarction (MI) in rats.

Materials and methods

Albino rats were administered HESC (100 and 500 mg/kg) and propranolol (10 mg/kg) once daily orally for 30 days. At the end of treatment period, MI was induced by administering isoproterenol (ISO) or by subjecting heart to ischemia reperfusion injury (IRI). Endogenous biomarkers (LDH and CK-MB) and antioxidants (SOD and catalase) were estimated in serum/perfusate and heart tissue homogenate (HTH).

Results

The LDH and CK-MB activities were elevated in HTH and depleted in serum/perfusate of HESC and propranolol groups when compared to ISO/IRI control. Further, it was found that both doses significantly increased endogenous antioxidants in HTH. Moreover, biochemical findings were supported by histopathological observations.

Conclusion

The result confirm, at least in part, for the use of Sida cordifolia in folk medicine to treat MI.     

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

Ethnopharmacological relevance

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

Aim of the study

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

Materials and methods

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

Results

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

Conclusions

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

CNS depressant and anticonvulsant activities of the alcoholic extract of leaves of Ziziyphus nummularia

Ethnopharmacological relevance

Ziziyphus nummularia (family: Rhamnaceae) is a xerophyte, grows in the grazing lands of the Thar Desert of Rajasthan. Ziziyphus nummularia (ZN) is used as sedative in ethnomedicine. The objective of this study is to investigate the anticonvulsant, anxiolytic and sedative activities of the alcoholic extract of leaves of Ziziyphus nummularia (EZN).

Materials and methods

The anticonvulsant effect of the EZN (100, 200 and 300 mg/kg) was evaluated in mice using the pentylenetetrazole and maximal electroshock induced seizure models. Its anxiolytic activity was evaluated using the elevated plus maze, hole board and open field models board methods, while the pentobarbital induced sleep was used to evaluate the sedative activity. The acute toxicity and effect on motor coordination were also assessed.

Results

EZN (100–300 mg/kg) protected the mice against the pentylenetetrazole induced convulsions; it causes a significant (P<0.05) dose dependent increase in latency of convulsion. Treatment with EZN reduced the duration of the tonic hind limb extension induced by electroshock. Mice treated with EZN preferred the open arm of the plus maze and were found to be devoid of open-arm avoidance. EZN potentiation the barbiturate induce sleep in mice, it causes a decrease in the sleep latency and increases the duration of sleep.

Conclusion

The results obtained from the experiments indicate that the EZN has CNS depressant and anticonvulsant activities.     

Anti-stress effect of astragaloside IV in immobilized mice

Ethnopharmacological relevance

Astragaloside IV, a major component extracted from the roots of Astragalus membranaceus (AM), possesses anti-inflammatory, anti-oxidative, anti-fibrotic, anti-infarction and immunoregulatory effects. To clarify anti-stress effect of AM, anxiolytic and anti-inflammatory effects of 80% ethanol extract of AM and astragaloside IV were investigated in immobilization stress model.

Materials and methods

The mice were orally administered with AM (50, 200, and 500 mg/kg), astragaloside IV (5, 10, and 20 mg/kg) and buspirone, a positive drug, 1 h before immobilization treated for 2 h. For anxiolytic activity assay, EPM test was performed in mice. For anti-inflammatory activity assay, serum levels of corticosterone, IL-6 and TNF-α were measured using ELISA kits.

Results

AM extract and astragaloside IV increased dose-dependently time spent on open arms and open arm entries in the EPM test. Anxiolytic effects of AM extract (500 mg/kg) and astragaloside IV (20 mg/kg) were comparable to those of buspirone (1 mg/kg). Their anxiolytic effects were blocked by WAY-100635 (0.5 mg/kg, i.p.), a 5-HT_1A receptor antagonist (p<0.01), but not by flumazenil (3 mg/kg, i.p.) and bicuculline (0.5 mg/kg, i.p.), GABA_A receptor antagonists. AM extract and astragaloside IV also reduced serum levels of corticosterone, IL-6 and TNF-α dose-dependently.

Conclusions

AM, particularly astragaloside IV, may ameliorate immobilized stress-induced anxiety and inflammation.     

Effect of Moringa oleifera Lam. leaves aqueous extract therapy on hyperglycemic rats

Ethnopharmacological relevance

In Indian traditional system of medicine, Moringa oleifera Lam. Syn. Moringa pterygosperma Gaerth (Moringaceae) is commonly used as healing herb to treat diabetes.

Aim of the study

The purpose of the present study was to assess the effect of M. oleifera leaves aqueous extract therapy on glycemic control, haemoglobin, total protein, urine sugar, urine protein and body weight.

Materials and methods

Variable doses of 100, 200 and 300 mg kg⁻¹ of aqueous extract were administered orally by gavage for evaluating their hypoglycemic and antidiabetic effects on fasting blood glucose (FBG), oral glucose tolerance test (OGTT) and post prandial glucose (PPG) of normal and streptozotocin (STZ) induced sub, mild and severely diabetic rats.

Results

The dose of 200 mg kg⁻¹ decreases blood glucose level (BGL) of normal animals by 26.7 and 29.9% during FBG and OGTT studies respectively. In sub and mild diabetic animals the same dose produced a maximum fall of 31.1 and 32.8% respectively, during OGTT. In case of severely diabetic animals FBG and PPG levels were reduced by 69.2 and 51.2% whereas, total protein, body weight and haemoglobin were increased by 11.3, 10.5 and 10.9% respectively after 21 days of treatment. Significant reduction was found in urine sugar and urine protein levels from +4 and +2 to nil and trace, respectively.

Conclusion

The study validates scientifically the widely claimed use of M. oleifera as an ethnomedicine to treat diabetes mellitus.     

Immunosuppressive activity of ethanolic extract of seeds of Moringa oleifera Lam. in experimental immune inflammation

Ethnopharmacological relevance

Traditionally, the plant Moringa oleifera Lam. (Moringaceae) is used for the treatment of ascites and rheumatism, while the dried seeds of the plant are used as an ‘anti-allergic’ agent.

Aim of the study

The aim of the study was to assess the efficacy of ethanolic extract of seeds from Moringa oleifera Lam. in experimental immune inflammation.

Materials and methods

Circulatory and splenic leukocyte counts, delayed-type hypersensitivity reactions and humoral antibody responses were measured in mice using SRBC as the antigen. In addition, macrophage phagocytosis was measured by the carbon clearance test.

Results

The extract dose-dependently (50, 100 and 200 mg/kg) inhibited spleen weight as well as circulatory leukocyte and splenocyte counts. The delayed-type hypersensitivity reaction was significantly inhibited (P < 0.01) by decreasing the mean foot pad thickness at 48 h. The production of the humoral antibody titer was significantly ameliorated at a dose of 100 and 200 mg/kg (P < 0.05 and P < 0.01, respectively). Furthermore, the extract caused a down-regulation of macrophage phagocytosis due to carbon particles.

Conclusion

Taken together, the above findings suggest that the seeds of Moringa oleifera have immunosuppressive activity.     

Citrus limetta leaves extract antagonizes the hypertensive effect of angiotensin II

Ethnopharmacological relevance

Citrus limetta Risso (Rutaceae) is widely used in Mexico for healing purposes, among them as antihypertensive treatment.

Aim of the study

To assess the antihypertensive effect of C. limetta leaves as one of its ethnomedical uses.

Materials and methods

The acute response of blood pressure to angiotensin II administration was measured in mice. Additionally, the acute oral toxicity profiles were determined.

Results

The findings of the current investigation showed that different concentrations of the aqueous extract prevented the raise of systolic blood pressure (p ≤ 0.001 vs. vehicle), diastolic blood pressure (p ≤ 0.0002 vs. vehicle) and mean blood pressure (p ≤ 0.0000 vs. vehicle); with a dose dependent effect for diastolic pressures at 125–500 mg/kg dosages. The 500 and 1000 mg/kg doses inhibited the action of Ang II in similar extent to telmisartan. Toxic signs or deaths were not observed in mice treated at 2000 mg/kg of C. limetta extract.

Conclusions

All doses of C. limetta aqueous extract, used in this assay, were safe and effective.     

Genotoxic and antigenotoxic effects of Hemidesmus indicus R. Br. root extract in cultured lymphocytes

Aim of the study

The genotoxic and antigenotoxic potential of the ethanolic extract of Hemidesmus indicus roots were evaluated in cultured human lymphocytes using cisplatin as the positive mutagen.

Materials and methods

Cytogenetic damage and cytotoxicity were determined in cells exposed to different doses of the extract, ranging from 2 to 32 μg/ml of culture medium, either alone or together with cisplatin.

Results

There was a significant reduction in cisplatin-induced frequencies of sister chromatid exchanges, chromosome aberrations and micronucleated binucleate cells at the lower concentrations of 4 and 8 μg/ml (P < 0.05). However, the extract by itself reduced the proliferative rate index, mitotic index and cytokinesis-block proliferative index (P < 0.05). Further, a significant increase in the percentage of chromosome aberrations was noticed at the higher concentrations.

Conclusion

Hemidesmus indicus root extract possesses significant genoprotective effect at the lower concentrations although it is cytotoxic and probably genotoxic at higher doses.     

Antibacterial activity of the roots,stems and leaves of Alchornea floribunda

Ethnopharmacological relevance

Alchornea floribunda Müll. Arg. is used in traditional medicine across Africa for the treatment of bacterial, fungal, parasitic and inflammatory disorders.

Aim of the study

To evaluate the antibacterial activity of the crude extracts of different plant parts in order to provide a scientific rationale for the proposed broad efficacy of Alchornea floribunda in the treatment of bacterial infections.

Materials and methods

Extracts of roots, stems and leaves were prepared using solvents of various polarities in order to extract a wide range of phytochemicals. The antibacterial activity of these crude extracts was evaluated by micro-dilution assay, against Gram-positive (i.e. Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus and Staphylococcus saprophyticus) as well as Gram-negative (i.e. Escherichia coli, Klebsiella pneumoniae, Moraxella catarrhalis and Proteus mirabilis) bacteria.

Results

Generally, the ethanol (EtOH), methanol (MeOH), ethyl acetate (EtOAc) and chloroform (CHCl₃) extracts demonstrated the best activities, with the leaves exhibiting the highest average activity for six of the eight pathogens. Of these, the ethanolic leaf extract was the most active against Staphylococcus aureus with an MIC value of 50 µg/mL. Some other notable activity was observed for the ethyl acetate and chloroform root extracts against Staphylococcus aureus (50 µg/mL), and for selected stem extracts against Staphylococcus aureus (50 µg/mL), Klebsiella pneumoniae (63 µg/mL) and Staphylococcus saprophyticus (63 µg/mL).

Conclusion

This study demonstrates the promising antibacterial activity of Alchornea floribunda against both Gram-positive and Gram-negative bacteria responsible for gastrointestinal, skin, respiratory and urinary ailments, and validates its use in the ethnopharmacology of the region.     

Evaluation of behavioral and pharmacological effects of Hedyosmum brasiliense and isolated sesquiterpene lactones in rodents

Ethnopharmacological relevance

Hedyosmum brasiliense Miq. (Chloranthaceae) is an essential Brazilian species largely found in the Atlantic Forest. It is popularly known as “cidrão” and in folk medicine, this aromatic species is widely used as a calmative/tranquilizer and to treat sleep disorders.

Aim of the study

To examine the neurochemical properties of ethanol extract (EEHb), fractions and compounds of fresh leaves of Hedyosmum brasiliense and the antidepressant effect of the isolated sesquiterpene lactones podoandin and 13-hydroxy-8,9-dehydroshizukanolide.

Materials, methods and results

The effects of EEHb were demonstrated by the open field, elevated-plus-maze, forced swimming, pentobarbital-induced sleeping time, PTZ-induced seizure, and inhibitory avoidance tests. EEHb did not show a protective effect against PTZ-induced convulsions. In the plus-maze test, EEHb (100 mg/kg, i.p.) exhibited an anxiolytic effect through the effective enhancement of the frequency and time spent in the open arms of the maze. Conversely, the time spent and the number of entrances to the closed arms were decreased. All these effects were also completely reversed by pre-treatment with flumazenil (2.5 mg/kg, i.p./a benzodiazepine receptor agonist), similar to the results observed with diazepam used as a positive standard. In this test, the anxiolytic effect of EEHb was also totally blocked by pre-treatment with reserpine (2.0 mg/kg, i.p.), a drug known to induce depletion of biogenic amines. In the forced swimming test, the treatment of EEHb (100 mg/kg, i.p. or 100 mg/kg, p.o.) given in acute and chronic form (10, 50 and 100 mg/kg), produced a decrease in immobility time, similar to that of imipramine (10 mg/kg, i.p.), the positive control. The dichloromethane and hexane fractions (100 mg/kg, p.o.) also produced a decrease in immobility time. In addition, the two isolated compounds tested in a single dose (10 mg/kg, i.p.), the antidepressant effect was observed only with the compound podoandin, which also caused a decrease in immobility time. EEHb (10–100 mg/kg) a dose-dependent manner also caused a decrease in barbiturate sleeping time in mice, and in high doses (100 mg/kg), did not interfere in memory consolidation.

Conclusions

The results suggest that EEHb presents psychopharmacological activities, including anxiolytic, antidepressant, and hypnotic effects.     

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.     

Inhibitory effects of Duchesnea chrysantha extract on ovalbumin-induced lung inflammation in a mouse model of asthma

Ethnopharmacological relevance

Duchesnea chrysantha (D. chrysantha) is a herb with anti-oxidative, anti-inflammatory and immune-enhancing properties.

Aim of the study

Asthma is an inflammatory disease of the lungs, and the hallmarks of the disease are increased inflammatory cell infiltration into the airways and poor respiratory function. Although there is the possibility that D. chrysantha may have an inhibitory effect on lung inflammation, the effects of D. chrysantha on asthma have not been fully investigated. In the present study, we investigated the anti-inflammatory activity of D. chrysantha extract (Dc extract) on lung inflammation in a murine model of ovalbumin-induced asthma.

Materials and methods

Dc extract was obtained from dried and powdered whole plants of D. chrysantha using 80% ethanol. BALB/c mice induced by ovalbumin sensitization and nebulization were used as a mouse model of asthma. RT-PCR and ELISA were performed to measure mRNA and protein expression of cytokines. We examined the effects of Dc extract on leukocyte infiltration and mucus secretion using periodic acid-Schiff staining as well as hematoxylin and eosin staining.

Results

Dc extract significantly inhibited leukocytosis and eosinophilia in the bronchoalveolar lavage (BAL) fluid (p < 0.01). Dc extract significantly reduced the elevated infiltration of inflammatory cells (p < 0.05) and inhibited the increased mucus secretion, despite the absence of significant value. Although Dc extract weakly inhibited the mRNA expression of IL-4, IL-5, IL-13, and eotaxin, it strongly inhibited the protein expression of IL-5 (p < 0.05) and eotaxin (p < 0.01) in BAL fluid. Ovalbumin-specific IgE levels in the serum and BAL fluid were blocked by Dc extract (p < 0.05).

Conclusions

These results suggest the possibility that Dc extract can exert suppressive effects on asthma and may provide evidence that Dc extract is a useful agent for the treatment of allergic airway disease.     

The effect of total extract of Securigera securidaca L. seeds on serum lipid profiles,antioxidant status,and vascular function in hypercholesterolemic rats

Aim of the study

Seeds of Securigera securidaca are used for the treatment of disorders such as hyperlipidemia, diabetes, and epilepsy in Iranian folk medicine. The possible hypolipidemic and antioxidative effects of hydroalcoholic extract of S. securidaca seeds as well as the effect of the extract on vascular reactivity were investigated in hypercholesterolemic rats.

Materials and methods

High-fat fed wistar rats received orally different doses of the extract for 20 days. At the end of the experiment vein blood and liver were collected to measure the lipid profile, lipid peroxidation, and antioxidative enzyme activities. The thoracic aorta was excised and used for isolated vessel preparation and histological study.

Results

The extract produced significant reductions (p < 0.05) in the level of low-density lipoprotein (LDL) and triglyceride with concomitant reduction in lipid deposition in the liver. The extract also suppressed markedly (p < 0.001) the hypercholesterolemia-induced elevation of malondialdehyde levels both in serum and liver. In hypercholesterolemic rats the endothelium-dependent vasodilatation was improved significantly (p < 0.05) by 100 mg/kg/day of the extract. However, in histological study no atherosclerotic lesion was observed.

Conclusion

These results suggest that S. securidaca seed in addition to decrease lipid levels and peroxidation, is able to improve vascular endothelium-dependent relaxation in hypercholesterolemia.     

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

Ethnopharmacological relevance

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

Aim of the study

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

Materials and methods

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

Results

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

Conclusion

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

Antihyperglycaemic activity of aqueous leaf extract of Combretum micranthum (Combretaceae) in normal and alloxan-induced diabetic rats

Aim of the study

To investigate antidiabetic effect of the leaves of Combretum micranthum G. Don, a medicinal plant used for treating diabetes in Northwestern Nigeria.

Materials and methods

Three doses (100 mg/kg, 200 mg/kg and 400 mg/kg) of the aqueous leaf extract of Combretum micranthum were administered to normal glucose loaded, subdiabetic and diabetic rats.

Results

Of the doses tested, 100 mg/kg of the extract was the most effective. It produces a significant hypoglycaemic and antidiabetic activity comparable to the effect of standard drug (0.6 mg/kg glibenclemide).

Conclusion

This study demonstrated the potential antidiabetic property of aqueous leaf extract of Combretum micranthum thus justifying its traditional usage.     

Toxicity studies of Tithonia diversifolia A. Gray (Asteraceae) in rats

Objective

To investigate the toxicity of an ethanolic extract of the aerial parts of Tithonia diversifolia, used in Nigeria to treat malaria, in rats.

Materials and methods

A 70% ethanol extract was administered orally to adult Wistar rats at various dosages (400–1600 mg/kg) and the animals sacrificed and various organs examined at a range of times from 30 min up to 24 h after administration.

Results

The studies showed a dose- and time-dependent toxic effect, which was reversible on the kidney and liver while there was no noticeable adverse effect on the morphology of the heart, spleen and brain.

Conclusion

A 70% ethanol extract of the aerial parts of Tithonia diversifolia, which had previously been shown to reduce parasitemia in mice infected with Plasmodium, displayed kidney and liver toxicity at the lowest dose tested. The use of this plant extract against malaria therefore raises concerns over its safety.