Analgesic, antiinflammatory and antidiabetic properties of Harpagophytum procumbens DC (Pedaliaceae) secondary root aqueous extract

South Africa is blessed with a rich floral biodiversity of medicinally useful plants. One such plant is Harpagophytum procumbens DC (Family: Pedaliaceae). H. procumbens is widely used in South African traditional medicine for the treatment, management and/or control of a variety of human ailments. In the present study, the analgesic effect of H. procumbens secondary root aqueous extract was evaluated in mice, using the 'hot-plate' and 'acetic acid' test methods; while the antiinflammatory and antidiabetic effects of the plant's secondary root extract were investigated in rats. Fresh egg albumin-induced pedal oedema and streptozotocin (STZ)-induced diabetes mellitus were used as experimental test models of inflammation and diabetes Diclofenac (DIC, 100 mg/kg i.p.) was used as a reference analgesic and antiinflammatory agent for comparison. Chlorpropamide (250 mg/kg p.o.) was used as a reference hypoglycaemic agent for comparison. H. procumbens root aqueous extract (HPE, 50-800 mg/kg i.p.) produced significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced nociceptive pain stimuli in mice. H. procumbens root extract (HPE, 50-800 mg/kg i.p.) also produced dose-related, significant reductions (p < 0.05-0.001) of the fresh egg albumin-induced acute inflammation of the rat hind paw oedema. Furthermore, the plant extract (HPE, 50-800 mg/kg i.p.) produced dose-dependent, significant reductions (p < 0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. The results of this experimental animal study indicate that H. procumbens root aqueous extract possesses analgesic, antiinflammatory and hypoglycaemic properties, and lend pharmacological support to the suggested folklore uses of Harpagophytum procumbens root in the management and/or control of painful, arthritic and other inflammatory conditions, as well as for adult-onset, type-2 diabetes mellitus in some communities of South Africa.     

Analgesic, anti-inflammatory and hypoglycaemic effects of Rhus chirindensis (Baker F.) [Anacardiaceae] stem-bark aqueous extract in mice and rats

In an attempt to scientifically evaluate some of the anecdotal, folkloric, ethnomedical uses of Rhus chirindensis Baker F. ('red currant'), the present study was undertaken to investigate the analgesic, anti-inflammatory and hypoglycaemic effects of the plant's stem-bark aqueous extract (RCE) in mice and rats. The analgesic effect of RCE was evaluated by 'hot-plate' and 'acetic acid' analgesic test methods in mice; while its anti-inflammatory and hypoglycaemic effects were investigated in rats, using fresh egg albumin-induced pedal oedema, and streptozotocin (STZ)-induced diabetes mellitus animal models. Morphine (MPN, 10 mg/kg), diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used as reference drugs for comparison. RCE (50-800 mg/kg i.p.) produced dose-dependent, significant (P<0.05-0.001) analgesic effects against thermally- and chemically-induced nociceptive pain in mice. The plant's extract (RCE, 50-800 mg/kg p.o.) also significantly (P<0.05-0.001) inhibited fresh egg albumin-induced acute inflammation, and caused dose-related, significant (P<0.05-0.001) hypoglycaemia in normal (normoglycaemic) and diabetic (hyperglycaemic) rats. The flavonoids, triterpenoids and other chemical compounds present in RCE are speculated to account for the observed pharmacological effects of the plant's extract in the experimental animal paradigms used. The findings of this experimental animal study indicate that Rhus chirindensis stem-bark aqueous extract possesses analgesic, anti-inflammatory and hypoglycaemic properties; and thus lend pharmacological credence to the anecdotal, folkloric, ethnomedical uses of the plant in the treatment and/or management of painful, arthritic, inflammatory conditions, as well as in the management and/or control of type 2 diabetes mellitus in some rural communities of South Africa.     

Antinociceptive, anti-inflammatory and antidiabetic effects of Bryophyllum pinnatum (Crassulaceae) leaf aqueous extract

In order to scientifically appraise some of the ethnomedical uses of Bryophyllum pinnatum leaves, the present study was undertaken to investigate the antinociceptive, anti-inflammatory and antidiabetic properties of the plant's leaf aqueous extract in experimental animal models. The antinociceptive effect of the herb's leaf extract was evaluated by the 'hot-plate' and 'acetic acid' test models of pain in mice. The anti-inflammatory and antidiabetic effects of the plant's extract were investigated in rats, using fresh egg albumin-induced pedal (paw) oedema, and streptozotocin (STZ)-induced diabetes mellitus. Diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used respectively as reference drugs for comparison. Bryophyllum pinnatum leaf aqueous extract (BPE, 25-800 mg/kg i.p.) produced significant (P<0.05-0.001) antinociceptive effects against thermally- and chemically-induced nociceptive pain stimuli in mice. The plant extract (BPE, 25-800 mg/kg p.o. or i.p.) also significantly (P<0.05-0.001) inhibited fresh egg albumin-induced acute inflammation and caused significant (P<0.05-0.001) hypoglycaemia in rats. The results of this experimental animal study suggest that Bryophyllum pinnatum leaf aqueous extract possesses antinociceptive, anti-inflammatory and hypoglycaemic properties. The different flavonoids, polyphenols, triterpenoids and other chemical constituents of the herb are speculated to account for the observed antinociceptive, anti-inflammatory and antidiabetic properties of the plant.     

Evaluation of the analgesic, anti-inflammatory and anti-diabetic properties of Sclerocarya birrea (A. Rich.) Hochst. stem-bark aqueous extract in mice and rats

In order to appraise some of the ethnomedical uses of Sclerocarya birrea (A. Rich.) Hochst., subspecies caffra (Sond.) Kokwaro [family: Anacardiaceae], the present study was undertaken to investigate the analgesic, anti-inflammatory and anti-diabetic properties of the plant's stem-bark aqueous extract in experimental models of pain, inflammation and diabetes mellitus. The analgesic effect of Sclerocarya birrea stem-bark aqueous extract was evaluated in mice, while its anti-inflammatory and anti-diabetic effects were investigated in rats. Diclofenac (DIC, 100 mg/kg p. o.) and chlorpropamide (250 mg/kg p. o.) were used respectively as reference analgesic, anti-inflammatory and anti-diabetic agents for comparison. Like diclofenac (DIC, 100 mg/kg p. o.), Sclerocarya birrea stem-bark aqueous extract (SBE, 100-800 mg/kg p. o.) produced dose-dependent, significant protection (p < 0.05-0.001) against electrical heat-induced pain. The plant extract (SBE, 25-800 mg/kg p. o.) also produced dose- and time-related, sustained and significant reductions (p < 0.05-0.001) in the fresh egg albumin-induced acute inflammation of the rat hind paw oedema. However, the analgesic and anti-inflammatory effects of the plant's extract were found to be approximately 10-15 times less than that of diclofenac. In one set of experiments involving hypoglycaemic/antidiabetic evaluation of the plant's extract, graded doses of Sclerocarya birrea stem-bark aqueous extract (SBE, 25-800 mg/kg p. o.) were separately administered to groups of fasted normal and fasted diabetic rats. In another set of experiments, a single dose of the plant's aqueous extract (SBE, 800 mg/kg p. o.) was used. The hypoglycaemic effect of this single dose of Sclerocarya birrea stem-bark aqueous extract (SBE, 800 mg/kg p. o.) was compared with that of chlorpropamide (250 mg/kg p. o.) in both fasted normal and fasted streptozotocin (STZ)-treated diabetic rats. Following acute treatment, relatively moderate to high doses of Sclerocarya birrea stem-bark aqueous extract (SBE, 25-800 mg/kg p. o.) produced dose-dependent, significant reductions (p < 0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. Chlorpropamide (250 mg/kg p. o.) also produced significant reductions (p < 0.05-0.001) in the blood glucose concentrations of the fasted normal and fasted diabetic rats. Administration of the single dose of Sclerocarya birrea stem-bark aqueous extract (SBE, 800 mg/kg p. o.) significantly reduced (p < 0.01-0.001) the blood glucose levels of both fasted normal (normoglycaemic) and fasted STZ-treated, diabetic rats. The results of this experimental animal study indicate that Sclerocarya birrea stem-bark aqueous extract possesses analgesic, anti-inflammatory and hypoglycaemic properties. These experimental findings lend pharmacological support to the suggested folkloric uses of the plant's stem-bark in the management and/or control of pain, inflammatory conditions, and adult-onset, type-2 diabetes mellitus in some communities of South Africa.     

Antinociceptive, anti-inflammatory and antidiabetic properties of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) corm ['African Potato'] aqueous extract in mice and rats

In order to scientifically appraise some of the anecdotal, folkloric, ethnomedical uses of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) corm ['African Potato'], the present study was undertaken to examine the antinociceptive, anti-inflammatory and antidiabetic properties of the corm's aqueous extract (APE) in mice and rats. The antinociceptive effect of APE was evaluated by 'hot-plate' and 'acetic acid' analgesic test methods in mice; while the anti-inflammatory and antidiabetic effects of the plant's extract were investigated in rats, using fresh egg albumin-induced pedal (paw) oedema, and streptozotocin (STZ)-induced diabetes mellitus models. Morphine (MPN, 10 mg/kg), diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used as reference drugs for comparison. H. hemerocallidea corm aqueous extract (APE, 50-800 mg/kg i.p.) produced dose-dependent, significant (P < 0.05-0.001) antinociceptive effects against thermally- and chemically-induced nociceptive pain stimuli in mice. The plant extract (APE, 50-800 mg/kg p.o.) also significantly (P < 0.05-0.001) inhibited fresh egg albumin-induced acute inflammation, and caused dose-related, significant (P < 0.05-0.001) hypoglycaemia in normal (normoglycaemic) and diabetic rats. The results obtained in this study suggest that the antinociceptive effects of the plant's extract are peripherally- and centrally-mediated. The findings of this experimental animal study indicate that H. hemerocallidea corm aqueous extract (APE) possesses antinociceptive, anti-inflammatory and antidiabetic properties; and thus lend pharmacological support to folkloric, anecdotal uses of 'African Potato' in the treatment and/or management of painful, arthritic inflammatory conditions, as well as in the management and/or control of type-2 diabetes mellitus in some parts of southern Africa.     

Analgesic and antiinflammatory effects of mollic acid glucoside, a 1 alpha-hydroxycycloartenoid saponin extractive from Combretum molle R. Br. ex G. Don (Combretaceae) leaf

The analgesic and antiinflammatory properties of mollic acid glucoside (MAG), a 1 alpha-hydroxycycloartenoid extract from Combretum molle leaf, have been investigated in mice and rats. The effects of graded doses of mollic acid glucoside (MAG, 5-80 mg/kg i.p.) were examined against thermally- and chemically-induced nociceptive pain in mice. Furthermore, the effects of graded doses of the plant extract (MAG, 5-80 mg/kg p.o.) were also investigated on rat paw oedema induced by subplantar injections of fresh egg albumin (0.5 mg/kg). Morphine (MPN, 10 mg/kg i.p.) and diclofenac (DIC, 100 mg/kg i.p.) were used as reference analgesic and antiinflammatory agents for comparison, respectively. Like DIC (100 mg/kg i.p.) and MPN (10 mg/kg i.p.), MAG (5-80 mg/kg i.p.) produced dose-dependent, significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced nociceptive pain in mice. The extractive (MAG, 5-80 mg/kg i.p.) also significantly reduced (p < 0.05-0.001) rat paw oedema induced by subplantar injections of fresh egg albumin in a dose-related fashion. However, the extract (MAG, 5-80 mg/kg i.p.) was found to be less potent than diclofenac (DIC) as an analgesic or antiinflammatory agent. Experimental evidence obtained from this laboratory animal study indicates that the Combretum molle leaf extractive (MAG) possesses analgesic and antiinflammatory properties, and thus lend pharmacological credence to the folkloric, ethnomedical uses of the plant's leaf in the management, control and/or treatment of painful, arthritic and other inflammatory conditions in some rural communities of southern Africa.     

Pharmacological evidence favouring the folkloric use of Diospyros mespiliformis Hochst in the relief of pain and fever

The methanol extract of Diospyros mespiliformis was evaluated for its claimed folkloric usage in the relief of pain and fever. Antipyretic, analgesic and anti-inflammatory effects of the extract were evaluated in rats and mice. Studies were carried out on yeast-induced pyrexia in rats, acetic acid-induced writhing in mice, formalin test and egg albumin-induced anti-inflammatory activity in rats. The extract (50 and 100 mg/kg i.p.) gave a potent antipyretic effect for 100 mg/kg and significant activity (P<0.05) against all the analgesic and anti-inflammatory models used. The LD(50) of the extract was estimated to be 513.80+/-33.92 mg/kg i.p. in mice. These results provide support for the use of the plant in relieving pain and fever.     

Ethnopharmacologic investigation of ginger (Zingiber officinale)

An ethanolic extract of the rhizomes of Zingiber officinale was investigated for anti-inflammatory, analgesic, antipyretic, antimicrobial and hypoglycaemic activities. In rats, the extract reduced carrageenan-induced paw swelling and yeast-induced fever but was ineffective in suppressing the writhing induced by intraperitoneal acetic acid. The extract produced blood glucose lowering in rabbits. The growth of both Gram-positive and Gram-negative bacteria was significantly inhibited. A dose-dependent inhibition of prostaglandin release effect was observed using rat peritoneal leucocytes.     

Anti-inflammatory, analgesic and anti-lymphocytic activities of the aqueous extract of Crinum giganteum

The anti-inflammatory, anti-lymphocytic and analgesic properties of Crinum giganteum, a popular herb used for the management of asthma and other respiratory disorders was investigated in rats and mice. The extract dose-dependently produced significant (P<0.05) inhibition of formalin induced pain in rats. It also demonstrated significant (P<0.01) inhibition of abdominal constriction induced with 0.75% v/v acetic acid in mice. On the cotton pellet induced granulomatous tissue formation in rats, the extract significantly (P<0.05) decreased the weight. However, no significant inhibition was observed in the egg albumin-induced inflammation in rats. Oral administration of this extract in rats for 14 days significantly affected (P<0.05) the total leukocyte count and the overall percentage lymphocytes. The intraperitoneal and per oral LD(50) were 627+/-5.8mg/kg and 1486+/-18.9 mg/kg in mice and 520+/-10.2mg/kg and 1023+/-4.3 mg/kg in rats, respectively. Preliminary phytochemical analysis of the extract indicates the presence of tannins. These results therefore indicate that C. giganteum bulb contains biologically active principles, which have potentials for the treatment of inflammatory processes.     

Hypoglycaemic activity of Nelumbo nucifera gaertn. (Fam. Nymphaeaceae) rhizome (methanolic extract) in streptozotocin-induced diabetic rats

The hypoglycaemic effect of the rhizome extract of Nelumbo nucifera was studied in streptozotocin-induced diabetic rats. A methanol extract of the plant obtained by soxhlet extraction from finely pulverized rhizomes was used. The LD₅₀ of the extract was found to be 2 g/kg. The extract (300 mg/kg and 600 mg/kg, orally) caused a reduction of blood glucose levels in streptozotocin-induced diabetic rats by 53% (p<0.001) and 55% (p<0.001) respectively at the end of 12 h. The results of this study indicate that the methanol extract of the rhizome possesses favourable hypoglycaemic activity in hyperglycaemic animals taking chlorpropamide as a standard.     

Analgesic and anticonvulsant properties of Tetrapleura tetraptera (Taub) (Fabaceae) fruit aqueous extract in mice

Previous studies in our laboratories and elsewhere have shown that the fruit of Tetrapleura tetraptera (Taub) (family: Fabaceae) is widely used in African traditional medicine for the management and/or control of an array of human ailments, including schistosomiasis, asthma, epilepsy, hypertension and so on. The present study was designed to investigate the analgesic and anticonvulsant effects of Tetrapleura tetraptera (Taub) fruit aqueous extract (TTE) in mice. Morphine (MPN, 10 mg/kg i.p.), diclofenac (DIC, 100 mg/kg i.p.), phenobarbitone (20 mg/kg i.p.) and diazepam (0.5 mg/kg i.p.) were used, respectively, as reference analgesic and anticonvulsant agents for comparison. T. tetraptera fruit aqueous extract (TTE, 50-800 mg/kg i.p.) produced dose-dependent, significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced pain in mice. Like the standard anticonvulsant agents (phenobarbitone and diazepam) used, T. tetraptera fruit aqueous extract (TTE, 50-800 mg/kg i.p.) significantly (p < 0.05-0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. Aqueous extract of the fruit (TTE, 50-800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only partially and weakly antagonized bicuculline (BCL)-induced seizures. However, the results of this experimental animal study indicate that Tetrapleura tetraptera (Taub) fruit aqueous extract (TTE) possesses analgesic and anticonvulsant properties. These findings lend pharmacological support to the suggested folkloric uses of the plant's fruit in the management and/or control of painful, arthritic inflammatory conditions, as well as for the management and/or control of epilepsy and childhood convulsions in some tropical African countries.     

Hypoglycaemic effect of Clausena anisata (Willd) Hook methanolic root extract in rats

This study was designed to examine the hypoglycaemic effect of Clausena anisata (Willd) Hook [family: Rutaceae] root methanolic extract in normal (normoglycaemic) and in streptozotocin-treated diabetic rats. Young adult, male Wistar rats (Rattus norvegicus) weighing 250-300 g were used. Diabetes mellitus was induced in the group of diabetic 'test' rats by intraperitoneal injections of streptozotocin (STZ, 90 mg/kg). In one set of experiments, graded doses of the methanolic root extract of C. anisata (CAME, 100-800 mg/kg p.o.) were administered to both fasted normal and fasted diabetic rats. In another set of experiments, 800 mg/kg of CAME, a dose of the plant extract which produced maximal hypoglycaemic effect in both fasted normal and diabetic rats in the previous set of experiments, was used. The hypoglycaemic effect of this single dose of C. anisata root methanolic extract (i.e. CAME, 800 mg/kg p.o.) was compared with those of insulin (5 micro U/kg s.c.) and glibenclamide (0.2 mg/kg p.o.) in both fasted normal and fasted diabetic rats. Following acute treatment, relatively moderate to high doses of CAME (100-800 mg/kg p.o.) produced dose-dependent, significant reductions (P<0.05-0.001) in the blood glucose concentrations of both fasted normal and fasted diabetic rats. On their own, both insulin (5 micro U/kg s.c.) and glibenclamide (0.2 mg/kg p.o.) produced significant reductions (P<0.01-0.001) in the blood glucose concentrations of the fasted normal and diabetic rats. At a dose of 800 mg/kg p.o., CAME reduced the mean basal blood glucose concentrations of fasted normal and fasted diabetic rats by 57.52 and 51.30%, respectively. C. anisata contains a diverse group of chemical compounds (see Table 1). Since methanol extractives of plants are usually known to contain many chemical compounds, each of which is capable of producing definite biological activities via different mechanisms, it is difficult to draw any logical conclusion on the mechanism of the hypoglycaemic effect of such a diverse mixture of chemical compounds contained in the plant extract used in this study. While it is possible that the hypoglycaemic effect of the plant extract may be due, at least in part, to its terpenoid and coumarin contents, the mechanism of its hypoglycaemic action remains largely speculative, and is unlikely to be due to the stimulation of pancreatic beta-cells and subsequent secretion of insulin. Although C. anisata root methanolic extract is less potent than insulin as an antidiabetic agent, the results of this experimental animal study indicate that the herb possesses hypoglycaemic activity; and thus lend credence to the suggested folkloric use of C. anisata root in the management and/or control of adult-onset, Type-2 diabetes mellitus in some communities of South Africa.     

Effect of ethanolic extract of Zingiber officinale on dyslipidaemia in diabetic rats

The lipid lowering and antioxidant potential of ethanolic extract of Zingiber officinale Roscoe (family, Zingiberaceae) was evaluated in streptozotocin (STZ)-induced diabetes in rats. Ethanolic extract of Zingiber officinale (200 mg/kg) fed orally for 20 days produced, significant antihyperglycaemic effect (P < 0.01) in diabetic rats. Further, the extract treatment also lowered serum total cholesterol, triglycerides and increased the HDL-cholesterol levels when compared with pathogenic diabetic rats (P < 0.01). STZ-treatment also induced a statistically significant increase in liver and pancreas lipid peroxide levels (P < 0.01) as compared to normal healthy control rats. Zingiber officinale extract treatment lowered the liver and pancreas thiobarbituric acid reactive substances (TBARS) values (P < 0.01) as compared to pathogenic diabetic rats. The results of test drug were comparable to gliclazide (25 mg/kg, orally), a standard antihyperglycaemic agent. The results indicate that ethanolic extract of Zingiber officinale Roscoe can protect the tissues from lipid peroxidation. The extract also exhibit significant lipid lowering activity in diabetic rats. The present study is the first pilot study to assess the potential of Zingiber officinale in diabetic dyslipidaemia.     

Anti-nociceptive and anti-inflammatory effects of methanolic extract of Asparagus pubescens root in rodents

The effect of methanolic extract of Asparagus pubescens was investigated on chemical, thermal-induced pain as well as fresh egg albumin-induced inflammation and pentylenetetrazol (PTZ)-induced convulsion in rodents. The extract dose-dependently (0.25-1.5 g/kg) inhibited acetic acid-induced writhing, formalin-induced pain licking and hot plate-induced pain in mice. The extract significantly inhibited both the fresh egg albumin-induced inflammation in rats as well as PTZ-induced convulsion in mice. These inhibitions were statistically significant (P < 0.02-0.001). It increased the latencies of both clonic and tonic convulsions and delayed their mortalities. Its ability to reduce both neurogenic and non-neurogenic pains may be related to its active constituents such as tannins, saponins, steroid and flavonoids.     

Analgesic and anti-inflammatory effects of Mangifera indica L. extract (Vimang)

Vimang is an aqueous extract of Mangifera indica used in Cuba to improve the quality of life in patients suffering from elevated stress. To assess its possible analgesic and antiinflammatory effects, the results of a standard extract evaluation are presented. Analgesia was determined using acetic acid-induced abdominal constriction and formalin-induced licking. Antiinflammatory effects were evaluated using carrageenan- and formalin-induced oedema. Vimang (50-1000 mg/kg, p.o.) exhibited a potent and dose-dependent antinociceptive effect against acetic acid test in mice. The mean potency (DE(50)) was 54.5 mg/kg and the maximal inhibition attained was 94.4%. Vimang (20-1000 mg/kg, p.o.) dose-dependently inhibited the second phase of formalin-induced pain but not the first phase. The DE(50) of the second phase was 8.4 mg/kg and the maximal inhibition was 99.5%, being more potent than indomethacin at doses of 20 mg/kg. Vimang (20-1000 mg/kg, p.o.) significantly inhibited oedema formation (p < 0.01 or p < 0.05) of both carrageenan- and formalin-induced oedema in rat, guinea-pigs and mice (maximal inhibitions: 39.5, 45.0 and 48.6, respectively). The inhibitions were similar to those produced by indomethacin and sodium naproxen, p.o. The different polyphenols found in Vimang could account for the antinociceptive and antiinflammatory actions reported here for the first time for M. indica bark aqueous extract.     

Analgesic and antiinflammatory properties of Scoparia dulcis L. Extracts and glutinol in rodents

The analgesic, antiinflammatory and antipyretic activities of the water (WE) and ethanolic (EE) extracts of Scoparia dulcis L. were tested in mice and rats. Both extracts (0.5 and 1 g/kg) p.o., prolonged the sleeping time induced by pentobarbital in mice, EE being more active than WE. Injections of EE (0.5–2 mg/kg i.v.) to anaesthetized rats induced a dose-related hypertension inhibited by alpha-blocker drugs; the hypertension was not obtained after oral treatment. EE (0.25-1 g/kg p.o.) but not WE, reduced writhings induced by acetic acid in mice. Glutinol (30 mg/kg p.o.), a major triterpene obtained from EE, produced the same effect. The tail flick response of mice was not influenced by either extract. EE (0.5 and 1 g/kg) and glutinol (30 mg/kg) p.o., reduced the paw oedema and pleurisy induced by carrageenin in rats, but only EE (1 g/kg) reduced the paw oedema induced by dextran or histamine. No effect of EE was detected on chronic inflammation induced by cotton pellets and in yeast-induced hyperthermia in rats. The results indicate that the extract of S. dulcis is endowed with analgesic effects probably related to the antiinflammatory activity of the plant. Those effects are related mainly to the presence of glutinol and flavonoids, which exert their action on the early phase of the acute inflammatory process.     

Hypoglycaemic effect of Triticum repens P. Beauv. in normal and diabetic rats

The hypoglycaemic effect of an aqueous extract of Triticum repens (TR) rhizomes was investigated in normal and streptozotocin (STZ) diabetic rats. After a single oral administration of the aqueous extract (20mg/kg) a significant decrease on blood glucose levels in STZ diabetic rats (p<0.001) was observed; the blood glucose levels were normalized after 2 weeks of daily oral administration of TR aqueous extract (20mg/kg) (p<0.001). Significant reduction on blood glucose levels were noticed in normal rats after both acute (p<0.001) and chronic treatment (p<0.001). In addition, no changes were observed in basal plasma insulin concentrations after treatment in either normal or STZ diabetic rats indicating that the underlying mechanism of this pharmacological activity seems to be independent of insulin secretion. We conclude that the aqueous extract of TR exhibits a potent hypoglycaemic activity in STZ rats without affecting basal plasma insulin concentrations.     

Analgesic, antiinflammatory and hypoglycaemic activities of Sida cordifolia

Sida cordifolia extracts of the aerial and root parts showed good analgesic, antiinflammatory and hypoglycaemic activities. The ethyl acetate (EA) extract of root (SCR-E) showed comparable antiinflammatory activity with indomethacin and possessed significantly higher activity when compared with that of the methanol extract of the root part (SCR-M). The ethyl acetate extract of both root and aerial parts of Sida cordifolia (SCR-E and SCA-E) showed very good central and peripheral analgesic activities at a dose of 600 mg/kg. The methanol extract of root (SCR-M) was found to possess significant hypoglycaemic activity.     

Anti-nociceptive and anti-inflammatory activities of the methanolic extract of Parinari polyandra stem bark in rats and mice

The methanolic extract of the stem bark of Parinari polyandra (family Rosaceae) was investigated for possible anti-nociceptive and anti-inflammatory effects in mice and rats. Three models were used to study the extracts effects on nociception which were the acetic acid-induced abdominal constriction test, hot-plate method (both in mice) and the formalin test in rats. The anti-inflammatory effects were investigated employing the albumin-induced hind-paw oedema in rats. Results of the study revealed the extract to have significant (P<0.05) anti-nociceptive effect at a dose of 200 mg/kg p.o. in mice and rats in all the models for anti-nociception while 100 mg/kg p.o. showed significant (P<0.05) effect in the acetic acid-induced abdominal constriction test and in phase I of the formalin test. The extract also exhibited anti-inflammatory effects which were found to be significant (P<0.05) at 200 mg/kg p.o. in the rats tested. Preliminary phytochemical screening of the extract showed the presence of flavonoids, tannins, and saponin glycoside. The results suggest the extract contains pharmacologically active principles. The result is in agreement with the local application of the plant in painful and inflammatory conditions.     

Hypoglycaemic activity of Anthocleista vogelii (Planch) aqueous extract in rodents

The hypoglycaemic effect of Anthocleista vogelii was studied in mice, rats and rabbits. Aqueous extract of the plant obtained by infusion from finely pulverized root was used. The extract (100, 400 and 800 mg/kg) induced significant hypoglycaemic activity in a dose-related fashion at 2 h after oral administration in mice and rats with ED₂₅ of 250 mg/kg and 350 mg/kg respectively. The extract (800 mg/kg, orally) similarly induced statistically significant lowering of blood glucose levels at 8 h in normoglycaemic rabbits. The extract (400 mg/kg and 800 mg/kg, orally) also caused reduction of blood glucose levels in alloxan-induced diabetic animals. The results of this study indicate that the aqueous extract of the roots of Anthocleista vogelii possess favourable hypoglycaemic activity both in normo and hyperglycaemic animals compared to chlorpropamide as a standard.