Antidiarrhoeic activity of Sclerocarya birrea bark extract and its active tannin constituent in rats

The antidiarrhoeic activity of the bark of Sclerocarya birrea was investigated. The lyophilized decoction demonstrated antidiarrhoeic activity in experimental models of diarrhoea induced by magnesium sulphate and sodium picosulphate. This antidiarrhoeic activity was related to an inhibition of intestinal transit rather than to inhibition of net secretion of fluid and electrolytes provoked by the laxative agents. A condensed tannin was isolated from the crude drug which produced inhibition in intestinal motility, and the monomer of which was identified as procyanidin.     

Effect of Sclerocarya birrea (Anacardiaceae) stem bark methylene chloride/methanol extract on streptozotocin-diabetic rats

Sclerocarya birrea (Anacardiaceae) is used as a traditional treatment of diabetes in Cameroon. In this study, we investigated the possible antidiabetic effect of the stem bark extract in diabetic rats. Diabetes was induced by intravenous injection of streptozotocin (STZ, 55 mg/kg) to male Wistar rats. Experimental animals (six per group), were treated by oral administration of plant extract (150 and 300 mg/kg body weight) and metformin (500 mg/kg; reference drug) for comparison, during 21 days. The stem bark methanol/methylene chloride extract of Sclerocarya birrea exhibited at termination, a significant reduction in blood glucose and increased plasma insulin levels in diabetic rats. The extract also prevented body weight loss in diabetic rats. The effective dose of the plant extract (300 mg/kg) tended to reduce plasma cholesterol, triglyceride and urea levels toward the normal levels. Four days after diabetes induction, an oral glucose tolerance test (OGTT) was also performed in experimental diabetic rats. The results showed a significant improvement in glucose tolerance in rats treated with Sclerocarya birrea extract. Metformin, a known antidiabetic drug (500 mg/kg), significantly decreased the integrated area under the glucose curve. These data indicate that Sclerocarya birrea treatment may improve glucose homeostasis in STZ-induced diabetes which could be associated with stimulation of insulin secretion.     

Antidiarrhoeal activity of seed extract of Albizzia lebbeck Benth

The antidiarrhoeal activity of the seed extract of Albizzia lebbeck (Benth.) was investigated employing conventional rodent models of diarrhoea, i.e. castor oil-induced diarrhoea, upper gastrointestinal transit (u.g.t.) and fluid secretion. It was found that the aqueous methanol extract of Albizzia lebbeck seeds (2.5-5 mg/kg i.p.) possessed antidiarrhoeal activity which strengthens the earlier use of the seeds in the treatment of diarrhoea and dysentery. The antidiarrhoeal dose of the extract was at least 10-30 times less than the LD(50) dose. The extract (2.5-5 mg/kg i.p.) potentiated the antidiarrhoeal activity of loperamide (1 mg/kg i.p.). Nalaxone (0.5 mg/kg i.p.) significantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract.     

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.     

Sclerocarya birrea (a. rich) hochst. [‘marula’] (anacardiaceae): a review of its phytochemistry,pharmacology and toxicology and its ethnomedicinal uses

A plethora of ethnotherapeutic properties and pharmacological actions have been attributed to Sclerocarya birrea (family: Anacardiaceae). It is one of the most highly valued indigenous trees of southern Africa. Reports in biomedical literature have indicated the presence of medicinally‐important chemical constituents in the plant, notably: polyphenols, tannins, coumarins, flavonoids, triterpenoids, phytosterols, and so forth. Pharmacological studies by various groups of investigators have shown that S. birrea possesses antidiarrhoeal, antidiabetic, anti‐inflammatory, antimicrobial, antiplasmodial, antihypertensive, anticonvulsant, antinociceptive and antioxidant properties, thus lending pharmacological support to the plant's folkloric, ethnotherapeutic uses in South African traditional medicine. In view of the immense medicinal importance of the plant, this review aimed at compiling all currently available information on S. birrea's chemical constituents, as well as its ethnomedicinal, pharmacological and toxicological properties. Copyright © 2009 John Wiley & Sons, Ltd.     

Antidiarrhoeal Activity of Hamelia patens Methanol Extract in Rats and Mice

The inhibitory action of Hamelia patens methanol extract was studied in vitro on uterus, ileum and duodenum, and the antidiarrhoeal activity was evaluated in vivo on mice and rats. It was found that for the uterus and intestine the inhibitory response was dose dependent and the major antidiarrhoeal effect was observed at a dose of 100 mg/kg.     

Experimental evaluation of Myracrodruon urundeuva bark extract for antidiarrhoeal activity

The bark of M. urundeuva (Anacardiaceae) used in popular medicine as an antidiarrhoeal agent has been investigated for its effects on castor oil-induced diarrhoea and on intestinal motility. In rats, the ethanol extract of stem bark significantly inhibited the castor oil-induced diarrhoea, small intestinal transit and accumulation of fluid volume at an oral dose of 400 mg/kg. Furthermore, the plant extract caused marked inhibition of the contractile responses evoked by acetylcholine and histamine on guinea-pig ileum in vitro. These results point to a possible antidiarrhoeic effect of M. urundeuva bark extract since inhibition of intestinal motility and secretion can greatly control clinical diarrhoea. Copyright © 1998 John Wiley & Sons, Ltd.     

Antidiarrhoeal activity of hot water extract of black tea (Camellia sinensis)

The effect of a hot water extract of black tea (Camellia sinensis (L.) O. Kuntze, Theaceae) on upper gastrointestinal transit and on diarrhoea was investigated employing conventional rodent models of diarrhoea. Black tea extract was found to possess antidiarrhoeal activity in all the models of diarrhoea used. Naloxone (0.5 mg/kg i.p.) significantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract.     

越桔原花青素对异丙肾上腺素诱导的大鼠心肌纤维化的抑制作用及机制

目的:探讨越桔原花青素(procyanidin from vaccinium,PC)对大鼠心肌纤维化的影响及其机制。方法:以异丙肾上腺素(isoprenaline,Iso)5 mg.kg-1.d-1背部皮下注射7 d构建大鼠心肌纤维化模型,同时以灌胃方式给予PC 100,200,400mg.kg-1.d-1,连续用药14 d,实验结束后测量大鼠心重指数(HW/BW)和左心室质量指数(LVW/BW);ELISA法测定血清中血管紧张素Ⅱ(angiotensinⅡ,AngⅡ),Ⅰ型,Ⅲ型胶原的含量;通过酶标仪用比色法检测血清中一氧化氮(nitric oxide,NO)含量的变化;分光光度法检测左心室心肌组织中丙二醛(malondialdehyde,MDA)含量;全自动生化仪检测血清中乳酸脱氢酶(lactate dehydrogenase,LDH)、肌酸磷酸激酶(creatine kinase,CK)含量。结果:与对照组比较,Iso模型组大鼠心重指数和左心室质量指数增加,血清中AngⅡ,Ⅰ型,Ⅲ型胶原的含量增加,左心室心肌组织中MDA含量增高,血清中NO含量降低、LDH和CK含量增加(P<0.05或P<0.01)。PC 200,400 mg.kg-1.d-1均能降低心重指数和左心室质量指数,降低血清中AngⅡ,Ⅰ型及Ⅲ型胶原的含量,PC 100,200,400 mg.kg-1.d-1可增加血清中NO含量、减少心肌组织中的MDA含量、降低血清中LDH和CK的含量,同模型组比较有统计学差异(P<0.05或P<0.01)。结论:PC可通过降低AngⅡ的水平、提高NO水平及抗氧化的作用而抑制胶原的合成,从而抑制大鼠心肌纤维化,并对心肌具有一定的保护作用。     

Hypotensive and vasorelaxant effects of the procyanidin fraction from Guazuma ulmifolia bark in normotensive and hypertensive rats

THE AIM OF THE STUDY: was to investigate the in vivo and in vitro cardiovascular activity of a procyanidin fraction (PCF) obtained from acetone extract of Guazuma ulmifolia bark which has traditionally been used as an antihypertensive agent. RESULTS: 10 mg/kg PCF doses orally administered to sugar-fed hypertensive rats decreased both the systolic arterial pressure and the heart rate, whereas the same doses intravenously administered induced arterial hypotension which was attenuated by NG-nitro-L-arginine methylester (L-NAME 31 mg/kg) pretreatment. In these experiments we employed carbachol as a positive control test. The PCF reduced the contraction induced by norepinephrine (1x10(-7) M) in isolated aortic rings of normotensive (IC50=35.3+/-12.4 ng/mL) and sugar-fed hypertensive (IC50=101.3+/-57.2 ng/mL) rats. This relaxant activity was inhibited by either vascular endothelium removal or L-NAME (30 microM) pretreatment, while indomethacin (10 microM) or atropine (10 microM) had no effect. Preliminary analysis of the PCF by HPLC-DAD-MS and FAB+ mass spectrometry allowed the detection of the main components such as the complex of procyanidin oligomers consisting mainly of tetramers and trimers. CONCLUSIONS: Guazuma ulmifolia bark possesses long-lasting antihypertensive and vasorelaxing properties linked to the endothelium related factors, where nitric oxide is involved.     

Inhibitory effects of the sesquiterpene T-cadinol on contractile responses in the isolated guinea-pig ileum

The smooth muscle relaxing effect of the sesquiterpene T-cadinol, isolated from scented myrrh (resin of Commiphora guidottii Chiov., Burseraceae), was investigated. The compound inhibited the contractile responses in the isolated guinea-pig ileum to histamine, carbachol, Ba²⁺ and K⁺ in a concentration dependent and reversible manner. The antagonism of the receptor-mediated contractions induced by histamine and carbachol was not of a competitive type. The contractions induced by Ba²⁺- and K⁺ were somewhat more sensitive to the action of T-cadinol than the receptor mediated contractions. It is suggested that the compound may interfere with a step of the contraction sequence common to all four spasmogens.     

Inhibitory effects of quercetin on guinea-pig ileum contractions

The inhibitory effect of quercetin on the guinea-pig ileum contractile responses was examined to further clarify its mechanism of action. Quercetin inhibited, from doses of 5 μM , the spontaneous phasic contractions of the guinea-pig ileum, as well as the phasic and tonic components of either acetylcholine- or KCl-elicited contractions, in a dose-dependent way. The former effect was reversible and was unaffected by nicotinic blockade. The tonic component of the contractions was more responsive to quercetin than the phasic component. The inhibition of the tonic contraction was, at least partially, due to the blockade of calcium channels by quercetin, since increasing calcium concentration in the tissue bath reversed the inhibition when the organ was contracted by KCl. Quercetin may also interfere with calcium release from intracellular stores, since it inhibited acetylcholine-elicited phasic contraction even in a calcium-free solution. Finally, quercetin shifted the concentration-response curves to carbachol downwards, without modifying the ED₅₀ of the agonist, whereas the concentration-response curves to CaCl₂ were shifted downwards and to the right. In conclusion, quercetin inhibits the contractile responses of guinea-pig ileum, decreasing the calcium concentration available for contractile machinery.     

Constituents of Croton menthodorus and their effects on electrically induced contractions of the guinea-pig isolated ileum

The present study examines the effects of the extracts [petroleum ether, CHCl(3), CHCl(3)MeOH (9:1) and MeOH], partially purified fractions and pure compounds from Croton menthodorus on the electrically induced contractions of the isolated guinea-pig ileum (ECI). The results of the experiments indicate that CHCl(3)/MeOH (9:1) and MeOH extracts, tested at concentrations of 100, 50 and 25 microg/mL, dose-dependently reduced the guinea-pig ileum contractions, whereas petroleum ether and CHCl(3) extracts did not affect it. Furthermore, the partially purified fractions III-VI from the CHCl(3)/MeOH extract, each tested at concentrations of 100, 50 and 25 microg/mL also inhibited ECI. Finally, pure compound 1 (6 x 10(-6), 3 x 10(-6), 1 x 10(-6) M) isolated and purified from the most active fraction III significantly reduced, in a dose-dependent manner, the electrical contractions of the ileum. Compound 1 was identified by NMR and EI-MS data as the morphinandien-7-one, O-methylflavinantine.     

Antibacterial activity of Marula (Sclerocarya birrea (A. rich.) Hochst. subsp. caffra (Sond.) Kokwaro) (Anacardiaceae) bark and leaves.

Marula bark is widely used for bacteria-related diseases by indigenous cultures in Africa. This study was undertaken to investigate whether the ethnobotanical use can be validated by laboratory studies. Bark and leaves were extracted with acetone and MIC values were determined using a microplate serial dilution technique with Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis as test organisms. All extracts were active with MIC values from 0.15 to 3 mg/ml. Based on minimum inhibitory concentration values, inner bark extracts tended to be the most potent followed by outer bark and leaf extracts, but the differences were not statistically significant. There were two major bioactive components visible after bioautography of leaf extracts: one strongly polar and the other highly non-polar. The bioactive components could be separated from 92% of the non-active dry matter by solvent-solvent fractionation into the carbon tetrachloride, chloroform and n-butanol fractions; these fractions, however, still contained many different compounds. Using bark may be detrimental to the plant, but leaf material can also be used for antibacterial application.     

原花青素类成分在防治2型糖尿病作用机制方面的研究进展

糖尿病是一种以升高血糖为主要特点的慢性疾病,长期高血糖会引发多种并发症。原花青素是一类广泛存在于植物中的多酚化合物,在降血糖、改善胰岛素抵抗、保护胰岛β细胞方面具有良好的作用,对于2型糖尿病的预防及治疗显示出较好的效果。该文对原花青素类成分调控2型糖尿病在促进葡萄糖吸收、保护胰岛β细胞、改善肠道微环境、调节糖尿病并发症等方面的研究进展进行综述,为该类成分进一步研究提供参考。     

Antidiarrhoeal activity of Hypoxis hemerocallidea Fisch. & C. A. Mey. (Hypoxidaceae) Corm (‘African potato’) aqueous extract in rodents

This study investigated the antidiarrhoeal activity of Hypoxis hemerocallidea corm aqueous extract (APE) on experimentally‐induced diarrhoea, gastrointestinal motility, intestinal transit and enteropooling in rodents. H. hemerocallidea corm aqueous extract (APE, 50–400 mg/kg, p.o.) produced dose‐dependent and significant (p < 0.05–0.01) protection of rats and mice against castor oil‐induced diarrhoea, inhibited intestinal transit and delayed gastric emptying. Like atropine (1 mg/kg, p.o.), APE (50–400 mg/kg, p.o.) produced dose‐dependent and significant (p < 0.05–0.01) antimotility effect, and caused dose‐related inhibition of castor oil‐induced enteropooling in the animals. Like loperamide (10 mg/kg, p.o.), APE (50–400 mg/kg, p.o.) dose‐dependently and significantly (p < 0.05–0.01) delayed the onset of castor oil‐induced diarrhoea, decreased the frequency of defaecation and reduced the severity of diarrhoea in the rodents. Compared with control animals, APE (50–400 mg/kg, p.o.) dose‐dependently and significantly (p < 0.05–0.01) decreased the volume of castor oil‐induced intestinal fluid secretion, and reduced the number, weight and wetness of faecal droppings. APE (50–400 mg/mL) also produced concentration‐related and significant (p < 0.05–0.01) inhibitions of the spontaneous, pendular contractions of the rabbit isolated duodenum, and attenuated acetylcholine (ACh, 0.1–5.0 µg/mL)‐induced contractions of the guinea‐pig isolated ileum. Although the precise mechanism of the antidiarrhoeal activity of APE could not be established, the results of this study indicate that APE possesses antidiarrhoeal activity. This finding supports the use of ‘African potato’ as a natural supplementary remedy for the treatment, management and/or control of diarrhoea in some rural communities of southern Africa. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of Aqueous Extract of Brickellia veronicaefolia on the Gastrointestinal Tract of Guinea-pig,Rats and Mice

The aqueous extract of Brickellia veronicaefolia inhibited gastric emptying time in rats and intestinal motility in mice, both effects were manifested in a dose-related fashion. The crude extract inhibited the contractions induced by acetylcholine and histamine concentration-dependently in the guinea-pig ileum. In the castor oil diarrhoea test, the extract showed 90% protection from diarrhoea at 150 mg/kg.     

Antispasmodic effect of Bersama abyssinica aqueous extract on guinea-pig ileum

The present study deals with the effect of one of the traditionally used Ethiopian medicinal plants, Bersama abyssinica, on gut motility. The experiment was carried out on isolated guinea-pig ileum with a standard spasmogen, histamine, in the absence and presence of the water extract of the medicinal plant. The spasmogenic effect of histamine was found to be antagonized by the extract in a nonreversible manner, indicating that B. abyssinica has a spasmolytic activity.     

Antiviral activity in vitro of Cupressus sempervirens on two human retroviruses HIV and HTLV

A proanthocyanidin polymer fraction (MW 1500–2000 daltons) from Cupressus sempervirens L. (Cupressaceae) exhibited true antiviral activity in vitro against two retroviruses, HIV and HTLV III B. In comparison with AZT no toxicity was observed with PPC at concentrations of 50 μg/mL which exceeded the IC₅₀ values (1.5 to 15 μg/mL for HIV and 5 to 25 μg/mL for HTLV). © 1998 John Wiley & Sons, Ltd.     

Smooth muscle relaxant activities of compounds isolated from malaysian medicinal plants on rat aorta and guinea-pig ileum

Muscle relaxant activities of six compounds isolated from Malaysian medicinal plants were investigated on the smooth muscles of the rat aorta and longitudinal muscle of the guinea-pig ileum. Except for goniothalamin, the other five compounds exhibited varying degrees of muscle relaxant activities on the two smooth muscles. Dicentrine, isocorydine, altholactone and usnic acid reduced the contractions to KCI and phenylephrine in the rat aorta, whilst atranorin slightly reduced the contractions to phenylephrine but not KCI. In addition, dicentrine and isocorydine markedly reduced the contractile response to phenylephrine in Ca²⁺-free Krebs solution. In the longitudinal muscle of the guinea-pig ileum, altholactone, atranorin, dicentrine and isocorydine inhibited to a greater extent the phasic than the tonic responses to KCI. All four compounds similarly inhibited the contractions induced by ACh. The results suggest that the relaxant activities of the compounds are attributed mainly to inhibition of Ca²⁺ influx via the calcium channels in the membrane of the smooth muscles. Furthermore, the greater sensitivity of dicentrine, isocorydine and altholactone against phenylephrine-induced contractions or KCI-induced phasic contractions are due to their abilities to inhibit intracellular Ca²⁺ release in these muscles.