Reversal of Coumarin-Induced Toxicity by the Extracts and Fractions of Ageratum conyzoides

Abstract: This study examined the antidotal effects of the methanol extract (MeOH) and fractions of Ageratum conyzoides L. (Asteraceae) on coumarin-induced toxicity in rats. The effects of these extracts on coumarin acute toxicity (LD 50 ) and mortality rate were assessed. The LD 50 of coumarin was increased by as much as 487.2 and 238.1% when co-administered with the MeOH extract (1 g/kg) and the methanol fraction, (MF) (1 g/kg) respectively. The MeOH extract and MF significantly (p#0.05) reduced coumarin-induced mortality to 0 and 40%, respectively when compared to the 100% mortality recorded for the control group. Vitamin K and activated charcoal, which were used as standard antidotes, also produced similar reductions in percentage mortality, but MeOH extract and MF performed better. The Hexane Fraction (HF) and the ethyl acetate fraction, (EF) did not significantly (p>0.05) affect coumarin-induced mortality. Maximal antidotal effect was recorded when MeOH extract was given within 3 h of coumarin administration. The MeOH extract and the MF demonstrated antidotal activities against acute poisoning by coumarin in rodents. On their own, the extracts did not produce any gross pathological change in the animals, and could therefore be harnessed as useful antidote in coumarin poisoning. Local activities of the phytoconstituents of A. conyzoides on the GIT which limits absorption and haemorrhagic damages are believed to be responsible for the reversal of the coumarin toxicity

Protective effects of Buchholzia coriacea seeds extract and fractions on blood glucose and hyperlipidemia in diabetic rats

Background: The Buchholzia coriacea seeds (Capparaceae) are used in Nigerian ethnomedicine for treatment of hyperglycemia. Our aim, therefore, is to evaluate antihyperglycemic and hypolipidemic effects of extract and fractions of Bulcholzia coriacea seeds.Methods: The cut, dried and pulverized seeds were extracted with a mixture of methanol-dichloromethane (1:1) which yielded the crude extract, MDE. The MDE was fractionated using bioactive guided procedure and yielded hexane fraction (HF), ethylacetate fraction (EF) and methanol fraction (MF). Alloxan-induced diabetes, normoglycemic test and oral glucose tolerance test (OGTT) were the antidiabetic models employed, while hypolipidemic study was performed using standard assay kits to determine the serum total cholesterol (TC) triglycerides (TG) and low density lipoproteins (LDL). Acute toxicity test of the extract was performed using Lorke’s method while qualitative and quantitative phytochemical analyses were also performed using standard procedures.Results: The results showed an oral median lethality dose (LD50) greater than 5000mg/kg. The extract and fractions showed significant antihyperglycemic effect comparable and in synergy to metformin, a standard agent. The extract (200mg/kg) showed the highest percentage blood glucose reduction (PBGR) of 52.89% while ethylacetate fraction (EF, 400mg/kg) showed PBGR of 50.84%. Also, the MDE and hexane fraction (HF) showed a significant reduction of TC, TG and LDL and related increase in HDL-C levels in diabetic treated rats.Conclusions: The extract and the fractions of Buchholzia coriacea seeds possess antihyperglycemic and antihyperlipidemic effects and showed same mechanism of action as metformin, thus providing scientific rationale for its folkloric use

Neuropharmacological evaluation of Annona senegalensis leaves

The neuropharmacological activities of methanol leaf extract (ME) of Annona senegalensis Pers (Annonaceae) and its bioactive fractions (MF and F7) were studied in rodents using pentylenetetrazol (PTZ)-induced seizures, pentobarbitone-induced sleep, apomorphine-induced stereotypy, open field, elevated plus maze (EPM) and rotarod performance tests. The extract and fractions inhibited PTZ-induced seizures, prolonged pentobarbitone-induced sleep, reduced stereotypic behaviour induced by apomorphine, decreased the frequency of line crossing and centre square entries and increased rearing in the air in the open field. The frequency of grooming and rearing against the wall were decreased, whereas the duration of grooming increased. Also, the extract and fractions increased the duration of stay in the open arm when compared to the closed arm of the EPM, and reduced the average time spent on the rotarod. Acute toxicity test showed an oral LD50 of ME greater than 5 g/kg in mice. Phytochemical analysis showed that ME tested positive for carbohydrates, reducing sugar, resins, saponins,  tannins, steroids, terpenoids, alkaloids, flavonoids and glycosides; MF tested positive for saponins, steroids, terpenoids, alkaloids, carbohydrates, reducing sugar, flavonoids and glycosides; while F7 tested positive for flavonoids. These findings suggest that leaves of A. senegalensis possess anticonvulsant, central depressant and anxiolytic-like properties attributable to flavonoids.Keywords: Annona senegalensis, anticonvulsant, anxiolytic, sedative, stereotypy

ANTIOXIDANT AND HEPATOPROTECTIVE POTENTIALS OF STEMONOCOLEUS MICRANTHUS HARMS (FABACEAE) STEM BARK EXTRACT

Objective: This study evaluated the antioxidant and hepatoprotective activities of the methanol-dichloromethane (1:1) extract of Stemonocoleus micranthus Harms (Fabaceae) stem bark (SME).Methods: In vitro ferric reducing power, hydrogen peroxide and α, α-diphenyl–β–dipicryl–hydrazyl (DPPH) free radical scavenging assays, were used to determine the antioxidant activity of SME (25, 50, 100, 200 and 400 µg/ml). Also the effects of SME (100, 200 and 400 mg/kg) on liver enzymes alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) in carbon tetrachloride (CCl4)-inducedhepaticoxidative damage were studied in rats.Results: The results showed that SME (25-400 µg/ml) significantly (P<0.01) reduced iron III (Fe3+) to iron II (Fe2+) with 400 µg/ml eliciting 135.4% reducing power. The SME demonstrated significant (P<0.01) hydrogen peroxide scavenging with 400 µg/ml eliciting 20.37% activity, comparable to ascorbic acid (20.32%). The SME (25-400 µg/ml) also elicited 77-81% DPPH free radical scavenging, lower than ascorbic acid (25-400 µg/ml) with 83-88% activity. The in vivo study showed that SME protected the rats from liver damage as shown by the reduction of liver enzymes in serum. The SME (400 mg/kg) elicited 7.7, 33.8 and 7.2% inhibition of ALP, ALT and AST respectively. The acute toxicity test revealed that SME has high margin of safety, with oral lethal dose (LD50)>5 g/kg. Phytochemical analyses on the extract revealed the presence of alkaloids, carbohydrates, flavonoids, glycosides, proteins, reducing sugars, saponins, resins, steroids, tannins, terpenoids, fats, and oils.Conclusion: The findings suggest that the methanol-dichloromethane extract of S. micranthus stem bark possess antioxidant and hepatoprotective effects.Keywords: Stemonocoleus micranthus, Antioxidant, Hepatoprotective, Albino rats, Ascorbic aci

Maximization of propylene in an industrial FCC unit

YesThe FCC riser cracks gas oil into useful fuels such as gasoline, diesel and some lighter products such as ethylene and propylene, which are major building blocks for the polyethylene and polypropylene production. The production objective of the riser is usually the maximization of gasoline and diesel, but it can also be to maximize propylene. The optimization and parameter estimation of a six-lumped catalytic cracking reaction of gas oil in FCC is carried out to maximize the yield of propylene using an optimisation framework developed in gPROMS software 5.0 by optimizing mass flow rates and temperatures of catalyst and gas oil. The optimal values of 290.8 kg/s mass flow rate of catalyst and 53.4 kg/s mass flow rate of gas oil were obtained as propylene yield is maximized to give 8.95 wt%. When compared with the base case simulation value of 4.59 wt% propylene yield, the maximized propylene yield is increased by 95%

Dichrostachys cinerea (L.) Wight et Arn (Mimosaceae) hydro-alcoholic extract action on the contractility of tracheal smooth muscle isolated from guinea-pig

<p>Abstract</p> <p>Background</p> <p><it>Dichrostachys cinerea </it>(L.) Wight et Arn. (Mimosaceae) is largely used in ethno-medically across Africa, and mainly employed for the treatment of asthma in Ivory Coast and Gabon. The paper analyses the relaxation induced by the methanolic extract of <it>D. cinerea </it>(Edici) in the guinea-pig trachea preparations (GPTPs). Purpose: This study aimed to bring out the scientific basis to the use of this plant leading to the validation of this phytomedicine.</p> <p>Method</p> <p>The aorta obtained from guinea-pigs was immediately placed in a Mac Ewen solution. Experiments were performed in preparations suspended between two L-shaped stainless steel hooks in a 10 ml organ bath containing Mac Ewen solution. The isometric contractile force of the aorta strips of guinea-pig were recorded by using a strain gauge. The different drugs were directly administered into the organ bath and the magnitude of GPTPs was evaluated.</p> <p>Results</p> <p>Phytochemical analysis of the methanolic extract of Dichrostachys <it>cinerea </it>(Edici) using chemical methods revealed the presence of flavenoids, tannins, sterols, triterpenes and polyphenols. Pharmacological studies performed in GPTPs show that of <it>Dichrostachys cinerea </it>(0.1 mg/ml - 2 mg/ml) evoked a broncho-constriction in GPTPs. Whereas, at concentration up to 2 mg/ml, Edici induced a significant dose-dependent relaxation in the GPTPs. KCl-, ACh- or histamine-evoked contractions of isolated trachea was significantly inhibited by increasing concentrations of Edici (3.5-10 mg/ml). Edici (10 mg/ml) as well as promethazine (0.25 mg/ml) significantly inhibited contractions induced by increasing concentrations of histamine (1×10^-7-1×10^-4mg/ml). In the presence of atropine at a concentration of 10^-6mg/ml, contractile response curve (CRC) evoked by ACh (1×10^-5-1×10^-2mg/ml) was significantly abolished in concentration-dependent manner. Edici did not significantly reduced ACh evoked contraction (10^-5-10^-2mg/ml).</p> <p>Conclusion</p> <p>These observations suggest that Edici could act through two mechanisms: firstly by activation of β-adrenergic or histaminergic receptors; and secondly muscarinic receptors may not be greatly involved, that justifying the use of the extract in traditional Medicine in Africa.</p

Acanthus montanus: An experimental evaluation of the antimicrobial, anti-inflammatory and immunological properties of a traditional remedy for furuncles

<p>Abstract</p> <p>Background</p> <p><it>Acanthus montanus </it>(Nees) T. Anderson (Acanthaceae) is a shrub widespread in Africa, the Balkans, Romania, Greece and Eastern Mediterranean. It is used in African traditional medicine for the treatment of urogenital infections, urethral pain, endometritis, urinary disease, cystitis, leucorrhoea, aches and pains. In southeastern Nigeria, the root is popular and acclaimed highly effective in the treatment of furuncles. This study was undertaken to experimentally evaluate the antimicrobial and anti-inflammatory properties of the root extract as well as its effect on phagocytosis and specific cell-mediated immune response which may underlie the usefulness of the roots in treatment of furuncles.</p> <p>Methods</p> <p>The aqueous root extract (obtained by hot water maceration of the root powder) was studied for effects on the growth of clinically isolated strains of <it>Pseudomonas aeruginosa </it>and <it>Staphylococcus aureus</it>. The anti-inflammatory activity was investigated using acute topical edema of the mouse ear induced by xylene, acute paw edema induced by agar in rats, formaldehyde arthritis in rats, vascular permeability induced by acetic acid in mice and heat- and hypotonicity-induced haemolysis of ox red blood cells (RBCs). Also evaluated were the effects on <it>in vivo </it>leukocyte migration induced by agar, phagocytic activity of macrophages on <it>Candida albicans </it>and specific cell-mediated immune responses (delayed type hypersensitivity reaction (DTHR) induced by sheep red blood cell (SRBC)). The acute toxicity and lethality (LD₅₀) in mice and phytochemical constituents of the extract were also determined.</p> <p>Results</p> <p>The extract moderately inhibited the growth of the test organisms and significantly (<it>P </it>< 0.05) inhibited (57%) topical acute edema in the mouse ear. It significantly (<it>P </it>< 0.05) suppressed the development of acute edema of the rat paw in a non-dose-related manner and was not effective in inhibiting the global edematous response to formaldehyde arthritis. It also inhibited vascular permeability induced by acetic acid in mice and the haemolysis of ox RBCs induced by heat- and hypotonicity. The extract increased total leukocyte and neutrophil counts and caused a significant (<it>P </it>< 0.05) dose-related increase in the total number of macrophages at the 800 mg/kg dose. On phagocytic activity, the extract evoked a significant (<it>P </it>< 0.05) increase in the number of macrophages with ingested <it>C. albicans </it>at 800 mg/kg dose, and significantly (<it>P </it>< 0.05) inhibited DTHR in a dose-related manner. Phytochemical tests on the extract revealed an abundant presence of alkaloids and carbohydrates while saponins, glycosides, and terpenoids occurred in trace amounts. Acute toxicity test established an oral and intraperitoneal LD₅₀greater than 5,000 mg/kg.</p> <p>Conclusion</p> <p>The effectiveness of the root of <it>A. montanus </it>in the treatment of furuncles may largely derive from mobilization of leukocytes to the site of the infection and activation of phagocytic activity as well as suppression of exacerbated immune responses by its constituents. Antimicrobial and anti-inflammatory activities are likely contributory mechanisms. Phytochemical constituents such as alkaloids and carbohydrates may be responsible for these pharmacological activities.</p

Studies on the antidiarrhoeal activity of Aegle marmelos unripe fruit: Validating its traditional usage

<p>Abstract</p> <p>Background</p> <p><it>Aegle marmelos </it>(L.) Correa has been widely used in indigenous systems of Indian medicine due to its various medicinal properties. However, despite its traditional usage as an anti-diarrhoeal there is limited information regarding its mode of action in infectious forms of diarrhoea. Hence, we evaluated the hot aqueous extract (decoction) of dried unripe fruit pulp of <it>A. marmelos </it>for its antimicrobial activity and effect on various aspects of pathogenicity of infectious diarrhoea.</p> <p>Methods</p> <p>The decoction was assessed for its antibacterial, antigiardial and antirotaviral activities. The effect of the decoction on adherence of enteropathogenic <it>Escherichia coli </it>and invasion of enteroinvasive <it>E. coli </it>and <it>Shigella flexneri </it>to HEp-2 cells were assessed as a measure of its effect on colonization. The effect of the decoction on production of <it>E. coli </it>heat labile toxin (LT) and cholera toxin (CT) and their binding to ganglioside monosialic acid receptor (GM1) were assessed by GM1-enzyme linked immuno sorbent assay whereas its effect on production and action of <it>E. coli </it>heat stable toxin (ST) was assessed by suckling mouse assay.</p> <p>Results</p> <p>The decoction showed cidal activity against <it>Giardia </it>and rotavirus whereas viability of none of the six bacterial strains tested was affected. It significantly reduced bacterial adherence to and invasion of HEp-2 cells. The extract also affected production of CT and binding of both LT and CT to GM1. However, it had no effect on ST.</p> <p>Conclusion</p> <p>The decoction of the unripe fruit pulp of <it>A. marmelos</it>, despite having limited antimicrobial activity, affected the bacterial colonization to gut epithelium and production and action of certain enterotoxins. These observations suggest the varied possible modes of action of <it>A. marmelos </it>in infectious forms of diarrhoea thereby validating its mention in the ancient Indian texts and continued use by local communities for the treatment of diarrhoeal diseases.</p

A review on herbal antiasthmatics

In traditional systems of medicine, many plants have been documented to be useful for the treatment of various respiratory disorders including asthma. In the last two decades the use of medicinal plants and natural products has been increased dramatically all over the world. Current synthetic drugs used in pharmacotherapy of asthma are unable to act at all the stages and targets of asthma. However some herbal alternatives employed in asthma are proven to provide symptomatic relief and assist in the inhibition of disease progression also. The herbs have shown interesting results in various target specific biological activities such as bronchodilation, mast cell stabilization, anti-anaphylactic, anti-inflammatory, anti-spasmodic, anti-allergic, immunomodulatory and inhibition of mediators such as leukotrienes, lipoxygenase, cyclooxygenase, platelet activating, phosphodiesterase and cytokine, in the treatment of asthma. This paper is an attempt to classify these pharmacological and clinical findings based on their possible mechanism of action reported. It also signifies the need for development of polyherbal formulations containing various herbs acting at particular sites of the pathophysiological cascade of asthma for prophylaxis as well as for the treatment of asthma