Compensatory depression of arterial pressure and reversal of ECG abnormalities by Annona muricata and Curcuma longa in hypertensive Wistar rats.

OBJECTIVES: Increasing hypertension incidence in Sub-Sahara Africa and the current cost of management of the metabolic disorder has necessitated research on medicinal plants employed in African Traditional Medicine for hypertension. Thus, this study evaluated antihypertensive effect of Annona muricata leaves or Curcuma longa rhizomes in experimentally-induced hypertensive male Wistar rats (n=70) which were unilaterally nephrectomized and daily loaded with 1% salt. Cardiovascular and haematological changes, as well as urinalysis were determined. METHODS: Rats were uninephrectomized and NaCl (1%) included in drinking water for 42 days. Extract-treated hypertensive rats were compared to normotensive, untreated hypertensive and hypertensive rats treated with lisinopril (5 mg/70 kg) or hydrochlorothiazide (12.5 mg/70 kg). A. muricata extract or C. longa extract were administered at 100, 200 or 400 mg/kg. Blood pressure (systolic, diastolic and mean arterial) and electrocardiogram was measured on day 41. Twenty-four-hour urine samples were collected from day 42. Blood samples were collected on day 43 for haematology (PCV, red cell indices, WBC and its differentials, and platelets). RESULTS: A. muricata or C. longa extracts caused a decline in elevated blood pressure of hypertensive rats. Heart rate and QT segment reduction coupled with prolonged QRS duration were reversed in extract-treated rats, with significant increases in hemogram parameters indicating increased blood viscosity. Also, leukocyturia, proteinuria and ketonuria with increased urine alkalinity, urobilinogen and specific gravity which are classical indicators of poor prognostic outcomes in hypertension were reversed in extract-treated rats. CONCLUSIONS: In conclusion, A. muricata and C. longa have cardioprotective effect with reversal of derangements in haemogram and urinalysis associated with hypertension.

Anti-inflammatory and analgesic effects of methanol extract of red cultivar Allium cepa bulbs in rats and mice.

OBJECTIVES: Several cultivars of Allium cepa L. have been studied for anti-inflammatory and analgesic activities but there is inadequate information on such biological activities of the concentrated extracts of the Nigerian grown red cultivar A. cepa bulb. METHODS: The anti-inflammatory models used in this study were Carrageenan-induced paw oedema and formalin-induced paw lick in rats, while acetic acid-induced abdominal writhing, hot plate reaction, hot water tail flick tests in mice were the analgesic models. RESULTS: At 30 min post-induction (pi), the inhibition of paw oedema (62.50%) by 200 mg/kg of methanol extract of red cultivar A. cepa bulb (MERCACB) was significantly (p<0.001) higher than that of indomethacin (15.63%) at 10 mg/kg. The paw oedema inhibition at 60 min pi by MERCACB (76.92%) was significantly higher than that of indomethacin (41.03%). At the early phase of formalin paw-lick test, the pain reaction time (PRT) of rat treated with MERCACB (400 mg/kg) was significantly lower than that of indomethacin and the control groups. The hotplate test revealed that PRT of mice treated with 800 mg/kg of MERCACB were significantly (p<0.01) longer in comparism to indomethacin and control groups. The PRT of mice subjected to thermal pain due to hot water and treated with 800 mg/kg of MERCACB was significantly (p<0.05) longer than that of the control group. CONCLUSIONS: These findings indicate that MERCACB possesses potent anti-inflammatory and analgesic properties which confirm the traditional use of the plant for the treatment of inflammatory diseases and may be useful as a future therapeutic agent.

Atrazine in fish feed and african catfish (Clarias gariepinus) from aquaculture farms in Southwestern Nigeria.

Extensive use of atrazine as herbicide in crop farming in Nigeria may lead to its accumulation in fish feed ingredients or aquatic ecosystem from aerosol or by runoff resulting in its residue in aquatic animals. Atrazine residues were determined in fish feed and catfish (Clarias gariepinus) fillets from commercial aquaculture farms in Southwestern Nigeria by matrix solvent particle dispersion and quantification using an ELISA kit. The mean atrazine concentrations in feed and fish were about 1.3-1.5 µg/kg and 1.4-1.8 µg/kg respectively. Atrazine was mostly detected in catfish from Ogun State (91.3%) and feed from Lagos State (80.0%) with mean concentrations of 1.4 ± 0.4 µg/kg and 1.5 ± 0.5 µg/kg, respectively. Mean atrazine concentration in catfish samples from Lagos State was significantly higher (P < 0.05) than the mean concentration in catfish samples from Ogun State. This study showed that the Estimated Average Daily Intake (EADI) of atrazine in fish samples from the selected states were below the Acceptable Daily Intake (ADI) value of 6 µg/kg for herbicide residues and thus within safe limit but their presence in fish is a cause for concern.

Simulation of hemo- and biochemical toxicities associated with chronic inhalation exposure to 2,2-Dichlorovinyl dimethyl phosphate (DDVP) in Wistar rat.

DDVP is a commonly used pesticide in Nigeria and those involved with DDVP manufacturing, packaging or utilizing facilities seldom use PPE to limit pesticide exposure. The study aim was to determine the impact of chronic exposure to DDVP by monitoring hematological and biochemical changes in Wistar rats. Male rats (n = 60; 150-180 g) were exposed to graded DDVP concentrations (0%, 20 %, 40 %, 60 %, 80 % and 100 %) via inhalation route for 60 days. Body weights were initially measured and then at 20-day intervals. Blood samples were collected for hematology and serum biochemistry on day 61. Results showed significant (p < 0.05) polycythemia, neutrophilia, thrombocytosis, hepatic and renal derangement in rats exposed to DDVP. Also, albumin, AST, ALP, creatinine, blood urea nitrogen, bilirubin levels and dyslipidemia significantly increased. Cholinergic signs and stunted growth were observed in higher concentrations. Study emphasized hazards of DDVP mishandling and risks of non-compliance with PPE use by workers in-contact with DDVP, as well as misuse/abuse in animals.

Persea Americana Seeds Cause Ileal Smooth Muscle Relaxation Via Stimulation of α-1 Adrenoceptors.

The effect of methanol extract of P. americana seeds on isolated ileal smooth muscle was studied for isometric response using 10 adult rabbits of both sexes. Reactivity and agonist-antagonist responses of rabbit ileum to the extract were determined in this study. The affinity, effective concentration to give 50% response (EC50) and maximum response were calculated from the concentration response curves (CRC) obtained. The result for the reactivity study showed the seed extract of P. americana caused concentration dependent relaxation of isolated rabbit ileum with threshold responses at concentration of 1×10-9 mg/ml and 120 mg/ml respectively. The extract-antagonist study showed an upward and right shift in CRC in the presence of phenoxybenzamine, a non-selective adrenergic antagonist, with the EC50 increased from 5.01 mg/ml to 12.59 mg/ml and affinity decreased from 0.20 to 0.08. Extract-antagonist study also showed a right and upward shift in the CRC with a greater magnitude in the presence of prazosin, an α1-adrenergic antagonist, with EC50 increased from 0.32 mg/ml to 25.12 mg/ml and a consequential decrease in the affinity from 3.13 to 0.04. In the presence of propranolol, a ß-adrenergic antagonist, a downward and left shift in the CRC was observed with the EC50 and PA2 remaining constant at 0.1 mg/ml and 10 respectively. P. americana concentration-dependently reduced or inhibited gastric motility, increasing transit time which is important for food absorption, thus a pro-nutritive and antispasmodic effect. The interaction with α1-adrenoceptors is beneficially in heart failure management. The plant can be developed as a drug candidate for management of hypertension.

Utilization of the Ability to Induce Activation of the Nuclear Factor (Erythroid-derived 2)-like Factor 2 (Nrf2) to Assess Potential Cancer Chemopreventive Activity of Liquorice Samples.

INTRODUCTION: Nuclear factor (erythroid-derived 2)-like factor 2 (Nrf2) is a transcription factor that regulates expression of many detoxification enzymes. Nrf2-antioxidant responsive element (Nrf2-ARE) signalling pathway can be a target for cancer chemoprevention. Glycyrrhiza glabra, common name, 'liquorice', is used as a sweetening and flavouring agent, and traditionally, to treat various ailments, and implicated to chemoprevention. However, its chemopreventive property has not yet been scientifically substantiated. OBJECTIVE: To assess the ability of liquorice root samples to induce Nrf2 activation correlating to their potential chemopreventive property. METHODS: The ability of nine methanolic extracts of liquorice root samples, collected from various geographical origins, to induce Nrf2 activation was determined by the luciferase reporter assay using the ARE-reporter cell line, AREc32. The antioxidant properties were determined by the 2,2-diphenyl-1-picryhydrazyl (DPPH) and the ferric-reducing antioxidant power (FRAP) assays. RESULTS: All extracts exhibited free-radical-scavenging property (RC50 = 136.39-635.66 µg/mL). The reducing capacity of ferrous ion was 214.46-465.59 µM Fe(II)/g. Nrf2 activation indicated that all extracts induced expression of ARE-driven luciferase activity with a maximum induction of 2.3 fold relative to control. These activities varied for samples from one geographical location to another. CONCLUSIONS: The present findings add to the existing knowledge of cancer chemoprevention by plant-derived extracts or purified phytochemicals, particularly the potential use of liquorice for this purpose. Copyright © 2016 John Wiley & Sons, Ltd.

Comparative Cytotoxicity of Glycyrrhiza glabra Roots from Different Geographical Origins Against Immortal Human Keratinocyte (HaCaT), Lung Adenocarcinoma (A549) and Liver Carcinoma (HepG2) Cells.

Glycyrrhiza glabra L. (Fabaceae), commonly known as 'liquorice', is a well-known medicinal plant. Roots of this plant have long been used as a sweetening and flavouring agent in food and pharmaceutical products, and also as a traditional remedy for cough, upper and lower respiratory ailments, kidney stones, hepatitis C, skin disorder, cardiovascular diseases, diabetes, gastrointestinal ulcers and stomach ache. Previous pharmacological and clinical studies have revealed its antitussive, antiinflammatory, antiviral, antimicrobial, antioxidant, immunomodulatory, hepatoprotective and cardioprotective properties. While glycyrrhizin, a sweet-tasting triterpene saponin, is the principal bioactive compound, several bioactive flavonoids and isoflavonoids are also present in the roots of this plant. In the present study, the cytotoxicity of the methanol extracts of nine samples of the roots of G. glabra, collected from various geographical origins, was assessed against immortal human keratinocyte (HaCaT), lung adenocarcinoma (A549) and liver carcinoma (HepG2) cell lines using the in vitro 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide cell toxicity/viability assay. Considerable variations in levels of cytotoxicity were observed among various samples of G. glabra.

Studies on the anti-inflammatory, analgesic and antipyrexic activities of betulinic acid derived from Tetracera potatoria.

BACKGROUND: The anti-inflammatory and anti-nociceptive activity of betulinic acid (BA) was investigated in this study. The triterpene was isolated from the ethyl acetate extract of Tetracera potatoria and its structure was verified by IR and NMR spectroscopy. The bioactivity of this compound was assessed using carrageenan-induced paw oedema in rats and carrageenan-induced pulmonary oedema in mice for the anti-inflammatory activity, while acetic acid-induced writhing test in mice and zymosan-induced fever in rats were used for analgesic test. MATERIALS AND METHODS: Rats and mice were randomly divided into groups of five animals. For each experiment, betulinic acid at 10, 20 or 40mg/kg b.w was administered intraperitoneally to the first three groups respectively. The fourth group was administered with indomethacin (10mg/kg) or acetylsalicylic acid (150mg/kg), while the fifth group was administered with distilled water (10ml/kg). Data obtained were expressed as mean±S.E.M and significant differences were determined at p<0.05. RESULTS: BA significantly reduced carrageenan-induced paw oedema by 11.0%, 45.7%, 68.6% or pulmonary oedema by 25.6, 29.2 and 45.13% dose dependently. 40 mg/kg of BA inhibited paw oedema by 68.6% comparably to acetylsalicylic acid (71.4%) or indomethacin (51.33%) respectively. Abdominal writhing was also significantly (p<0.05) reduced to 17.20 writhes by BA (40mg/kg) comparable to Indomethacin (16.3writhes). Fever was inhibited by BA most significantly by 3hours post-injection of zymosan (1.00, 1.45, 0.00°C) and this inhibitory effect was higher than that observed for acetylsalicylic acid (0.30°C). CONCLUSION: Betulinic acid derived from Tetracera potatoria exhibited potent anti-inflammatory, analgesic or antipyrexic activity which is comparable to indomethacin or acetylsalicyclic acid.