Preliminary phytochemical screening, antioxidant and anti-hyperglycaemic activity of Moringa oleifera leaf extracts

Moringa oleifera plant has been widely used for a vast number of folkloric medicinal purposes. The research aimed to investigate the antioxidant and antihyperglycaemic activity of Moringa oleifera leaf extracts obtained using different solvent systems for extraction. The solvent extracts of Moringa oleifera were: water extract [100% Mo WE], 50% Methanolic extract [50% MoME], 100% Methanolic extract [100% MoME], 50% Ethanolic extract [50% MoEE], and 100% Ethanolic extract [100% MoEE]. The in vitro antioxidant activity was evaluated by the use of the 1,1-diphenyl-2-picryl hydrazyl [DPPH] scavenging assay which showed the hydro-alcoholic extracts to have the highest reducing power, though lower than that of the standard, vitamin C. The hypoglyceamic activity was evaluated for the extracts at graded doses of 200mg/kg, 300mg/kg and 400mg/kg in wistar rats. Relative to the positive control, all treatment groups showed a significant statistical decrease in blood glucose levels. The decrease trends as metformin [84.14%] >50% MoEE 300mg/kg [83.72%] >MoWE 300mg/kg [82.42%] > 50% MoEE 200mg/kg [82.32%] >100% MoEE 400mg/kg [81.96%] >50% MoME [80.69%] >100% MoME 300mg/kg [78.47%] >50% MoME 200mg/kg [66.34%]. Overall, the 50% MoEE at a dose of 300mg/kg showed superior antioxidant properties, weight restorative and pronounced hypoglyceamic effects. The weight restorative effect of high dose alcoholic extract of Moringa oleifera was also observed in the study. This study establishes novel and foundational considerations for further isolation and characterization studies for the hypoglyceamic compounds in the plant

Investigation of the antioxidant activity and quantification of the amount of heavy Metals and some vitamins in carrot

Background: Carrot is a root vegetable from the Umbelliferae family. It is a biennial plant grown for their edible root. Carrots are a good source of carbohydrates and minerals like Calcium, Phosphorus, Iron and Magnesium and may contain toxic amounts of metals as a result of run off effects. It is also rich in carotene, niacin, riboflavin, thiamine and vitamin C.Objectives: To determine the amounts of toxic heavy metals, quantify the amounts of vitamins A and E and investigate the antioxidant activities of Carrot.Method: The research investigated the antioxidant properties of carrot on the basis of the radical scavenging activity on DPPH (1,1-diphenyl-2-picryl hydrazyl), heavy metal analysis were carried out using Flame Atomic Absorption Spectrophotometer while analysis of vitamins was done using HPLC (High Performance Liquid Chromatography).Result: The carrot sample analyzed contained considerable amount of some toxic metals of interest (Cr 0.024, 0.105ppm; Cu 15.76, 30.95ppm; Fe 66.94, 103.95ppm; Zn 16.57, 44.22ppm; Pb 0.018, 0.021ppm) in the leaves and root respectively. The samples also contain a very good amount of the vitamin A (12.863, 44.977ppm) and Vitamin E (0.087, 0.22ppm) in leaves and root respectively. It also showed some antioxidant activity and test positive for most phytochemicals.Conclusion: The actual concentrations of the respective heavy metals found in two parts of the D. carota samples were within the threshold limit but there was slight variation in the amount present in the root D. carota as compared to its leaf. The root had more concentrations of the metals and this could be due to the fact that the root is more exposed to these metals during plant uptake

Phytochemical Screening and Antioxidant Activities of some Selected Medicinal Plants Used for Malaria Therapy in Southwestern Nigeria

Purpose: Oxidative stress has been shown to play an important role in the development of anaemia in malaria. Indeed; increase in total antioxidant status has been shown to be important in recovery from malaria. The antioxidant activities of four medicinal plants traditionally used in the treatment of malaria in southwestern Nigeria were determi- ned. Methods: The ethanolic extracts of the leaves of Carica papaya Linn. [Caricaceae] ; stem bark of Magnifera indica Linn. [Anacardiaceae]; leaves of Psidium guajava Linn. [Myrtaceae] and the leaves of Vernonia amygdalina Del. [Compositae]; were used in the present study. The plant parts commonly used in the locality in malaria therapy were employed in this study. The plants were screened for the presence of phytochemicals and; their effect on 2;2-Diphenyl-1-picryl-hydrazyl radical (DPPH) was used to determine their free radical scavenging activity. Results: Phytochemical screening of the plants showed the presence of flavonoids; terpenoids; saponins; tannins and reducing sugars. M. indica did not contain cardiac glycosides and alkaloids while; P. guajava also showed the absence of alkaloids and anthraquinones. Anthraquinones was similarly absent from V. amygdalina. Concentrations of the plant extracts required for 50inhibition of DPPH radical scavenging effect (IC50) were recorded as 0.04 mg/ml; 0.313 mg/ml; 0.58 mg/ml; 2.30 mg/ml and 0.054 mg/ml for P. guajava; M. Indica; C. papaya; V. amygdalina and Vitamin C; respectively. Conclusion : All the plants showed potent inhibition of DPPH radical scavenging activity; P. guajava being the most potent. The free radical scavenging (antioxidant) activities of these plants probably contribute to the effectiveness of the above plants in malaria therapy

Phytochemical Screening and Free Radical Scavenging Activities of the Fruits and Leaves of Allanblackia floribunda Oliv (Guttiferae)

Purpose: To compare the phytochemical constituents in the leaves and fruits of Allanblackia floribunda and determine their free radical scavenging activity. Methods: The fruit and leaves of AF collected from the uncultivated farmlands of Okeigbo; Ondo State; Nigeria; were dried; milled and extracted with methanol. Phytochemical screening was carried out according to standard procedures. Free radical scavenging activity was determined by measuring the decrease in the visible absorbance of 2;2-diphenyl-1-picrylhydrazyl (DPPH) on addition of the plant extract. The mean inhibitory concentration (IC50); which is the concentration of extract needed to decrease the initial absorbance of DPPH by 50was determined graphically. Total phenolic; flavonoids and proanthocyanidin contents were determined by spectro-photometric methods. Results: Alkaloids; anthraquinones; tannins; saponins; steroids; terpenoids; flavonoids and cardiac glycosides were found to be present in both the fruits and leaves. Only AF fruit contained phlobatannins. IC50 values of 0.01; 0.02 and 0.1 mg/ml were recorded for Vitamin E; AF leaves and AF fruits respectively. Total phenolic; total flavonoid and proanthocyanidin contents were 65; 0.07 and 2.38 mg/g of powdered plant material for AF fruits; and 12; 51.35; 19.5 mg/g of powdered plant material for AF leaves as gallic acid; rutin and catechin equivalents respectively. Conclusion: AF leaves are five times more potent as a free radical scavenger compared to the fruits though the fruit was found to contain a higher phenolic content

Phytochemical Screening and Free Radical Scavenging Activities of the Fruits and Leaves of Allanblackia floribunda Oliv (Guttiferae)

Purpose: To compare the phytochemical constituents in the leaves and fruits of Allanblackia floribunda and determine their free radical scavenging activity. Methods: The fruit and leaves of AF collected from the uncultivated farmlands of Okeigbo; Ondo State; Nigeria; were dried; milled and extracted with methanol. Phytochemical screening was carried out according to standard procedures. Free radical scavenging activity was determined by measuring the decrease in the visible absorbance of 2;2-diphenyl-1 -picrylhydrazyl (DPPH) on addition of the plant extract. The mean inhibitory concentration (IC50); which is the concentration of extract needed to decrease the initial absorbance of DPPH by 50was determined graphically. Total phenolic; flavonoids and proanthocyanidin contents were determined by spectro-photometric methods. Results: Alkaloids; anthraquinones; tannins; saponins; steroids; terpenoids; flavonoids and cardiac glycosides were found to be present in both the fruits and leaves. Only AF fruit contained phlobatannins. IC50 values of 0.01; 0.02 and 0.1 mg/ml were recorded for Vitamin E; AF leaves and AF fruits respectively. Total phenolic; total flavonoid and proanthocyanidin contents were 65; 0.07 and 2.38 mg/g of powdered plant material for AF fruits; and 12; 51.35; 19.5 mg/g of powdered plant material for AF leaves as gallic acid; rutin and catechin equivalents respectively. Conclusion: AF leaves are five times more potent as a free radical scavenger compared to the fruits though the fruit was found to contain a higher phenolic content

Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51 percent increase in oxidative stress in lungs (control group: 0.037 ± 0.002; variable stress: 0.056 ± 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57 percent increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 ± 0.42; stressed: 3.65 ± 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Oxidative stress in the latissimus dorsi muscle of diabetic rats

The purpose of the present study was to investigate the effects of experimental diabetes on the oxidant and antioxidant status of latissimus dorsi (LD) muscles of male Wistar rats (220 +/- 5 g, N = 11). Short-term (5 days) diabetes was induced by a single injection of streptozotocin (STZ, 50 mg/kg, iv; glycemia >300 mg/dl). LD muscle of STZ-diabetic rats presented higher levels of thiobarbituric acid reactive substances (TBARS) and chemiluminescence (0.36 +/- 0.02 nmol/mg protein and 14706 +/- 1581 cps/mg protein) than LD muscle of normal rats (0.23 +/- 0.04 nmol/mg protein and 7389 +/- 1355 cps/mg protein). Diabetes induced a 92 percent increase in catalase and a 27 percent increase in glutathione S-transferase activities in LD muscle. Glutathione peroxidase activity was reduced (58 percent) in STZ-diabetic rats and superoxide dismutase activity was similar in LD muscle of both groups. A positive correlation was obtained between catalase activity and the oxidative stress of LD, as evaluated in terms of TBARS (r = 0.78) and by chemiluminescence (r = 0.89). Catalase activity also correlated inversely with glutathione peroxidase activity (r = 0.79). These data suggest that an increased oxidative stress in LD muscle of diabetic rats may be related to skeletal muscle myopathy

Effect of trolox C on cardiac contratucture induced by hydrogen peroxide

Hydrogen peroxide (H2O2) perfused into the aorta of the isolated rat heart induces a positive inotropic effect, with cardiac arrhythmia such as extrasystolic potentiation or cardiac contractures, depending on the dose. The last effect is similar to the "stone heart" observed in reperfusion injury and may be ascribed to lipoperoxidation (LPO) of the membrane lipids, to protein damage, to reduction of the ATP level, to enzymatic alterations and to cardioactive compounds liberated by LPO. These effects may result in calcium overload of the cardiac fibers and contracture ("stone heart"). Hearts from male Wistar rats (300-350g) were perfused at 31°C with Tyrode, 0.2 mM trolox C, 256 mM H2O2 or trolox C + H2O2. Cardiac contractures (baseline elevation of the myograms obtained) were observed when hearts were perfused with H2O2 (Tyrode: 5.9 + 3.2; H2O2: 60.5 + 13.9 percent of the initial value); perfusion with H2O2 increased the LPO of rat heart homogenates measured by chemiluminescence (Tyrode: 3,199 + 259; H2O2: 5,304 + 133 cps mg protein(-1) 60 min(-1), oxygen uptake (Tyrode: 0.44 + 0.1; H2O2: 3.2 + 0.8 nmol min(-1) mg protein(-1) and malonaldehyde (TBARS) foramtion (Tyrode: 0.12 + 0; H2O2: 0.37 + 0.1 nmol/ml). Previous perfusion with 0.2 mM trolox C reduced the LPO (Chemiluminescence: 4,098 + 531), oxygen uptake (0.51 + 0) and TBARS (0.13 + 0) bud did not prevent the H2O2-induced contractures (33.3 + 16 percent). ATP (Tyrode: 2.84 + 0; H2O2: 0.57 + 0) and glycogen levels (Tyrode: 0.46 + 0; H2O22: 0.26 + 0) were reduced by H2O2. Trolox did not prevent these effects (ATP: 0.84 + 0 and glycogen: 0.27 + 0). Trolox C is known to be more effective than alpha-tocopherol or gamma-tocopherol in reducing LPO though it lacks the phytol portion of vitamin E to be fixed to the cell membranes. Trolox C, unlike vitamin A, did not prevent the glycogen reduction induced by H2O2. Trolox C induced a positive chronotropic effect that resulted in higher energy consumption. The reduction of energy level seemed to be more important than LPO in the mechanism of H2O2-induced contracture.

Baroreflex and chemoreflex dysfunction in streptozotocin-diabetic rats

Several investigators have demonstrated that streptozotocin (STZ) diabetes induces changes in the autonomic control of the cardiovascular system. Changes in cardiovascular function may be related to peripheral neuropathy. The aim of the present study was to a changes in heart rate (HR) and arterial pressure (AP) as well as baroreflex and chemoreflex sensitivity in STZ-induced diabetic male Wistar rats (STZ, 50 mg/kg, iv, 15 days). Intra-arterial blood pressure signals were obtained for control and diabetic rats (N = 9, each group). Data were processed in a data acquisition system (CODAS, 1 kHz). Baroreflex sensitivity was evaluated by measuring heart rate changes induced by arterial pressure varíation produced by phenyiephrine and sodium nitroprusside injection. Increasing doses of potassium cyanide (KCN) were used to evaluate bradycardic and pressor responses evoked by chemoreflex activation. STZ induced hyperglycemia (447 ñ 49 vs 126 ñ 3 mg/dl), and a reduction in AP (99 + 3 vs 118 + 2mmHg), resting HR (296 ñ 11 vs 355 ñ 16 bpm) and plasma insulin levels (16 ñ 1 vs 57 + 11 muU/ml). We also observed that the reflex bradycardia (-1.68 ñ 0.1 vs -1.25 ñ 0.1 bpm/mmHg, in the diabetic group) and tachycardia (-3.68 ñ 0.5 vs -1.75 ñ 0.3 bpm/mmHg, in the diabetic group) produced by vasopressor and depressor agents were impaired in the diabetic group. Bradycardia evoked by chemoreflex activation was attenuated in diabetic rats (control: -l7 + 1,-86 + 19,-l85 ñ 18, -208 + 17 vs diabetic: -7 + 1,-23 ñ 5,-95 ñ 13, - 140 + 13 bpm), as also was the pressor response (control: 6 ñ 1,30 ñ 7,54 + 59 ñ 5 vs diabetic: 6 ñ 1,8 ñ 2,33 ñ 4,42 ñ 5 mmhg). In conclusion the cardiovascular responses evoked by baroreflex and chemoreflex activation are impaired in diabetic rats. The alterations of caradiovascular responses may be secondary to the autonomic dysfunction of cardiovascular control.

An in vivo method for estimating the concentration of crotamine in a solution

A very sensitive method for estimating the concentration of crotamine in a solution was developed. This method was based on the based on the time required for the appearance of permanent hyperextension of the rear legs of mice as a function of the dose administered. This method can be used to determine toxin doses as low as 0.32 mg/kg(-1). Its high specificity for crotamine means that it can be used to measure toxin concentrations in the presence of other proteins and polypeptides.

Changes in blood pressure control in aged rats

The aging process is related to several changes in cardiovascular, metabolic and autonomic functions. However, descriptions of changes in arterial pressure (AP), baroreflex sensitivity and associated variations of serum glucose and insulin are controversial. The aim of this paper was to study AP, sensitivity and changes in plasma levels of glucose and insulin of young (10 weeks, 239 ñ 4.3 g) and aged (18-24 months, 412 ñ 8.5 g) male Wistar rats AP pulses were videotaped and processed on a microcomputer, using an analog-to-digital converter (beat-to-beat analysis). Baroreflex sensitivity was evaluated measuring heart rate changes induced by mean arterial pressure (MAP) variations produced by phenylephrine and socium nitroprosside injection (N = 10 in each group). Plasma glucose (N = 10 in each group) and plasma insulin (N = 6 in each group) were quantified by a colorimetric enzymatic test and radioimmunoassay,respectively. Ther were no differences in systolic, diastolic or mean AP (110 ñ 5 vs 107 ñ 3 mmHg) between aged and young rats. The tachycardic reponse to the reduction of AP was impaired in aged compared to young rats (-1.95 ñ 0.29 vs -3.26 ñ 0.49 bpm/mmHg), while the bradycardic response to increases in AP was similar (-1.02 ñ 0.22 vs -1.5 ñ 0.26 bpm/mmHg). Basal levels of glucose (83 ñ 6 vs 62 ñ 4mg/dl) and insulin (8.3 ñ 2 vs 4 ñ 0.5 µU/ml) were different. Thus, the reflex tachycardia evoked by a fall in AP is depressed in old rats. The observed higher basal insulin and glucose levels in aged rats may contribute to the imapairment of the baroreflex control

La circulación asistida en el manejo de la angina inestable: presentación preliminar de los primeros 20 casos / The circulación assisted in management of unstable angina: preliminary report of first 20 cases

Se presenta un reporte preliminar de los primeros 20 pacientes en los cuales se utilizó la contrapulsación aórtica como método de asistencia circulatoria. Se revisan los 10 casos en los cuales se utilizó el balón de contrapulsación intraórtico en enfermos que fueron sometidos a revascularización miocárdica de urgencia. De estos 10, 8 eran portadores de angina inestable refractaria a tratamiento médico y 2 fueron operados luego de complicaciones de angioplastia coronaria transluminal percutánea. Hubo 3 muertes (30%) entre los 10 pacientes: 1 por ruptura del balón con embolismo gaseoso fatal, y por falla de ventrículo izquierdo postoperatoria con evidencia de un IM preoperatorio y 1 por un síndrome de dificultad respiratoria de adulto en el postoperatorio tardío. Se presentan los principios de acción de la contrapulsación aórtica y se revisa la literatura sobre el manejo de la angina inestable