Research Publications

Arthur Nwafor

Drug-induced shape change in erythrocytes correlates with membrane potential change and is independent of glycocalyx charge

Arthur Nwafor, W. Terence Coakley                         15 September 1985

 

Abstract

The influence of the anionic drugs indomethacin, barbitone, salicylate and the cationic drugs chlorpromazine and tetracaine on the morphology of human erythrocytes suspended in solutions of different chloride concentration (thus altering cell membrane potential) and constant osmolality, has been examined. As expected, the anionic and cationic drugs produced echinocytes and stomatocytes respectively in 145 mM NaCl. The cationic drugs induced fewer stomatocytes in 60 mM chloride than in 145 mM chloride at 37°. Tetracaine induced echinocytes in 60 mM chloride at 20°. Indomethacin and barbitone produced echinocytes in 145 mM chloride and stomatocytes in 60 mM chloride. Salicylate no longer produced echinocytes when the chloride concentration was reduced. Cells exposed to salicylate in 60 mM chloride were less cupped than the control cells. We suggest that the distribution of the charged form of the drug across the membrane is in equilibrium with the distribution of chloride ions. Changes in the intracellular drug concentration when the extracellular chloride is varied could then account for the observed shape changes in a manner which is consistent with the bilayer couple hypothesis for drug-membrane interactions.

Cell glycocalyx charge depletion did not affect the shape induced by either the cationic or anionic drugs. The result suggests that any sialic acid dependent electric potential at the bilayer surface is small compared to the cell's zeta potential.

http://www.sciencedirect.com/science/article/pii/0006295285903545

 

 

Tetracaine modifies the fragmentation mode of heated human erythrocytes and can induce heated cell fusion

W. Terence Coakley, Arthur Nwafor, John Owen Thomas Deeley

 

Abstract

It is known that human erythrocytes in saline fragment by development of an unstable surface wave on the cell rim when cells are heated through the denaturation temperature of the structural protein, spectrin. Here the influence of tetracaine on the fragmentation process has been recorded and analysed by video microscopy of cells heated in rectangular glass microcapillaries. The number of waves per cell rim decreases with increasing tetracaine concentration until, at 0.5 mM tetracaine, wave growth on the cell rim is suppressed on most cells and the cells internalize membrane at the cell dimple. The rate constant for the change in the number of waves per cell with increasing tetracaine concentration is 9.6 mM−1 at a heating rate of 0.5 K/s. 50% of heated cells internalize membrane at 0.14 mM tetracaine. When cells are heated rapidly in suspension in test tubes the presence of tetracaine reduces the temperature for 50% haemolysis from 66°C for washed control cells to 60.5°C for cells in 2 mM tetracaine. Cells heated in microcapillaries in tetracaine concentrations of 3 mM and higher begin to swell before the spectrin denaturation temperature is reached. Cell fusion was observed at and above the spectrin denaturation temperature in cells heated in 3 and 4 mM tetracaine. It was also noted that the morphology of erythrocytes maintained in 3.6 mM tetracaine for times up to 30 min at 37°C or 20°C was strongly dependent on temperature and time.


Keywords

  • Externalization;
  • Internalization;
  • Tetracaine;
  • Cell fusion;
  • Surface wave growth;
  • (Erythrocyte membrane)

19 January 1983                http://www.sciencedirect.com/science/article/pii/0005273683904169

 

 

Charge-independent effects of drugs on erythrocyte morphology

Arthur Nwafor, W.Terence Coakley

15 March 1986

Abstract

The effects of chlorpromazine, tetracaine, indomethacin, barbitone and benzyl alcohol on human erythrocyte shape have been examined. Cationic and anionic drugs produced stomatocytes and echinocytes respectively as expected for cells in isotonic saline. Particular attention has been directed here to some features of drug induced morphology change which are independent of the charge of the drug. It was found that (i) the direction (increase or decrease) of the extent of morphological change as temperature was increased from 20 to 37°, (ii) the exposure time for maximum shape change (0–2 min), and (iii) the time course of cell morphology (0–30 min) were different for similarly charged drugs. The influence of low concentrations of the drugs on the thermal fragmentation patterns of the cells has been determined. A single index has been derived which allows comparison of the morphological effects of cationic and anionic drugs.

It was concluded that, while the type (stomatocyte or echinocyte) of shape change observed was dependent on the charge of the drug, cell morphology at drug concentrations high enough to produce marked shape change at 37° was strongly influenced by charge independent drug-specific effects.


http://www.sciencedirect.com/science/article/pii/0006295286900821

 

 

CONTRACEPTIVE EFFICACY OF HYDRO-METHANOLIC FRUIT EXTRACT OF XYLOPIA AETHIOPICA IN MALE ALBINO RATS

*Ologhaguo M. Adienbo; Arthur Nwafor. and Ronami S. Ogbomade.

2013

ABSTRACT

The rising human population, particularly in the developing countries, and the attendant socioeconomic effects necessitates the need for its effective regulation. This study aims at exploring the contraceptive efficacy of the fruit extract of Xylopia aethiopica (Dunal) A Rich, a plant with wide ethnomedicinal, pharmacological and social values, in combating this public health challenge. Forty eight adult male and 48 female wistar rats were used for the study. The males, randomly selected into two groups: 30 days treatment and 30 days reversal groups; each further divided into 3 test and 1 control group of 6 animals each. Daily oral doses of 0.5, 2.0 and 10.0mg/kg body weight respectively were given to the test groups for 30 days followed by 30 days of extract withdrawal. 6 animals were sacrificed from each treatment group animals on day 31 and on day 61 for the reversal group animals. Body weight of the animals were measured at beginning of study and before each sacrifice. Fertility test was done after 30 days of extract treatment and after 30 days withdrawal while testicular and epididymal weight, testosterone as well as sperm parameters were assessed on the day of each sacrifice. Results show a reversible dose dependent negative effect in body and organ weight, sperm parameters and in fertility parameters. Therefore, xylopia aethiopica has antifertility potentials which could be explored for contraceptive purposes.

 

Key words: xylopia aethiopica, contraceptive, antifertility, reproductive function.

http://ijabbr.com/pdf_7799_6bf9579b1e7aa3b4e8e59586f8d50541.html

 

 

HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY (HPTLC) FINGERPRINT PROFILE OF HYDROMETHANOLIC CHLOROFORM EXTRACT OF XYLOPIA AETHIOPICA (DUNAL) A. RICH (ANNONACEAE) FRUITS

Arthur Nwafor, Doris Chinwe Nworah, MacStephen O Adienbo November 08, 2014;

ABSTRACT

Dried fruits of xylopia aethiopica are used in traditional system of medicine for the treatment of many diseases in Nigeria. This study evaluated the HPTLC fingerprint in the chloroform fraction of aqueous- methanol (1:4 w/w) extract of xylopia aethiopica fruits. The results revealed the purity, identity/structural characteristics and bioactive components of about eighty-one (81) phytotherapeutic chemicals consisting phytosteroid γ-Sitosterol (1%), carbohydrate (1.5%), alkaloids (22 %), flavonoids (31% ) terpenes (44.5%)   as well as fatty acids ( unsaturated, 54.3% and saturated 22.2%) and others (protein/amino acids etc., 23.5%) which have important clinical implications in determination of molecular targets and /or mechanisms of action of the physio-chemicals responsible for the various biological activities.

 

KEYWORDS: HPTLC, Xylopia Aethiopica, Fingerprint

http://bmrjournals.com/uploads/0777b2dc49de10e77f3db80b3f164a4d9b22c74baf7e5006c33325c6138429e5/Manuscript/2015-03-02_06-21-14-AMPM%2011.pdf

 

 

Prolonged exposure to oil and gas flares ups the risks for hypertension

Egwurugwu, Jude Nnabuife1, *, Nwafor, Arthur                     2013

Abstract: This study was done to assess the impacts of prolonged exposure to oil/gas flares on blood pressure measures in humans in the Niger Delta Region of Nigeria. The study was carried out among chronically exposed residents (475) and non-exposed individuals (315). All the subjects were matched for age, sex, occupation, education. Blood pressure was measured with manual mercury sphygmomanometer in sitting position after at least 10 minutes rest. The results showed that the test group subjects had statistically significant increase in systolic blood pressure(SBP),diastolic blood pressure(DBP) and mean arterial blood pressure(MAP) compared with the control(p<0.05). The males had higher prevalence of high blood pressure than the females (p<0.05). Results also showed that the blood pressure measures increased with age. In conclusion, prolonged exposure to oil/gas flares increased the incidence of hypertension and this may increase the risks for cardiovascular diseases.

 

Keywords: Gas Flare, Hypertension, Prolonged Exposure, Cardiovascular Disease

http://contropiano.org/img/2014/10/10.11648.j.ajhr.20130103.15.pdf

 

 

Impairments in testicular function indices in male wistar rats: a possible mechanism for infertility induction by Xylopia aethiopica fruit extract

Ologhaguo Macstephen Adienbo*, Arthur Nwafor, Datonye Victor Dapper

20 December 2014

ABSTRACT

Background: The accumulating evidence about alterations in male fertility necessitates the need to screen more medicinal plants for their effect on male reproductive functions. This study is aimed at evaluating the effects of fruit extract of Xylopia aethiopica on testicular functions in males using wistar rats as models.

Methods: Forty eight adult male rats, randomly divided into four groups of 12 each, were used for the study. Group 1 (control), while groups 2, 3 and 4 (test groups). Daily oral doses of 0.5, 2.0 and 10.0 mg/kg b.w. of hydro-methanol extract were given to the test groups for 30 days followed by 30 days withdrawal. From each group, 6 animals were sacrificed on days 31 and 61 of the study and samples collected: Testes and epididymis were each weighed; blood was assayed for serum testosterone; testes processed for tissue biochemical studies.

Results: Results show significant (P <0.05) reductions in the weight of reproductive organs, serum testosterone; testicular glycogen, cholesterol, protein and malondialdehyde; while testicular superoxide dismutaase increased.

Conclusions: It was concluded that Xylopia aethiopica impairs testicular functions in rats and therefore fertility in males.

 

Keywords: Xylopia aethiopica, Testicular functions, Antifertility, Infertility

https://www.researchgate.net/profile/Ologhaguo_Adienbo2/publication/276305854_Impairments_in_Testicular_Function_Indices_in_Male_Wistar_Rats_A_Possible_Mechanism_for_Infertility_Induction_by_Xylopia_aethiopica_Fruit_Extract/links/55a01b1308ae967fb3e96f03.pdf

 

 

ISSN (e)-2347-176x

The Beneficial Effects of Methanol Extract of Annona Muricata Seeds on Acute Hemolytic Anemia in Albino Wistar Rats

 

Agbai Emmanuel Onuka 1, Mounmbegna Pouonkoussou Emmanuel 2

Professor Nwafor Arthur       Agbai Emmanuel Onuka

 

2014

 

Abstract

The effect of methanol extract of annona muricata seed on packed cell volume, hemoglobin concentration, red cell count, alanine and aspartate aminotransferases, and alkaline phosphatases was investigated using albino wistar rats. Acute hemolytic anemia was induced with phenylhydrazine. The rats packed cell volume was used to determine anemia. Only rats that exhibited anemia were used. They were treated with annona muricata extract for four weeks and these hematological and liver enzymes were investigated. The results showed that extract caused a significant increase in packed cell volume, hemoglobin concentration, and red cell count (P < 0.05), but caused a fall in alanine and aspartate aminotransferases, and alkaline phosphatases (P < 0.05) back to normal. The histopathological studies showed absence of and/or mild liver congestion and inflammation after treatment with extract.The results suggest that annona muricata seed extract is beneficial in the treatment of hemolytic anemia induced liver injury.

 

Keywords: annona muricata. phenylhydrazine. packed cell volume. hemoglobin concentration. red blood cell. alanine aminotransferase. aspartate aminotransferase. alkaline phosphatase

 

https://www.researchgate.net/profile/Philippe_Emmanuel_Mounmbegna/publication/262188035_The_Beneficial_Effects_of_Methanol_Extract_of_Annona_Muricata_Seeds_on_Acute_Hemolytic_Anemia_in_Albino_Wistar_Rats/links/00b49536ffa3b1c34b000000.pdf

 

 

Jun, 2014 ISSN: 2277 – 4688

The hematological action of ethanol extracts of Gongronema latifolium and Ocimum gratissimum in Alloxan induced Diabetic rats

Agbai Emmanuel Onuka1, Prof. Nwafor Arthur2, Ugwu Felix Nnaemeka

 

ABSTRACT

Hematological indices after treatment with low dose concentration of individual extract of gongronema latifolium (200 mg/kg), ocimum gratissimum (200 mg/kg) and combined extracts of gongronema latifolium and ocimum gratissimum (400 mg/kg) in alloxan induced diabetes mellitus was studied in rats for thirty days. The PCV, Hb concentration, RBC count, MCV, MCH and MCHC were evaluated. The results showed a significant increase (P < 0.05) in PCV, Hb concentration and RBC count in groups administered with individual extracts and combined extracts without statistically significant difference (P > 0.05) in MCV, MCH and MCHC. It is concluded that low dose concentration of ethanol extracts gongronema latifolium, ocimum gratissimum and/or combined extracts increased PCV, Hb concentration and RBC count without change in MCV, MCH and MCHC levels.

 

Keywords: Gongronema latifolium, Ocimum gratissimum, Blood, Alloxan.

 

http://www.ijapbc.com/files/05-10-2015_1/03-3205R.pdf

 

 

ISSN (e)-2347-176x

Polyherbal Extract of Ocimum Gratissimum and Gongronema Latifolium on Reproductive Functions in Alloxan Induced Diabetic Male Rats

 

Author:

Agbai Emmanuel Onuka*, Mounmbegna Pouonkoussou Phillpe Emmanuel** Prof. Nwafor Arthur***

 

Abstract

Background: Reproductive functions are impaired in diabetes mellitus. Polyherbal extracts from ocimum gratissimum and gongronema latifolium extracts on reproductive hormones and sperm parameters were studied in alloxan induced diabetic rats.

Materials and Methods: Twenty five adult male albino rats were used in the study. Twenty rats were made diabetic using 100 mg/kg body weight of alloxan monohydrate (intraperitoneal injection). The rats were divided into five groups I (control), II (diabetic control), III, IV and V. The rats were treated with 200mg/kg of ocimum gratissimum (group III), 200mg/kg of gongronema latifolium (group IV), and 200mg/kg per extract of ocimum gratissimum and gongronema latifolium (group V) for 21 days.

Results: The rats treated with polyherbal extracts showed significantly reduced levels of FSH, LH, testosterone, sperm count, sperm motility, sperm morphology and viability. The same results was obtained in rats treated with gongronema latifolium (200mg/kg) except in rats treated ocimum gratissimum extract (200mg/kg) that showed elevated testosterone levels.

Conclusion: These findings showed that polyherbal treatment from ocimum gratissimum and gongronema latifolium do not restore reproductive functions in alloxan induced diabetic rats.

 

Keywords: gongronema latifolium. ocimum gratissimum. testosterone. follicle stimulating hormone. luteinizing hormone. sperm parameters

 

http://jmscr.igmpublication.org/v2-i4/36%20jmscr.pdf

 

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