Mechanisms of action of traditional herbal medicines used in the management of diabetes mellitus: a review of the literature

Background: The prevalence of diabetes mellitus is increasing rapidly in both developed and developing countries. There are various conventional medicines used for the management of the disease, but there is also increased interest in the use of traditional herbal medicines. Although the concepts of illness and diseases in traditional medicine may differ from conventional medicine the outcomes are similar. The antihyperglycemic effects of various herbal medicines prescribed by traditional healers in the management of diabetes mellitus have been proven scientifically using several in-vitro and in-vivo models as well as clinical studies in humans.Materials and methods: Literature search was done in several databases. Firstly, the search was conducted using the key terms: diabetes mellitus and traditional medicine, diabetes mellitus and herbs, diabetes mellitus and plants, traditional concepts of health and sickness and diabetes mellitus. After identifying the herbs or plants used in diabetes a search was then conducted by name of herb and efficacy in management of diabetes mellitus.Results: This review highlights the similarities and differences in mechanisms of action of various traditional herbal medicines and conventional medicines. The major observation is that, herbal medicines often have multiple mechanisms of action ideally making them combination therapies. The review further highlights the need to develop an algorithm of a minimum battery of in-vitro and animal studies that can provide solid evidence of the potential of traditional medicines as anti-diabetic treatments.Conclusion: Traditional herbal medicines often have multiple phytoconstituents and hence multiple mechanisms of action ideally making them combination therapies.Keywords: traditional herbal medicines, diabetes mellitus, mechanisms of actio

Enhanced hypoglycaemic effects of metformin by valsartan in a diabetic rat model

The objective of this study was to establish the effect of valsartan on the hypoglycaemic effect of metformin. Forty-four 8-week-old Sprague-Dawley rats were fed on a high fat diet or standard diet for six weeks. Diabetes mellitus was induced by administering alloxan monohydrate 120 mg/kg intraperitoneally in rats on high fat diet. Valsartan had no significant effect on blood glucose levels in non-diabetic rats. Treatment of diabetic rats with a combination of metformin and valsartan at 5mg/kg (-10.8±8.5%), 15 mg/kg (-43.0±13.7%), and 30 mg/kg (-28.6±9.1%) for 14 days resulted in significant differences in the change in blood glucose levels compared to treatment with metformin alone (+9.5±9.1%) (F=4.351; d.f.=3;16; p=0.0201). Valsartan enhanced the hypoglycaemic effects of metformin in diabetic rats after two weeks of treatment. However, valsartan did not have significant effect on glucose tolerance in both nondiabetic and diabetic rats.Keywords: hypoglycaemia, valsartan, metformin, diabete

Effect of Irbesartan on Glucose Tolerance in a Type 2 Diabetes Mellitus Mouse Model

Background: Angiotensin receptor blockers (ARBs) have been reported to affect glycaemic control in both animals and humans. A few studies have evaluated the effects of irbesartan on blood glucose levels and ARBs are recommended in patients with comorbid diabetes and hypertension. However, the effect of irbesartan on insulin resistance and glucose tolerance is inconclusive and contradicting. Objectives: To evaluate the effect of irbesartan on blood glucose levels and glucose tolerance in diabetic and non-diabetic mice. Materials and methods: Diabetes was induced in 18 obese BALB/c mice fed on high fat diet using alloxan monohydrate 150mg/kg via the intra-peritoneal route. Non-diabetic mice were assigned to three treatment groups (n=6/group) and each group received either of the following treatments: 20mg/kg irbesartan or 75mg/kg irbesartan or vehicle. Diabetic mice were also divided into three groups and each group received one of the three treatments mentioned above. Drug administration was done daily via oral gavage for 14 days. Blood glucose levels were measured on day 1 (baseline values), day 8, and day 13 of treatment.  An oral glucose tolerance test was carried out on day 14 after administration of 50% dextrose at the dose of 1g/kg body weight. Blood glucose levels at 15, 30, 60 and 120 minutes were measured during the oral glucose tolerance test. Results: Irbesartan at the dose of 20mg/kg (-39.44% ±8.96, p=0.0177) and 75mg/kg (-40.07% ±6.27, p=0.0111) significantly lowered blood glucose levels in diabetic mice. However, irbesartan 20mg/kg (-14.87% ±10.13, p>0.9999) and 75mg/kg (-9.07%±3.77, p>0.9999) did not significantly change blood glucose levels in non-diabetic mice. In non-diabetic mice there was only a modest difference in AUC in the irbesartan20mg/kg (AUC=28.73mmol/Lmin, p=0.6435), 75mg/kg (AUC=26.66mmol/Lmin, p>0.9999) compared to the non-diabetic control (AUC=26.63 mmol/Lmins). Although there was a slight improvement in glucose tolerance in diabetic mice, irbesartan 20mg/kg (AUC=55.35mmol/Lmin, p>0.9999) and 75mg/kg (AUC=45.54mmol/Lmin, p=0.1737) had no significant effect on glucose tolerance compared to the diabetic control group (AUC=63.53mmol/Lmin). Conclusion: At standard treatment doses, irbesartan had a significant hypoglycaemic effect without significantly improving glucose tolerance in diabetic mice. Key words: Irbesartan, glycemic effects, glucose tolerance, Type 2 diabetes, mouse mode

ACUTE AND SUB-ACUTE TOXICITY OF UTHULI LWEZICHWE™, A TRADITIONAL MEDICINE USED IN THE MANAGEMENT OF DIABETES MELLITUS IN KWAZULU NATAL, SOUTH AFRICA

Background: The number of people using traditional medicines in the management of chronic diseases is increasing. The safety profile of some of the formulations, however, has not been scientifically demonstrated. This study assessed the acute and sub-acute toxicity of Uthuli Lwezichwe™ (UL), a traditional medicine used by a traditional healer in the management of diabetes mellitus. Materials and Methods: In the acute toxicity assay, one female Sprague dawley rat was administered 1000mg/kg body weight (BW) of Uthuli lwezichwe™ and observed for 14 days. In the sub-acute assay, 24 Sprague dawley rats were randomized into four groups. With one group as the control, the other groups were administered varying daily doses (100 mg, 300 mg, 1000 mg/kg BW) of UL for 28 days. Phytochemical analysis of UL was done using Liquid Chromatography – Quadrupole Time of Flight - Mass Spectrometer (LC-QTOF-MS). Results: There were no significant differences in liver function biomarkers and kidney function biomarkers between the control and all the treatment groups. Histological examination of the kidney however, showed enlarged bowman’s space and distal convoluted tubule diameter and area in the 1000mg/kg UL treated group compared to the control group. Similarly, histological examinations of the liver showed increased sinusoidal space and decreased central vein area in the 1000mg/kg UL treated group. A number of phytoconstituents were identified in UL. Conclusion: The maximum safe dose was determined to be between 300 – 1000 mg/kg BW. We recommend a chronic toxicity study to assess the long-term effects

MECHANISMS OF ACTION OF TRADITIONAL HERBAL MEDICINES USED IN THE MANAGEMENT OF DIABETES MELLITUS: A REVIEW OF THE LITERATURE

Background: The prevalence of diabetes mellitus is increasing rapidly in both developed and developing countries. There are various conventional medicines used for the management of the disease, but there is also increased interest in the use of traditional herbal medicines. Although the concepts of illness and diseases in traditional medicine may differ from conventional medicine the outcomes are similar. The antihyperglycemic effects of various herbal medicines prescribed by traditional healers in the management of diabetes mellitus have been proven scientifically using several in-vitro and in-vivo models as well as clinical studies in humans. Materials and methods: Literature search was done in several databases. Firstly, the search was conducted using the key terms: diabetes mellitus and traditional medicine, diabetes mellitus and herbs, diabetes mellitus and plants, traditional concepts of health and sickness and diabetes mellitus. After identifying the herbs or plants used in diabetes a search was then conducted by name of herb and efficacy in management of diabetes mellitus. Results: This review highlights the similarities and differences in mechanisms of action of various traditional herbal medicines and conventional medicines. The major observation is that, herbal medicines often have multiple mechanisms of action ideally making them combination therapies. The review further highlights the need to develop an algorithm of a minimum battery of in-vitro and animal studies that can provide solid evidence of the potential of traditional medicines as anti-diabetic treatments. Conclusion: Traditional herbal medicines often have multiple phytoconstituents and hence multiple mechanisms of action ideally making them combination therapies

Are expenses and losses incurred as a result of embezzlement tax-deductable?

The study analyses whether taxpayers may deduct for tax purposes losses and expenses which they incur as a result of embezzlement activities. Whilst the SCA finally got the chance and held that income which is illegally obtained by a taxpayer as a result of illegal activities indeed forms part of the taxpayer s gross income, the SCA is still to get the chance to pronounce whether taxpayers should be allowed to deduct expenses and losses which are incurred as a result of embezzlement activities which may be perpetrated by shareholders, partners, senior managers, junior employees and people unrelated to the taxpayers. The study utilises legislation, cases and commentary from South Africa and other jurisdictions. For a deduction to be allowed for losses and expenditure which are incurred as a result of embezzlement, it must be established that losses and expenditure which the taxpayer incurs as a result of embezzlement are sufficiently close to the taxpayer s production of income as held by the court in CoT v Rendle.1 As required by section 11(a) of the Act, embezzlement losses and expenditure which are incurred in the production of income may be allowed for deduction. For a deduction to be allowed, the risk of incurring the loss or the expenditure must be inherent to the business enterprise of the taxpayer. The study concludes by proffering recommendations which our courts can consider when they get an opportunity to pronounce on whether losses and expenditure which taxpayers incur as a result of embezzlement activities come before our courts again. The study recommends that losses and expenditure which are incurred by taxpayers as a result of embezzlement activities by partners and shareholders in a firm should not be allowed for deduction, and that they should rather be treated as drawings by those partners or shareholders. The study recommends that losses and expenditure which are incurred as a result of embezzlement activities by senior managers in a firm may be allowed if the senior managers did not occupy a position which is akin to that of a shareholder of the company. The study recommends, in line with the decision in Rendle2 that losses and expenditure which are incurred as a result of embezzlement activities by people unrelated to the company should be allowed for deduction. The study also recommends that losses and expenses incurred as a result of embezzlement by junior employees should be allowed for deduction. Finally, the study recommends that as embezzlement activities are secretive and may take long to be detected, the Act must be interpreted flexibly so that taxpayers are not restricted to claiming embezzlement losses and expenditure in the years in which the embezzlement activities occur, as taxpayers may be disadvantaged if they discover embezzlement after some period. Taxpayers should be allowed to claim for tax deductions in the year which they discover the embezzlement losses, even though the losses might have been incurred in prior years. This is the approach which was advanced in the United States cases in Alison v United States3 and United States v Stevenson-Chislett Inc4 and also the approach which is used by the United States Treasury.Mini Dissertation (LLM)--University of Pretoria, 2015.Mercantile LawLLMUnrestricte

Nurses’ experiences on the use of Afrikaans for nursing documentation and handovers at a central hospital in the Western Cape

Thesis (MCur)--Stellenbosch University, 2017.ENGLISH SUMMARY : Background: A traditionally Afrikaans central hospital in the Western Cape continues to use mostly Afrikaans for handovers and documentation despite an increase in the presence of isiXhosa speaking nurses. As not all isiXhosa speaking nurses are Afrikaans competent, it was necessary to explore the experiences of nurses regarding the use of Afrikaans for documentation and handovers, and how it may influence team cohesion and the quality of patient care rendered. Methods: A qualitative approach with a descriptive phenomenological design was used to explore nurses’ experiences on the use of Afrikaans for nursing documentation and handovers at a central hospital in the Western Cape. Purposive sampling was applied to select 12 participants of different language backgrounds and nursing categories. Permission to conduct the study was granted by the Health Research Ethics Committee of Stellenbosch University, the central hospital where the study took place and the individual participants. Data collection occurred with the use of semi-structured interviews which were transcribed verbatim and analysed using Colaizzi’s seven-step phenomenological method. Results: The four themes that formed the essential structure of the phenomenon were: differences which disunite, reverberations, historical influences and language discourses. Participants from different racial and language groups had varying experiences of the use of Afrikaans in the workplace. Language incompatibilities and the hegemonic role of Afrikaans in certain wards caused feelings of being ‘othered’, isolation and team divisions. Non-Afrikaans speaking participants felt that the use of Afrikaans for handovers and documentation impeded their ability to perform certain nursing duties and contributed to instances of omitted nursing care which may affect the quality of care rendered. Participants cited historical occurrences such as Apartheid as contributing to the use of Afrikaans at the institution and implicated those in higher positions for perpetuating the disregard for non-Afrikaans speakers. Certain Afrikaans speakers were adamant about holding on to their language lest it go into extinction. Some participants from both language groups felt that a common language, preferably English, would benefit all nurses involved in patient care. Conclusion: The findings of this study demonstrated that the use of Afrikaans for documentation and handovers does not contribute to team cohesion and the rendering of quality patient care. This could be attributed to the perceived lack of managers to enhance the implementation of language practices that accommodates non-Afrikaans speaking staff. It is recommended that institutions should implement language policies relevant to their nursing population demographics in order to improve quality of patient care delivered and increase cohesion of multi-cultural teams.AFRIKAANSE OPSOMMING : Agtergrond: `n Tradisioneel Afrikaanse sentrale hospitaal in die Wes-Kaap gaan voort om meestal Afrikaans vir verslaggewing en dokumentasie te gebruik, ten spyte van `n toename in die teenwoordigheid van isiXhosa-sprekende verpleegsters. Siende nie alle isiXhosa-sprekende verpleegsters ook Afrikaans magtig is nie, was dit nodig om verpleegsters se ervarings te ondersoek oor die gebruik van Afrikaans vir dokumentasie en verslaggewing, en hoe dit spaneenheid en die gehalte van die gelewerde pasientsorg beinvloed. Metodes: `n Kwalitatiewe benadering met `n beskrywende fenomenologiese ontwerp was gebruik om verpleegsters se ervarings rakende die gebruik van Afrikaans vir verplegingsdokumentasie en verslaggewing by `n sentrale hospitaal in die Wes-Kaap te ondersoek. Doelgerigte steekproefneming is aangewend om 12 deelnemers van verskillende taal agtergronde en verpleegkategoriee te kies. Toestemming om die studie te loods is van die Gesondheidsnavorsing- en Etiekkommittee te Universiteit Stellenbosch, die sentrale hospitaal waar die studie plaasgevind het en die individuele deelnemers verkry. Dataversameling is deur middel van semi-gestruktureerde onderhoude wat verbatim getranskribeer is, gedoen en volgens Colaizzi se sewe-stap fenomenologies metode geanaliseer. Resultate: Die vier temas wat die essensiele struktuur van die fenomeen geskep het was: verskille wat verdeel, nagevolge, historiese invloede en taalgesprekke. Deelnemers van verskillende ras- en taalgroepe het verskillende ervarings oor die gebruik van Afrikaans in die werksplek gehad. Die onverenigbaarheid van taal en die oorheersende rol van Afrikaans in sekere sale het die gevoel van "anderswees", isolasie en verdeeldheid in die span geskep. Nie-Afrikaanssprekende deelnemers het gevoel dat die gebruik van Afrikaans vir verslaggewing en dokumentasie hulle vermoens beperk het om sekere verplegingstake te voltooi, en dat dit bygedra het tot gevalle van die gebrek aan verpleegsorg wat die gehalte van pasientsorg mag beinvloed. Deelnemers het historiese gebeurtenisse soos Apartheid genoem as een van die bydraende faktore tot die gebruik van Afrikaans by die onderneming en het diegene in hoer posisies geimpliseer vir die voordurende minagting van nie-Afrikaans sprekendes. Sekere Afrikaanssprekendes was vasbeslote om vas te hou aan hulle taal uit vrees dat dit tot uitsterwing gedoem sal wees. Sommige deelnemers van altwee taalgroepe het gevoel dat `n gemeenskaplike taal, verkieslik Engels, alle verpleegsters betrokke in pasientesorg sal bevoordeel. Gevolgtrekking: Die bevindinge van die studie het gedemonstreer dat die gebruik van Afrikaans vir dokumentasie en verslaggewing nie tot hegtigheid van die span en die lewering van gehalte verpleegsorg bydra nie. Dit kan toegeskryf word aan die waargeneemde trae bydraes van bestuurders om die implementering van taalpraktyke wat nie-Afrikaanssprekende personeel akkommodeer, te verhoog. Daar word aanbeveel dat ondernemings taalbeleide wat relevant is tot hulle verpleegsters se populasie demografie implementeer, ten einde die kwaliteit van pasientesorg en begrip tussen multi-kulturele spanne te bevorder

Effect of irbesartan on blood glucose levels in a mice model of type 2 diabetes mellitus

Angiotensin receptor blockers (ARBs) have been reported to affect glycaemic control in both animals and humans. A few studies have evaluated the effects of irbesartan on blood glucose levels. However, only one study evaluated the effect of irbesartan on insulin resistance and glucose tolerance. Objective: To evaluate the effect of irbesartan on blood glucose levels and glucose tolerance in diabetic and non-diabetic mice Method: A total of 48 mice were divided into 8 groups (n=6) where group 1-4were fed on standard diet and group 5-8were fed on high fat diet. Diabetes was induced in mice fed on high fat diet using alloxan monohydrate 150mg/kg via the intra-peritoneal route. Group 1, 2 and 3 were non-diabetic and received irbesartan at 20mg/kg, 50mg/kg and 75mg/kg for 13 days, respectively. Group 4 acted as the non-diabetic control and received water. After induction of diabetes, group 5, 6 and 7 received irbesartan 20mg/kg, 50mg/kg and 75mg/kg for 13 days, respectively, whilst group 8 acted as the diabetic control and received distilled water. Drug administration was done via oral gavage. Blood glucose levels were measured on selected days. Oral glucose tolerance test was carried out on day 14 after the commencing of drug dosing via administration of 1g/kg body weight to all the mice and measuring the blood glucose levels at 15, 30, 60 and 120 minutes. Results: Irbesartan at the dose of 20mg/kg and 75mg/kg significantly lowered (-39%, and 40%, respectively; p<0.05) blood glucose levels in diabetic mice. Irbesartan 20mg/kg, 50mg/kg and 75mg/kg did not significantly change blood glucose levels (-15%, -3% and 9%) in non-diabetic mice. In diabetic mice, irbesartan 20mg/kg and 75mg/kg improved glucose tolerance (Area under the curve [AUC] = 55.35mmol/Lmins and 45.54mmol/Lmins, respectively). However, the improvements were not statistically significant compared to the diabetic control group (AUC=63.53mmol/Lmins; p<0.05). Unlike in the diabetic mice, all the doses of irbesartan had no effect on glucose tolerance in non-diabetic mice (p<0.05) Conclusion: Low and high dose irbesartan had significant hypoglycaemic effects and improved glucose tolerance in diabetic mice. However, all doses of irbesartan had no significant effects on blood glucose levels and glucose tolerance in non-diabetic mice

Isolation and Activity Determination of Enzyme Phosphatase Secreted by Aspergillus niger

The use of enzymes on industrial scale saves a lot of energy and avoids pollution, thus holding a promise for green and economically sustainable alternative strategies in industrial transformations.  Generally, the fungi Aspergillus niger secretes enzymes which can be used in different industries. Thus, coming up with these enzymes in large amounts will definitely result in reduced costs encountered in importing them for industrial use.  This study focussed on isolation and activity determination of an enzyme phosphatase secreted by Aspergillus niger.  This enzyme can be of great importance in molecular biology industries, particularly for recombinant DNA technology.  For this study, pure cultures of Aspergillus niger were used.  Aspergillus niger was resuscitated on potato dextrose agar and then subcultured in Adam’s medium, a medium specific for the production of phosphatase.  Cells were centrifuged and the filtrate was collected whilst the residue was discarded. The filtrate was expected to contain the crude enzyme phosphatase since Aspergillus niger secretes the extracellular enzyme into the medium. Disodium phenyl phosphate was used as a substrate for the determination of the phosphatase activity. The enzyme activity was determined spectrophotometrically by reading absorbance of phenol formed in the presence of enzyme and the substrate. The concentration of phenol liberated was then used to calculate the enzyme activity expressed in King Armstrong Units (KAU).  Further work on enzyme activity determination was done by varying enzyme and substrate concentrations.  Results showed that the isolated alkaline phosphatase had activity of 4.0 KAU and 4.5 KAU at 25 ºC and 37 ºC respectively. Acidic phosphatase had activity of 5 KAU and 7 KAU at 25 ºC and 37 ºC respectively. Rate of activity increased upon increasing enzyme concentration and substrate.  Thus, Aspergillus niger produces the enzyme phosphatase, however, there is need to induce the production of these enzymes for industrial use

Antibacterial Activity of Melia azedarach Leaves against Salmonella typhi and Streptococcus pneumoniae

Antimicrobial drug resistance is increasingly becoming an important global problem.  Among the major causes for concern is drug resistant Streptococcus pneumoniae and Salmonella typhi, which have become resistant to at least one antibiotic.  This challenge has lead scientists to investigate plants as potential sources of antimicrobial agents since they have been used to treat diseases long before the discovery of antibiotics.  In Zimbabwe, typhoid is a leading cause of mortality and morbidity due to poor sanitation and poor treatment regimes.  Traditionalists are using Melia azedarach leaves for the treatment of diarrhea, a typhoid symptom.  Thus, this study focused on validating the use of M. azedarach leaves for medicinal purposes by determining their antibacterial activity against S. pneumoniae and S.typhi, the causative agent of typhoid fever.  Melia azedarach leaf constituents were extracted using ethanol, ethylacetate, hexane, dichloromethane and methanol.  Their antibacterial activities were assessed using the agar disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays.  Haemolysis assay was carried out to determine the toxicity of the potent extracts.  The ethanol and hexane extracts showed antibacterial activity against S. typhi whilst dichloromethane and hexane extracts showed antibacterial activity against S. pneumoniae.  Minimum inhibitory concentrations for ethanol and hexane against S. typhi were &lt; 1 µg/ml and 15.6 µg/ml respectively, whilst their minimum bactericidal concentrations were 31.25 µg/ml and 250 µg/ml.  The MICs for dichloromethane and hexane extracts against S. pneumoniae were 31.25 µg/ml and 62.5 µg/ml respectively, whilst their MBCs were 31.25 µg/ml and 125 µg/ml.  The extracts ethanol, hexane and dichloromethane had haemolytic activity of 63 %, 62 % and 59 % respectively.  Therefore, these results validate the use of M. azedarach leaves for medicinal purposes.  However, these leaves may be toxic to human consumption, thus there is need for further investigation on their toxicity in vivo