Vicky Jocelyne Ama Moor

Syzyguim guineense Extracts Show Antioxidant Activities and Beneficial Activities on Oxidative Stress Induced by Ferric Chloride in the Liver Homogenate

The aim of this study was to determine the in vitro antioxidant activity, free radical scavenging property and the beneficial effects of extracts of various parts of Syzygium guineense in reducing oxidative stress damage in the liver. The effects of extracts on free radicals were determined on radicals DPPH, ABTS, NO and OH followed by the antioxidant properties using Ferric Reducing Antioxidant Power assay (FRAP) and hosphomolybdenum (PPMB). The phytochemical screening of these extracts was performed by determination of the phenolic content. The oxidative damage inhibition in the liver was determined by measuring malondialdehyde (MDA) as well as the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and peroxidase. Overall, the bark extract of the ethanol/water or methanol showed the highest radical scavenging activities against DPPH, ABTS and OH radicals compared to the other extracts. This extract also contained the highest phenolic content implying the potential contribution of phenolic compounds towards the antioxidant activities. However, the methanol extract of the root demonstrated the highest protective effects of SOD and CAT against ferric chloride while the hydro-ethanol extract of the leaves exhibited the highest inhibitory effects on lipid peroxidation. These findings suggest that antioxidant properties of S. guineense extracts could be attributed to phenolic compounds revealed by phytochemical studies. Thus, the present results indicate clearly that the extracts of S. guineense possess antioxidant properties and could serve as free radical inhibitors or scavengers, acting possibly as primary antioxidants. The antioxidant properties of the bark extract may thus sustain its various biological activities.

Phenolic Content of Hypodaphnis Zenkeri and Its Antioxidant Effects against Fenton Reactions’ Mediated Oxidative Injuries on Liver Homogenate

Under oxidative stress conditions, endogenous antioxidant defenses are unable to completely inactivate the free radicals generated by an excessive production of reactive oxygen species (ROS). This state causes serious cell damage leading to a variety of human diseases. Natural antioxidants can protect cells against oxidative stress. Hypaodaphnis zenkeri (H. zenkiri) is a plant consumed as a spice in the Cameroonian diet, and its bark has been used in traditional medicine for the treatment of several diseases. The present study aims at investigating the antioxidant activity, which includes free radical scavenging and protective properties of an extract from H. Zenkiri against oxidative damage on a liver homogenate. The free radical assays determined the scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (OH), nitrite oxide (NO) and 2,2-azinobis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radicals and the enzymes, whose protection was to be considered in the liver homogenate, including superoxide dismutase, catalase, and peroxidase. The antioxidative activities were studied using the ferric reducing antioxidant power (FRAP), reductive activity, and phosphomolybdenum antioxidant power (PAP) methods. In addition, the phenolic contents of the extracts were examined. The results showed that these extracts demonstrated significant scavenging properties and antioxidant activities, with the hydro-ethanolic extract of the bark of H. zenkeri (EEH) being the most potent. This extract had the highest total polyphenol (21.77 ± 0.05 mg caffeic acid (CAE)/g dried extract (DE)) and flavonoids (3.34 ± 0.13 mg quercetin (QE)/g dried extract) content. The same extract had significantly greater protective effects on enzyme activities compared to other extracts. The high performance liquied chromatography (HPLC) profile showed higher levels of caffeic acid, OH-tyrosol acid, and rutin in the leaves compared to the bark of H. zenkeri. In conclusion, the ethanolic and hydro-ethanolic extracts of the bark and leaves from H. zenkeri showed an antioxidant and protective potential against oxidative damage.

Antioxidant and Synergistic Antidiabetic Activities of a Three-Plant Preparation Used in Cameroon Folk Medicine

Introduction. Several plant preparations like a mixture of aqueous extracts of Spilanthes africana; Portulaca oleracea; and Sida rhombifolia are currently utilized in Foumban (West Cameroon) to manage diabetes. The aim of this study is to investigate the antidiabetic property of the aqueous mixture of three plant extracts (1 : 1 : 1) on streptozotocin induced diabetes rats. Methods. Diabetes was induced to rats by intraperitoneal (i.p.) injection of streptozotocin (STZ) at a dose of 50 mg/kg b.w. The diabetic rats received different dosages of the mixture of extracts for 21 days and glibenclamide 6.5 mg/kg b.w. as positive control. Results. The results showed that the mixture of extracts significantly (p < 0.05) decreased the level of the glycaemia, the total cholesterol, triglyceride, and LDL-cholesterol as well as MDA, AST, ALT, and creatinine levels. It also increased significantly the concentration of HDL-cholesterol, glutathione, and TAOS. A great reduction of the atherogenic indexes CT/HDL and LDL/HDL of the treated groups was observed. Each extract and the mixture demonstrated significant scavenging property on DPPH and OH radicals and present a good antioxidant property. Conclusion. The mixture of plant extracts has hypoglycemic, antioxidant, and hypolipidemic properties and can be used for the management of diabetes mellitus.

Relative adrenal insufficiency in adults with sickle cell disease

Rheological modifications observed in sickle cell anemia are associated with ischemic complications that can cause target organ functional impairment. The objective was to investigate adrenal function of adult patients with sickle cell disease. In this cross-sectional study conducted in a tertiary referral hospital of the capital city of Cameroon, we enrolled ten crisis-free adult patients with sickle cell disease (SCD) and ten age- and sex-matched healthy individuals. We assessed adrenal function by testing basal cortisol levels and 60 min after tetracosactide (Synacthen®) injection using immuno-chemiluminescence method. Post-stimulatory cortisol was defined as primary endpoint and secondary endpoints include basal cortisol levels, post-stimulatory cortisol increments and the fold increase of cortisol one hour after stimulation. Sickle cell patients had an impairment of adrenal function despite no significant difference between patients’ and controls’ for basal or post-stimulatory cortisol levels. In fact, one patient in two failed to achieve a two-fold increase in cortisol levels after stimulation (5/10) as opposed to 1 in 10 in the control population (1/10), P = 0.070. The percent increment of cortisol after stimulation was lower in patients versus controls (133 vs 207, P = 0.047). Relative adrenal insufficiency is frequent in sub-Saharan adult patients with sickle cell disease despite normal basal cortisol levels. Our results suggest that adrenal function require further investigation during SCD crises as these represent an important stress and may worsen the prognosis.

Insulin resistance and associated factors among HIV-infected patients in sub-Saharan Africa: a cross sectional study from Cameroon

Introduction: little is known on the magnitude and correlates of insulin resistance in HIV-infected people in Africa. We determined the prevalence of insulin resistance and investigated associated factors in HIV-infected adult Cameroonians. Methods: we conducted a cross-sectional studyat the Yaounde Central Hospital, Cameroon; during which we enrolled HIV-infected people aged 30 to 74 years with no previous history of cardiovascular disease. The homeostatic model assessment of insulin resistance (HOMA-IR) index served to assess insulin sensitivity with insulin resistance defined by values of 2.1 or higher. Results: we included 452 patients (20% men). Their mean age was 44.4 ± 9.8 years and 88.5% of them were on antiretroviral therapy (93.3% on first line regimen including Zidovudine, lamivudine and Efavirenz/Nevirapine). Of all participants, 28.5% were overweight, 19.5% had obesity and 2.0% had diabetes. The prevalence of insulin resistance was 47.3% without any difference between patients on ART and those ART-naive (48.5% vs. 38.5%; p = 0.480). Obesity was the only factor independently associated with insulin resistance (adjusted odds ratio: 2.28; 95% confidence interval: 1.10-4.72). Conclusion: insulin resistance is present in nearly half of HIV-infected patients in Cameroon despite a low prevalence rate of diabetes, and is associated with obesity.

Assessment of the 10-year risk of cardiovascular disease among a group of patients on maintenance hemodialysis: A cross-sectional study from Cameroon:

Objective To assess the 10-year risk of cardiovascular disease and potential impacting factors among patients undergoing hemodialysis in Yaoundé, Cameroon. Design A cross-sectional study in January 2016. Setting Patients were recruited at the dialysis unit of the Yaoundé University Teaching Hospital, Cameroon. Participants These were hemodialysis patients aged 20 years and above, dialyzing in the above unit since at least 3 months and volunteering to be enrolled in the study. Main outcome measures The risk of cardiovascular disease was assessed using the Framingham risk score. Results We included 44 patients. The risk of cardiovascular disease ranged from less than 1% to more than 30% with a median of 12.3% (interquartile range 4.9–24.4). Twenty hemodialysis patients (45.5%) had a low risk of cardiovascular disease (<10%), 10 (22.7%), a moderate risk (10–20%), and 14 (31.8%) presented a high risk of cardiovascular disease (>20%). In multivariable linear regression analysis, duration on dialysis (adjusted β = 0.11; p = 0.003), number of weekly sessions of physical activity (adjusted β = −1.35; p = 0.018), fasting serum glucose levels (adjusted β = 4.22; p = 0.022), serum triglycerides levels (adjusted β = 5.94; p = 0.033), and serum urea levels (adjusted β = −2.08; p = 0.039) were independently impacting our patients’ risk of cardiovascular disease. Conclusion Around 55% of our study population presented a moderate or high risk of cardiovascular disease. Duration on dialysis, number of physical activity sessions per week, fasting serum glucose, serum triglycerides, and serum urea levels may impact our hemodialysis patients’ risk of cardiovascular disease.

Renin angiotensin aldosterone system altered in resistant hypertension in Sub-Saharan African diabetes patients without evidence of primary hyperaldosteronism:

Background The renin-angiotensin-aldosterone system may be altered in patients with resistant hypertension. This study aimed to evaluate the relation between renin-angiotensin-aldosterone system activity and resistant hypertension in Cameroonian diabetes patients with resistant hypertension. Methods We carried out a case-control study including 19 diabetes patients with resistant hypertension and 19 diabetes patients with controlled hypertension matched to cases according to age, sex and duration of hypertension since diagnosis. After collection of data, fasting blood was collected for measurement of sodium, potassium, chloride, active renin and plasma aldosterone of which the aldosterone-renin ratio was derived to assess the activity of renin-angiotensin-aldosterone system. Then, each participant received 2000 ml infusion of saline solution after which plasma aldosterone was re-assayed. Results Potassium levels were lower among cases compared to controls (mean: (4.10 ± 0.63 mmol/l vs. 4.47 ± 0.58 mmol/l), though nonsignificant (p = 0.065). Active renin, plasma aldosterone both before and after the dynamic test and aldosterone-renin ratio were comparable between cases and controls (all p values > 0.05). Plasma aldosterone significantly decreased after the dynamic test in both groups (p < 0.001), but no participant exhibited a post-test value>280 pmol/l. We found a significant negative correlation between potassium ion and plasma aldosterone (ρ = −0.324; p = 0.047), the other correlations being weak and unsignificant. Conclusion Although this study failed to show an association between RH and primary hyperaldosteronism in our context, there was a hyperactivity of renin-angiotensin-aldosterone system. Moreover, this study confirms the importance of potassium dosage when screening the renin-angiotensin-aldosterone system.

Atherogenic index of plasma and 10-year risk of cardiovascular disease in adult Africans living with HIV infection: A cross-sectional study from Yaoundé, Cameroon:

Background The paucity of data regarding the association between atherogenic index of plasma and risk of cardiovascular disease in HIV-infected populations living in sub-Saharan Africa prompted us to conduct this study which aimed to assess the relationship between atherogenic index of plasma and risk of cardiovascular disease among a Cameroonian HIV-infected population. Methods This was a cross-sectional study conducted among 452 HIV-infected adults in Yaoundé, Cameroon. Risk of cardiovascular disease was calculated using the Framingham risk score; atherogenic index of plasma was derived as log (triglycerides/high-density lipoproteins cholesterol). Results Participants’ mean age (80% females) was 44.4 ± 9.8 years. Atherogenic index of plasma values ranged from –0.63 to 1.36 with a median of 0.11 (25th–75th percentiles: –0.08-0.31). Most participants (88.5%) were on antiretroviral treatment. There was a significant correlation between atherogenic index of plasma and fasting plasma glucose (r = 0.116; p = 0.014), atherogenic index of plasma and total cholesterol (r = –0.164; p < 0.001). Atherogenic index of plasma was significantly associated with the risk of cardiovascular disease either in univariable (β = 5.05, 95% CI: 3.31–6.79; p < 0.001, R2 = 0.067) or in multivariable linear regression model after adjusting for socio-demographic, clinical and biological confounders (adjusted β = 3.79, 95% CI: 1.65 – 4.88; p < 0.001, R2 = 0.187). Conclusion Atherogenic index of plasma may be an independent factor impacting the risk of cardiovascular disease among Cameroonian HIV-infected people. More studies are needed to better elucidate the association between atherogenic index of plasma and risk of cardiovascular disease in our setting.