Neuroprotective effects of Lippia javanica (Burm.F.) Spreng. Herbal tea infusion on Lead-induced oxidative brain damage in Wistar rats.

BACKGROUND: Though Lippia javanica (Burm.f.) Spreng antioxidant activity has been demonstrated, its effect in protecting the brain from lead (Pb)-induced oxidative damage is unknown. This study investigated the effect of L. javanica against Pb-induced oxidative stress, inflammation, apoptosis and acetylcholinesterase activity in rat's brain. METHODS: L. javanica herbal tea infusion was prepared, its phytochemical constituent was revealed by liquid chromatography-Mass spectrometer (LC-MS) and was administered simultaneously with Pb. Four groups of male Wistar rats (n = 5/group) were used: control received distilled water; Pb-acetate group received 50 mg Pb/ Kg bodyweight (bw), treatment group received 50 mg Pb/ Kg Pb-acetate + 5 ml/kg bw L. javanica and L. javanica group received 5 ml/Kg bw of L. javanica tea infusion only. After 6 weeks of treatment, oxidative status, acetylcholinesterase activity, inflammation and apoptosis was assessed in brain tissue which was also histologically examined. RESULTS: Mean brain and heart weight was reduced (p < 0.05) while liver and spleen weights were increased (p < 0.05) in Pb exposed animals but were prevented by L. juvanica treatment. Treatment with L. javanica increased (p < 0.05) overall brain antioxidant status (glutathione and superoxide dismutase activities) and reduced lipid peroxidation (p < 0.05) compared to the Pb exposed animals. Pro-inflammatory cytokine tumour necrotic factor-alpha, pro-apoptosis Bax protein and anticholinesterase activity were reduced (p < 0.05) in Pb-L. javanica treated animals compared to the Pb exposed group. Histological examination confirmed neuroprotective effects of L. javanica as evidenced by reduced apoptosis/necrosis and inflammation-induced vacuolization and oedema in the hippocampus. The L. javanica treatment alone had no detrimental effects to the rats. LC-MS analysis revealed L. javanica to be rich in phenolics. CONCLUSIONS: This study demonstrated that L. javanica, rich in phenolics was effective in reducing Pb-induced brain oxidative stress, inflammation, apoptosis, acetylcholinesterase activity and neuronal damage.

Antibacterial and Antioxidant Activity of Different Extracts of Some Wild Medicinal Mushrooms from Nigeria.

This study assessed the antioxidant properties and antibacterial effects of hot water, cold water, and ethanol extracts of Agaricomycetes mushrooms Trametes betulina, Pleurotus ostreatus, Agaricus bisporus var. albidus, and A. bisporus var. avellaneus against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. The mushroom extracts were assessed for total phenolic content as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging activities. The multiantibiotic resistance index (MARI) of the bacterial isolates was assessed and the antimicrobial activity of the mushroom extracts was assayed with the agar disc diffusion method. The agar well diffusion assay was performed to determine their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The test bacteria were multidrug resistant against antibiotics, with P. aeruginosa having the highest MARI followed by K. pneumoniae and E. coli. Cold water extracts showed a better antibacterial effect compared to the others and a concentration/effect correlation was observed (from 5 to 500 mg/mL). Ethanol extracts from P. ostreatus and hot water extracts from T. betulina were the most effective in inhibiting and lysing E. coli and K. pneumoniae, respectively, at a MIC and MBC of 3.90 mg/mL. The tested extracts, especially P. ostreatus extract, showed high DPPH and hydrogen peroxide scavenging potential as well as high total phenolic content compared to standard antioxidants. This study showed that the screened agaricomycetous mushrooms possess antibacterial activity against bacterial pathogens as well as antioxidant activity due to their high phenolic content.

Lippia javanica (Zumbani) herbal tea infusion attenuates allergic airway inflammation via inhibition of Th2 cell activation and suppression of oxidative stress.

BACKGROUND: Lippia javanica (lemon bush) is commonly used in the treatment of respiratory ailments, including asthma in southern African countries but there is no scientific evidence to support this claim. This study investigated the anti-inflammatory, antioxidant and anti-asthmatic effects of L. javanica using a rat model of asthma. METHODS: A 5% w/v L. javanica tea infusion was prepared and characterised by liquid chromatography-mass spectrometer (LC-MS). Animals were intraperitoneally sensitized with ovalbumin (OVA) and subsequently challenged intranasal with OVA on day 15 except the control group. Animals were grouped (n = 5/group) for treatment: unsensitised control, sensitised control, sensitised + prednisolone and sensitised + L. javanica at 50 mg/kg/day and 100 mg/kg/day - equivalent to 1 and 2 cups of tea per day, respectively. After 2 weeks of treatment, bronchoalveolar lavage fluid (BALF) was collected for total and differential white blood cell (WBC) count. Nitric oxide (NO), lipid peroxidation and antioxidants were also assessed in BALF. Ovalbumin specific IgE antibody and inflammatory cytokines: IL-4, IL-5, IL-13 and TNF-alpha were measured in serum. Lung and muscle tissues were histological examined. RESULTS: L. javanica was rich in phenolic compounds. OVA sensitisation resulted in development of allergic asthma in rats. L. javanica treatment resulted in a reduction in total WBC count as well as eosinophils, lymphocytes and neutrophils in BALF. L. javanica inhibited Th2-mediated immune response, which was evident by a decrease in serum IgE and inflammatory cytokines: IL-4, IL-5, IL-13 and TNF-α. L. javanica treatment also reduced malondialdehyde (MDA) and NO, and increased superoxide dismutase, glutathione and total antioxidant capacity. Histology showed significant attenuation of lung infiltration of inflammatory cells, alveolar thickening, and bronchiole smooth muscle thickening. CONCLUSION: L. javanica suppressed allergic airway inflammation by reducing Th2-mediated immune response and oxidative stress in OVA-sensitized rats which may be attributed to the presence of phenolic compound in the plant. This finding validates the traditional use of L. javanica in the treatment of respiratory disorders.

Relationship between Endothelial Function, Antiretroviral Treatment and Cardiovascular Risk Factors in HIV Patients of African Descent in South Africa: A Cross-Sectional Study.

Limited information on the effect of antiretroviral treatment (ART) on vascular function in South Africans of African descent living with human immunodeficiency virus (HIV) is available. The relationship between ART, vascular function and cardiovascular risk factors in South Africans of African ancestry with HIV was therefore studied. This cross-sectional study recruited 146 HIV-positive individuals on ART (HIV+ART+), 163 HIV-positive individuals not on ART (HIV+ART-) and 171 individuals without HIV (HIV-) in Mthatha, Eastern Cape Province of South Africa. Flow-mediated dilation (FMD) test was performed to assess endothelial function. Anthropometry and blood pressure parameters were measured. Lipid profile, glycaemic indices, serum creatinine as well as CD4 count and viral load were assayed in blood. Urinary albumin to creatinine ratio (ACR) was determined as a marker of cardiovascular risk. Obesity and albuminuria were positively associated with HIV, and HIV+ART+ participants had significantly higher HDL cholesterol. Dyslipidaemia markers were significantly higher in hypertensive HIV+ART+ participants compared with the controls (HIV+ART- and HIV- participants). FMD was not different between HIV+ART+ participants and the controls. Moreover, HIV+ART+ participants with higher FMD showed lower total cholesterol and LDL cholesterol comparable to that of HIV- and HIV+ART- participants. A positive relationship between FMD and CD4 count was observed in HIV+ART+ participants. In conclusion, antiretroviral treatment was associated with cardiovascular risk factors, particularly dyslipidaemia, in hypertensive South Africans of African ancestry with HIV. Although, ART was not associated with endothelial dysfunction, flow-mediated dilatation was positively associated with CD4 count in HIV-positive participants on ART.

Cardiovascular Risk Factors and Their Relationship with Vascular Dysfunction in South African Children of African Ancestry.

Vascular dysfunction is known to be an initiator of the development and progression of cardiovascular diseases (CVDs). However, there is paucity of information on the relationship of vascular dysfunction with cardiovascular risk factors in children of African ancestry. This study investigated the relationship between cardiovascular risk factors and vascular function in South African children of African ancestry. A cross-sectional study on 6-9-year-old children in randomly selected rural and urban schools of the Eastern Cape Province of South Africa was conducted. General anthropometric indices were measured, followed by blood pressure (BP) measurements. The pulse wave velocity (PWV) was measured using a Vicorder. Albumin to creatinine ratio (ACR), asymmetric dimethylarginine (ADMA), 8-hydroxy-2deoxyguanosine (8-OHdG) and thiobarbituric acid reactive substance (TBARS) were assayed in urine. Children from urban settings (10.8%) had a higher prevalence of overweight/obesity than their rural counterparts (8.5%) while the prevalence of elevated/high blood pressure was higher in rural (23.2%) than urban children (19.0%). Mean arterial blood pressure (MAP) and diastolic blood pressure (DBP) increased with increasing PWV (p < 0.05). Body mass index (BMI), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) positively associated (p < 0.05) with PWV. Creatinine, albumin and ACR significantly (p < 0.005) increased with increasing ADMA. ADMA associated positively (p < 0.05) with creatinine and 8-OHdG. In conclusion, vascular dysfunction was associated with obesity, high blood pressure, oxidative stress and microalbuminuria in South African children of African ancestry.

Gut permeability is associated with hypertension and measures of obesity but not with Endothelial Dysfunction in South African youth.

BACKGROUND: Though gut permeability has shown to be associated with measures of obesity and hypertension, its relationship with endothelial dysfunction, an early predictor for cardiovascular diseases remains unknown. OBJECTIVE: This study assessed the relationship between hypertension, measures of obesity, gut permeability and endothelial dysfunction. METHODS: A cross-sectional quantitative study which enrolled 151 South African youths was conducted. Anthropometric and blood pressure measurements were performed. Zonulin, a marker for gut permeability; adiponectin, an anti-inflammatory molecule, as well as asymmetric dimethylarginine (ADMA) and Nitric oxide (NO) which are markers for endothelialfunction were assayed. RESULTS: Approximately eighteen percent (17.88%) of the participants were hypertensive while 40.4% were pre-hypertensive. Adiponectin significantly increased in hypertensive subjects and negatively correlated (p<0.05) with measures of obesity but was not associated with gut permeability and endothelial dysfunction. Increased body mass index (BMI) and visceral fat (VF) predicted reduced adiponectin (inflammation). Zonulin was significantly higher (p<0.05) in hypertensive subjects and positively associated (p<0.05) with systolic blood pressure (SBP) in females. A positive relationship (p<0.05) was observed between zonulin and measurements of obesity. Moreover, zonulin negatively associated (p<0.05) with ADMA but positively associated (p<0.05) with NO in males. Increased VF and waist circumference predicted gut permeability. CONCLUSION: Gut permeability was associated with hypertension and measures of obesity but not with markers of endothelial dysfunction in a South African youth population.

Insulin Resistance is Associated with Gut Permeability Without the Direct Influence of Obesity in Young Adults.

OBJECTIVE: Recent findings have associated insulin resistance and obesity with increased gut permeability. However, it still remains unclear whether obesity may be the underlining factor for the association between gut permeability and insulin resistance. This study investigated the relationship between gut permeability, measures of obesity, and markers of insulin resistance in young adults. MATERIALS AND METHODS: A cross-sectional quantitative study which enrolled 151 young South African adults was conducted. Anthropometric measurements were performed to assess obesity. Adiponectin, leptin, and zonulin, a marker for gut permeability, were assayed. Insulin and fasting glucose were assayed and used to determine insulin resistance (HOMA-IR), insulin sensitivity (%S) and beta cell function (%B). RESULTS: Decreased adiponectin and increased leptin were associated (p<0.05) with obesity. HOMA-IR inversely correlated (p<0.05) with adiponectin but positively with leptin to adiponectin (Lept/ADP) ratio (p<0.05) in females. Markers of insulin resistance were not associated (p>0.05) with obesity. Overweight/obese (O/O) females had a significantly (p<0.01) higher zonulin concentration than lean females. Zonulin positively associated (p<0.05) with body mass index and visceral fat, as well as with HOMA-IR and insulin concentration. Lept/ADP ratio, an inflammatory marker, was associated with risk of insulin resistance. Increased insulin, a maker for insulin resistance, was associated with risk of gut permeability. CONCLUSION: Insulin resistance was associated with gut permeability without a direct influence by obesity in young adults. The lack of relationship between obesity and insulin resistance was possibly mediated by the contribution of obesity to gut permeability. This finding suggests that gut permeability may be a potential independent risk factor for the development of insulin resistance in healthy obese young adults.

Association of Hypertension and Obesity with Risk Factors of Cardiovascular Diseases in Children Aged 6-9 Years Old in the Eastern Cape Province of South Africa.

Cardiovascular disease (CVD) risk factors are known to begin early in life, but limited data on the relationship of obesity and hypertension with other known CVD risk factors, such as endothelial dysfunction, oxidative stress, and chronic low-grade inflammation is available on children. In this cross-sectional study involving 6-9 years old school children aged from the Eastern Cape Province of South Africa the relationship between obesity/hypertension and other risk factors for CVDs was investigated. General anthropometric parameters were measured, followed by blood pressure (BP) measurements and pulse wave velocity (PWV). Urine samples were collected for the determination of albumin, creatinine, asymmetric dimethylarginine (ADMA), 8-hydroxy-2deoxyguanosine (8-OHdG), and thiobarbituric acid-reactive substance (TBARS). Overweight/obesity (19.28%) and pre-hypertension/hypertension (42.16%) were prevalent in children. Mid-upper arm circumference (MUAC), a marker of obesity, was positively correlated with ADMA, while ADMA and PWV were significantly different (p < 0.05) between hypertensive and normotensive children. Also, TBARS and 8-OHdG were significantly (p < 0.05) increased in hypertensive subjects. Creatinine was significantly (p < 0.05) increased in obese, as well as in hypertensive children, and positively associated with waist circumference (WC) and neck circumference (NC). In conclusion, obesity and hypertension were associated with renal-cardiovascular disease risk, while oxidative stress showed a possible association with obesity in 6 to 9 year old South African children of African descent. This suggests that South African children of African descent may be becoming more prone to developing CVDs, and therefore may require early intervention for the prevention of CVDs in the near future.