Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Fanie Rautenbach is active.

Publication


Featured researches published by Fanie Rautenbach.


Journal of Photochemistry and Photobiology B-biology | 2011

Photoprotection by honeybush extracts, hesperidin and mangiferin against UVB-induced skin damage in SKH-1 mice

Antoinette Petrova; Lester M. Davids; Fanie Rautenbach; Jeanine L. Marnewick

The possible mechanism of photoprotection by polyphenolic extracts of honeybush and the two most abundant polyphenols found in honeybush, hesperidin and mangiferin were determined using a mouse model. Ethanol: acetone soluble extracts and pure honeybush compounds were applied topically to the skin of SKH-1 mice before daily exposures to ultraviolet B (UVB) (180 mJ/cm²) for 10 days. The honeybush extracts reduced signs of sunburn, such as erythema, peeling and hardening of the skin and also significantly (P < 0.05) reduced edema, epidermal hyperplasia and the induction of cyclooxygenase-2 (COX-2), ornithine decarboxylase (ODC), GADD45 and OGG1/2 expression. The fermented honeybush extract significantly (P < 0.05) reduced lipid peroxidation and depletion of the antioxidant enzymes catalase and superoxide dismutase. Hesperidin and mangiferin were less effective. These results show that extracts of honeybush and to some extent, hesperidin and mangiferin, renders protection against UVB-induced skin damage. The mechanisms investigated suggest that honeybush extracts protected the skin via modulation of induced-oxidative damage, inflammation and cell proliferation. Other specific biological properties such as modulation of signaling pathways could also be involved.


Journal of Food Science | 2010

Antioxidant Capacity and Antioxidant Content in Roots of 4 Sweetpotato Varieties

Fanie Rautenbach; M. Faber; Sunette Laurie; Robert Laurie

The antioxidant contents (beta-carotene, chlorogenic acid, and vitamin C) as well as the antioxidant capacity (ORAC, FRAP, and ABTS) of 4 sweetpotato varieties were measured in this study. The sweetpotato varieties were cultivated under different water regimes and also subjected to thermal processing. The results show that the 2 orange-fleshed varieties (Resisto and W-119) contain significant more beta-carotene, chlorogenic acid, and vitamin C than the 2 cream-fleshed varieties (Bosbok and Ndou). Thermal processing decreased the carotenoid and vitamin C content of all the varieties but increased the chlorogenic acid content and antioxidant capacity. Drought stress appears to increase the beta-carotene, vitamin C, and chlorogenic acid contents as well as the antioxidant capacity of some of the sweetpotato varieties, especially W-119.


The South African journal of clinical nutrition | 2009

South African dietary total antioxidant capacity based on secondary intake data in relation to dietary recommendations

Hannelise Louwrens; Fanie Rautenbach; Irma Venter

Abstract Objective: In this exploratory study, the average adult South African dietary total antioxidant capacity (TAC) was estimated using secondary data and was evaluated against that determined for dietary intake recommendations. Design: The average adult South African dietary TAC was estimated using a report published by the Department of Health that summarises food consumption studies conducted in South Africa between 1983 and 2000. This estimated adult South African dietary TAC was evaluated against that determined for dietary intake recommendations incorporating the five-a-day concept and the basic food groups and beverages (tea and coffee). Results: The average adult South African dietary TAC was estimated as 11 433 micromoles (µmoles) Trolox equivalents (TE)/person/day, with beverages (tea) being the main contributor (38.5%). The dietary TAC based on the recommended five-a-day concept and other dietary intake recommendations was 20 513 µmoles TE/person/day, with beverages again being the main contributor (47.8%). Conclusions: Compared to the TAC of the five-a-day concept and other dietary intake recommendations, the South African population consumes about half of this estimated TAC per day. It is especially in the vegetable group and beverages where actual consumption is well below the coupled TAC. Grains are the only food group where consumption is above the coupled TAC. The five-a-day concept is only the aim for minimum intake and not the ultimate goal. An increase in these foods, along with beverages (tea) and whole grains to the recommended servings, can uphold the dietary TAC and health benefits.


Journal of analytical and bioanalytical techniques | 2014

Optimization and Validation of a Reverse-Phase High Performance Liquid Chromatography Assay with Ultra-Violet Detection for Measuring Total L-Ascorbic Acid in Food and Beverage Products

Olivia L Parbhunath; Fanie Rautenbach; Glenda Davison; Jeanine L. Marnewick

In accordance with national and international regulatory standards, namely ISO/IEC 17025, the validation of chromatography methods is becoming necessary. This study provides an optimized and fully validated reversephase high performance liquid chromatography (RP-HPLC) assay with ultra-violet (UV) detection for the measurement of L-ascorbic acid (L-AA) in fruit, vegetable and food products. Several commercial fruit juices and teas, fresh fruit and vegetables and food extract products were analyzed using a high performance liquid chromatographic system with UV detection. Chromatographic separation of L-AA was achieved on a reverse phase C18 150 mm×4.6 mm, 0.5 μm column with UV detection of 245 nm at room temperature. Distilled water/acetonitrile/formic acid (99: 0.9: 0.1, v/v/v) at a flow rate of 1 mLmin-1 was used as the mobile phase, in isocratic mode. Samples were extracted in 4.5% metaphosphoric acid solution and filtered through a 0.45 μm membrane. The method was validated for accuracy, precision, linearity, range, limit of detection, limit of quantification, specificity, stability, robustness and system suitability in accordance with ISO 17025 validation requirements. Validation results demonstrated a linear response within a range of 5 to 125 μg/mL with a correlation coefficient of 0.999 was obtained. Mean recoveries ranged from 99 to 103% and 92 to 96% for L-AA standards and samples, respectively. The method was found to be precise (COV’s <5%) and specific with no interferences from coexisting peaks. The LOD and LOQ were 0.61 μg/mL and 1.84 μg/mL respectively. The successful optimization and validation of the proposed method should make it easily applicable for routine laboratory analysis of L-AA measurement in various fruit and vegetable products.


Molecules | 2015

Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities

Olugbenga K. Popoola; Jeanine L. Marnewick; Fanie Rautenbach; Emmanuel I. Iwuoha; Ahmed A. Hussein

Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1–3) and six known (4–10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe2+-induced lipid peroxidation (IC50 = 5.12 ± 0.90; 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC50 = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors.


Acta Biochimica Polonica | 2016

Isolation and antioxidant activity of flavonoids from Holarrhena floribunda (G.don) leaves.

Jelili A. Badmus; Okobi Eko Ekpo; Fanie Rautenbach; Jeanine L. Marnewick; Ahmed A. Hussein; Donavon Hiss

Bioactive polyphenolics are ubiquitously present in plants and may play an important role in the prevention and management of certain human diseases. Three known flavonoids viz Kaemperol-3-O-rutinoside (1), quercetin-3-O-glucoside (2) and kaemperol-3-O-glucoside (3) and inseparable mixture (1:1) of quercetin-3-O-glucose/galactose (4) were isolated, and identified for the first time from Holarrhena floribunda. The antioxidant capacity using the ORAC, FRAP and TEAC assays and inhibition of lipid peroxidation were measured for isolated flavonoids. The result showed that compounds 2 and 4 showed significantly increased ORAC, TEAC, and FRAP activities with low pro-oxidant potential as well as improved lipid peroxidation inhibition levels when compared to compounds 1 and 3. The most active compounds were found to be flavonoids with a quercetin basic structure. These results imply that the isolated flavonoid glycosides are responsible for the antioxidant activity of the plant leaves and it forms the scientific basis for its traditional usage.


Journal of Ethnopharmacology | 2011

Effects of rooibos (Aspalathus linearis) on oxidative stress and biochemical parameters in adults at risk for cardiovascular disease

Jeanine L. Marnewick; Fanie Rautenbach; Irma Venter; Henry Neethling; Dee Blackhurst; Petro Wolmarans; Muiruri Macharia


Journal of Food Composition and Analysis | 2010

Hydrophilic and lipophilic antioxidant capacity of commonly consumed South African fruits, vegetables, grains, legumes, fats/oils and beverages.

Fanie Rautenbach; Irma Venter


Molecules | 2015

Inhibition of Oxidative Stress and Skin Aging-Related Enzymes by Prenylated Chalcones and Other Flavonoids from Helichrysum teretifolium

Olugbenga K. Popoola; Jeanine L. Marnewick; Fanie Rautenbach; Farouk Ameer; Emmanuel I. Iwuoha; Ahmed A. Hussein


Free Radical Biology and Medicine | 2012

Rooibos: Effect on Iron Status of South African Adults at Risk for Coronary Heart Disease

Jeanine L. Marnewick; Irma Venter; Fanie Rautenbach; Henry Neethling; Maritha Kotze

Collaboration


Dive into the Fanie Rautenbach's collaboration.

Top Co-Authors

Avatar

Jeanine L. Marnewick

Cape Peninsula University of Technology

View shared research outputs
Top Co-Authors

Avatar

Irma Venter

Cape Peninsula University of Technology

View shared research outputs
Top Co-Authors

Avatar

Ahmed A. Hussein

University of the Western Cape

View shared research outputs
Top Co-Authors

Avatar

Henry Neethling

Cape Peninsula University of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Emmanuel I. Iwuoha

University of the Western Cape

View shared research outputs
Top Co-Authors

Avatar

Muiruri Macharia

Cape Peninsula University of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Antoinette Petrova

Cape Peninsula University of Technology

View shared research outputs
Top Co-Authors

Avatar

Donavon Hiss

University of the Western Cape

View shared research outputs
Researchain Logo
Decentralizing Knowledge