Rooibos (Aspalathus linearis) is a plant that grows in South Africa, its leaves are used to make a herbal tea.
There are two varieties of Rooibos: Green Rooibos - unfermented tea; Red Rooibos - fermented tea.
Rooibos tea contains no caffeine and has a relatively low level of tannins compared to traditional black or green tea.
As a fresh leaf, rooibos contains a high content of ascorbic acid (vitamin C), which is lost when made into tea.
Red rooibos tea is fully oxidized giving it a unique polyphenol profile consisting of aspalathin, rutin, orientin, as well as many other flavonoids such as flavanols, flavones, and flavanones, and chemicals such as dihydrochalcones, and nothofagin.
Studies have shown its composition in polyphenols (dihidrochalcones: aspalathin, nothofagin; free flavones and glycosides: orientin, iso-orientin, vitexin, isovitexin, luteolin, luteolin-7-O-β-D-glucoside; free flavonols and glycosides: quercetin, hyperoside, rutin; tannins).
Green rooibos tea is unfermented giving it a different polyphenol profile compared to red rooibos; consisting of varying concentrations of specific flavonoids, luteolin, and orientin, which are naturally found in Red Rooibos tea.
The processed leaves and stems contain benzoic and cinnamic acids.
Red Rooibos has moderate Antioxidant Activity
Treatment with Green Rooibos Tea Extract reversed Oxidative Stress induced by obesity from high caloric diet.
The plant is utilized in traditional medicine as a relaxing drink due to its caffeine free and low tannin composition.
Disease / Symptom Treatment
A. linearistea became known as a healthy drink after the success in the treatment of chronic restlessness, in a colicky baby by administration of Rooibos tea infusion.
Red Rooibos Tea Stimulates Osteoblast Mineralization in a Dose-Dependent Manner.
Study Type: Chemical Analysis
Title: Chemical Analysis and Antioxidant Activity Of Some Rooibos Tea Products
Author(s): ALEXANDRA EPURE, ILIOARA ONIGA, DANIELA BENEDEC, DANIELA HANGANU, ANA-MARIA GHELDIU, ANCA TOIU, LAURIAN VLASE
Institution(s): Department of Pharmacognosy, Faculty of Pharmacy, “Iuliu Hațieganu” University of Medicine and Pharmacy, 8 V. Babeș Street, Cluj-Napoca, Romania; Department of Pharmaceutical Technology and Biopharmacy, “Iuliu Hațieganu” University of Medicine and Pharmacy, 8 V. Babeș Street, Cluj-Napoca, Romania
Publication: Farmacia, the official journal of the Romanian Society of Pharmaceutical Sciences
Date: April 2019
Abstract: The Rooibos tea, known as well as red tea, has lately gain attention due to its reported rich antioxidant composition. The aim of this research was to determine the polyphenol content and antioxidant capacity of 6 commercial types of Rooibos tea available on the Romanian market. The analyses of polyphenolic compounds were carried out using chromatographic and spectrophotometric methods. The total polyphenol content (TPC) was assessed by the Folin-Ciocâlteu method and some polyphenols were identified by HPLC: ferulic, sinapic acids, hyperoside, isoquercitrin, rutin, quercitrin, quercetin, luteolin, kaempferol etc. The results showed qualitative and quantitative differences between the samples. The evaluation of antioxidant capacity was performed using DPPH (α,α-diphenyl-β-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods, and a moderate activity has been highlighted for all the analysed samples.
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Study Type: Human Study: In Vitro
Title: Red Rooibos Tea Stimulates Osteoblast Mineralization in a Dose-Dependent Manner
Author(s): Michael D. McAlpine, William Gittings, Adam J. MacNeil, and Wendy E. Ward
Institution(s): Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada
Publication: MDPI: Beverages
Date: December 2019
Abstract: Most studies show a positive association between higher tea intake and bone mineral density (BMD), while associations with fracture are inconclusive. Although a few studies have investigated the potential effects of rooibos tea on the bone cell metabolism, only 1 or 2 doses were tested or specific flavonoids were evaluated in isolation. A dose-response study is needed to comprehensively identify whether a level that modulates bone cell activity is associated with dietary or supplemental levels of red rooibos (RR) tea. We investigated if RR tea stimulates mineralization in a dose-dependent manner. Mineralization was induced in Saos-2 cells in the presence of RR tea (0.1–10 µg/mL of polyphenols) or control (dH2O) for 5 days. Cell activity, mRNA, protein expression and activity of key regulators of mineralization were measured. A positive dose-dependent relationship was observed between RR tea concentration and mineralization accompanied with similar trends in cell activity. With high concentrations of tea, protein expression of enzymes directly regulating mineralization (ALP and NPP1) were unchanged but ALP activity was significantly elevated. Osteopontin (OPN) was significantly downregulated midway through mineralization while sclerostin (SOST) was upregulated in response to higher concentrations of RR tea. In conclusion, RR tea stimulated osteoblast mineralization in a dose-dependent manner and were accompanied with downregulation of OPN, increased ALP activity, and increased cell activity.
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Study Type: Animal Study
Title: THE EFFECTS OF A GREEN ROOIBOS EXTRACT ON THE REPRODUCTIVE FUNCTION OF OBESITY-INDUCED INSULIN RESISTANT OR HYPERTENSIVE MALE WISTAR RATS
Author(s): Claudine Manirafasha
Institution(s): Faculty of Medicine and Health Sciences at Stellenbosch University
Publication: Stellenbosch University Library SUNScholar Research Repository
Date: December 2019
Abstract: Diet-induced obesity (DIO) due to a high caloric diet (HCD) predisposes an individual to the development of diabetes and cardiovascular diseases, with high prevalence in young populations. Existing evidence supports the sentiment that insulin resistance and hypertension (HT) affect male reproduction. A greater understanding of the influence of insulin resistance and/or HT on male reproduction is required in order to prevent or treat male infertility. Due to the limitations of orthodox drugs, there is currently a strong movement towards and support for studies on phytomedicine. Rooibos (Aspalathus linearis) has been used in several studies and is known to have natural antioxidant effects and anti-obesogenic, antidiabetic, anti-hypertensive and anti-infertility activities. Currently, the company Afriplex (Pty) Ltd is producing an aspalathin-rich laboratory standardized extract prepared from green rooibos called Afriplex GRTTM (GRT). However, there is very little knowledge regarding the use of GRT in obesity-related insulin resistance and/or HT, and specifically, its effects on male reproductive health.