Rooibos (Aspalathus linearis) and its Major Flavonoids — Potential Against Oxidative Stress-Induced Conditions

Reactive species are products of normal cellular metabolism and may be deleterious or beneficial. At low/moderate concentrations, reactive species are involved in physiological roles including cell signalling, defense against infectious agents and mitogenic responses. However, unbalanced defense mechanism of antioxidants, overproduction of reactive species or incorporation of free radicals into the living system from the environment may result in oxidative stress, a deleterious process that can lead to damage of important cell structures, including lipids and membranes, proteins and nucleic acids. The role of oxidative stress as a contributing factor in the pathophysiology of various diseases is increasingly being recognized, and augmenting the oxidative defense capacity of the cell through the intake of antioxidants as a way of preventing free radical-mediated cellular injuries is becoming a popular strategy. Much attention is being focused on the health beneficial role of phenolic phytochemicals derived from plants. They are considered to play an important role as physiologically functional foods and for the prevention of clinical conditions related to oxidative stress, even though their modes of action may still not be fully understood. Rooibos (Aspalathus linearis) is a popular South African tisane enjoyed for its taste and aroma. Rooibos has been made in the Cederberg mountain region of South Africa for generations and has been used medicinally for alleviation of allergies, asthma, infantile colic and skin problems. The potential antioxidative, immune-modulating, chemopreventive and chemotherapeutic actions of rooibos have been reported in several studies. This review provides a comprehensive data on the current knowledge of the biological and chemotherapeutic activity of rooibos and its major flavonoids. Most recent in vitro and in vivo (animal and human) studies were conducted with special attention paid to clinical conditions in which oxidative stress has been implicated. The conclusion described directions for future rooibos research to establish its activity and utility as a human chemopreventive and therapeutic agent

The Potential of South African Herbal Tisanes, Rooibos and Honeybush in the Management of Type 2 Diabetes Mellitus

Diabetes mellitus is a metabolic disease that can lead to high morbidity, mortality and long-term complications. Available treatment strategies, which are mainly based on treating hyperglycemia, with insulin and other pharmacological agents are not completely efficient and can even lead to development of unwanted side effects. Scientific evidence suggests that bioactive compounds from teas and other plant-based foods, which are known source of natural antioxidants, could be an attractive strategy to preferentially treat and manage type 2 diabetes mellitus (T2DM) and thus, have significant therapeutic implications. In this review, we attempt an in-depth analysis and discussion of the current progress in our understanding of the antidiabetic potential of two commercialized South Africa herbal tisanes—Rooibos and Honeybush and their polyphenols

Red Palm Oil Ameliorates Oxidative Challenge and Inflammatory Responses Associated with Lipopolysaccharide-Induced Hepatic Injury by Modulating NF-κβ and Nrf2/GCL/HO-1 Signaling Pathways in Rats

Lipopolysaccharide (LPS), a well-conserved cell wall component of Gram positive bacteria, exerts its toxic effects via inducing oxidative and pro-inflammatory responses. Red palm oil (RPO) is a unique natural product with a balanced ratio of saturated and unsaturated fatty acids, with reported antioxidant and anti-inflammatory effects. In this study, we assess the protective effect and mechanistic action of RPO using a lipopolysaccharide (LPS)-induced hepatic injury model. Male Wistar rats were assigned into four groups (10 animals/group): normal control (NC), RPO, LPS and RPO + LPS. Animals in the RPO and RPO + LPS groups were administered RPO (200 μL/day) for 28 days. On the 27th day of experiment, animals in LPS and RPO + LPS groups were injected with LPS (0.5 mg/kg body weight). Animals were sacrificed 24 h later, and blood and liver tissues harvested for biochemical and molecular analysis. RPO resolved hepatic histological dysfunction induced by LPS, and lowered alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyl transferase activities in the serum. Hepatic malondialdehyde and conjugated dienes, as well as pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6 and TNFα were significantly diminished (p < 0.05) by RPO pre-treatment. Activity of hepatic antioxidant enzymes including superoxide dismutase, glutathione reductase, glutathione peroxidase, as well as glutathione redox status (GSH:GSSG), and markers of antioxidant capacity that decreased as a result of LPS injection were improved by RPO pre-treatment. Mechanistically, RPO up-regulated mRNA expression of redox sensitive transcription factor Nrf2 and its downstream targets GCL and HO-1, while also suppressing the expression of NFκβ and associated inflammatory protein, Iκβ kinase (IκKβ). In conclusion, this study highlights the ameliorating effects of RPO against LPS-induced hepatic injury and revealed the Nrf2/GCL/HO-1 and NFκβ signaling axis as potential contributing mechanisms

Free and bound phenols from Cymbopogon citratus mitigated hepatocellular injury in streptozotocin-induced type 1 diabetic male rats via decrease in oxidative stress, inflammation, and other risk markers

Background/Aim: Diabetes mellitus is a debilitating disease still prevailing in the developing world. This study aimed to examine the protective potentials of Cymbopogon citratus extracts (crude (CCC), free (CFP), and bound phenol (CBP) fractions), in streptozotocin (STZ)-induced type 1 diabetic male rats. Methods: Forty-five (45) animals of about 3–4 months were used for the study. About forty animals were induced with STZ. After induction and confirmation of diabetes, animals were grouped (five animals per group) into nine groups; group 1 (Control), group 2 received 50 mg/kg body weight (bw) (STZ). Groups 3, 4 and 5 were healthy animals and received C. citratus extracts (200 mg/kg bw CCC, 100 mg/kg bw CFP, and 100 mg/kg bw CBP) respectively; while groups 6 – 9 were diabetic group (induced with STZ) and later treated with C. citratus extracts (200 mg/kg bw CCC, 100 mg/kg bw CFP, 100 mg/kg bw CBP, and metformin (200 mg/kg bw) respectively for 14 days. Then, the animals were euthanized, blood/serum was collected, liver samples were collected and divided into two; for biochemical and histopathological studies. Liver biomarkers (ALT, AST, ALP, GGT), fructose-1,6-bisphosphatase, hexokinase, antioxidant enzymes (SOD, CAT, and GST) activities, albumin, bilirubin, hepatic glucose, GSH, MDA, pro-and anti-inflammatory cytokines concentrations, were estimated using standard protocols. Results: Our results revealed that C. citratus extracts counteracted the deleterious effects of type 1 diabetes induction with STZ by optimizing the liver biomarkers, antioxidants enzymes, MDA and GSH levels, reducing the levels of pro-inflammatory cytokines and increasing anti-inflammatory. Conclusion: Our results correlated with previous researches; the free phenols fraction revealed brilliant results above others. These suggested that C. citratus could serve as an alternative therapy in ameliorating liver complications linked to oxidative damage and inflammation in STZ-induced type-1 diabetes

The combination of red palm oil and rooibos show anti-inflammatory effects in rats

CITATION: Katengua-Thamahane, E. et al. 2014. The combination of red palm oil and rooibos show anti-inflammatory effects in rats. Journal of Inflammation, 11(1):41, doi:10.1186/s12950-014-0041-4.The original publication is available at http://www.journal-inflammation.com/content/11/1/41Background Red palm oil (RPO) and rooibos have been shown to exhibit cardioprotective properties. RPO is rich in essential fatty acids and fat soluble antioxidants while rooibos contains polyphenolic compounds with a unique composition of flavonoids. They exert their biological effects in different cellular compartments. Therefore the combination of these two natural food compounds has the potential to enhance the spectrum of available dietary antioxidants in different cellular compartments, which could result in an enhanced protection against certain pathological conditions such as inflammation. Methods Male Wistar rats weighing 150-200&#160;g were supplemented with RPO, rooibos or their combination for 28&#160;days. The Langendorff system and the lipoposaccharide (LPS)-induced inflammatory model were used to establish if RPO and rooibos, when supplemented alone or in combination, will reverse the negative effects of LPS on cardiac function at baseline. The effect of dietary intervention was also investigated on modulation of pro-inflammatory and anti-inflammatory cytokines in plasma and myocardial tissue. Results and discussion The LPS resulted in induction of systemic inflammation as evidenced by increased levels of IL-1&#946; in plasma of LPS-treated rats compared to their non-treated control counterparts. Dietary supplementation and LPS treatment did not have an effect on baseline cardiac functional parameters. However, the elevation of IL-1&#946; levels in plasma of LPS-induced rats consuming either RPO or rooibos alone were paralleled with increased levels of the anti-inflammatory cytokine, IL-10. The combination of rooibos and RPO was associated with enhanced endogenous production of myocardial IL-10 in LPS-induced rats. Conclusion The results of this study indicate that RPO and rooibos when supplemented individually showed anti-inflammatory effect at systemic level while their combination exhibited an enhanced anti-inflammatory effect in the myocardial tissue. Therefore, the findings in the current study argue that the combination of these two natural food substances could be beneficial in clinically relevant conditions where inflammation plays a role.Publishers’ versio