Green rooibos (Aspalathus linearis) promotes gut health: insight into mechanisms.

ETHNOPHARMACOLOGICAL RELEVANCE: Paralleling the increasing incidence of gastrointestinal disorders world-wide, therapeutic investigations of nutraceuticals to promote gastrointestinal health are gaining popularity. Although anecdotally well-known for its gut health promoting potential, sparse scientific evidence supports this action of Aspalathus linearis (Burm.f.) R. Dahlgren - or rooibos - at the gastrointestinal epithelial level. AIM OF THE STUDY: Traditionally, rooibos is considered to exert antispasmodic, anti-inflammatory, and anti-nociceptive effects in the gut. However, the direct effect on intestinal epithelium is unknown. Thus, to assess the validity of anecdotal claims, two larval zebrafish models were utilized to evaluate effects of rooibos on intestinal health. MATERIALS AND METHODS: Firstly, a larval zebrafish model of gastrointestinal inflammation (2-day TNBS-exposure) was employed. Co-administration of 6α-methylprednisolone served as an internal treatment control. Assessments included live imaging techniques and post-mortem immunofluorescent staining of epithelial tight junction proteins. In addition, whole body H2O2 and prostaglandin E2 assays were performed. Secondly, a gastrointestinal motility assay was performed, with known pro- and anti-kinetic mediators to assess the effect of rooibos to alter functional outcome in vivo. RESULTS: Aqueous and ethanol extracts of green rooibos rescued TNBS-induced reductions in neutral red stained length of larval mid-intestines. Subsequent experiments confirmed the rescue capacity of the aqueous green rooibos extract regarding whole body oxidative and inflammatory status. Concerning tight junction proteins, only the aqueous green rooibos extract - and not prednisolone - normalized both zona occludens-1 and occludin expression levels when compared the TNBS group. In terms of gastrointestinal motility, the aqueous green rooibos extract significantly reduced the extent of gut motility dysregulation achieved by kinetic modulators. CONCLUSIONS: Data indicates the potential of a 2 mg/ml aqueous extract of green rooibos to improve gastrointestinal integrity and functionality in vivo, suggesting beneficial effects of rooibos may already occur at the level of the gut. This provides some evidence to support indigenous knowledge.

Neuroprotective and anxiolytic potential of green rooibos (Aspalathus linearis) polyphenolic extract.

South African rooibos (Aspalathus linearis) tea is globally consumed for its health benefits and caffeine free nature, but no information is available on the neuroprotective capacity of (unfermented) green rooibos. Our aim was to investigate the cytoprotective activity of green rooibos in neuronal cells, including probing antioxidant and enzyme inhibitory properties that could explain observed effects in these cells. We also investigated the anxiolytic potential of green rooibos using zebrafish larval models. Green rooibos extract (Green oxithin™) was assessed for its neuroprotective potential in Neuro-2a cells treated with different concentrations of the extract (12.5-25-50-100 µg mL-1) and different concentrations of hydrogen peroxide (250 or 125 µM) as oxidizing agent. Cell viability (MTT) and redox status (intracellular ROS) were also quantified in these cells. Antioxidant properties of the extract were quantified using cell-free systems (DPPH, ORAC and xanthine/xanthine oxidase), and potential neuroprotection evaluated in terms of its potential to inhibit key enzymes of the CNS (monoamine oxidase A (MOA-A), acetylcholinesterase (AChE) and tyrosinase (TYR)). Results demonstrated that green rooibos extract exerted significant cytoprotective properties in Neuro-2a cells, particularly when exposed to lethal 250 µM hydrogen peroxide, increasing cell survival by more than 100%. This may be ascribed (at least partially) to its capacity to limit intracellular ROS accumulation in these cells. Data from cell-free systems confirmed that green rooibos was able to scavenge free radicals (synthetic and physiological) in a dose dependent manner with a similar profile activity to vitamins C and E. Green rooibos also acted as a moderate MAO-A inhibitor, but had no significant effect on AChE or TYR. Finally, zebrafish larvae treated with lower doses of green rooibos demonstrated a significant anxiolytic effect in the light-dark anxiety model. Using the PTZ excitotoxicity model, green rooibos was shown to rescue GABA receptor signalling, which together with its demonstrated inhibition of MAO-A, may account for the anxiolytic outcome. Current data confirms that green rooibos could be considered a "functional brain food" and may be a good option as starting ingredient in the development of new nutraceuticals.

Targeting Stem Cells in Chronic Inflammatory Diseases.

Mesenchymal stem cell (MSC) dysfunction is a serious complication in ageing and age-related inflammatory diseases such as type 2 diabetes mellitus. Inflammation and oxidative stress-induced cellular senescence alter the immunomodulatory ability of MSCs and hamper their pro-regenerative function, which in turn leads to an increase in disease severity, maladaptive tissue damage and the development of comorbidities. Targeting stem/progenitor cells to restore their function and/or protect them against impairment could thus improve healing outcomes and significantly enhance the quality of life for diabetic patients. This review discusses the dysregulation of MSCs' immunomodulatory capacity in the context of diabetes mellitus and focuses on intervention strategies aimed at MSC rejuvenation. Research pertaining to the potential therapeutic use of either pharmacological agents (NFкB antagonists), natural products (phytomedicine) or biological agents (exosomes, probiotics) to improve MSC function is discussed and an overview of the most pertinent methodological considerations given. Based on in vitro studies, numerous anti-inflammatory agents, antioxidants and biological agents show tremendous potential to revitalise MSCs. An integrated systems approach and a thorough understanding of complete disease pathology are however required to identify feasible candidates for in vivo targeting of MSCs.

D-galactose: a model of accelerated ageing sufficiently sensitive to reflect preventative efficacy of an antioxidant treatment.

Considering that the phenomenon of accelerated ageing contributes to early onset of various chronic diseases, modelling of the relevant dysregulated systems or responses is vital for research aimed at identification of potential therapeutic targets. Here, we aimed to establish a model capable of simulating the redox and inflammatory changes of accelerated ageing-specifically, the aim was early phase accelerated ageing, which would allow therapeutic intervention in a preventative approach prior to clinical disease manifestation. A secondary aim was to evaluate the sensitivity of the model to reflect preventative treatment efficacy. Daily D-galactose injections (250 mg/kg body mass/day) for 8 weeks in 9-week-old male Wistar rats induced a model of early accelerated ageing (decreased plasma FRAP; P < 0.05 and altered inflammatory signalling) and an aged profile in lymph node ultrastructure, but did not yet result in telomere shortening. Preventative daily oral antioxidant administration (grape seed-derived polyphenol, 100 mg/kg body mass) prevented tissue ageing, beneficially modulated the inflammatory response, including neutrophil chemokinetic capacity, and tended to increase absolute telomere length. Data suggests that using a mild model of D-galactose administration than those employed to induce neurodegeneration, simulated the point where oxidative stress starts to overwhelm the endogenous antioxidant response and where a pro-inflammatory phenotype switch manifests. Furthermore, despite the expected small effect size, the model was sufficiently sensitive to reflect benefits of preventative antioxidant treatment in the context of ageing. This model presents a practical model for use in drug discovery, particularly in the context of preventative medicine aimed at limiting oxidative stress-associated ageing. Since this starting point of accelerated ageing as illustrated by current data, is not expected to reflect major ageing-associated changes yet, we recommend that future preventative drug discovery studies employ a longitudinal study design in order to clearly demonstrate the delay of this starting point by preventative strategies.

Aspalathus linearis (Rooibos) - a functional food targeting cardiovascular disease.

Increasing consumer bias toward natural products and the considerable wealth of indigenous knowledge has precipitated an upturn in market-driven research into potentially beneficial medicinal plants. In this context, Aspalathus linearis (Rooibos) has been identified to be a promising candidate which may impact cardiovascular disease (CVD), which is one of the most widely studied chronic diseases of modern times. Despite these efforts, ischemic heart disease remains the number one cause of mortality globally. Apart from genetic predisposition and other aetiological mechanisms specific to particular types of CVD, co-factors from interlinked systems contribute significantly to disease development and the severity of its clinical manifestation. The bioactivity of Rooibos is directed towards multiple therapeutic targets. Experimental data to date include antioxidant, anti-inflammatory and anti-diabetic effects, as well as modulatory effects in terms of the immune system, adrenal steroidogenesis and lipid metabolism. This review integrates relevant literature on the therapeutic potential of Rooibos in the context of CVD, which is currently the most common of non-communicable diseases. The therapeutic value of whole plant extracts versus isolated active ingredients are addressed, together with the potential for overdose or herb-drug interaction. The body of research undertaken to date clearly underlines the benefits of Rooibos as both preventative and complementary therapeutic functional food in the context of CVD.

Regulation of redox status in neuronal SH-SY5Y cells by blueberry (Vaccinium myrtillus L.) juice, cranberry (Vaccinium macrocarpon A.) juice and cyanidin.

Blueberry and cranberry are fruits with high polyphenol content, particularly anthocyanins. As cyanidin derivatives have been identified as one of the most representative polyphenols in berry juices, cyanidin has been designated for a better comparison and understanding of the potential neuroprotection of juices obtained from two Vaccinium species. Neuroblastoma SH-SY5Y cells were previously treated with different concentrations of lyophilized blueberry juice, cranberry juice or cyanidin for 24 h and oxidative stress was then generated with hydrogen peroxide (100 µM) for 30 min. Cytoprotective properties of cranberry juice, blueberry juice or cyanidin were evaluated using different methodologies such as mitochondrial activity (MTT), TBARS and ROS production, antioxidant enzymes (CAT, SOD) and antioxidant properties (ORAC, FRAP). Results indicated that blueberry and cranberry juices as well as cyanidin increased mitochondrial activity and reduced intracellular ROS production and lipid peroxidation induced by hydrogen peroxide. Furthermore, these berry juices and cyanidin upregulated the activity of the antioxidant enzymes catalase and superoxide dismutase. Finally, in vitro antioxidant capacities were confirmed by ORAC and FRAP assays demonstrating the potential of cyanidin and cyanidin-containing products for pharmaceutical or nutritional applications to prevent oxidative stress in neuronal cells.

Natural antioxidants in prevention of accelerated ageing: a departure from conventional paradigms required.

The modern lifestyle is characterised by various factors that cause accelerating ageing by the upregulation of oxidative stress and inflammation-two processes that are inextricably linked in an endless circle of self-propagation. Inflammation in particular is commonly accepted as aetiological factor in many chronic disease states, such as obesity, diabetes and depression. In terms of disease prevention or treatment, interventions aimed at changing dietary and/or exercise habits have had limited success in practise, mostly due to poor long-term compliance. Furthermore, other primary stimuli responsible for eliciting an oxidative stress or inflammatory response-e.g. psychological stress and anxiety-cannot always be easily addressed. Thus, preventive medicine aimed at countering the oxidative stress and/or inflammatory responses has become of interest. Especially in developing countries, such as South Africa, the option of development of effective strategies from plants warrants further investigation. A brief overview of the most relevant and promising South African plants which have been identified in the context of inflammation, oxidative stress and chronic disease is provided here. In addition, and more specifically, our group and others have shown considerable beneficial effects across many models, after treatment with products derived from grapes. Of particular interest, specific cellular mechanisms have been identified as therapeutic targets of grape-derived polyphenols in the context of inflammation and oxidative stress. The depth of these studies afforded some additional insights, related to methodological considerations pertaining to animal vs. human models in natural product research, which may address the current tendency for generally poor translation of positive animal model results into human in vivo models. The importance of considering individual data vs. group averages in this context is highlighted.

Immunomodulatory effects of Sceletium tortuosum (Trimesemine™) elucidated in vitro: Implications for chronic disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Sceletium tortuosum, among other Sceletium species, was traditionally used by the Khoisan people of Southern Africa for relief of pain-related ailments. However, the commercial availability of this supplement has greatly expanded due to anecdotal claims of its mood-elevating and anxiolytic properties. Unrelated research has elucidated a significant link between cytokines and the mediation of depression. Therefore, the effect of Sceletium supplementation on immune cell functionality is of interest, since the efficacy of potential depression treatments could, at least in part, rely on downregulation of pro-inflammatory signalling. AIM OF THE STUDY: The current study evaluated the immunomodulatory effects of a Sceletium extract, both basally and in the context of acute endotoxin stimulation. MATERIALS AND METHODS: Primary human monocytes were supplemented with either a 0.01mg/ml or 1mg/ml Sceletium extract dose, with or without E. coli LPS stimulation in vitro, for 24h. Mitochondrial viability, as an indirect measure of cytotoxicity, and cytokine release in response to the treatment intervention were assessed. RESULTS: Sceletium extract treatment was associated with increased mitochondrial viability, as well as up-regulated IL-10 release under basal conditions. LPS exposure significantly decreased mitochondrial viability, but this was prevented completely under Sceletium-treated conditions. The acute inflammatory response to LPS stimulation was not negatively affected. Sceletium treatment conferred most significant effects at a dose of 0.01mg/ml. CONCLUSIONS: Sceletium exerts significant cytoprotective effects in the setting of endotoxin stimulation. Cytokine assessment indicated that Sceletium possesses mild anti-inflammatory properties, but does not hinder the mounting of an adequate immune response to acute immune challenge. These findings indicate that Sceletium may be beneficial for the attenuation of cytokine-induced depression, as well as in systemic low-grade inflammation.

High-mesembrine Sceletium extract (Trimesemine™) is a monoamine releasing agent, rather than only a selective serotonin reuptake inhibitor.

ETHNOPHARMACOLOGICAL RELEVANCE: Extracts from and alkaloids contained in plants in the genus Sceletium have been reported to inhibit ligand binding to serotonin transporter. From this, the conclusion was made that Sceletium products act as selective serotonin-reuptake inhibitors. However, other mechanisms which may similarly result in the anxiolytic or anti-depressant effect ascribed to Sceletium, such as monoamine release, have not been investigated. AIMS OF THE STUDY: The current study investigated simultaneously and at two consecutive time points, the effect of high-mesembrine Sceletium extract on both monoamine release and serotonin reuptake into both human astrocytes and mouse hippocampal neurons, as well as potential inhibitory effects on relevant enzyme activities. MATERIALS AND METHODS: Human astrocytes and mouse hippocampal cells were treated with citalopram or Sceletium extract for 15 and 30min, after which protein expression levels of serotonin transporter (SERT) and vesicular monoamine transporter-2 (VAMT-2) was assessed using fluorescent immunocytochemistry and digital image analysis. Efficacy of inhibition of acetylcholinesterase (AChE) and monoamine oxidate-A (MAO-A) activity were assessed using the Ellman and Olsen methods (and appropriate controls) respectively. RESULTS: We report the first investigation of mechanism of action of Sceletium extract in the context of serotonin transport, release and reuptake in a cellular model. Cell viability was not affected by Sceletium treatment. High-mesembrine Sceletium extract down-regulated SERT expression similarly to citalopram. In addition, VMAT-2 was upregulated significantly in response to Sceletium treatment. The extract showed only relatively mild inhibition of AChE and MAO-A. CONCLUSIONS: We conclude that the serotonin reuptake inhibition activity ascribed to the Sceletium plant, is a secondary function to the monoamine-releasing activity of high-mesembrine Sceletium extract (Trimesemine(TM)).

Sutherlandia frutescens may exacerbate HIV-associated neuroinflammation.

BACKGROUND: Neuroinflammation is central to the aetiology of HIV-associated neurocognitive disorders (HAND) that are prevalent in late stage AIDS. Anti-retroviral (ARV) treatments are rolled out relatively late in the context of neuroinflammatory changes, so that their usefulness in directly preventing HAND is probably limited. It is common practice for HIV+ individuals in developing countries to make use of traditional medicines. One such medicine is Sutherlandia frutescens - commonly consumed as a water infusion. Here its efficacy as an anti-inflammatory modality in this context was investigated in an in vitro co-culture model of the blood-brain barrier (BBB). METHODS: Single cultures of human astrocytes (HA), HUVECs and primary human monocytes, as well as co-cultures (BBB), were stimulated with HIV-1 subtype B & C Tat protein and/or HL2/3 cell secretory proteins after pre-treatment with S.frutescens extract. Effects of this pre-treatment on pro-inflammatory cytokine secretion and monocyte migration across the BBB were assessed. RESULTS: In accordance with others, B Tat was more pro-inflammatory than C Tat, validating our model. S.frutescens decreased IL-1ß secretion significantly (P < 0.0001), but exacerbated both monocyte chemoattractant protein-1 (P < 0001) - a major role player in HIV-associated neuroinflammation - and CD14+ monocyte infiltration across the BBB (P < 0.01). CONCLUSIONS: Current data illustrates that the combined use of HL2/3 cells and the simulated BBB presents an accurate, physiologically relevant in vitro model with which to study neuroinflammation in the context of HIV/AIDS. In addition, our results caution against the use of S.frutescens as anti-inflammatory modality at any stage post-HIV infection.

Chronic Prosopis glandulosa treatment blunts neutrophil infiltration and enhances muscle repair after contusion injury.

The current treatment options for soft tissue injuries remain suboptimal and often result in delayed/incomplete recovery of damaged muscle. The current study aimed to evaluate the effects of oral Prosopis glandulosa treatment on inflammation and regeneration in skeletal muscle after contusion injury, in comparison to a conventional treatment. The gastrocnemius muscle of rats was subjected to mass-drop injury and muscle samples collected after 1-, 3 h, 1- and 7 days post-injury. Rats were treated with P. glandulosa (100 mg/kg/day) either for 8 weeks prior to injury (up until day 7 post-injury), only post-injury, or with topically applied diclofenac post-injury (0.57 mg/kg). Neutrophil (His48-positive) and macrophage (F4/80-positive) infiltration was assessed by means of immunohistochemistry. Indicators of muscle satellite cell proliferation (ADAM12) and regeneration (desmin) were used to evaluate muscle repair. Chronic P. glandulosa and diclofenac treatment (p<0.0001) was associated with suppression of the neutrophil response to contusion injury, however only chronic P. glandulosa treatment facilitated more effective muscle recovery (increased ADAM12 (p<0.05) and desmin (p<0.001) expression), while diclofenac treatment had inhibitory effects on repair, despite effective inhibition of neutrophil response. Data indicates that P. glandulosa treatment results in more effective muscle repair after contusion.

Hoodia gordonii extract targets both adipose and muscle tissue to achieve weight loss in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Hoodia gordonii (Masson) Sweet ex Decne (family Apocynaceae) is consumed globally as a natural appetite suppressant. While this effect-and its subsequent effect of weight loss-has been reported in the scientific literature, no information is available on the specific tissue types affected that accounts for the significant weight loss reported after consumption of the plant. Furthermore, most studies are performed on lean animals, so that the response of overweight or obese individuals to this plant supplement remains largely unknown. MATERIALS AND METHODS: Twelve lean and twelve obese male Wistar rats were supplemented with different doses of Hoodia gordonii extract (80 or 160 mg/kg body mass twice daily) in a placebo-controlled study, for a period of 14 days. RESULTS: All supplemented rats exhibited significant weight loss (P<0.001). This could be ascribed to decrease in both adipose cell size and skeletal muscle fibre size. CONCLUSIONS: We conclude that the weight loss seen after consumption of Hoodia gordonii is due to loss of both adipose and muscle mass.

African drumming: a holistic approach to reducing stress and improving health?

AIMS: Very little data are available on the physical requirements for drumming and the potential health benefits of particularly djembe drumming. We hypothesized that djembe drumming constitutes low-to-moderate intensity exercise, and that drumming would simultaneously reduce stress and anxiety levels and benefit cardiovascular health. METHODS: Two study populations, middle-aged experienced drummers and a younger novice group participated in 40-min djembe drumming sessions. Measurements of blood pressure, blood lactate and stress and anxiety levels were taken before and after sessions. Also, heart rate was monitored at 5-s intervals throughout each session. RESULTS: Participation in drumming significantly decreased the Stress Anxiety Index scores acutely, both in a middle-aged (P < 0.01) and younger population (P < 0.001). SBP was significantly decreased in the older population postdrumming (141 ±â€Š24 vs. 153 ±â€Š26  mmHg; P < 0.01). Blood lactate levels remained below 4  mmol/l in all individuals and together with heart rate suggest that drumming may be categorized as low-to-moderate intensity exercise. CONCLUSION: Djembe drumming may improve cardiovascular health, without the cardiovascular risks to unhealthy or older populations that are associated with higher intensity exercise, and at the same time may decrease stress and anxiety levels. Furthermore, participation in drumming did not result in acute hypotension in normotensive individuals.

Hoodia gordonii: to eat, or not to eat.

ETHNOPHARMACOLOGICAL RELEVANCE: Hoodia gordonii (family Apocynaceae) has become known globally for its claimed effect of appetite suppression. Despite a relatively large body of evidence of the plant׳s chemical make-up, peer-reviewed studies to provide scientific information on physiological effects of Hoodia gordonii are relatively sparse. The role of the pregnane glycoside P57-commonly accepted to be responsible for appetite suppression-has been questioned recently. Furthermore, a variety of physiological side-effects associated with consumption of the plant in extracted form questions its suitability for consumption. Although adverse effects have been described before, the relative abundance of non-peer-reviewed data originating from patent documents and lay publication for advertising, which specifically only focus on beneficial outcomes, skews the view of the risk-benefit-balance. Here we provide a review of peer-reviewed studies on the plant׳s physiological effects. Novel data from an in vivo rodent study further elucidate the benefit-to-risk ratio associated with consumption. CONCLUSIONS: we conclude that although Hoodia gordonii seems to have a desired effect on appetite and weight loss, this effect may at least in part be a secondary symptom of the serious adverse effects that are associated with consumption of the high doses required to achieve therapeutic clinical effect.

Rooibos influences glucocorticoid levels and steroid ratios in vivo and in vitro: a natural approach in the management of stress and metabolic disorders?

SCOPE: To determine the effect of Rooibos (Aspalathus linearis) on glucocorticoid biosynthesis and inactivation in vivo and in vitro. METHODS AND RESULTS: Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) analyses of in vivo studies showed that human Rooibos consumption increased cortisone plasma levels in males (p = 0.0465) and reduced cortisol:cortisone ratios in males and females (p = 0.0486) at risk for cardiovascular disease. In rats, corticosterone (CORT) (p = 0.0275) and deoxycorticosterone (p = 0.0298) levels as well as the CORT:testosterone ratio (p = 0.0009) decreased following Rooibos consumption. The inactivation of cortisol was investigated in vitro by expressing 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) and type 2 (11ßHSD2) in CHO-K1 cells. Rooibos inhibited 11ßHSD1, which resulted in a significant reduction in the cortisol:cortisone ratio (p < 0.01). No significant effect was detected on 11ßHSD2. In vitro studies in adrenal H295R cells showed that Rooibos and rutin, one of the more stable flavonoid compounds present in Rooibos, significantly reduced the levels of cortisol and CORT in cells stimulated with forskolin to mimic a stress response. CONCLUSION: In vivo studies demonstrate that Rooibos significantly decreased glucocorticoid levels in rats and steroid metabolite ratios linked to metabolic disorders--cortisol:cortisone in humans and CORT:testosterone in rats. Results obtained at cellular level elucidate possible mechanisms by which these effects were achieved.

Central and peripheral effects of Sutherlandia frutescens on the response to acute psychological stress.

Sutherlandia frutescens is widely used in indigenous medicine for the treatment of stress- and anxiety-related disorders, and although anecdotal evidence has been scientifically confirmed, relatively little data are available on its potential mechanisms of action. We manipulated a rodent model of acute psychological stress by acutely administering a low dose (4 mg/kg body mass) of S. frutescens extract 30 min prior to stress exposure (1 h restraint), to elucidate both its central and peripheral mechanisms of action in the context of acute stress. After 1 h of exposure to stress, acute restraint resulted in a significant increase in plasma corticosterone levels (56 ± 33 versus 499 ± 50 ng/ml; P < 0.0001) and anterior pituitary adrenocorticotropic hormone (ACTH) levels (0.066 ± 0.017 versus 0.202 ± 0.033% fluorescent area; P = 0.07), while decreasing hippocampal glucocorticoid receptor (GR) and gamma-aminobutyric acid (GABA)(A)α1 receptor levels (both P < 0.05). While the low dose of S. frutescens administered did not seem to have an effect on the down-stream stress response, it abolished the stress-induced down-regulation of GR, in a manner independent of GABA(A)α1 receptor. Results suggest a non-sedative effect of low-dose S. frutescens and points to central mechanisms of action that is in support of the anecdotal claims for its effectiveness as complimentary treatment in chronic stress-associated diseases.

Contusion injury with chronic in vivo polyphenol supplementation: leukocyte responses.

INTRODUCTION: In vivo, daily proanthocyanidolic oligomer (PCO) supplementation before and after experimental skeletal muscle contusion injury has been shown to result in a blunted neutrophil response in tissue, quicker macrophage infiltration into muscle, and faster recovery due to a left shift in time course of inflammation. The current study investigated effects of PCO on circulatory neutrophils and macrophage subpopulations as well as in vitro neutrophil migration. METHODS: Primary cultured neutrophils obtained from control animals were incubated in media with 20% conditioned plasma. To obtain conditioned media, male Wistar rats were supplemented with PCO (20 mg·kg(-1)d(-1)) or placebo (PLA) for 2 wk before a mass-drop contusion injury. Conditioned plasma was prepared from blood collected at different time points after injury (12 h, 1 d, 3 d, and 5 d). Macrophage subpopulation distribution, inflammatory cytokine, and myeloperoxidase levels were assessed for all time points. RESULTS: On day 1 postinjury, circulating neutrophil numbers were significantly lower in PLA than PCO, suggesting that extravasation from the blood was reduced by PCO. Concurrently, neutrophil migration in vitro was blunted in the presence of conditioned plasma from PCO supplemented rats compared with PLA supplemented rats. Plasma M1 and M2c macrophage numbers differed over time and between groups. M1 macrophage numbers peaked on day 3 with PCO supplementation, followed by a rise in M2c macrophages on day 5, when M1 macrophages numbers were still high in PLA. CONCLUSIONS: We conclude that PCO supplementation limits neutrophil migration capacity in vitro despite a chemotactic gradient. Furthermore, the earlier appearance of type M2 macrophages suggests a switch to an anti-inflammatory phenotype after injury even in circulation.

Evaluation of a nisin-eluting nanofiber scaffold to treat Staphylococcus aureus-induced skin infections in mice.

Staphylococcus aureus is a virulent pathogen and a major causative agent of superficial and invasive skin and soft tissue infections (SSSTIs). Antibiotic resistance in S. aureus, among other bacterial pathogens, has rapidly increased, and this is placing an enormous burden on the health care sector and has serious implications for infected individuals, especially immunocompromised patients. Alternative treatments thus need to be explored to continue to successfully treat infections caused by S. aureus, including antibiotic-resistant strains of S. aureus. In this study, an antimicrobial nanofiber wound dressing was generated by electrospinning nisin (Nisaplin) into poly(ethylene oxide) and poly(d,l-lactide) (50:50) blend nanofibers. Active nisin diffused from the nanofiber wound dressings for at least 4 days in vitro, as shown by consecutive transfers onto plates seeded with strains of methicillin-resistant S. aureus (MRSA). The nisin-containing nanofiber wound dressings significantly reduced S. aureus Xen 36 bioluminescence in vivo and viable cell numbers in a murine excisional skin infection model. The bacterial burden of wounds treated with nisin-containing nanofiber wound dressings was 4.3 × 10(2) CFU/wound, whereas wounds treated with control nanofiber wound dressings had 2.2 × 10(7) CFU/wound on the last day of the trial (day 7). Furthermore, the wound dressings stimulated wound closure of excisional wounds, and no adverse effects were observed by histological analysis. Nisin-containing nanofiber wound dressings have the potential to treat S. aureus skin infections and to potentially accelerate wound healing of excisional wounds.

Postcontusion polyphenol treatment alters inflammation and muscle regeneration.

PURPOSE: Given the major role that oxidants play in cellular damage, and the recent focus on antioxidants as treatment for muscle injuries, the aim of this study was to examine the effect of short-term postinjury grape seed-derived polyphenol supplementation on muscle inflammation and repair processes after contusion injury. METHODS: Experimental injury of the right gastrocnemius muscle was achieved by drop-mass method (200 g from a height of 50 cm), after which rats were gavaged with either 0.9% saline (placebo-PLA) or 20 mg·kg⁻¹·d⁻¹ of proanthocyanidolic oligomer (PCO) from 2 h after contusion injury, for up to 14 d after injury. Blood samples and injured muscle were collected at 4 h and at days 1, 3, 5, 7, and 14 after injury. RESULTS: Compared to an uninjured control group, PCO supplementation resulted in an earlier peak in number of activated satellite cells in contusion-injured muscle tissue (4 h for PCO vs day 3 for PLA, n = 4 per time point per group) and fetal myosin heavy chain expression (day 5 for PCO, P < 0.01 with no change in PLA, n = 3 per time point per group), indicative of quicker muscle regeneration. PCO supplementation limited neutrophil infiltration and facilitated earlier macrophage infiltration into the injured area (n = 4 per group). PCO also resulted in an earlier return toward control levels of muscle proinflammatory cytokines on day 3 (P < 0.01 for interleukin 6 and P < 0 05 for tumor necrosis factor α, both n = 3 per group). CONCLUSIONS: Data show that short-term postinjury PCO supplementation was able to quicken muscle regeneration by facilitating earlier recruitment of activated satellite cells and to modulate the immune system in favor of an anti-inflammatory status.

Accelerated skeletal muscle recovery after in vivo polyphenol administration.

Acute skeletal muscle damage results in fiber disruption, oxidative stress and inflammation. We investigated cell-specific contributions to the regeneration process after contusion-induced damage (rat gastrocnemius muscle) with or without chronic grape seed-derived proanthocyanidolic oligomer (PCO) administration. In this placebo-controlled study, male Wistar rats were subjected to PCO administration for 2 weeks, after which they were subjected to a standardised contusion injury. Supplementation was continued after injury. Immune and satellite cell responses were assessed, as well as oxygen radical absorption capacity and muscle regeneration. PCO administration resulted in a rapid satellite cell response with an earlier peak in activation (Pax7⁺, CD56⁺, at 4 h post-contusion) vs. placebo groups (PLA) (P<.001: CD56⁺ on Day 5 and Pax7⁺ on Day 7). Specific immune-cell responses in PLA followed expected time courses (neutrophil elevation on Day 1; sustained macrophage elevation from Days 3 to 5). PCO dramatically decreased neutrophil elevation to nonsignificant, while macrophage responses were normal in extent, but significantly earlier (peak between Days 1 and 3) and completely resolved by Day 5. Anti-inflammatory cytokine, IL-10, increased significantly only in PCO (Day 3). Muscle fiber regeneration (MHC(f) content and central nuclei) started earlier and was complete by Day 14 in PCO, but not in PLA. Thus, responses by three crucial cell types involved in muscle recovery were affected by in vivo administration of a specific purified polyphenol in magnitude (neutrophil), time course (macrophages), or time course and activation state (satellite cell), explaining faster effective regeneration in the presence of proanthocyanidolic oligomers.