The Potential of South African Herbal Tisanes, Rooibos and Honeybush in the Management of Type 2 Diabetes Mellitus. Molecules. 2018;23:3207. [PMID: 30563087 PMCID: PMC6321617 DOI: 10.3390/molecules23123207]

Fermented Rooibos tea (Aspalathus linearis) Ameliorates Sodium Fluoride-Induced Cardiorenal Toxicity, Oxidative Stress, and Inflammation via Modulation of NF-κB/IκB/IκKB Signaling Pathway in Wistar Rats

High dose of fluoride intake is associated with toxic effects on kidney and cardiac tissues. This study evaluated the potential protective effect of fermented rooibos tea (RTE) on sodium fluoride (NaF)-induced cardiorenal toxicity in rats. Male Wistar rats (n = 56) were randomly allocated into one of seven equal groups: control, NaF (100 mg/kg orally), NaF + RTE (2%, w/v), NaF + RTE (4%, w/v), NaF + lisinopril (10 mg/kg orally), 2% RTE, and 4% RTE. The experiment lasted for 14 days and RTE was administered to the rats as their sole source of drinking fluid. NaF induced cardiorenal toxicity indicated by elevated level of urea, creatinine, LDH, creatinine kinase-MB, and cardiac troponin I in the serum, accompanied by altered histopathology of the kidney and heart. Furthermore, levels of H2O2, malondialdehyde, and NO were elevated, while GSH level was depleted in the kidney and heart due to NaF intoxication. Protein levels of c-reactive protein, TNFα, IL-1B, and NF-κB were increased by NaF in the serum, kidney, and heart. RTE at 2% and 4% (w/v) reversed cardiorenal toxicity, resolved histopathological impairment, attenuated oxidative stress and inhibited formation of pro-inflammatory markers. RTE at both concentrations down-regulates the mRNA expression of NF-κB, and upregulates the mRNA expression of both IκB and IκKB, thus blocking the activation of NF-κB signaling pathway. Taken together, these results clearly suggest that the protective potential of rooibos tea against NaF-induced cardiorenal toxicity, oxidative stress, and inflammation may be associated with the modulation of the NF-κB signaling pathway.

The health benefits of rooibos tea in humans (aspalathus linearis)-a scoping review

Natural remedies in the treatment of health conditions are an appealing option for many individuals. Previous studies reported that fermented and unfermented rooibos tea have considerable anti-inflammatory and antioxidative properties. Most of this knowledge, however, originates from animal and cell culture studies. The aims of this review are to evaluate the existing, but limited, body of knowledge regarding rooibos tea interventions in humans and to identify the gaps in the literature. The PRISMA extension for Scoping Reviews (PRISMA-ScR) guidelines were followed in the collation of this scoping review. Among the databases searched were Google Scholar, PubMed, Cochrane Library, Scopus, and Web of Science. This review comprised 18 publications, with half (50%) of the studies being conducted in South Africa. There were 488 participants in all, ranging in age from six to 83 years, in the investigations. Rooibos tea was either fermented, unfermented, or black in 62% of the studies. Doses ranging from 200 to 1,200 ml were employed. In both healthy and at-risk individuals, rooibos has been shown to enhance lipid profiles, boost antioxidant status, and lower blood glucose levels. The existing findings suggests that rooibos consumption demonstrated to improve lipid profiles, boost antioxidant status, and lower blood glucose levels in both apparently healthy, and individual at-risk individuals or diagnosed of chronic conditions. Thus, it can be presumed that rooibos tea provides some health benefits, yet these findings are based on a limited number of human intervention studies and a small total sample size. Additionally, a variety of rooibos dosages and types of tea in the experiments had inconsistent results that were probably impacted by the amount consumed. Future studies should include a dose-response study in humans, as well as large scaled clinical trials to evaluate the health effects of Rooibos.

The effect of Aspalathin linearis, Cyclopia intermedia and Sutherlandia frutescene on sperm functional parameters of healthy male wistar rats

Introduction: Rooibos (Aspalathin linearis), honeybush (Cyclopia intermedia), and sutherlandia (Sutherlandia frutescene) are three Southern Africa indigenous plants, of which the extracts have become house-hold items and are consumed on a large scale. Although, they are known for their antioxidant properties, studies have highlighted danger in the excessive intake. Therefore, the current study investigated whether treatment with rooibos, honeybush, and sutherlandia will impact sperm functional parameters positively or otherwise, in healthy rats. Methods: Fourteen-week-old pathogen-free adult male Wistar rats (250-300 g) were randomly divided into four groups of ten, including a control, rooibos (RF), honeybush (HB) and a sutherlandia (SL) group. After 7 weeks of treatment, animals were sacrificed. Spermatozoa were retrieved from the cauda epididymis for motility, morphology and concentration analysis and the testis was used for all biochemical assays. Results: The infusion treated animals (RF, HB, and SL) presented with a non-significant decrease of -14.3%, -18.2%, -17.2% and -24.8%, -20.7%, -27.3% in total motility and progressive motility when compared to the control group, respectively. There was a significant increase in number of spermatozoa with slow speed (p = 0.03), especially in SL treated group compared to the control (p = 0.03). Additionally, there was an increase of 28.8%, 31.7%, 23% in superoxide dismutase (SOD) activity of RF, HB and SL compared to control, respectively. This was accompanied with a percentage decrease of -21.1%, -23.7%, 45.9% in malondialdehyde (MDA) levels compared to the control group. Conclusion: In summary, animals treated with the respective infusions presented with a percentage increase in SOD activity but have reduced sperm motility and decreased normal morphology. Paradoxically, they presented with increased sperm concentration. Hence, it is presumed that rooibos, honeybush and sutherlandia may enhance sperm quantity (concentration) but may impair sperm quality (motility morphology) when consumed by healthy animals.

Relevance of Indian traditional tisanes in the management of type 2 diabetes mellitus: a review

Background

Tisanes are a potential source of phytochemicals to reduce disease risk conditions and are used to protect from non-communicable diseases, globally. A few tisanes have gained more popularity than others depending on their chemical composition based on the geographical origin of the used herb. Several Indian tisanes have been claimed to have traits beneficial to people with or at a high risk of type 2 diabetes mellitus. Under the concept, the literature was reviewed and compiled into a document to highlight the chemical uniqueness of popular Indian traditional tisanes to be more informative and potent as per modern medicine to overcome type 2 diabetes mellitus.

Methods

An extensive literature survey was conducted using computerized database search engines, such as Google Scholar, PubMed, ScienceDirect, and EMBASE (Excerpta Medica database) for herbs that have been described for hyperglycemia, and involved reaction mechanism, in-vivo studies as well as clinical efficacies published since 2001 onwards using certain keywords. Compiled survey data used to make this review and all findings on Indian traditional antidiabetic tisanes are tabulated here.

Results

Tisanes render oxidative stress, counter the damage by overexposure of free radicals to the body, affect enzymatic activities, enhance insulin secretion, etc. The active molecules of tisanes also act as anti-allergic, antibacterial, anti-inflammatory, antioxidant, antithrombotic, antiviral, antimutagenicity, anti-carcinogenicity, antiaging effects, etc. WHO also has a strategy to capitalize on the use of herbals to keep populations healthy through effective and affordable alternative means with robust quality assurance and strict adherence to the product specification.

Influence of Flavonoid-Rich Fraction of Monodora tenuifolia Seed Extract on Blood Biochemical Parameters in Streptozotocin-Induced Diabetes Mellitus in Male Wistar Rats

Diabetes mellitus is a metabolic disorder caused by either the total destruction of the pancreatic beta cells that secrete insulin for the uptake of glucose from the circulation or as a result of the inability of body cells to respond to the presence of insulin in the blood. The present study investigated the effect of a flavonoid-rich fraction of Monodora tenuifolia seed extract (FFMTSE) on blood parameters in streptozotocin (STZ)-induced diabetic male Wistar rats. The rats were divided into seven groups (n = 6). Group 1: normal control rats, Group 2: rats + FFMTSE (25 mg/kgbwt), Group 3: rats + FFMTSE (50 mg/kgbwt), Group 4: diabetic control rats, Group 5: diabetic rats + FFMTSE (25 mg/kgbwt), Group 6: diabetic rats + FFMTSE (50 mg/kgbwt), and Group 7: diabetic rats + Metformin. The assessment of the lipid profile, kidney functions (urea and creatinine), and cardiac biomarkers (LDH and CK-MB) were carried out in the plasma using established protocols. The results showed a significant increase in the concentrations of triacylglycerol, cholesterol, LDL-cholesterol, VLDL-cholesterol, urea, and creatinine, as well as in cardiac enzyme activities in diabetic rats. However, the administration of the FFMTSE significantly improved the observed biochemical parameters. In addition, an increased concentration of HDL-cholesterol concentration was observed in the diabetic rats upon treatment with FFMTSE. These findings indicate that FFMTSE could be a potent anti-nephropathy and anti-cardiomyopathy agent in diabetic conditions.

Eco-physiological response of secondary metabolites of teas: Review of quality attributes of herbal tea

Herbal tea is a rich source of secondary metabolites which are reputed to have medicinal and nutritional efficacy. These secondary metabolites are influenced by the abiotic and biotic stresses that improve the production of herbal teas in terms of biomass production, accumulation and partitioning of assimilates of compounds. In this study, various examples of herbal teas have been shown to respond differently to secondary metabolites affected by environmental factors. Thus, the meta-analysis of this study confirms that different herbal teas' response to environmental factors depends on the type of species, cultivar, and the degree of shade that the plant is exposed. It is also evident that the metabolic processes are also known to optimize the production of secondary metabolites which can thus be achieved by manipulating agronomic practices on herbal teas. The different phenolic compound in herbal teas possesses the antioxidant, antimicrobial, antiatherosclerosis, anti-inflammatory, antimutagenic, antitumor, antidiabetic and antiviral activities that are important in managing chronic diseases associated with lifestyle. It can be precluded that more studies should be conducted to establish interactive responses of biotic and abiotic environmental factors on quality attributes of herbal teas.

The toxic contaminants of Aspalathus linearis plant material as well as herb-drug interactions may constitute the health risk factors in daily rooibos tea consumers

Rooibos tea is brewed using Aspalathus linearis plant material sensitive to environmental contamination. This review covers the safety data from preclinical experiments as well as human studies and delivers a report on its hepatic activity. In vitro tea investigation reveals antioxidative and anti-mutagenic features and ability to modulate microsomal enzymes. In rodent research, it exerts protective or neutral impact on liver functions and morphology, yet several human case reports suggest possible acute hepatic damage. Summarizing rooibos consumption seems to be safe in terms of hepatotoxicity; however, there may be designated a group of consumers with higher risk of liver irritation. The contamination of plant material may contribute to herb-induced liver injury. Due to the impact on CYPs, there is a possible risk of herb-drug interactions affecting bioavailability of some co-administered medicines. Caution should be exercised in patients receiving the treatment with allopathic medicines to avoid untoward alteration of drug plasma concentration.

Co-Treatment of Caco-2 Cells with Doxorubicin and Gold Nanoparticles Produced from Cyclopia intermedia Extracts or Mangiferin Enhances Drug Effects

Mangiferin (MGF) is a natural and valuable polyphenol found in significant levels in many plant species, including Cyclopia intermedia (C. intermedia). In a previous study, we synthesized gold nanoparticles (AuNPs) using MGF and a water extract of C. intermedia and reported that these AuNPs have very low cytotoxicity toward a human colon cancer (Caco-2) cell line. Although the study also showed that these biogenic AuNPs in combination with doxorubic (DOX) significantly augmented the cytotoxic effects of DOX in Caco-2 cells, the mechanism of the enhanced effect was not fully understood, and it was also not known if other cell lines would be sensitive to this co-treatment. In the present study, we examined the cytotoxicity of the co-treatment in Caski, HeLa, HT-29, KMST-6 and MDA-321 cell lines. Additionally, we investigated the mechanistic effects of this co-treatment in Caco-2 cells using several assays, including the adenosine triphosphate (ATP), the oxidative stress, the mitochondrial depolarization, the colony formation, the APOPercentage and the DNA fragmentation assays. We also assessed the intracellular uptake of the biogenic AuNPs. The study showed that the biogenic AuNPs were effectively taken up by the cancer cells, which, in turn, may have enhanced the sensitivity of Caco-2 cells to DOX. Moreover, the combination of the biogenic AuNPs and DOX caused a rapid depletion of ATP levels, increased mitochondrial depolarization, induced apoptosis, reduced the production of reactive oxygen species (ROS) and inhibited the long-term survival of Caco-2 cells. Although the study provided some insight into the mechanism of cytotoxicity induced by the co-treatment, further mechanistic and molecular studies are required to fully elucidate the enhanced anticancer effect of the co-treatment.

Network Pharmacology- and Molecular Dynamics Simulation-Based Bioprospection of Aspalathus linearis for Type-2 Diabetes Care

The medicinal herb Aspalathus linearis (rooibos) is globally recognized in type-2 diabetes mellitus (T2DM) treatment due to its known and distinctive compounds. This work utilized network pharmacology (NP) coupled with molecular dynamics simulation in gaining new insight into the anti-diabetic molecular mechanism of action of rooibos teas. It looked at the interactions between rooibos constituents with various relevant protein receptors and signaling routes associated with T2DM progression. The initial analysis revealed 197 intersecting gene targets and 13 bioactive rooibos constituents linked to T2DM. The interactions between proteins and compounds to the target matrix were generated with the Cystoscope platform and STRING database. These analyses revealed intersecting nodes active in T2DM and hypoxia-inducible factor 1 (HIF-1) as an integral receptors target. In addition, KEGG analysis identified 11 other pathways besides the hub HIF-1 signaling route which may also be targeted in T2DM progression. In final molecular docking and dynamics simulation analysis, a significant binding affinity was confirmed for key compound-protein matrices. As such, the identified rooibos moieties could serve as putative drug candidates for T2DM control and therapy. This study shows rooibos constituents' interaction with T2DM-linked signaling pathways and target receptors and proposes vitexin, esculin and isovitexin as well as apigenin and kaempferol as respective pharmacologically active rooibos compounds for the modulation of EGFR and IGF1R in the HIF-1 signaling pathway to maintain normal homeostasis and function of the pancreas and pancreatic β-cells in diabetics.

Herbal tea, a novel adjuvant therapy for treating type 2 diabetes mellitus: A review

Type 2 diabetes mellitus (T2DM) is a metabolic, endocrine disease characterized by persistent hyperglycemia. Several studies have shown that herbal tea improves glucose metabolism disorders in patients with T2DM. This study summarizes the published randomized controlled trials (RCTs) on herbal tea as a adjuvant therapy for treating T2DM and found that herbal teas have potential add-on effects in lowering blood glucose levels. In addition, we discussed the polyphenol contents in common herbal teas and their possible adverse effects. To better guide the application of herbal teas, we further summarized the hypoglycemic mechanisms of common herbal teas, which mainly involve: 1) improving insulin resistance, 2) protecting islet β-cells, 3) anti-inflammation and anti-oxidation, 4) inhibition of glucose absorption, and 5) suppression of gluconeogenesis. In conclusion, herbal tea, as a novel adjuvant therapy for treating T2DM, has the potential for further in-depth research and product development.

Hypoglycemic, Hypolipidemic and Antioxidant Potentials of Ethanolic Stem Bark Extract of Anacardium occidentale in Streptozotocin-Induced Diabetic Rats

Diabetes mellitus is one of the most widespread diseases affecting the world's population causing substantial morbidity, mortality and long-term complications. This study was designed to investigate possible hypoglycemic, hypolipidemic and antioxidant effect of ethanolic stem bark extract of Anacardium occidentale in streptozotocin (STZ)-induced diabetic rats. Twenty-eight STZ (60 mg/kg body weight)-induced diabetic, male albino rats were randomly distributed into Groups II-V (7 rats each) and orally administered with water, metformin (14.2 mg/kg), 200 mg/kg Anacardium occidentale extract and 400 mg/kg Anacardium occidentale extract respectively daily for 15 days. Group I rats were untreated with STZ and serves as control all under the same sham handling. Blood samples were taken for measurement of fasting blood glucose (FBG) and lipid profile. Liver and kidney tissue samples were taken for determination of glycemic indices (glucose and glycogen), as well as redox status markers such as malondialdehyde (MDA), total glutathione (GSH), activities of superoxide dismutase (SOD) and glutathione-s-transferase (GST). Results showed that treatment with 200 and 400 mg/kg Anacardium occidentale stem bark extract reversed hyperglycemia and hyperlipidemia induced by STZ similar to what was observed with the standard drug, metformin. Similarly, both extract concentration produced a significant reduction in MDA while the activity of SOD and GST, as well as concentration of GSH were elevated. This study suggested that ethanolic stem bark extract of Anacardium occidentale at 200 and 400 mg/kg can ameliorate diabetes and its associated complications via its hypoglycemic, hypolipidemic, antioxidant and free radical scavenging properties.

Chemical Fingerprinting Profile and Targeted Quantitative Analysis of Phenolic Compounds from Rooibos Tea (Aspalathus linearis) and Dietary Supplements Using UHPLC-PDA-MS

Aspalathus linearis (Burm.f.) R. Dahlgren, commonly known as rooibos tea, was consumed traditionally by the indigenous South African inhabitants as an herbal remedy. Beside antioxidant properties, it displays antiallergic, antispasmodic, and hypoglycemic activities. An ultra-high-performance liquid chromatography method coupled with photodiode array and mass spectrometry detectors were developed for the determination of 14 phenolic constituents from leaves and stems of A. linearis. The efficient separation was performed within 30 min at a temperature of 30 °C by using C-18 column as the stationary phase and water/acetonitrile with 0.05% formic acid as the mobile phase. Method validation for linearity, repeatability, limits of detection, and limits of quantification was achieved. The limits of detection from 0.2–1 μg/mL were reported for the standard compounds. Their total content varied substantially (1.50–9.85 mg/100 mg sample) in 21 dietary supplements. The presence of regioisomers and diastereomers which co-elute on a variety of stationary phases make separation for quantification purposes challenging. This method was found to be efficient in providing low retention times and excellent resolution for this type of phytochemicals. The established method is suitable for chemical fingerprint analysis of A. linearis and cost-effective for quality control of rooibos tea products.

Green Synthesis of Metallic Nanoparticles Using Some Selected Medicinal Plants from Southern Africa and Their Biological Applications

The application of metallic nanoparticles (MNPs), especially that of silver, gold, cobalt, and zinc as antimicrobial, anticancer, drug delivery, contrast, and bioimaging agents has transformed the field of medicine. Their functions, which are attributed to their physicochemical properties, have gained prominence in various technological fields. Although MNPs can be produced via rigorous physical and chemical techniques, in recent years, a biological approach utilizing natural materials has been developed. With the increasing enthusiasm for safe and efficient nanomaterials, the biological method incorporating microorganisms and plants is preferred over physical and chemical methods of nanoparticle synthesis. Of these bio-entities, plants have received great attention owing to their capability to reduce and stabilize MNPs in a single one-pot protocol. South Africa is home to ~10% of the world's plant species, making it a major contributor to the world's ecological scenery. Despite the documented contribution of South African plants, particularly in herbal medicine, very few of these plants have been explored for the synthesis of the noble MNPs. This paper provides a review of some important South African medicinal plants that have been utilized for the synthesis of MNPs. The enhanced biological properties of the biogenic MNPs attest to their relevance in medicine. In this endeavour, more of the African plant biodiversity must be explored for the synthesis of MNPs and be validated for their potential to be translated into future nanomedicine.

Rooibos (Aspalathus linearis) influence on health and ovarian functions

This paper reviews provenance, processing and properties of rooibos (Aspalathus linearis, Brum.f) and its numerous biologically active constituents, as well as the currently available knowledge concerning their physiological and medicinal effects and their possible extra- and intracellular mechanisms of action. Search for literature was performed in agreement with the preferred reporting items for systematic review criteria in Cochrane Library, PubMed, Web of Science and SCOPUS databases between the years 2000 and 2021. The limited number of in vitro studies suggests an influence of rooibos on basic ovarian cell functions, as well as its potential applicability to control female reproduction and prevent the effect of environmental contaminants on ovarian functions. Nevertheless, further studies are required for better understanding of the character and mechanisms of action, as well as of rooibos' application in reproductive biology and medicine.

In vitro effects of aqueous extract of fermented rooibos (Aspalathus linearis) on human sperm function

Aspalathus linearis (rooibos) is a herbal medicinal plant originally from South Africa's fynbos and well known for its medicinal effects in treating different medical conditions. Rooibos contains significant levels of antioxidants capable of inhibiting the production of reactive oxygen species, which may improve seminal parameters. This study focussed on investigating the direct effect of fermented rooibos on human sperm functions in vitro. Semen samples collected by masturbation from unproven fertile donors (n = 25) and infertile patients (n = 25) after 3-5 days' abstinence were liquefied and centrifuged (300 × g; 10 min) in human tubular fluid medium containing 1% bovine serum albumin. Afterwards, semen samples (7.5 × 10⁶ /ml) were incubated at 37°C for one hour with aqueous extract of fermented extract in sperm preparation medium (0, 0.10, 1.0, 10 and 100 μg/ml) and assessed. Our data showed that fermented rooibos did not affect functional sperm parameters (motility, vitality, intracellular reactive oxygen species and acrosome reaction, p > .05), in vitro except in the reduced percentage of intact mitochondrial membrane potential and DNA fragmentation (p < .05). The decrease in DNA fragmentation generates the possibility of using the extract in patients prior to assisted reproductive techniques.

Buckwheat, rooibos, and vitex extracts can mitigate adverse effects of xylene on ovarian cells in vitro

This study examines whether selected functional food and medicinal plants can mitigate the adverse effects of xylene on ovarian cells. The influences of xylene (0, 10, 100, or 1000 ng/mL), buckwheat (Fagopyrum esculentum), rooibos (Aspalathus linearis), vitex (Vitex agnus-castus), extracts (10 μg/mL each), and a combination of xylene with these plant additives on cultured porcine ovarian granulosa cells are compared. Cell viability, proliferation (PCNA accumulation), apoptosis (accumulation of bax), and release of progesterone (P4) and estradiol (E2) were analyzed by the trypan blue tests, quantitative immunocytochemistry, and enzyme-linked immunosorbent assays, respectively. Xylene suppressed all measures of ovarian cell function. Rooibos prevented all of xylene's effects, whereas buckwheat and vitex prevented four of five of the analyzed effects (buckwheat prevented xylene influence on viability, PCNA, bax, and E2; vitex prevented xylene action on viability, PCNA, and P4 and E2). These observations show that xylene has the potential to suppress ovarian cell functions, and that buckwheat, rooibos, and vitex can mitigate those effects, making them natural protectors against the adverse effects of xylene on ovarian cells.

Protective effects of medicinal plant against diabetes induced cardiac disorder: A review

ETHNOPHARMACOLOGY RELEVANCE

Nowadays, there is an increase in global tendency to use medicinal plants as preventive and therapeutic agents to manage diabetes and its long-term complications such as cardiovascular disorders owing to their availability and valuable traditional background.

AIM OF STUDY

This review aims to introduce common medicinal plants, which have been demonstrated to have cardioprotective effects on diabetes and their mechanisms of action.

MATERIALS AND METHODS

Online literature databases, including Web of Sciences, PubMed, Science Direct, Scopus and Google Scholar were searched without date limitation by May 2020. The following keywords (natural products or medicinal plants or herbal medicine or herb or extract) and (diabetes or antidiabetic or hyperglycemic) and (cardiomyopathy or heart or cardioprotective or cardiac or cardio) were used, and after excluding non-relevant articles, 81 original English articles were selected.

RESULTS

The surveyed medicinal plants induced cardioprotective effects mostly through increasing antioxidant effects leading to attenuating ROS production as well as by inhibiting inflammatory signaling pathways and related cytokines. Moreover, they ameliorated the Na+/K + ATPase pump, the L-type Ca₂⁺ channel current, and the intracellular ATP. They also reduced cardiac remodeling and myocardial cell apoptosis through degradation of caspase-3, Bax, P53 protein, enhancement of Bcl-2 protein expression as well as downregulation of TGFβ1 and TNFα expression. In addition, the extracts improved cardiac function through increasing EF% and FS% as well as restoring hemodynamic parameters.

CONCLUSIONS

The reviewed medicinal plants demonstrated cardioprotective manifestations in diabetes through intervention with mechanisms involved in the diabetic heart to restore cardiovascular complications.

Gold Nanoparticles Synthesized Using Extracts of Cyclopia intermedia, Commonly Known as Honeybush, Amplify the Cytotoxic Effects of Doxorubicin

Cyclopia intermedia (C. intermedia) is an indigenous South African shrub used to prepare the popular medicinal honeybush (HB) tea. This plant contains high levels of mangiferin (MGF), a xanthonoid that was reported to have numerous biological activities, including anti-tumor activity. MGF and extracts that contain high concentrations of MGF, such as extracts from Mangifera indica L. or mango have been used to synthesize gold nanoparticles (AuNPs) using green nanotechnology. It has previously been shown that when AuNPs synthesized from M. indica L. extracts are used in combination with doxorubicin (DOX) and Ayurvedic medicine, the anti-tumor effects appear to be augmented. It has also been demonstrated that MGF used in combination with DOX resulted in enhanced anti-tumor effects. In this study, C. intermedia (HB) and MGF were used to synthesize HB-AuNPs and MGF-AuNPs, respectively. The physicochemical properties of the AuNPs were characterized by the UV-Visible Spectroscopy (UV-Vis), dynamic light scattering (DLS), Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD) and high-resolution transmission electron microscopy (HR-TEM). The cytotoxicity of HB-AuNPs and MGF-AuNPs were assessed on human colon (Caco-2), prostate (PC-3) and glioblastoma (U87) cancer cells; as well as normal breast epithelial (MCF-12A) cells using the MTT assay. Both HB-AuNPs and MGF-AuNPs demonstrated relatively low cytotoxicity in these cells. However, when these nanoparticles were used in combination with DOX, the cytotoxicity of DOX was significantly augmented.

Effects of benzene on gilts ovarian cell functions alone and in combination with buckwheat, rooibos, and vitex

We aimed to examine the influence of benzene and of three dimethyl sulfoxide (DMSO) plant extracts-buckwheat (Fagopyrum Esculentum), rooibos (Aspalathus linearis), and vitex, (Vitex Agnus-Castus), and the combination of benzene with these three plant extracts on basic ovarian cell functions. Specifically, the study investigated the influence of benzene (0, 10, 100, or 1000 ng/mL) with and without these three plant additives on porcine ovarian granulosa cells cultured during 2 days with and without these additives. Cell viability, proliferation (accumulation of proliferating cell nuclear antigen, PCNA), apoptosis (accumulation of Bcl-2-associated X protein , bax), and the release of progesterone (P) and estradiol (E) were analyzed by the Trypan blue test, quantitative immunocytochemistry, and enzyme-linked immunosorbent assay, respectively. Benzene reduced cell viability, as well as P and E release. Plant extracts, given alone, were able directly promote or suppress ovarian cell functions. Furthermore, buckwheat and rooibos, but not vitex prevented the inhibitory action of benzene on cell viability. Buckwheat induced the stimulatory action of benzene on proliferation. Rooibos and vitex promoted benzene effect on cell apoptosis. All these plant additives were able to promote suppressive action of benzene on ovarian steroidogenesis.These observations show that benzene may directly suppress ovarian cell viability, P, and E release and that buckwheat, rooibos, and vitex can directly influence ovarian cell functions and modify the effects of benzene-prevent toxic influence of benzene on cell viability and induce stimulatory action of benzene on ovarian cell proliferation, apoptosis, and steroidogenesis. The observed direct effects of benzene and these plants on ovarian cells functions, as well as the functional interrelationships of benzene and these plants, should be taken into account in their future applications.

Sequential extracts of red honeybush (Cyclopia genistoides) tea: Chemical characterization, antioxidant potentials, and anti-hyperglycemic activities

The antioxidant, antidiabetic, and anti-obesogenic potentials of different extracts (dichloromethane, ethyl acetate, ethanol, and aqueous) of the red honeybush (Cyclopia genistoides) tea were investigated in vitro and ex vivo. All extracts exhibited significant scavenging and reducing power activities, with the aqueous and ethyl acetate extracts being the most potent. In vitro antidiabetic analysis revealed the extracts to be potent inhibitors of α-glucosidase and lipase activities. All extracts increased catalase and SOD activities, and glutathione level in oxidative pancreatic injury. GC-MS analysis revealed the presence of fatty acids, fatty acid ester, phytols, sterols, saccharide, ketones, and triterpenes. These results imply that the sequential extracts of honeybush tea (particularly the aqueous and ethyl acetate extracts) may not only exhibit antioxidant potentials but also mediate anti-hyperglycemia activities by inhibiting lipid and carbohydrate digestion. PRACTICAL APPLICATIONS: Red honeybush tea is enjoyed widely in South Africa and around the world due to its no caffeine and very low tannin content, as well as many healthcare attributes. There are however no scientific reports for its sequential extraction of different solvents on antidiabetic effects. The different extracts of honeybush tea (particularly the aqueous and ethyl acetate extracts) inhibited lipid and carbohydrate digestive enzymes linked to type 2 diabetes (T2D), as well as modulate oxidative pancreatic injury. These findings will promote its utilization as a potential nutraceutical in the management of diabetes and its complications.

Regenerative medicine of pancreatic islets

The pancreas became one of the first objects of regenerative medicine, since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted. The number of people living with diabetes mellitus is currently approaching half a billion, hence the crucial relevance of new methods to stimulate regeneration of the insulin-secreting β-cells of the islets of Langerhans. Natural restrictions on the islet regeneration are very tight; nevertheless, the islets are capable of physiological regeneration via β-cell self-replication, direct differentiation of multipotent progenitor cells and spontaneous α- to β- or δ- to β-cell conversion (trans-differentiation). The existing preclinical models of β-cell dysfunction or ablation (induced surgically, chemically or genetically) have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation. The ultimate goal, sufficient level of functional activity of β-cells or their substitutes can be achieved by two prospective broad strategies: β-cell replacement and β-cell regeneration. The “regeneration” strategy aims to maintain a preserved population of β-cells through in situ exposure to biologically active substances that improve β-cell survival, replication and insulin secretion, or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β- to β-cell conversion. The “replacement” strategy implies transplantation of β-cells (as non-disintegrated pancreatic material or isolated donor islets) or β-like cells obtained ex vivo from progenitors or mature somatic cells (for example, hepatocytes or α-cells) under the action of small-molecule inducers or by genetic modification. We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally active β-cells, the innermost hope of millions of people globally.

The Combination Effect of Aspalathin and Phenylpyruvic Acid-2-O-β-D-glucoside from Rooibos against Hyperglycemia-Induced Cardiac Damage: An In Vitro Study

Recent evidence shows that rooibos compounds, aspalathin and phenylpyruvic acid-2-O-β-d-glucoside (PPAG), can independently protect cardiomyocytes from hyperglycemia-related reactive oxygen species (ROS). While aspalathin shows more potency by enhancing intracellular antioxidant defenses, PPAG acts more as an anti-apoptotic agent. Thus, to further understand the protective capabilities of these compounds against hyperglycemia-induced cardiac damage, their combinatory effect was investigated and compared to metformin. An in vitro model of H9c2 cardiomyocytes exposed to chronic glucose concentrations was employed to study the impact of such compounds on hyperglycemia-induced damage. Here, high glucose exposure impaired myocardial substrate utilization by abnormally enhancing free fatty acid oxidation while concomitantly suppressing glucose oxidation. This was paralleled by altered expression of genes involved in energy metabolism including acetyl-CoA carboxylase (ACC), 5′ AMP-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor-alpha (PPARα). The combination treatment improved myocardial substrate metabolism, maintained mitochondrial membrane potential, and attenuated various markers for oxidative stress including nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and glutathione content. It also showed a much-improved effect by ameliorating DNA damage when compared to metformin. The current study demonstrates that rooibos compounds offer unique cardioprotective properties against hyperglycemia-induced and potentially against diabetes-induced cardiac damage. These data also support further exploration of rooibos compounds to better assess the cardioprotective effects of different bioactive compound combinations.

Effect of herbal tea on glycemic control in patients with type 2 diabetes: Protocol for a systematic review and meta-analysis

BACKGROUND

Type 2 diabetes (T2D) is a significant health concern worldwide, and good glycemic control is the basis of avoiding disease progression. Herbal tea, as a convenient and effective medication method, has gained popularity among many diabetic patients. However, there are no systematic reviews or meta-analyses to evaluate the clinical efficacy of herbal tea on T2D.

METHODS

Four English electronic databases and 4 Chinese electronic databases were searched for randomized controlled trials (RCTs) meeting inclusion criteria; Clinical trials were searched to explore the relevant unpublished data. Fasting blood glucose and glycated hemoglobin will be measured as primary outcomes. Secondary outcomes include 2-hour postprandial blood glucose, fasting insulin, and homeostasis model assessment-insulin resistance. The heterogeneity of data will be investigated by Chi-square and I test; subgroup analysis and sensitivity analysis will be conducted to explore the sources of heterogeneity; funnel plot will be used to evaluate publication bias; finally, we will use grading of recommendations assessment, development, and evaluate system method to evaluate the quality of evidence. Merging analysis of data will be performed using Rev Man 5.3 software.

RESULTS

The results will be published in a peer-reviewed journal.

CONCLUSIONS

The systematic review will confirm whether herbal tea consumption is benefit to the glycemic control in patients with T2D.

PROSPERO REGISTRATION NUMBER

CRD42019129863.