Protective effects of an herbal formulation of Radix Astragali , Radix Codonopsis and Cortex Lycii on streptozotocin-induced apoptosis in pancreatic β -cells: an implication for its treatment of diabetes mellitus

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Potential of galled leaves of Goji (Lycium chinense) as functional food

Background

Goji (Lycium) is a popular traditional health food, and its fruit and root extracts have been found to possess antioxidant, anti-inflammatory, and hypocholesterolemia-inducing abilities. Goji leaves also contain high amounts of phenolic compounds, similar to its fruit, and their extracts also exhibit several pharmaceutical effects. The induction of galls on Goji leaves reduces their photosynthetic ability and fruit yield, which raise their farming costs, thereby leading to economic loss. However, the defense mechanisms induced by infection may elevate the secondary metabolite content of the leaves, which might provide more nutritive compounds.

Method

Content of chlorophyll, carotenoids, polyphenols, and flavonoids in the extracts of normal and infected Goji leaves (L. chinense) were analyzed. The relative content of chlorogenic acid and rutin, two major phenolic compounds in Goji leaves, were determined by LC-MS/MS. Antioxidant activity was presented by demonstrating the DPPH scavenging percentage. The extract of Goji fruit (L. barbarum) was also analyzed to show a comparative result.

Results

In this study, we found that in infected Goji leaves, the polyphenol content was significantly increased. The level of chlorogenic acid was increased by 36% in galled leaves. The content of rutin in galled leaves was also elevated. Testing the antioxidant activities also showed that the extracts of galled leaves have higher DPPH scavenging abilities.

Conclusions

Our results demonstrated that galled Goji leaves have higher functional value, and may have potential as being consumed as health food.

Curculigo pilosa mitigates against oxidative stress and structural derangements in pancreas and kidney of streptozotocin-induced diabetic rats

Background Curculigo pilosa (African crocus) is widely used in folklore medicine to treat diabetes mellitus and its associated complications. This study was carried out to evaluate this traditional claim by mechanistic investigation of the effect of corn steep liquor extract of Curculigo pilosa and its n-butanol and methanol solvent fractions on hyperglycemia mediated oxidative damage in pancreas and kidney of streptozotocin-induced diabetic rats. Methods Diabetes mellitus was induced by single intraperitoneal administration of (50 mg/kg) streptozotocin and diabetic rats were treated orally with the extract(s) once in a day for 28 days. After experimental period, the effect of the extract(s) on hyperglycemia mediated oxidative stress was assessed by determination of lipid peroxidation (LPO), reduced glutathione (GSH), nitric oxide (NO), hydrogen peroxide (H2O2) and activities of catalase (CAT) and superoxide dismutase (SOD) enzymes. Also histopathology studies were conducted to substantiate the protective effects on pancreas and kidney. Results Oral administration of the extract significantly (p<0.05) mitigated the hyperglycemia mediated oxidative damage via improving the antioxidant system, inhibit the generation of lipid peroxide, hydrogen peroxide and nitric oxide. Also administration of extracts improved the structural architecture of the pancreas and kidney tissues in diabetic rats. Conclusion The results obtained in this study provide resounding scientific support for the folkloric use of Curculigo pilosa in the management of diabetes mellitus and its complications.

Quality evaluation for Radix Astragali based on fingerprint, indicative components selection and QAMS

Radix Astragali (RA) is one of the most widely used Chinese herbs prescribed in many Chinese formulas to reinforce 'Qi' and treat vital energy deficiency. This study combined fingerprinting with quantitative analysis multi-components by a single marker (QAMS) to improve the quality control standard for RA on the basis of existing quality control methods of traditional Chinese medicinal materials. UPLC-ESI-TOF-MS technique was used to evaluate the quality of RA by fingerprinting and QAMS. Using the anti-inflammatory, anti-oxidation and anti-anoxic activities to screen characteristic components of RA, the calycosin-7-O-β-d-glucoside (CG), ononin, astragaloside IV, astragaloside II, calycosin and astrageloside I significantly inhibited ear edema in mice, the calycosin and CG had good antioxidant activity and the astragaloside I had a significant anti-hypoxia activity. Astragaloside I, astragaloside II, astragaloside IV, ononin, calycosin and CG had significant pharmacological actions. These components were comprehensively used as the indicative components for the quality control of RA. Astragaloside I was used as the internal standard of the relative correction factors of CG (13.45), ononin (0.51), calycosin (12.08), astragaloside IV (0.73) and astragaloside II (0.81). Astragaloside I and CG were used as internal standards of the relative correction factors of the flavonoids and saponins of ononin (1.11), calycosin (0.04), astragaloside IV (0.73) and astragaloside II (0.81). The study combined fingerprinting with QAMS to improve the quality control standard for RA.

Can highly cited herbs in ancient Traditional Chinese medicine formulas and modern publications predict therapeutic targets for diabetes mellitus?

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes among all age groups worldwide was estimated to be more than 382 million in 2013. Traditional Chinese medicine (TCM) has been practiced for thousands of years, and substantial valuable experience and prescriptions have been accumulated in the TCM system for the treatment of diabetes. In recent decades, a large amount of experimental and clinical data has been published on the use of herbal medicines related to these ancient TCM prescriptions.

AIM OF THE STUDY

This study aimed to discover a method for the investigation of potential antidiabetic herbs from the large amount of data in ancient TCM formulas and modern publications and to verify this method through an in vitro bioactivity study.

MATERIALS AND METHODS

In our review, the most frequently cited TCM herbs were selected as potential antidiabetic herb candidates on the basis of TCM philosophical theory (ancient TCM formulas) and Western medicine philosophical theory (modern publications). The ethanol and aqueous extracts of the selected herbs were screened for their α-glucosidase inhibitory, glucose-stimulated insulin secretion (GSIS), and intestinal glucose transport inhibitory effects.

RESULTS

Twelve herbs [Terminalia chebula Retz., fructus immaturus, dried; Poria cocos (Schw) Wolf., sclerotium, dried; Zea mays L., stigma, dried; Pueraria lobata (Willd.) Ohwi, radix, dried; Cucurbita moschata (Duch. ex Lam.) Duch. ex Poiret, fructus, dried; Lycium barbarum L., fructus, dried; Glycine max (L.) Merr., semen, fermented; Glycyrrhiza uralensis Fisch., radix and rhizoma, dried; Dioscorea opposita Thunb., rhizoma, dried; Morus alba L., folium, dried, Morus alba L., fructus, dried; and Polygonatum odoratum (Mill.) Druce, rhizoma, dried] were finally selected as candidates with potential glucose-lowering effects after a review was performed of herbs that are frequently cited in ancient TCM formulas and modern publications. The bioactive study results demonstrated that both the ethanol extracts and crude polysaccharides of M. alba L., fructus, dried, and M. alba L., folium, dried, and the crude polysaccharides of T. chebula Retz., fructus immaturus, dried, exhibited α-glucosidase inhibitory effects. Moreover, the crude polysaccharides of P. cocos (Schw) Wolf., sclerotium, dried; Z. mays L., stigma, dried; and T. chebula Retz., fructus immaturus, dried, exhibited favorable GSIS effects, and the ethanol extracts of P. odoratum (Mill.) Druce, rhizoma, dried; T. chebula Retz., fructus immaturus, dried; and G. uralensis Fisch., radix and rhizoma, dried, significantly decreased glucose transport across the cell monolayer.

CONCLUSIONS

Our review and the preliminary bioactive study revealed that 10 of the 12 recommended edible TCM herbs had favorable antidiabetic effects, demonstrating that TCM herbs with a high prescription and publication frequency may provide insights into the potential therapeutic targets of diabetes mellitus and may aid in the discovery of effective compounds complementary to currently used medicines. Such a literature and medicine review is a useful method of exploring potential antidiabetic herbs by using the wealth of information in ancient TCM formulas and modern publications.

Acupuncture paired with herbal medicine for prediabetes: study protocol for a randomized controlled trial

Background

Type-2 diabetes has become a major disease and is known to seriously impair people’s health worldwide. Prediabetes includes impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) and is the most critical period for preventing type-2 diabetes, as it can be identified and reversed. Studies in the past decade have indicated that acupuncture and Chinese herbal medicine may be beneficial for treating prediabetes. However, a randomized controlled trial (RCT) should be conducted to obtain more clinical evidence on this topic.

Methods/design

An RCT will be implemented in this study, using a72-week study period (24 weeks for the intervention and 48 weeks for follow-up). Participants will be recruited from the Fifth Affiliated Hospital of Guangzhou Medical University in China. Eighty participants will be randomized to the treatment group (acupuncture plus herbal medicine and health education) or the control group (health education only), 40 participants in each. People included in this study must have been diagnosed with prediabetes using Western medicine criteria. The endpoint indices include the incidence of diabetes mellitus and the reversion rate. The primary outcome is fasting plasma glucose (FPG) level, 2-h plasma glucose (2-hPG) level after a 75-g oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA_1c) level. Secondary outcomes include the following: Body Mass Index (BMI); hemorheology, including shear rates of whole-blood viscosity and plasma viscosity. Safety indices include hepatic (ALT, AST) and renal function (BUN, Cr) and records of adverse events, including diarrhoea, colds, pharyngitis, and sleep disorders. Quality control will be implemented, including quality control of the laboratory, researchers, participants, investigational drugs, data and documents, occurrence of bias, supervision, among others, according to uniform standard operating procedures (SOPs) which have been established by the Good Clinical Practice (GCP) office of the Fifth Affiliated Hospital of Guangzhou Medical University.

Discussion

The aim of this study is to evaluate the efficacy and safety of acupuncture paired with herbal medicine for the treatment of patients with prediabetes.

Trial registration

Chinese clinical trials register ChiCTR-INR-16008891. Registered on 23 July 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2014-4) contains supplementary material, which is available to authorized users.

Antidiabetic Mechanisms of Rosa canina Fruits: An In Vitro Evaluation

Rosa canina fruits have been used traditionally for the treatment of diabetes mellitus and its complications. The aim of current study was to evaluate the in vitro mechanism of action of R canina in managing diabetes mellitus. Cell proliferation and cytotoxicity assay were performed on pancreatic β-cells, βTC6. The protective activity of the extract on streptozotocin-induced death in βTC6 cells was studied. The effect of R canina on the metabolism of glucose in HepG2, a hepatocellular carcinoma cell line, was evaluated. The effect of the extract on glucose diffusion across the dialysis membrane, which is a comfortable model for assessing cellular glucose absorption, was evaluated. The results obtained from current study confirmed that R canina extract can act as a growth factor for pancreatic β-cell line providing a novel mechanism for the observed antidiabetic effect of this natural agent. Further preclinical studies are necessary to evaluate the perfect mechanism of action of R canina in diabetes mellitus.

Anti-diabetic effects of Caulerpa lentillifera: stimulation of insulin secretion in pancreatic β-cells and enhancement of glucose uptake in adipocytes

OBJECTIVE

To evaluate anti-diabetic effect of Caulerpa lentillifera (C. lentillifera).

METHODS

The inhibitory effect of C. lentillifera extract on dipeptidyl peptidase-IV and α-glucosidase enzyme was measured in a cell free system. Then, interleukin-1β and interferon-γ induced cell death and insulin secretion were measured in rat insulinoma (RIN) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit, respectively. Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting, using 3T3-L1 adipocytes.

RESULTS

C. lentillifera extract significantly decreased dipeptidyl peptidase-IV and α-glucosidase enzyme activities, and effectively inhibited cell death and iNOS expression in interleukin-1β and interferon-γ induced RIN cells. Furthermore, C. lentillifera extract significantly enhanced insulin secretion in RIN cells and glucose transporter expression and glucose uptake in 3T3-L1 adipocytes.

CONCLUSIONS

Thus, our results suggest that C. lentillifera could be used as a potential anti-diabetic agent.

Activity-guided isolation of NF-κB inhibitors and PPARγ agonists from the root bark of Lycium chinense Miller

ETHNOPHARMACOLOGICAL RELEVANCE

The root bark of Lycium chinense Miller, Lycii radicis cortex, has been used in traditional Chinese medicine (TCM) to treat different inflammation-related symptoms, such as diabetes mellitus. The pro-inflammatory transcription factor nuclear factor kappa B (NF-κB) is a key regulator of inflammation, while the transcription factor peroxisome proliferator-activated receptor gamma (PPARγ) is a key modulator of genes involved in diabetes development. To identify putative active compound(s) from Lycii radicis cortex inhibiting NF-κB or activating PPARγ.

MATERIAL AND METHODS

Using activity-guided fractionation, six extracts with different polarity, isolated fractions, and purified compounds from Lycii radicis cortex were tested for NF-κB inhibition and PPARγ activation in vitro. The structure of the purified compounds was elucidated by NMR and MS techniques.

RESULTS

The ethyl acetate extract and the methanol extract of Lycii radicis cortex suppressed tumor necrosis factor alpha (TNF-α)-induced activation of NF-κB, while the dichloromethane extract activated PPARγ. Nine phenolic amide analogues, including trans-N-(p-coumaroyl)tyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), dihydro-N-caffeoyltyramine (4), three neolignanamides (5-7), and two lignanamide (8, 9), were isolated and their inhibitory potential on NF-κB was determined (1-4 were also contained in water decoction). Two of the nine isolated phenolic amides inhibited TNF-α-induced NF-κB activation. Trans-N-caffeoyltyramine was verified as the key component responsible for the NF-κB inhibition with an IC50 of 18.4μM in our cell-based test system. Activation of PPARγ was attributed to a palmitic-acid enriched fraction which displayed concentration-dependent effect ablated upon co-treatment with the PPARγ antagonist T0070907.

CONCLUSIONS

Phenolic amides were confirmed as main components from Lycii radicis cortex responsible for NF-κB inhibition. Fatty acids were identified as the major plant constituent responsible for the PPARγ activation. Structure-activity relationship analysis suggests that the NF-κB inhibitory activity of trans-N-caffeoyltyramine may be attributed to its Michael acceptor-type structure (α,β-unsaturated carbonyl group). The data of this study contribute to a better understanding of the molecular mechanism of action of Lycii radicis cortex extracts in the context of inflammation.

Radix astragali injection enhances recovery from sudden deafness

OBJECTIVES

An acute interruption of the blood supply to the inner ear is one of the most likely causative factors for sudden deafness (SD). Reactive oxygen species (ROS) have been suggested to be important mediators of the tissue injury during cochlear ischemia and reperfusion. Radix astragali (RA) is natural antioxidant. The aim of this study was to investigate the efficacy of RA in patients with SD.

PATIENTS AND METHODS

We compared the hearing gains from hearing impairment in 46 ears treated with RA with 46 ears treated with non-RA. RA was given intravenously daily for 10 days. There were no significant differences in clinical or audiological data between RA and non-RA groups.

RESULTS

The hearing gain at 250, 500, 1000, 2000, and 4000 Hz in RA group was much higher than that of non-RA group correspondingly (P < .01). Also, the hearing gain at PTA (pure-tone average of 250, 500, 1000, 2000, and 4000 Hz) in RA group was significantly higher than that of non-RA group (P < .01).

CONCLUSION

The recovery of hearing was significantly better after treatment of RA than non-treatment of RA. RA can be valuable concurrent therapy for patients with SD.

Streptozotocin-nicotinamide-induced diabetes in the rat. Characteristics of the experimental model

Administration of both streptozotocin (STZ) and nicotinamide (NA) has been proposed to induce experimental diabetes in the rat. STZ is well known to cause pancreatic B-cell damage, whereas NA is administered to rats to partially protect insulin-secreting cells against STZ. STZ is transported into B-cells via the glucose transporter GLUT2 and causes DNA damage leading to increased activity of poly(ADP-ribose) polymerase (PARP-1) to repair DNA. However, exaggerated activity of this enzyme results in depletion of intracellular NAD(+) and ATP, and the insulin-secreting cells undergo necrosis. The protective action of NA is due to the inhibition of PARP-1 activity. NA inhibits this enzyme, preventing depletion of NAD(+) and ATP in cells exposed to STZ. Moreover, NA serves as a precursor of NAD(+) and thereby additionally increases intracellular NAD(+) levels. The severity of diabetes in experimental rats strongly depends on the doses of STZ and NA given to these animals. Therefore, in diabetic rats, blood glucose may be changed in a broad range--from slight hyperglycemia to substantial hyperglycemia compared with control animals. Similarly, blood insulin may be only slightly decreased or substantial hypoinsulinemia may be induced. In vitro studies demonstrated that the insulin-secretory response to glucose is attenuated in STZ-NA-induced diabetic rats compared with control animals. This is due to reduced B-cell mass as well as metabolic defects in the insulin-secreting cells. Results of numerous experiments have demonstrated that this model of diabetes is useful in studies of different aspects of diabetes.

Immuno-enhancement effects of Shenqi Fuzheng Injection on cyclophosphamide-induced immunosuppression in Balb/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Codonopsis and Radix Astragali, of which Shenqi Fuzheng Injection (SFI) is composed, are commonly used in traditional Chinese medicine to improve immune function against chronic diseases.

AIM OF THE STUDY

The present study was thus designed to systematically elucidate the in vivo immuno-enhancement effects of SFI in immunosuppressed mice induced by cyclophosphamide (Cy) treatment.

MATERIALS AND METHODS

Balb/c mice were injected intraperitoneally (i.p.) once daily with low-dose (2.5 g raw materials/kg), intermediate-dose (5 g raw materials/kg), high-dose (10 g raw materials/kg) of SFI for 10 consecutive days, respectively, accompanied by i.p. injection of Cy (80 mg/kg) on Days 4-6.

RESULTS

Compared with vehicle group, low-, intermediate- and high-dose SFI treatment accelerated recovery dose-dependently of spleen index, peripheral white blood cell and bone marrow cell counts, enhanced T cell and B cell proliferation responses, as well as splenic nature killer cell activity and peritoneal macrophage phagocytosis, and restored the level of interleukin-2 in the serum. Furthermore, SFI treatment promoted recovery of the amount of peripheral white blood cells on Day 6, rather than recombinant human Granulocyte Colony-Stimulating Factor (rhG-CSF) did.

CONCLUSIONS

These results demonstrate, for the first time, that chronic treatment with SFI results in accelerating recovery of immunosuppression in Cy-treated mice, which is competent in taking into consideration for both precautions and remedy. Our findings provide experimental evidences for further researches and clinical application in cancer patients undergoing chemotherapy.

The healing and anti-scar effects of astragaloside IV on the wound repair in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Astragaloside IV is the chief ingredient of Radix Astragali, which has been used in the Traditional Chinese Medicine as a major component of many polyherbal formulations for the repair and regeneration of injured organ and tissues. This study is to investigate the influence of astragaloside IV on both of the wound healing and scar formation.

MATERIALS AND METHODS

For the in vitro evaluation, the influence of the astragaloside IV in the wound scratch test of keratinocytes and the secretion of transforming growth factor-β1, a key factor contributing to scar formation were determined. With the rat skin excision model, the in vivo regulation of astragaloside IV on wound closure, angiogenesis and collagen disposition were also evaluated.

RESULTS

Astragaloside IV was shown to significantly promote the migration of keratinocytes in wound scratching assay. The superior effect of Astragaloside IV was observed at 100 μmol/L, in which the recover rates was increased with 2 and 3 folds after 48 h and 96 h respectively than that of blank control (P<0.01). Animal skin closure measurement showed that astragaloside IV could stimulate the wound healing, e.g. with 21% recover in contrast to the 8% of blank control at the 6th day. Biomechanic and Masson's trichrome stain analysis indicated that astragaloside IV may improve the strength of the repaired skin and promoted the angiogenesis and collagen synthesis. Meanwhile, the picrosirius-sirus red stain and Elisa test definitely showed the anti-scar effects of astragaloside IV by decreasing the levels of collagen I/III and TGF-β1 secretion by firbroblasts with a dose-dependent manner (25-100 μmol/L).

CONCLUSIONS

Astragaloside IV was shown a promising natural product with both healing and anti-scar effects for wound treatment. These results give the evidence for the application of astragaloside IV in the treatment of injury.

Radix Astragali injection enhances recovery from acute acoustic trauma

CONCLUSION

The average recovery of hearing and cessation of tinnitus was significantly better after treatment with Radix Astragali (RA) than after non-treatment with RA. RA can be valuable adjuvant therapy for patients with acute acoustic trauma (AAT).

OBJECTIVES

AAT is one of the early indications for the use of RA. The reasons for administering RA to patients with AAT are based on experimental studies showing that noise exposure results in the formation of reactive oxygen species (ROS), which trigger metabolic damage to the organ of Corti. RA is a natural antioxidant. The aim of this study was to investigate the efficacy of RA in patients with AAT.

METHODS

We compared the recovery from hearing impairment and tinnitus in 40 ears treated with RA with 40 ears treated with non-RA. RA was given intravenously daily for 10 days. There were no significant differences in clinical or audiological data between RA and non-RA groups.

RESULTS

The average recovery of hearing at both high and speech frequencies was significantly better and tinnitus persisted less commonly in the RA group than in the non-RA group. Normal hearing at the end of the follow-up period was regained in 27 ears in the RA group and in 21 ears in the non-RA group (p < 0.01).

Suppression of low-density lipoprotein oxidation, vascular smooth muscle cell proliferation and migration by a herbal extract of Radix Astragali, Radix Codonopsis and Cortex Lycii

Background

Atherosclerosis is a major cause of death in developed world. Atherosclerosis is characterized by low-density lipoprotein deposition in the arterial wall which ultimately begets the formation of lesions. Rupture of lesions finally leads to clinical events such as heart attack and stroke. Atherosclerosis is a complication associated with diabetes. In patients with diabetes, the risk of atherosclerosis is three to five folds greater than in non-diabetics. Our previous study showed that a herbal extract of Radix Astragali, Radix Codonopsis and Cortex Lycii, namely SR10, could improve glucose homeostasis both in vitro and in vivo. In this study, we want to further investigate the efficacy of SR10 in treating atherosclerosis.

Method

The inhibitory effect of SR10 on low-density lipoprotein oxidation was investigated using free radical-induced erythrocyte hemolysis model and copper ion-induced low-density lipoprotein oxidation model. Since vascular smooth muscle cell proliferation and migration are important processes in atherogenesis, we also examined the effect of SR10 in inhibiting these events.

Results

Our results showed that SR10 inhibited erythrocyte hemolysis with IC₅₀ value at 0.25 mg/ml and significantly prolonged low-density lipoprotein oxidation in vitro. SR10 attenuated platelet derived growth factor-BB-induced vascular smooth muscle cell proliferation by promoting cell cycle arrest at G₀/G₁ phase as well as inhibiting vascular smooth muscle cell migration.

Conclusion

The potential application of SR10 in treating atherosclerosis has been implied in this study. Animal model will be needed to further verify the efficacy of SR10 in future.

Effects of a multi-herbal extract on type 2 diabetes

BACKGROUND

An aqueous extract of multi-hypoglycemic herbs of Panax ginseng C.A.Meyer, Pueraria lobata, Dioscorea batatas Decaisne, Rehmannia glutinosa, Amomum cadamomum Linné, Poncirus fructus and Evodia officinalis was investigated for its anti-diabetic effects in cell and animal models.

METHODS

Activities of PPARγ agonist, anti-inflammation, AMPK activator and anti-ER stress were measured in cell models and in db/db mice (a genetic animal model for type 2 diabetes).

RESULTS

While the extract stimulated PPARγ-dependent luciferase activity and activated AMPK in C2C12 cells, it inhibited TNF-α-stimulated IKKβ/NFkB signaling and attenuated ER stress in HepG2 cells. The db/db mice treated with the extract showed reduced fasting blood glucose and HbA1c levels, improved postprandial glucose levels, enhanced insulin sensitivity and significantly decreased plasma free fatty acid, triglyceride and total cholesterol.

CONCLUSION

The aqueous extract of these seven hypoglycemic herbs demonstrated many therapeutic effects for the treatment of type 2 diabetes in cell and animal models.

Antihyperglycemic and antioxidative effects of a herbal formulation of Radix Astragali, Radix Codonopsis and Cortex Lycii in a mouse model of type 2 diabetes mellitus

There is emerging evidence that the generation of reactive oxygen species (ROS), which leads to dysfunction of pancreatic beta-cells, is a major factor in the development of type 2 diabetes mellitus. Antioxidation is one of the therapeutic strategies to overwhelm the imbalance in ROS production. In this study, a herbal formulation SR10, comprising Radix Astragali, Radix Codonopsis and Cortex Lycii, was examined for its antidiabetic and antioxidative effects using the diabetic +db/+db mouse model. The results showed that SR10 was effective in decreasing the blood glucose level in chronic treatment by improving beta-cell function. The activities and expression of antioxidant enzymes, catalase and superoxide dismutase, were up-regulated when treated with SR10. Moreover, SR10 treatment did not exhibit any toxic effect to the host.