Berberine ameliorates renal injury in streptozotocin-induced diabetic rats by suppression of both oxidative stress and aldose reductase:

Anti-inflammatory, antioxidant, and immunomodulatory effects of Berberis vulgaris and its constituent berberine, experimental and clinical, a review

Berberis vulgaris (B. vulgaris or barberry) is a medicinal plant that has been used for various purposes in traditional medicine. Berberine is one of the main alkaloids isolated from B. vulgaris and other plants. Both B. vulgaris and berberine have shown anti-inflammatory, antioxidant, and immunomodulatory effects in different experimental models and clinical trials. This review aims to summarize the current evidence on the mechanisms and applications of B. vulgaris and berberine in modulating inflammation, oxidative stress, and immune responses. The literature search was performed using PubMed, Scopus, and Google Scholar databases until August 2023. The results indicated that B. vulgaris and berberine could inhibit the production of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), interleukin 6 (IL-6), and interleukin-17 (IL-17), and enhance the expression of anti-inflammatory cytokines, such as interleukin 10 (IL-10) and transforming growth factor-β (TGF-β), in various cell types and tissues. B. vulgaris and berberine can also scavenge free radicals, increase antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and reduce lipid peroxidation and DNA damage. B. vulgaris and berberine have been reported to exert beneficial effects in several inflammatory, oxidative, and immune-related diseases, such as diabetes, obesity, cardiovascular diseases, neurodegenerative diseases, autoimmune diseases, allergic diseases, and infections. However, more studies are needed to elucidate the optimal doses, safety profiles, and potential interactions of B. vulgaris and berberine with other drugs or natural compounds.

Active natural compounds perturb the melanoma risk-gene network

Cutaneous melanoma is an aggressive type of skin cancer with a complex genetic landscape caused by the malignant transformation of melanocytes. This study aimed at providing an in silico network model based on the systematic profiling of the melanoma-associated genes considering germline mutations, somatic mutations, and genome-wide association study signals accounting for a total of 232 unique melanoma risk genes. A protein-protein interaction network was constructed using the melanoma risk genes as seeds and evaluated to describe the functional landscape in which the melanoma genes operate within the cellular milieu. Not only were the majority of the melanoma risk genes able to interact with each other at the protein level within the core of the network, but this showed significant enrichment for genes whose expression is altered in human melanoma specimens. Functional annotation showed the melanoma risk network to be significantly associated with processes related to DNA metabolism and telomeres, DNA damage and repair, cellular ageing, and response to radiation. We further explored whether the melanoma risk network could be used as an in silico tool to predict the efficacy of anti-melanoma phytochemicals, that are considered active molecules with potentially less systemic toxicity than classical cytotoxic drugs. A significant portion of the melanoma risk network showed differential expression when SK-MEL-28 human melanoma cells were exposed to the phytochemicals harmine and berberine chloride. This reinforced our hypothesis that the network modeling approach not only provides an alternative way to identify molecular pathways relevant to disease but it may also represent an alternative screening approach to prioritize potentially active compounds.

Neuroprotective Properties of Berberine: Molecular Mechanisms and Clinical Implications

Berberine (BBR), an isoquinoline alkaloid natural product, is isolated primarily from Coptis chinensis and other Berberis plants. BBR possesses various bioactivities, including antioxidant, anti-inflammation, anticancer, immune-regulation, and antimicrobial activities. Growing scientific evidence underscores BBR's substantial neuroprotective potential, prompting increased interest and scrutiny. In this comprehensive review, we elucidate the neuroprotective attributes of BBR, delineate the underlying molecular mechanisms, and assess its clinical safety and efficacy. The multifaceted molecular mechanisms responsible for BBR's neuroprotection encompass the attenuation of oxidative stress, mitigation of inflammatory responses, inhibition of apoptotic pathways, facilitation of autophagic processes, and modulation of CYP450 enzyme activities, neurotransmitter levels, and gut microbiota composition. Furthermore, BBR engages numerous signaling pathways, including the PI3K/Akt, NF-κB, AMPK, CREB, Nrf2, and MAPK pathways, to confer its neuroprotective effects. This comprehensive review aims to provide a substantial knowledge base, stimulate broader scientific discourse, and facilitate advancements in the application of BBR for neuroprotection.

A Review of Fibraurea tinctoria and Its Component, Berberine, as an Antidiabetic and Antioxidant

Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia caused by resistance to insulin action, inadequate insulin secretion, or excessive glucagon production. Numerous studies have linked diabetes mellitus and oxidative stress. People with diabetes usually exhibit high oxidative stress due to persistent and chronic hyperglycemia, which impairs the activity of the antioxidant defense system and promotes the formation of free radicals. Recently, several studies have focused on exploring natural antioxidants to improve diabetes mellitus. Fibraurea tinctoria has long been known as the native Borneo used in traditional medicine to treat diabetes. Taxonomically, this plant is part of the Menispermaceae family, widely known for producing various alkaloids. Among them are protoberberine alkaloids such as berberine. Berberine is an isoquinoline alkaloid with many pharmacological activities. Berberine is receiving considerable interest because of its antidiabetic and antioxidant activities, which are based on many biochemical pathways. Therefore, this review explores the pharmacological effects of Fibraurea tinctoria and its active constituent, berberine, against oxidative stress and diabetes, emphasizing its mechanistic aspects. This review also summarizes the pharmacokinetics and toxicity of berberine and in silico studies of berberine in several diseases and its protein targets.

Effect of berberine in comparison to metformin on the biophysical and biochemical parameters in diabetic albino Wistar rats

Introduction: Diabetic endothelial dysfunction is accompanied by increased oxidative stress and upregulated proinflammatory and inflammatory mediators in the endothelial vasculature. Aim of this study is to investigate the effect of Berberine, a natural alkaloid, on the oxidative stress, inflammation and its anti-oxidant effect in streptozotocin diabetic rats and to compare the effectiveness of FF with that of Metformin (Met) Material & Methods: This experimental animal study was conducted at animal house. The sample size included 174 albino wistar rats divided into 3 Groups, one control groups (C) Diabetic and untreated and two test groups. T1 Diabetic and treated with metformin 75 mg/kgwt/day) and T2 (T – Diabetics treated with Berberine(Ber) 100 mg/kgwt/day), with 58 rats in each group (29 male & 29 female). All the rats were treated with streptozotocin intra peritoneally and the diabetic state was induced.  T1 group was treated with metformin 75 mg/kg/wt/day. The T2 group of rats were treated with Berberine at a dose of 100 mg/kgwt/day. Blood sample was drawn from retro orbital plexus of animals and the biophysical and biochemical parameters were tested at an interval of 3, 6 and 12-months duration.

A review on the neuroprotective effect of berberine against chemotherapy-induced cognitive impairment

Chemobrain is one of the major side effects of chemotherapy, despite increased research, the mechanisms underlying chemotherapy-induced cognitive changes remain unknown. Though, several possibly important candidate mechanisms have been identified and will be studied further in the future. Chemobrain is characterized by memory loss, cognitive impairment, difficulty in language, concentration, acceleration, and learning. The major characteristic of chemobrain is oxidative stress, mitochondrial dysfunction, immune dysregulation, hormonal alteration, white matter abnormalities, and DNA damage. Berberine (BBR) is an isoquinoline alkaloid extracted from various berberine species. BBR is a small chemical that easily passes the blood-brain barrier (BBB), making it useful for treating neurodegenerative diseases. Many studies on the pharmacology of BBR have been reported in the past. Furthermore, several clinical and experimental research indicates that BBR has a variety of pharmacological effects. So, in this review, we explore the pathogenesis of chemobrain and the neuroprotective potential of BBR against chemobrain. We also introduced the therapeutic role of BBR in various neurodegenerative and neurological diseases such as Alzheimer's, Parkinson's disease, mental depression, schizophrenia, anxiety, and also some stroke.

Physiological and Pathological Roles of Aldose Reductase

Aldose reductase (AR) is an aldo-keto reductase that catalyzes the first step in the polyol pathway which converts glucose to sorbitol. Under normal glucose homeostasis the pathway represents a minor route of glucose metabolism that operates in parallel with glycolysis. However, during hyperglycemia the flux of glucose via the polyol pathway increases significantly, leading to excessive formation of sorbitol. The polyol pathway-driven accumulation of osmotically active sorbitol has been implicated in the development of secondary diabetic complications such as retinopathy, nephropathy, and neuropathy. Based on the notion that inhibition of AR could prevent these complications a range of AR inhibitors have been developed and tested; however, their clinical efficacy has been found to be marginal at best. Moreover, recent work has shown that AR participates in the detoxification of aldehydes that are derived from lipid peroxidation and their glutathione conjugates. Although in some contexts this antioxidant function of AR helps protect against tissue injury and dysfunction, the metabolic transformation of the glutathione conjugates of lipid peroxidation-derived aldehydes could also lead to the generation of reactive metabolites that can stimulate mitogenic or inflammatory signaling events. Thus, inhibition of AR could have both salutary and injurious outcomes. Nevertheless, accumulating evidence suggests that inhibition of AR could modify the effects of cardiovascular disease, asthma, neuropathy, sepsis, and cancer; therefore, additional work is required to selectively target AR inhibitors to specific disease states. Despite past challenges, we opine that a more gainful consideration of therapeutic modulation of AR activity awaits clearer identification of the specific role(s) of the AR enzyme in health and disease.

Network Pharmacology Analysis of ZiShenWan for Diabetic Nephropathy and Experimental Verification of Its Anti-Inflammatory Mechanism

Background

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). The inflammatory response plays a critical role in DN. ZiShenWan (ZSW) is a classical Chinese medicinal formula with remarkable clinical therapeutic effects on DN, but its pharmacological action mechanisms remain unclear.

Aim

In this study, a network pharmacology approach was applied to investigate the pharmacological mechanisms of ZSW in DN therapy. Based on the results of network analysis, the core targets and signaling pathways related to anti-inflammatory effect were verified via experiments in vivo.

Methods

The candidate chemical ingredients of ZSW as well as its putative targets and known therapeutic targets of DN were acquired from appropriate databases. The “herb-ingredient-target” network for ZSW in DN treatment was established. The protein–protein interaction (PPI) network of potential targets was constructed to screen the core targets. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. In addition to biochemical and pathological indicators, the core targets and signaling pathways associated with inflammation were partially validated in db/db mice at molecular level.

Results

A total of 56 active ingredients in ZSW and 166 DN-related targets were selected from databases. A high proportion of core targets and top signaling pathways participate in inflammation. ZSW markedly alleviated renal injuries pathologically and regulated related biomarkers. In particular, ZSW significantly inhibited the exaggerated release of inflammatory cytokines such as interleukin (IL)-1β, IL-6, tumor necrosis factor receptor (TNF)-ɑ, and monocyte chemotactic protein (MCP)-1 as well as regulating p38 mitogen-activated protein kinases (MAPK) and phosphoinositide 3-kinase (PI3K)–protein kinase B (Akt) signaling pathways in db/db mice.

Conclusion

This study first comprehensively investigated the active ingredients, potential targets, and molecular mechanism of ZSW as a therapy for DN. ZSW achieved renoprotective effects in DN via regulation of multiple targets and signaling pathways, especially by alleviating inflammation. Results indicate that ZSW is a promising multi-target therapeutic approach for DN treatment.

The ameliorative activity of Chrysobalanus orbicularis in streptozotocin-induced type II diabetes mellitus rat model

Chrysobalanus orbicularis is a medicinal plant present in West Africa in the Itsekiri speaking part of Nigeria. It is used conventionally in diabetes mellitus management. This research investigates the ameliorative activity of the aqueous leaf extract of C. orbicularis in a streptozotocin-induced diabetic rat model. Freshly prepared streptozotocin (40 mg/kg body weight [BW]) was administered intraperitoneally to induce diabetes. Three diabetic groups were placed on aqueous leaf extract of C. orbicularis at 11.076, 22.134, and 44.268 mg/kg BW respectively; a group was placed on metformin (44.28 mg/kg BW), and the other two groups were the diabetic control and normal control. The experiment lasted for 28 days, thereafter, fasting blood glucose levels and body weight variations were recorded. Also, glycogen level, antioxidant enzyme, hexokinase and glucose-6-phosphatase activities, malonaldehyde (MDA) as well as glucose transporters 2 and 4 levels were analyzed using standard procedures. Diabetic rats administered aqueous extract of C. orbicularis leaf significantly (p < 0.05) decreased the fasting blood glucose and MDA levels, and glucose-6-phosphatase activity. In addition, administration of aqueous extract of C. orbicularis leaf to diabetic rats demonstrated a momentous increase in liver glycogen level, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, glutathione transferase, and hexokinase activities as well as GLUT-2 and GLUT-4 levels. The data from this study suggest that the aqueous extract of C. orbicularis leaf may be beneficial in the management of diabetic mellitus and its secondary effects.

Mechanisms and Efficacy of Chinese Herbal Medicines in Chronic Kidney Disease

As the current treatment of chronic kidney disease (CKD) is limited, it is necessary to seek more effective and safer treatment methods, such as Chinese herbal medicines (CHMs). In order to clarify the modern theoretical basis and molecular mechanisms of CHMs, we reviewed the knowledge based on publications in peer-reviewed English-language journals, focusing on the anti-inflammatory, antioxidative, anti-apoptotic, autophagy-mediated and antifibrotic effects of CHMs commonly used in kidney disease. We also discussed recently published clinical trials and meta-analyses in this field. Based on recent studies regarding the mechanisms of kidney disease in vivo and in vitro, CHMs have anti-inflammatory, antioxidative, anti-apoptotic, autophagy-mediated, and antifibrotic effects. Several well-designed randomized controlled trials (RCTs) and meta-analyses demonstrated that the use of CHMs as an adjuvant to conventional medicines may benefit patients with CKD. Unknown active ingredients, low quality and small sample sizes of some clinical trials, and the safety of CHMs have restricted the development of CHMs. CHMs is a potential method in the treatment of CKD. Further study on the mechanism and well-conducted RCTs are urgently needed to evaluate the efficacy and safety of CHMs.

Therapeutic application of nutraceuticals in diabetic nephropathy: Current evidence and future implications

Diabetes mellitus (DM) is a common metabolic disease which may cause several complications, such as diabetic nephropathy (DN). The routine medical treatments used for DM are not effective enough and have many undesirable side effects. Moreover, the global increased prevalence of DM makes researchers try to explore potential complementary or alternative treatments. Nutraceuticals, as natural products with pharmaceutical agents, have a wide range of therapeutic properties in various pathologic conditions such as DN. However, the exact underlying mechanisms have not been fully understood. The purpose of this review is to summarize recent findings on the effect of nutraceuticals on DN.

Efficiency and Safety of Chinese Herbal Medicine in the Treatment of Prediabetes: A Systemic Review and Meta-Analysis of Randomized Controlled Trials

Objective

The aim of this study was to review existing evidence on the efficiency and safety of Chinese herbal medicine for the treatment of prediabetes.

Methods

Randomized controlled trials (RCTs) of Chinese herbal medicine (CHM) to treat prediabetes were searched in the following databases from their inception date onwards until 2 May 2020: MEDLINE, Cochrane, EMBASE, Web of Science, EBSCO, CINAHL, CNKI, VIP database, CBM, and Wanfang database. Quality assessment of included trials was accessed according to the guidance in Cochrane. Researchers independently assessed the validity of included trials and extracted outcome data for synthesis. RevMan 5.3 was used for the meta-analysis.

Results

Twenty-two RCTs including 3923 participants were included in the study. Our findings upon the 22 RCTs showed CHM is effective in the treatment of prediabetes, which can statistically reduce the incidence of diabetes (RR = 0.48; 95% CI = (0.41, 0.57); P < 0.001), increase the incidence of normalization of prediabetes (RR = 1.76; 95% CI = (1.57, 1.96); P < 0.001), and lower FPG (MD = −0.38; 95% CI = (−0.60, −0.16); P < 0.001), 2hPG (MD = −1.13; 95% CI = (−1.60, −0.67); P < 0.001), TG (MD = −0.23; 95% CI = (−0.33, −0.13); P < 0.001), TC (MD = −0.34; 95% CI = (−0.52, −0.16); P < 0.001), and BMI (MD = −0.48; 95% CI = (−0.78, −0.18); P < 0.001) after treatment, and there was no difference of HbA1c (P > 0.05).

Conclusion

CHM is effective for the treatment of prediabetes. CHM can statistically reduce the incidence of diabetes, increase the incidence of normalization of prediabetes, and lower the FPG, 2hPG, TG, TC, and BMI levels, but with no significant difference in HbA1c. In addition, CHM was relatively safe in clinical practice. More high-quality RCTs should be conducted to strengthen the finding.

Protective effects of Vitex pseudo-negundo leaves on diabetic-induced nephropathy in rats

Objectives The belief of therapeutic effects of herbal remedies in diseases such as diabetes is rooted in medical history. The present study evaluated protective efficacy of the hydroalcoholic extract of Vitex pseudo-negundo leaves (VLHE) on the renal disorders in streptozotocin-induced diabetic rats. Methods Fifty Wistar male rats were recruited and divided into five groups of 10, including healthy controls and diabetic controls: three diabetic groups of which first group was treated with glibenclamide, and two groups treated with 250 and 500 mg/kg of VLHE, respectively, for six weeks. Renal biochemical tests and tissue histopathological evaluation were performed and the antioxidant status was examined. Results There were significant decreases in superoxide dismutase and glutathione peroxidase activities and increases in malondialdehyde levels in renal tissue of diabetic groups compared with healthy controls. In the VLHE-treated rats, fasting blood sugar, blood urea nitrogen and creatinine were declined, serum albumin elevated, kidney weight lowered, lipid peroxidation and reinforcement of the activities of antioxidant enzymes decreased compared with healthy groups. Histological assessments revealed that the vacuolar degeneration of tubules and shrinkage of glomeruli in VLHE-treated rats was decreased compared with diabetic rats. Conclusions The study suggested that administrating of VLHE in nephropathic rats ameliorated the disease by reduction of oxidative stress and increase in renal antioxidant enzyme activities.

Effect of Berberine on Glycation, Aldose Reductase Activity, and Oxidative Stress in the Lenses of Streptozotocin-Induced Diabetic Rats In Vivo-A Preliminary Study

Diabetes mellitus affects the eye lens, leading to cataract formation by glycation, osmotic stress, and oxidative stress. Berberine, an isoquinoline alkaloid, is a natural compound that has been reported to counteract all these pathological processes in various tissues and organs. The goal of this study was to evaluate whether berberine administered at a dose of 50 mg/kg by oral gavage for 28 days to rats with streptozotocin-induced diabetes reveals such effects on the biochemical parameters in the lenses. For this purpose, the following lenticular parameters were studied: concentrations of soluble protein, non-protein sulfhydryl groups (NPSH), advanced oxidation protein products (AOPP), advanced glycation end-products (AGEs), thiobarbituric acid reactive substances (TBARS), and activities of aldose reductase (AR), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Diabetes induced unfavorable changes in the majority of the examined parameters. The administration of berberine resulted in an increased soluble protein level, decreased activity of AR, and lowered AOPP and AGEs levels. The results suggest that berberine administered orally positively affects the lenses of diabetic rats, and should be further examined with regard to its anticataract potential.

Protective effect of Berberine on reproductive function and spermatogenesis in diabetic rats via inhibition of ROS/JAK2/NFκB pathway

BACKGROUND

Diabetes mellitus (DM) induces impairment of male reproductive system and is considered as a key factor that could partially provide an explanation for male infertility. Thus, understanding the mechanism underlying DM-induced infertility will aid in the identification of novel therapeutic stratagems.

OBJECTIVES

To delineate the role of ROS/JAK2/NFκB pathway in DM-induced low reproductive function and impaired spermatogenesis. Additionally, to investigate the protective effect of monomeric Berberine (BB) that inhibits ROS/JAK2/NFκB pathway, in the pathogenesis of DM-induced infertility.

METHODS

12-week-old male Sprague-Dawley rats were divided into four groups: control group, DM group, control plus BB group, and DM plus BB group. Streptozotocin was used to induce DM. After treating the rats with BB for 4 weeks, fertility tests were conducted to investigate the reproductive function, and testis weight along with sperm motility was assessed through microscope. Oxidative stress was evaluated by DHE staining. TUNEL staining was utilized to detect the state of apoptosis. Cell experiments were carried out to define the role of BB in vitro. Immunohistochemistry, immunofluorescence, and Western blotting were employed to measure the protein expression.

RESULTS

Our results indicate that the reproductive function of DM rats was low, accompanied by decreased testis weight and sperm motility in addition to the impairment of the seminiferous tubules. However, there was a significant improvement in the reproductive function parameters in the BB-treated DM rats. Subsequently, our data revealed that DM rats produce an increased level of ROS in the testis, which activates JAK2 further activating the NFκB pathway, leading to increased apoptosis and impaired cells in the testicles. However, BB could attenuate the ROS production and abrogate activation of JAK2/NFκB pathway, thus inhibiting the apoptosis in the testicular cells of DM rats.

CONCLUSION

ROS/JAK2/NFκB pathway is involved in the DM-induced low reproductive function and impaired spermatogenesis. BB can play a protective role in preserving the reproductive function and spermatogenesis in DM by inhibiting ROS/JAK2/NFκB pathway.

Berberine restored nitrergic and adrenergic function in mesenteric and iliac arteries from streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Perivascular neuropathy was reported to involve in the vascular disorders associated with diabetes. The dried rhizomes of Coptis chinensis Franch. (Latin name: Coptidis Rhizoma; common name: Huang Lian in China), used frequently in Traditional Chinese medicine to treat diabetes (Xiaoke), have been confirmed to possess beneficial effects on diabetic peripheral neuropathy by modern clinical and pharmacological studies. Berberine (BBR), the main effective component of Huang Lian in the treatment of diabetes, is reported to ameliorate diabetic central and peripheral neuropathy. However, the effects of BBR on nerve function of mesenteric and iliac arteries are unclear.

AIM OF THE STUDY

To investigate the effects of BBR on the diabetes-induced changes in nitrergic and adrenergic function in mesenteric and iliac arteries.

MATERIALS AND METHODS

In this study, the animals were randomized into three groups: control rats, diabetic rats, and diabetic rats gavaged with BBR. We established diabetic rat model using intraperitoneal injection of streptozotocin (STZ, 55 mg kg^-1). Two weeks after model establishment, those in the BBR-treated groups were gavaged with berberine chloride (Sichuan Xieli Fharmaceutical. Co., Ltd; 200 mg·kg^-1·day^-1) diluted in distilled water for another 2 weeks. The superior mesenteric artery and iliac artery were excised. Electric field stimulation (EFS) was used to induce arterial vasoconstriction and explore (1) the diabetes-induced changes in neurogenic function of the superior mesenteric artery and iliac artery; (2) the effects of BBR on neurovascular dysfunction in the early stage of STZ-induced diabetic rats. Nitric oxide (NO) and noradrenaline (NA) released from the nitrergic and adrenergic nerves were quantified using fluorescence assays and ELISA, respectively.

RESULTS

EFS induced frequency-dependent vasoconstrictions in both superior mesenteric and iliac artery, and the contractile responses of arteries were abolished by 0.1 μmol·L^-1 tetrodotoxin (TTX), or inhibited by 1 μmol·L^-1 phentolamine or increased by 0.1 mmol·L^-1 N^ω-Nitro-L-arginine methyl ester hydrochloride (L-NAME). In superior mesenteric artery, but not in iliac artery, the changes of contractile responses with L-NAME were significantly decreased in diabetic rats, and NO release was less also. In contrast, in iliac artery of diabetic rats, but not in superior mesenteric artery, the changes of contractile responses with phentolamine were increased, and NA release was increased significantly. All these changes in diabetic rats on both superior mesenteric artery and iliac artery were reversed by treated with BBR.

CONCLUSIONS

In the STZ-induced early diabetic rats, neural control of mesenteric and iliac vasomotor tone are altered differently. The diminished nitrergic nerve in superior mesenteric artery and enhanced adrenergic nerve in iliac artery both contributed to increased vasocontrictor responses. All these changes in diabetic rats were reversed by BBR, suggesting a novel mechanism of BBR in balance of neural regulation of vascular tone.

Rhizoma coptidis as a Potential Treatment Agent for Type 2 Diabetes Mellitus and the Underlying Mechanisms: A Review

Diabetes mellitus, especially type 2 diabetes mellitus (T2DM), has become a significant public health burden. Rhizoma coptidis (RC), known as Huang Lian, is widely used for treating diabetes in China. The bioactive compounds of RC, especially alkaloids, have the potential to suppress T2DM-induced lesions, including diabetic vascular dysfunction, diabetic heart disease, diabetic hyperlipidemia, diabetic nephropathy, diabetic encephalopathy, diabetic osteopathy, diabetic enteropathy, and diabetic retinopathy. This review summarizes the effects of RC and its bioactive compounds on T2DM and T2DM complications. Less research has been conducted on non-alkaloid fractions of RC, which may exert synergistic action with alkaloids. Moreover, we summarized the pharmacokinetic properties and structure-activity relationships of RC on T2DM with reference to extant literature and showed clearly that RC has potential therapeutic effect on T2DM.

Effects of berberine on the growth performance, antioxidative capacity and immune response to lipopolysaccharide challenge in broilers

This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response-related genes in lipopolysaccharide (LPS)-challenged broilers. We assigned 120 one-day-old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T-SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS-induced decreases in the mRNA expression of nuclear factor-kappa B (NF-κB), TNF-α, IL-1β, inducible nitrite synthase and cyclooxygenase-2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF-κB signalling and the expression of inflammatory mediators.

Quantification of Berberine in Berberis vulgaris L. Root Extract and Its Curative and Prophylactic Role in Cisplatin-Induced In Vivo Toxicity and In Vitro Cytotoxicity

Cisplatin is amongst the most potent chemotherapeutic drugs with applications in more than 50% of cancer treatments, but dose-dependent side effects limit its usefulness. Berberis vulgaris L. (B. vulgaris) has a proven role in several therapeutic applications in the traditional medicinal system. High-performance liquid chromatography was used to quantify berberine, a potent alkaloid in the methanolic root extract of B. vulgaris (BvRE). Berberine chloride in BvRE was found to be 10.29% w/w. To assess the prophylactic and curative protective effects of BvRE on cisplatin-induced nephrotoxicity, hepatotoxicity, and hyperlipidemia, in vivo toxicity trials were carried out on 25 healthy male albino Wistar rats (130-180 g). Both prophylactic and curative trials included a single dose of cisplatin (4 mg/kg, i.p.) and nine doses of BvRE (500 mg/kg/day, orally). An array of marked toxicity effects appeared in response to cisplatin dosage evident by morphological condition, biochemical analysis of serum (urea, creatinine, total protein, alanine transaminase, aspartate transaminase, total cholesterol, and triglyceride), and organ tissue homogenates (malondialdehyde and catalase). Statistically-significant (p < 0.05) variations were observed in various parameters. Moreover, histological studies of liver and kidney tissues revealed that the protective effect of BvRE effectively minimized and reversed nephrotoxic, hepatotoxic, and hyperlipidemic effects caused by cisplatin in both prophylactic and curative groups with relatively promising ameliorative effects in the prophylactic regimen. The in vitro cell viability effect of cisplatin, BvRE, and their combination was determined on HeLa cells using the tetrazolium (MTT) assay. MTT clearly corroborated that HeLa cells appeared to be less sensitive to cisplatin and berberine individually, while the combination of both at the same concentrations resulted in growth inhibition of HeLa cells in a remarkable synergistic way. The present study validated the use of BvRE as a protective agent in combination therapy with cisplatin.

Combating Neurodegenerative Diseases with the Plant Alkaloid Berberine: Molecular Mechanisms and Therapeutic Potential

Neurodegenerative diseases are among the most serious health problems affecting millions of people worldwide. Such diseases are characterized by a progressive degeneration and / or death of neurons in the central nervous system. Currently, there are no therapeutic approaches to cure or even halt the progression of neurodegenerative diseases. During the last two decades, much attention has been paid to the neuroprotective and anti-neurodegenerative activities of compounds isolated from natural products with high efficacy and low toxicity. Accumulating evidence indicates that berberine, an isoquinoline alkaloid isolated from traditional Chinese medicinal herbs, may act as a promising anti-neurodegenerative agent by inhibiting the activity of the most important pathogenic enzymes, ameliorating intracellular oxidative stress, attenuating neuroinflammation, triggering autophagy and protecting neurons against apoptotic cell death. This review attempts to summarize the current state of knowledge regarding the therapeutic potential of berberine against neurodegenerative diseases, with a focus on the molecular mechanisms that underlie its effects on Alzheimer's, Parkinson's and Huntington's diseases.

Study of nuclear factor-2 erythroid related factor-2 activator, berberine, in paclitaxel induced peripheral neuropathy pain model in rats

OBJECTIVES

The role of nuclear factor-2 erythroid related factor-2 (Nrf2) activator, berberine (BBR), has been established in rat model of streptozotocin induced diabetic neuropathy. Around 30-40% of cancer patients, on paclitaxel (PTX) chemotherapy develop peripheral neuropathy. The present study was contemplated with the aim of establishing the neuropathy preventive role of BBR, in paclitaxel induced peripheral neuropathy model in rats.

METHODS

A total of 30 Wistar rats were divided into five groups as follows: Group I: dimethyl sulfoxide; Group II: PTX+ 0.9% NaCl; Group III: Amitriptyline (ATL) + PTX; Group IV: BBR (10 mg/kg) + PTX and Group V: BBR (20 mg/kg) + PTX. Animals were assessed for tail flick latency, tail cold allodynia latency, histopathological scores, oxidative stress parameters, and mRNA expression of the Nrf2 gene in the sciatic nerve.

KEY FINDINGS

Berberine significantly increased the tail flick and tail cold allodynia latencies and significantly decreased the histopathological score. BBR reduced oxidative stress by significantly decreasing the lipid peroxidation, increasing the superoxide dismutase and reduced glutathione levels in the sciatic nerve. BBR also increased the mRNA expression of Nrf2 gene in rat sciatic nerve.

CONCLUSIONS

All of these results showed the neuropathy preventing role of BBR in PTX induced neuropathy pain model in rats.

Juzentaihoto hot water extract alleviates muscle atrophy and improves motor function in streptozotocin-induced diabetic oxidative stress mice

A decrease in skeletal muscle mass and motor function occurs in diabetic patients. In type 1 diabetic patients, in particular, fast-type fiber-dominated muscle atrophy occurs due to increased oxidative stress and inflammation. Juzentaihoto is a herbal medicine that has been found to be effective in reducing oxidative stress. In this study, juzentaihoto hot water extract (JTT) was administered prophylactically to mice with diabetic oxidative stress, which was induced by an injection of streptozotocin, and the effects on skeletal muscle mass, motor function, and antioxidant activity were evaluated. In mice that were administered JTT, skeletal muscle atrophy and loss of motor function were suppressed. Additionally, the administration of JTT increased the mRNA expression level of Sirt1 and the activity of superoxide dismutase in the gastrocnemius. In addition to skeletal muscle atrophy, atrophy of the liver, spleen and thymus gland, and kidney hypertrophy were also suppressed. Furthermore, in order to evaluate the antioxidant activity of 10 constituent crude drugs that comprise juzentaihoto, Sirt1 transcriptional activity in C2C12 cells was evaluated. The Sirt1 transcriptional activity was increased by Cinnamomi Cortex, Astragali Radix, and Glycyrrhizae Radix extracts. These three constituent crude drugs play an important function in the antioxidant action of juzentaihoto, suggesting that juzentaihoto can prevent muscle atrophy by decreasing oxidative stress.

Modeling Diabetic Corneal Neuropathy in a 3D In Vitro Cornea System

Diabetes mellitus is a disease caused by innate or acquired insulin deficiency, resulting in altered glucose metabolism and high blood glucose levels. Chronic hyperglycemia is linked to development of several ocular pathologies affecting the anterior segment, including diabetic corneal neuropathy and keratopathy, neovascular glaucoma, edema, and cataracts leading to significant visual defects. Due to increasing disease prevalence, related medical care costs, and visual impairment resulting from diabetes, a need has arisen to devise alternative systems to study molecular mechanisms involved in disease onset and progression. In our current study, we applied a novel 3D in vitro model of the human cornea comprising of epithelial, stromal, and neuronal components cultured in silk scaffolds to study the pathological effects of hyperglycemia on development of diabetic corneal neuropathy. Specifically, exposure to sustained levels of high glucose, ranging from 35 mM to 45 mM, were applied to determine concentration-dependent effects on nerve morphology, length and density of axons, and expression of metabolic enzymes involved in glucose metabolism. By comparing these metrics to in vivo studies, we have developed a functional 3D in vitro model for diabetic corneal neuropathy as a means to investigate corneal pathophysiology resulting from prolonged exposure to hyperglycemia.

Berberine: Botanical Occurrence, Traditional Uses, Extraction Methods, and Relevance in Cardiovascular, Metabolic, Hepatic, and Renal Disorders

Berberine-containing plants have been traditionally used in different parts of the world for the treatment of inflammatory disorders, skin diseases, wound healing, reducing fevers, affections of eyes, treatment of tumors, digestive and respiratory diseases, and microbial pathologies. The physico-chemical properties of berberine contribute to the high diversity of extraction and detection methods. Considering its particularities this review describes various methods mentioned in the literature so far with reference to the most important factors influencing berberine extraction. Further, the common separation and detection methods like thin layer chromatography, high performance liquid chromatography, and mass spectrometry are discussed in order to give a complex overview of the existing methods. Additionally, many clinical and experimental studies suggest that berberine has several pharmacological properties, such as immunomodulatory, antioxidative, cardioprotective, hepatoprotective, and renoprotective effects. This review summarizes the main information about botanical occurrence, traditional uses, extraction methods, and pharmacological effects of berberine and berberine-containing plants.

Preventive use of berberine in inhibition of lead-induced renal injury in rats

The kidney is one of the main organs affected by lead toxicity. We investigated the effects of berberine on lead-induced nephrotoxicity in adult male Wistar rats. Animals received an aqueous solution of lead acetate (500 mg Pb/L in the drinking water) and/or berberine (50 mg/kg, i.g.) for 8 weeks. Lead caused an increase in malondialdehyde (P < 0.001) and total oxidant status (P < 0.01), and a decrease in reduced glutathione (P < 0.001), catalase (P < 0.01), superoxide dismutase (P < 0.001), and total antioxidant capacity (P < 0.05). Berberine prevented the prooxidant and antioxidant imbalance induced by lead (P < 0.001). Berberine corrected the increased relative kidney weight (P < 0.05) and biomarkers of renal function (creatinine (P < 0.001), urea (P < 0.05), uric acid (P < 0.001), albumin (P < 0.01), and total protein (P < 0.05)) in lead group. It also attenuated lead-induced abnormal renal structure. The results confirmed renoprotective effects of berberine in an animal model of lead-induced nephrotoxicity by molecular, biochemical, and histopathological analysis through inhibiting lipid peroxidation and enhancing antioxidant defense system mechanisms. Therefore, berberine makes a good candidate to protect against the deleterious effect of chronic lead intoxication.

Healing effects of sumac (Rhus coriaria) in streptozotocin-induced diabetic rats

Context Sumac [Rhus coriaria L. (RC) (Anacardiaceae)] is used as a folk medicine in the treatment of diabetes in Turkey. Objective This study investigates the in vivo healing and protective effects of lyophilized extract sumac against streptozotocin (STZ)-induced diabetic complications. Materials and methods Toxicity test was conducted in three different dosages (250, 500 and 1000 mg/kg of plant extracts, respectively). Six groups of seven rats each were used in experiments. Groups were designed as Normal control, Diabetic (DM), DM + AC-20 mg/kg, DM + Extract-100 mg/kg, DM + Extract 250 mg/kg and DM + Extract 500 mg/kg group. Experimental diabetes [50 mg/kg, intraperitoneal (i.p.)] was induced by STZ. The effects of oral administration of the extract for 21 d on the level of serum glucose, insulin, C-peptide, lipid profile (LP), hepatic and renal damage biomarkers (HRDB), diabetic serum biomarkers (DSB), glycosylated haemoglobin (HbA1c), antioxidant defence system constituents (ADSCs), malondialdehyde (MDA) and α-glucosidase activity in small intestine tissue were evaluated. Results The extract decreased the levels of blood glucose in diabetic groups (an average of 31%). Triglyceride, total cholesterol, high-density lipoprotein and low-density lipoprotein levels were balanced by plant extract (500 mg/kg) supplementation in the diabetic group. Decreased levels of aspartate aminotransferase (89%), alanine aminotransferase (91%), lactate dehydrogenase (35%), alkaline phosphatase (47%), creatinine (25%) and urea (29%) were detected in plant extract (500 mg/kg) supplemented diabetic group. Additionally, a considerable increase in the HRDB, DSB, LP, MDA and fluctuated ADSC levels were restored in RC-extract supplemented groups. Conclusion RC lyophilized extract has a healing effect on diabetes and diabetes-related complications.

In vitro and in vivo inhibition of aldose reductase and advanced glycation end products by phloretin, epigallocatechin 3-gallate and [6]-gingerol

Hyperglycemic stress activates polyol pathway and aldose reductase (AR) key enzyme responsible for generating secondary complications during diabetes. In this study the therapeutic potential of phloretin, epigallocatechin 3-gallate (EGCG) and [6]-gingerol were evaluated for anti-glycating and AR inhibitory activity in vitro and in vivo systems. Human retinal pigment epithelial (HRPE) cells were induced with high glucose supplemented with the phloretin, EGCG and [6]-gingerol. Aldose reductase activity, total advanced glycation end products (AGEs) and enzyme inhibitor kinetics were assessed. Male C57BL/6J mice were randomly assigned to one of the different treatments (bioactive compounds at 2 concentrations each) with either a low fat diet or high fat diet (HFD). After sixteen weeks, AGE accumulation and AR activity was determined in heart, eyes and kidney. High glucose induced toxicity decreased cell viability compared to the untreated cells and AR activity increased to 2-5 folds from 24 to 96h. Pre-treatment of cells with phloretin, EGCG and [6]-gingerol improved cell viability and inhibited AR activity. The enzyme inhibition kinetics followed a non-competitive mode of inhibition for phloretin and EGCG whereas [6]-gingerol indicated uncompetitive type of inhibition against AR. Data from the animal studies showed high plasma glucose levels in HFD group over time, compared to the low fat diet. HFD group developed cataract and AR activity increased to 4 folds compared to the group with low fat diet. Administration of EGCG, phloretin and [6]-gingerol significantly reduced blood sugar levels, AGEs accumulation, and AR activity. These findings could provide a basis to consider using the selected dietary components alone or in combination with other therapeutic approaches to prevent diabetes-related complications in humans.

Reactive oxygen species: sources, consequences and targeted therapy in type 2 diabetes

Oxidative stress has been considered as a central mediator in the progression of diabetic complication. The intracellular reactive oxygen species (ROS) leads to oxidative stress and it is raised from the mitochondria as well as by activation of five major pathways: increased polyol pathway flux, activation of protein kinase C (PKC) pathway, increased formation of advanced glycation end products (AGEs), over activity of hexosamine pathway and increased production of angiotensin II. The increased ROS through these pathways leads to β-cell dysfunction and insulin resistance, responsible for cell damage and death. This review not only highlights the sources of ROS production and their involvement in the progression of diabetes, but also emphasizes on pharmacological interventions and targeting of ROS in type 2 diabetes. This review summarizes the ROS as potential therapeutic targets, based on a putative mechanism in the progression of the diabetes. It also summarizes current knowledge of ROS activation in type 2 diabetes as well as ROS as a possible target for its treatment. Eventually, it would be a promising target for various strategies and drugs to modulate ROS levels in diabetes.

Coptis chinensis Polysaccharides Inhibit Advanced Glycation End Product Formation

Coptis chinensis Franch (Huanglian) is commonly used to treat diabetes in China. In this study, the effects of the C. chinensis Franch polysaccharides (CCP) on advanced glycation end product (AGE) formation in vitro and in streptozotocin-induced diabetic mice were investigated. CCP significantly inhibited all the three periods of nonenzymatic protein glycation in vitro, including Amadori product, dicarbonyl compound, and AGE formation (P < .01). In diabetic mice, the administration of CCP not only improved both bodyweight and serum insulin and decreased fasting blood glucose and glycated serum protein concentrations but also decreased the AGE accumulations and morphological abnormalities in pancreas and liver. The inhibitory effects of CCP on AGE formation afford a potential therapeutic use in the prevention and treatment of diabetes.

Antidiabetic properties of lyophilized extract of acorn (Quercus brantii Lindl.) on experimentally STZ-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Acorn obtained from the Quercus brantii Lindl. (QB) tree has been used in Turkish folk medicine. Some studies have reported as an antioxidant, antimicrobial, anti-inflammatory, gastroprotective, antitumoural of QB properties previously. however, its effect on the management of type diabetic 2 and oxidative stress complications is still unexplored. The aims of our study were the evaluation of the protective effect and antioxidant role of acorn lyophilized seed plant extract against STZ-induced diabetic complications as oxidative stress, hepatotoxicity and nephropathy, lipidemia and serum biomarkers of diabetes (SBD).

MATERIALS AND METHODS

In-vivo studies were performed on STZ-induced diabetic rats Experiment was designed as I [Normal Control (NC)], II [Diabetes mellitus (DM)], III [DM+Acarbose (20mg/kg b.w) (DM+AC-20)], IV [DM+QB (100mg/kg b.w) (DM+QB-100)], V [DM+QB (250 mg/kg b.w) (DM+QB-250)] and VI [DM+QB (500 mg/kg b.w) (DM+QB-500)] groups.

RESULTS

This study showed that the biochemical analysis showed a considerable increase in the HRDB, DB, LP, MDA and fluctuated ADSC in the II group as compared to that of control group whereas, AC and the plant lyophilized seed plant extract supplementations diet restored the STZ-induced diabetic complications towards the control. α-glycosidase activity in DM group showed statistically significant increase with respect to control group in small intestine. Moreover, in accordance with the effects of seed extract; in diabetic rat groups to whom acorn seed extract and acarbose were given, the levels of almost all the concerned parameters were reached to the ones measured at control group. As a result, it was concluded that acorn seed extract had certain healing effects on many complications caused by diabetes.

Renoprotective effects of berberine as adjuvant therapy for hypertensive patients with type 2 diabetes mellitus: Evaluation via biochemical markers and color Doppler ultrasonography

Diabetes and hypertension are complex and serious diseases that may ultimately lead to renal complications. Adequate control of blood glucose and blood pressure contributes to decreased renal risks, but may not be sufficient for certain patients. The current study was undertaken to investigate the renoprotective effects of berberine as an adjuvant therapy to standard hypotensive and hypoglycemic treatment in hypertensive patients with type 2 diabetes mellitus (T2DM). In this 2-year clinical study, 69 hypertensive patients with T2DM, whose blood pressure and fasting plasma glucose (FPG) were adequately controlled by hypotensive and oral hypoglycemic agents prior to the study, were enrolled and randomly assigned into control (33 cases) and add-on (36 cases) groups. Berberine was orally administrated to the patients in the add-on group concomitantly with standard hypotensive and hypoglycemic treatment. Baseline characteristics, including the levels of FPG, glycated hemoglobin, systolic blood pressure, diastolic blood pressure, serum creatinine, urinary albumin-to-creatine ratio (UACR), urinary osteopontin and kidney injury molecule-1 (KIM-1) were determined. Furthermore, the oxidative stress markers malondialdehyde, urinary 8-hydroxy-2'-deoxyguanosine, superoxide dismutase, glutathione peroxidase and total-antioxidant capacity, and the inflammatory parameters vascular adhesion molecule-1, C-reactive protein and high molecular weight-adiponectin were evaluated. In addition, ultrasonographic parameters, including peak systolic velocity, end diastolic velocity and renal arterial resistance index were determined. After treatment, it was observed that the control and add-on treatments were able to adequately control blood pressure and blood glucose. Patients in the add-on group exhibited significant reductions in renal damage biochemical markers (UACR, urinary osteopontin and KIM-1) and improved renal hemodynamics, in addition to reduced inflammation and oxidative stress. The present results suggest that berberine is beneficial for hypertensive patients with T2DM as add-on therapy to standard hypotensive and hypoglycemic agents.

Application of berberine on treating type 2 diabetes mellitus

Traditional Chinese medicine (TCM) performs a good clinical practice and is showing a bright future in the treatment of diabetes mellitus (DM). TCM treatment has certain advantages of less toxicity and/or side effects, and herbs could provide multiple therapeutic effects. Berberine (BBR) is a classical natural medicine. In this review, we summarize the application of BBR in the treatment of DM from two aspects. First, modern pharmacological effects of BBR on glucose metabolism are summarized, such as improving insulin resistance, promoting insulin secretion, inhibiting gluconeogenesis in liver, stimulating glycolysis in peripheral tissue cells, modulating gut microbiota, reducing intestinal absorption of glucose, and regulating lipid metabolism. BBR is used to treat diabetic nephropathy (DPN), diabetic neuropathy (DN), and diabetic cardiomyopathy due to its antioxidant and anti-inflammatory activities. Second, the clinical application of BBR is reviewed, such as listing some clinical trials on the effectiveness and safety of BBR, explaining applicable stage and syndrome, the reasonable dose and dose formulation, and the toxicity and/or side effects. This review provides scientific evidence about BBR, as well as introducing some traditional Chinese medical theory and clinical experience, in order to guide clinician to use BBR more suitably and reasonably.

Barberry administration and pro-oxidant-antioxidant balance in patients with metabolic syndrome

Background:

Metabolic syndrome is the constellation of several cardiometabolic risk factors, and is associated with a heightened risk of coronary heart disease (CHD). The pro-oxidant–antioxidant balance (PAB) is a measure of factors that promote and control oxidative stress. PAB may also be associated with the risk factors of CHD.

Objectives:

This study aimed to explore the impact of supplementation with barberry, a fruit rich in antioxidants, on PAB in patients with metabolic syndrome.

Patients and Methods:

A total of 106 patients diagnosed with metabolic syndrome were randomized in two groups: case and control. The case group received three capsules of barberry and the control group received three capsules of placebo for 6 weeks. Serum PAB was measured in all patients before and after the intervention.

Results:

There was no significant difference between the groups regarding their baseline PAB values (P = 0.32). A significant decrease in PAB was observed in the barberry group (P = 0.022), whilst there was no significant change in the control group (P = 0.18). The magnitude of change in PAB during the study was significantly greater in the case group compared to the control group (P = 0.01).

Conclusions:

Barberry supplementation reduces oxidative burden in patients with metabolic syndrome.

Syndrome Differentiation of Diabetes by the Traditional Chinese Medicine according to Evidence-Based Medicine and Expert Consensus Opinion

In Chinese medicine, diabetes belongs to the category of “Xiaoke disease (disease with symptoms of frequent drinking and urination)”; in the traditional sense, its pathogenesis is “Yin deficiency and dryness-heat.” However, over time, changes in the social environment and lifestyle have also changed the use of traditional Chinese medicine (TCM) in diabetes. In this study, we performed diabetes syndrome differentiation using TCM according to evidence-based medicine and expert consensus opinion.

The renoprotective effects of berberine via the EP4-Gαs-cAMP signaling pathway in different stages of diabetes in rats

AIMS

To investigate the renoprotective roles of berberine (BBR) in different stages of diabetic nephropathy (DN) in streptozotocin (STZ)-induced diabetic rats fed a high-sugar and high-fat diet.

METHODS

Diabetes was induced in mice by intraperitoneal injection of STZ, and the mice were then randomly divided into groups: normal, diabetes, high-sugar and high-fat and BBR (high, median and low dose) groups. The body weight (BW), kidney weight to body weight (KW/BW), blood urea nitrogen, urine total protein to urine creatinine ratio and serum creatinine were measured on different weeks throughout the study. The protein levels of E prostanoid receptor 4 (EP4), Gαs and content of cAMP in the kidney were, respectively, detected by western blot analysis and RIA analysis.

RESULTS

In the DN rats, there was remarkable renal damage. BBR restored renal functional parameters, suppressed alterations in histological and ultrastructural changes in the kidney tissues and increased EP4, Gαs and cAMP levels compared with those of the DN model group. In addition, BBR has different therapeutic effects during the different stages of the development of DN, and it works best in the sixth week.

CONCLUSION

These studies demonstrate, for the first time, that BBR exerts renoprotective effects in different stages of DN via EP4- Gαs- AC-cAMP signaling pathway in STZ-induced DN rats fed a high-sugar and high-fat diet.

The antihyperglycemic effects of Rhizoma Coptidis and mechanism of actions: a review of systematic reviews and pharmacological research

Rhizoma Coptidis (Huang Lian in Chinese pinyin) is among the most widely used traditional Chinese herbal medicines and has a profound history of more than 2000 years of being used as a therapeutic herb. The antidiabetic effects of Rhizoma Coptidis have been extensively investigated in animal experiments and clinical trials and its efficacy as a promising antihyperglycemic agent has been widely discussed. In the meantime, findings from modern pharmacological studies have contributed the majority of its bioactivities to berberine, the isoquinoline alkaloids component of the herb, and a number of experiments testing the antidiabetic effects of berberine have been initiated. Therefore, we conducted a review of the current evidence profile of the antihyperglycemic effects of Rhizoma Coptidis as well as its main component berberine and the possible mechanism of actions, in order to summarize research evidence in this area and identify future research directions.

Berberine attenuates high glucose-induced proliferation and extracellular matrix accumulation in mesangial cells: involvement of suppression of cell cycle progression and NF-κB/AP-1 pathways

Berberine has been shown to have renoprotective effects on diabetes through attenuating TGF-β1 and fibronectin (FN) expression. However, how berberine regulates TGF-β1 and FN is not fully clear. Here we investigated whether berberine inhibited TGF-β1 and FN expression in high glucose-cultured mesangial cells. Berberine significantly inhibited mesangial cell proliferation and hypertrophy by increasing the cell population in G1-phase and reducing that in S-phase. In addition, berberine reversed high glucose-induced down-regulation of cyclin-dependent kinase inhibitor p21(Waf1)/(Cip1) and p27(Kip1). Berberine inhibited p65 translocation to the nucleus and c-jun phosphorylation induced by high glucose. Furthermore, berberine attenuated high glucose-induced expression of TGF-β1 and FN. Using a luciferase reporter assay, we found that high glucose-induced transcription activity of NF-κB and AP-1 was blocked by berberine. Electrophoretic mobility shift assay showed that high glucose increased that NF-κB and AP-1 DNA binding activity. These data indicate that berberine inhibited mesangial cell proliferation and hypertrophy by modulating cell cycle progress. In addition, berberine suppressed high glucose-induced TGF-β1 and FN expression by blocking NF-κB/AP-1 pathways.

Antioxidant and anti-inflammatory activities of berberine in the treatment of diabetes mellitus

Oxidative stress and inflammation are proved to be critical for the pathogenesis of diabetes mellitus. Berberine (BBR) is a natural compound isolated from plants such as Coptis chinensis and Hydrastis canadensis and with multiple pharmacological activities. Recent studies showed that BBR had antioxidant and anti-inflammatory activities, which contributed in part to its efficacy against diabetes mellitus. In this review, we summarized the antioxidant and anti-inflammatory activities of BBR as well as their molecular basis. The antioxidant and anti-inflammatory activities of BBR were noted with changes in oxidative stress markers, antioxidant enzymes, and proinflammatory cytokines after BBR administration in diabetic animals. BBR inhibited oxidative stress and inflammation in a variety of tissues including liver, adipose tissue, kidney and pancreas. Mechanisms of the antioxidant and anti-inflammatory activities of BBR were complex, which involved multiple cellular kinases and signaling pathways, such as AMP-activated protein kinase (AMPK), mitogen-activated protein kinases (MAPKs), nuclear factor erythroid-2-related factor-2 (Nrf2) pathway, and nuclear factor- κ B (NF- κ B) pathway. Detailed mechanisms and pathways for the antioxidant and anti-inflammatory activities of BBR still need further investigation. Clarification of these issues could help to understand the pharmacology of BBR in the treatment of diabetes mellitus and promote the development of antidiabetic natural products.

Improvement of superoxide dismutase and catalase in streptozotocin-nicotinamide-induced type 2-diabetes in mice by berberine and glibenclamide

Abstract Context: Diabetes mellitus (DM) type 2 is a chronic disease characterized by hyperglycemia and insulin resistance. Oxidative stress participates in development and progression of DM, in which changes of superoxide dismutase (SOD) and catalase (CAT) were noted in DM mice. Berberine has been widely used as an alternative medicine and proved to be effective for the treatment of DM and dyslipidemia. Objective: Impacts of berberine on transcriptional regulation of SOD and CAT and their enzyme activities, including the level of malondialdehyde (MDA) formation, were examined in the DM type 2-induced mice to clarify its antioxidation potential, compared with a common hypoglycemic drug, glibenclamide. Materials and methods: Noninsulin-dependent diabetes was induced in mice by a single intraperitoneal streptozotocin-nicotinamide injection. Diabetic mice were treated daily with glibenclamide (10 mg/kg/d) and/or berberine (100 mg/kg/d) for 2 weeks. The fasting blood glucose and the MDA levels in the mouse liver, brain and kidneys were monitored using Glucometer® (Accu-Check® Advantage II Performa kits, Roche Diagnostics, Germany) and thiobarbituric acid substance assay, respectively. The expression of SOD and CAT mRNA were determined in the mouse liver and the activities of SOD and CAT enzymes were determined in mouse liver, brain and kidneys, respectively. Results: Berberine exhibited similar hypoglycemic potential as glibenclamide to lower area under the curve of the fasting blood glucose. In DM type 2 mice, berberine increased the hepatic CuZn-SOD mRNA expression and the kidney SOD and CAT activities to normal levels. Moreover, DM-induced lipid peroxidation by increasing of MDA levels in both the liver and brain and lipid peroxidation status was restored by berberine. Conclusion: Berberine possessed hypoglycemic properties and strong potential to improve the oxidant-antioxidant balance, though the combination treatment of berberine and glibenclamide did not show additional benefit over the treatment with berberine alone.

Fructus mume formula in the treatment of type 2 diabetes mellitus: a randomized controlled pilot trial

Background. "Fructus Mume or Dark Plum" (pilule form) has been used for many years in Traditional Chinese Medicine (TCM) and may be a valid treatment for type 2 diabetes mellitus (T2DM). Aim. One aspect toward efficacy validation is the evaluation of the blood glucose-lowering effect of Fructus Mume (FM) with T2DM patients in a randomized controlled trial (RCT). Methods. This pilot study uses a RCT procedure to assess efficacy of FM and Metformin. The trial was for 12 weeks, with 80 T2DM subjects. Both groups were standardized in their diet and exercise routine. Comparisons of several variables were analyzed. Results. No significant differences were found between groups in the fasting and postprandial glucose levels although both had significant decreases. The values of glycosylated hemoglobin were significantly reduced in both groups. For patients whose body mass index (BMI) was <23, neither FM nor Metformin had an effect on BMI; for those with a BMI between 23 and 25 or the BMI was >25, both FM and Metformin significantly reduce the BMI. Conclusions. In this pilot study, it was demonstrated that Fructus Mume formula may reduce the levels of blood glucose in patients with type 2 diabetes.

D-saccharic acid 1,4-lactone protects diabetic rat kidney by ameliorating hyperglycemia-mediated oxidative stress and renal inflammatory cytokines via NF-κB and PKC signaling

Increasing evidence suggests that oxidative stress is involved in the pathogenesis of diabetic nephropathy (DN) and this can be attenuated by antioxidants. D-Saccharic acid 1,4-lactone (DSL) is known for its detoxifying and antioxidant properties. Our early investigation showed that DSL can ameliorate alloxan (ALX) induced diabetes mellitus and oxidative stress in rats by inhibiting pancreatic β-cell apoptosis. In the present study we, therefore, investigated the protective role of DSL against renal injury in ALX induced diabetic rats. ALX exposure (at a dose of 120 mg/kg body weight, i. p., once) elevated the blood glucose level, serum markers related to renal injury, the production of reactive oxygen species (ROS), and disturbed the intra-cellular antioxidant machineries. Oral administration of DSL (80 mg/kg body weight) restored all these alterations close to normal. In addition, DSL could also normalize the aldose reductase activity which was found to increase in the diabetic rats. Investigating the mechanism of its protective activity, we observed the activation of different isoforms of PKC along with the accumulation of matrix proteins like collagen and fibronectin. The diabetic rats also showed nuclear translocation of NF-κB and increase in the concentration of inflammatory cytokines in the renal tissue. The activation of mitochondria dependent apoptotic pathway was observed in the diabetic rat kidneys. However, treatment of diabetic rats with DSL counteracted all these changes. These findings, for the first time, demonstrated that DSL could ameliorate renal dysfunction in diabetic rats by suppressing the oxidative stress related signalling pathways.

Berberine ameliorates renal injury by regulating G proteins-AC- cAMP signaling in diabetic rats with nephropathy

Diabetic nephropathy (DN) is a progressive kidney disease that is caused by injury to glomerulus and glomerular mesangial cells (MCs) proliferation play a critical role in the pathogenesis of DN. The current studies were undertaken to investigate the protective effects and the possible molecular mechanism of berberine on streptozotocin (STZ)-induced DN rats. Male Wistar rats were randomly assigned to normal control and DN groups of comparable age. Three DN groups received 50, 100 and 200 mg/kg of berberine for 8 weeks via daily intragastrically, respectively. The G proteins-adenylyl cyclase (AC)-cAMP signaling pathway and glomerular MCs proliferation were examined in STZ-induced diabetic rat kidney. Enhanced MCs proliferation and remarkable renal injury were concomitant with activation of Gαi and inhibition of Gαs and cAMP in DN model group. Berberine treatment for 8 weeks abolished the above changes by upregulating the expression of Gαs protein and downregulating the expression of Gαi protein, increasing cAMP level, and inhibiting MCs proliferation compared with model group. Taken together, for the first time, these results demonstrated that berberine can relieve renal injury in DN rats through mediating G proteins-AC-cAMP signaling pathway and inhibiting the abnormal proliferation of MCs by increasing cAMP level, suggesting that berberine could be a potential therapeutic agent for the treatment of DN.

Renoprotective effects of berberine and its possible molecular mechanisms in combination of high-fat diet and low-dose streptozotocin-induced diabetic rats

Berberine (BBR), an effective compound of Chinese traditional herbal medicine, has preventive effects on diabetes and its complications. In this study, we investigated the therapeutic effects and underlying molecular mechanisms of BBR in rats with high-fat diet and streptozotocin (STZ)-induced diabetic nephropathy model. BBR (50, 100, 200 mg/kg/d) were orally administered to male Sprague-Dawley rats after STZ injection and conducted for 8 weeks. Renal damage was evaluated by kidney weight to body weight ratio (KW/BW), urine microalbumin (UMAlb), urine protein for 24 h (UP24 h), urine creatinine (UCr), and histological examination. Type IV collagen and transforming growth factor-beta1 (TGF-β1) were detected by immunohistochemistry and ultrastructure of glomeruli was observed. Fasting blood glucose (FBG),serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c) in serum and G protein-coupled receptor kinases (GRKs), cAMP in kidney were measured. Remarkable renal damage, hyperglycemia and hyperlipidemia were observed in DN rats. BBR could restore renal functional parameters, suppress alterations in histological and ultrastructural changes in the kidney tissues, improve glucose and lipid metabolism disorders, and increase cAMP levels compared with those of DN model group. Furthermore, BBR down-regulated total protein expression of GRK2, GRK3 and up-regulated expression of GRK6 of renal cortex in DN rats, but had a slight effects on GRK4 and GRK5. These studies demonstrate, for the first time, that BBR exerts renoprotection in high-fat diet and STZ-induced DN rats by modulating the proteins expression of GRKs in G protein- AC-cAMP signaling pathway.