Evaluation of the Anti-Diabetic Activity of Polysaccharide from Cordyceps cicadae in Experimental Diabetic Rats.

Cordyceps cicadae is a medicinal fungus used in treating night sweat, childhood convulsions, vision improvement and pain. This study was designed to evaluate the anti-diabetic activity of the crude polysaccharide (SHF) from the mycelium and body portion of C. cicadae. Diabetes mellitus was induced in the rat with a single intravenous injection of alloxan monohydrate (150 mg/kg). In other to evaluate the anti-diabetic effects of C. cicadae polysaccharide in alloxan-induced diabetic rats, the crude polysaccharide (SHF at 100, 200 and 400 mg/kg body weight) and glibenclamide were administered orally to diabetic rats for 30 days. Blood glucose level, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphate (ALP), creatinine (CREA), urea, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH) were determined. SHF showed significant reduction in blood glucose in diabetic rats. Treatment of diabetic rats also resulted an improvement in body weights, increased HDL, SOD and GSH, as well as decreased TC, TG, LDL, MDA, urea, CREA, ALT, AST and ALP. These results suggested that C. cicadae polysaccharide displayed anti-hyperglycemic, anti-hyperlipidemic and antioxidant activities and could be a promising therapeutic source in managing diabetes mellitus and its associated complications.

Proteomic-Based Approach to the Proteins Involved in 1-Deoxynojirimycin Accumulation in Silkworm Bombyx mori (Lepidoptera: Bombycidae).

1-Deoxynojirimycin (DNJ) is the most abundant poly-hydroxylated alkaloid in the latex of mulberry leaves and it protects mulberry from insect predation. However, silkworms can survive the poisoning effect of DNJ and accumulate DNJ by consumption of the mulberry leaves. In order to determine the molecular mechanism of DNJ accumulation in silkworm, comparative proteomic analysis was employed to evaluate protein expression in two groups of silkworm bodies (the third instar silkworm bodies had the maximum content of DNJ throughout life, and the newly hatched silkworm bodies had no DNJ). Our results indicated some differentially expressed proteins in the third instar silkworm involved in material metabolism, energy metabolism, oxidation-reduction, detoxification, immune, and transport regulation may correspond to the accumulation of DNJ. Furthermore, the expression levels of five selected differentially expressed protein-encoding genes namely heat shock cognate protein (Hsp 70), glutathione S-transferase sigma 1 (GST), serine protease precursor (Ser), hemolymph protein (30K), and thiol peroxiredoxin (TPx) were investigated by quantitative real-time PCR and the accumulation of DNJ was measured by HPLC. Correlation analysis showed that the expression levels of Hsp70 and Ser were negatively correlated to DNJ accumulation with weak correlation, while 30K, GST, and TPx genes had positive correlation with DNJ accumulation. The findings suggested that these three proteins were probably important in the physiological process of DNJ accumulation in silkworm.

Ameliorative potential of Cortex Lycii on enzymes involved in carbohydrate metabolism in streptozotocin-nicotinamide induced diabetic rats.

Cortex Lycii (root back of Lycium chinense) has is a famous traditional Chinese medicine which displays several pharmacological activities including antioxidant and antidiabetic properties. We investigated the effect of the ethyl acetate fraction (QCL) of Cortex Lycii on the enzymes involved in the metabolism of carbohydrate in diabetic rat models. Streptozotocin-nicotinamide (110 and 65mg/kg body weight, respectively) was used to induce diabetes. Diabetic rats were treated with QCL (100, 200 and 400 mg/kg) and glibenclamide (600 µg/kg) daily for six weeks. Upon the completion of treatment, fasting blood glucose (FBG), insulin, glycosylated haemoglobin (HbA1c), haemoglobin (Hb), hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, phosphoenolpyruvate carboxykinase and fructose-1,6-bisphosphatase levels were measured by biochemical assays. Likewise, the body weight, food and water intake was monitored and measured. Diabetic rats displayed significant elevation in the blood glucose, glycosylated hemoglobin and a marked decrease in plasma insulin and hemoglobin. Furthermore, the levels of key enzymes including fructose-1,6-bisphosphatase, glucose-6-phosphatase phosphoenolpyruvate carboxykinase were significantly increased while the activity levels of hexokinase, glucose-6-phosphate dehydrogenase and glycogen were significantly down regulated in diabetic rats. However, treatment of diabetic rats with Cortex Lycii led to a significant reduction the FGB, food and water intake and an increase in the plasma insulin level. Treatment with Cortex Lycii also reversed the altered activity profiles of the key enzymes mentioned above in a dose dependent manner. Our results suggested that Cortex Lycii has a promising therapeutic option in the management of diabetic complications relating to glucose homeostasis and carbohydrate metabolism.

In vitro and in vivo aphrodisiac properties of the seed extract from Allium tuberosum on corpus cavernosum smooth muscle relaxation and sexual behavior parameters in male Wistar rats.

BACKGROUND: Allium tuberosum is a well-known spice as well as a herb in traditional Chinese medicine, used for increasing libido and treating erectile dysfunction. However, not many studies have been done to evaluate the sexual enhancing properties of A. tuberosum. The aim of this study was to evaluate the aphrodisiac and vasorelaxant properties of A. tuberosum on corpus cavernosum smooth muscle (CCSM) as well as checking the effect on enhancing male rat sexual behavior, libido, potency as well as its spermatogenic properties. METHOD: The seeds were powdered and sequentially extracted with hexane, ethyl acetate and butanol. Male Wistar rats were administered with graded doses of the n-BuOH extracts (ATB) of A. tuberosum (50, 100, 200 and 400 mg/kg) and Viagra was used as the positive control drug. The extract/drug was administered by gastric probe once daily for 45 days and the sexual behavior was analyzed by exposing the male rats to female rats in the estrus period. RESULTS: ATB relaxed corpus cavernosum smooth muscle (68.9%) at a concentration of 200 µg/ml. The results obtained from the animal studies indicated that ATB significantly increased mount frequency (MF), intromission frequency (IF), ejaculation frequency (EF), ejaculation latency (EL) and markedly reduced post ejaculatory interval (PEI), mount latency (ML), and intromission latency (IL). Furthermore, a remarkable increase in the test for potency was observed as witnessed by marked increase in erections, quick flips, long flips and total reflex. In addition, ATB significantly improved the sperm viability and count as well as increased the concentrations of testosterone, follicle stimulating hormone (FSH), and phosphatases in the treated animals. CONCLUSION: Thus our results suggest that A. tuberosum could stimulate sexual arousal and enhance sexual execution in male rats, thus providing valuable experimental evidence that A. tuberosum possesses sexual enhancing properties.

Effect of the Polyphenol Rich Ethyl Acetate Fraction from the Leaves of Lycium chinenseMill. on Oxidative Stress, Dyslipidemia, and Diabetes Mellitus in Streptozotocin-Nicotinamide Induced Diabetic Rats.

Lycium chinenseMill., popularly known as boxthorn, is a plant that is traditionally used for treating night sweat, cough, inflammation and diabetes mellitus. However, the leaves have received little or no attention despite their potentials as a potent therapeutic agent. This study was aimed at investigating the hypoglycemic and hypolipidemic effects of the polyphenols-rich ethyl acetate fraction from the leaves of Lycium chinenseMill. on streptozotocin-nicotinamide induced diabetic rats. The ethyl acetate fraction (LFE) was selected and orally gavaged at 100, 200, and 400 mg/kg dose to streptozotocin (STZ)-nicotinamide induced diabetic rats. The rats' body weight, fasting blood glucose (FBG), lipid profile and oxidative stress markers were evaluated after the treatment period. Treatment with LFE resulted in a significant decrease in the FBG level, altered lipid profiles, and reduced the activities of the enzymes alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT) in the treated diabetic rats. Furthermore, LFE significantly elevated the antioxidant status (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities) and reducing malondialdehyde (MDA) levels in the treated rats. The present study has revealed that L. chinenseMill. possess anti-hyperglycemic and anti-hyperlipidemic properties which is mediated through modulation of oxidative stress and polyphenolics might be responsible for the action.

Anti-Ulcerogenic Properties of Lycium chinense Mill Extracts against Ethanol-Induced Acute Gastric Lesion in Animal Models and Its Active Constituents.

The objective of this study was to explore the gastroprotective properties of the aerial part of Lycium chinense Mill (LCA) against ethanol-induced gastric mucosa lesions in mice models. Administration of LCA at doses of 50, 100, 200 and 400 mg/kg body weight prior to ethanol consumption dose dependently inhibited gastric ulcers. The gastric mucosal injury was analyzed by gastric juice acidity, glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO) activities. Furthermore, the levels of the inflammatory mediators, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) in serum were also analyzed using ELISA. Pathological changes were also observed with the aid of hematoxylin-eosin (HE) staining. Our results indicated that LCA significantly reduced the levels of MPO, MDA and increased SOD and GSH activities. Furthermore, LCA also significantly inhibited the levels of TNF-α, IL-6, and IL-1ß in the serum of ulcerated mice in a dose dependent manner. Immunohistological analysis indicated that LCA also significantly attenuated the overexpression of nuclear factor-κB in pretreated mice models. This findings suggests Lycium chinense Mill possesses gastroprotective properties against ethanol-induced gastric injury and could be a possible therapeutic intervention in the treatment and management of gastric ulcers.

N6 -(2-hydroxyethyl)-adenosine from Cordyceps cicadae protects against diabetic kidney disease via alleviation of oxidative stress and inflammation.

This study investigated the kidney-protective ability of N6 -(2-hydroxyethyl)-adenosine (HEA) in alloxan-induced diabetic rats. Diabetes was induced in the rats by the administration of alloxan monohydrate (150 mg/kg, i.p) and treated with HEA for 6 weeks. Diabetic rats displayed marked increase in blood glucose, serum creatinine (Scr), and blood urea nitrogen (BUN), in addition to high excretion of urinary protein and albumin. Furthermore, diabetic rats showed decreased renal levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and increased malondialdehyde (MDA) as well as renal concentrations of pro-inflammatory mediators (TNF-α, IL-6, IL-1ß, and TGF-ß1). Treatment of diabetic rats with HEA (20 and 40 mg/kg) significantly increased the renal antioxidant level, reduced the levels of blood glucose, Scr, BUN, urinary protein, albumin, and pro-inflammatory mediators in a dose-dependent fashion. Histological evaluation of the kidney of diabetic rats indicated that HEA also ameliorated glomerular and tubular changes. PRACTICAL APPLICATIONS: HEA is a bioactive constituent isolated from Cordyceps cicadae and has been shown to possess antihyperglycemic, kidney protective, antioxidant, and antiinflammatory effects in diabetic rats. HEA stimulated the antioxidant enzymes' activities in the kidney tissues as well as reduced pro-inflammatory mediators, indicating its antidiabetic and renoprotective effects in diabetic models. The results showed that HEA attenuated oxidative stress and inflammation in kidney tissues.

Neuroprotective effect of trans-N-caffeoyltyramine from Lycium chinense against H2O2 induced cytotoxicity in PC12 cells by attenuating oxidative stress.

Natural products play a critical role in the promotion of good health as regards the prevention and management of oxidative stress related and neurodegenerative disorders. Oxidative stress has been implicated in several apoptotic pathways associated with cell damages in neuronal disorders. The aim of this study was to investigate the antioxidant effect of trans-N-caffeoyltyramine (TNC) isolated from Cortex lycii against hydrogen peroxide (H2O2) induced cell damages in PC12 cells as well as its mechanism of action. The results obtained indicated that pretreatment with TNC before the exposure of cells to H2O2 toxicity lead to a significant increase in the cell viability and the antioxidant enzyme activities catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) and reduced the level of malondialdehyde (MDA). Furthermore, TNC attenuated the influx of Ca2+, ROS formation and restored the impaired mitochondria membrane potential (MMP). Thus TNC may be used as an alternative therapy for the prevention and treatment of neuronal disorders elicited by oxidative stress.

Allium tuberosum: Antidiabetic and hepatoprotective activities.

Allium tuberosum (AT) is traditionally used for treating nocturnal emissions, abdominal pain, diarrhea, sexual dysfunction and asthma. This study aimed at investigating the antidiabetic and hepatoprotective activities of the butyl alcohol fraction from the methanolic extract of A. tuberosum. For the antidiabetic activity, rats were induced with diabetes by intraperitoneal injection of 150mg/kg alloxan and treated for 30days with AT extract (100, 200 and 400mg/kg). Animals were sacrificed after the study and the fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), HDL, malondialdehyde (MDA) catalase, superoxide dismutase and glutathione levels were determined. The hepatoprotective assay, mice were pretreated for seven days with AT (100, 200 and 400mg/kg) and silymarin (100mg/kg or). Thereafter 10ml/kg of 2% v/v CCl4 was administered intraperitoneally on the 7th day to induce acute liver injury. Blood and liver samples were obtained and serum enzymes ALT, AST, ALP, SOD, GSH, CAT, MDA and pro-inflammatory mediators were assessed. AT significantly decrease FBG, serum TG, TC, MDA levels and significant increased HDL, SOD, GSH and CAT activities in the diabetic rats. In addition, AT significantly inhibited MDA, IL-1b, IL-6 and TNF-α levels and prevented the depletion of the antioxidant enzymes GSH, SOD and CAT activities in CCl4 induced liver damage. Furthermore, AT markedly reduced AST, ALT and ALP levels in the CCl4 treated mice groups. In conclusion, the antidiabetic and hepatoprotective effect of AT may be associated with its antioxidant and its ability to inhibit the pro-inflammatory mediators.

Anti-oxidative, anti-secretory and anti-inflammatory activities of the extract from the root bark of Lycium chinense (Cortex Lycii) against gastric ulcer in mice.

The evaluation of the antioxidant, anti-secretory and anti-inflammatory potentials of the ethyl acetate fraction (ELC) from the root bark of Lycium chinense against ethanol-induced gastric ulcer in mice and the possible mechanisms underlying this action was performed. The results indicated that oral administration of ELC (50, 100, 200 and 400 mg/kg) before ethanol-induced ulcer increased the gastric mucus content, restored the superoxide dismutase and glutathione levels, reduced malondialdehyde levels and inhibited the activity of myeloperoxidase. Furthermore, ELC displayed its anti-secretory activity by decreasing the gastric juice and increased the gastric pH and reduced pro-inflammatory markers and caspase-3 tissue levels. These results suggest that L. chinense displays gastroprotective properties as a result of its antioxidant, anti-inflammatory, anti-secretory and anti-apoptotic effects.

Lycium chinensis Mill attenuates glutamate induced oxidative toxicity in PC12 cells by increasing antioxidant defense enzymes and down regulating ROS and Ca(2+) generation.

Lycium chinensis Mill is a famous traditional Chinese medicine which displays several medicinal activities including antioxidant and neuroprotective activities. However, the mechanism of action towards the neuroprotective action has not been fully elucidated. This work was aimed at investigating the neuroprotective effects of L. chinensis Mill against glutamate-induced oxidative neurotoxicity in PC12 cells. Oxidative cell death was induced with 5mM glutamate in PC12 cells. Cell viability, LDH release, intracellular Ca(2+) concentration, reactive oxygen species (ROS) accumulation, GSH-Px, CAT and SOD antioxidant enzyme levels were measured. Our results indicated that pretreatment of PC12 cells with L. chinensis Mill extracts markedly attenuated the loss of cell viability, the release of lactate dehydrogenase (LDH), Ca(2+) overload, ROS generation, and cell apoptosis induced by glutamate toxicity. Furthermore, L. chinensis Mill extracts also significantly increased the levels of innate antioxidant enzymes GSH-Px, SOD and CAT in glutamate-induced PC12 cells. Conclusively, our results provided substantial evidence that L. chinensis Mill protected PC12 cells against glutamate-induced cell death by attenuating ROS generation, Ca(2+) influx, and increased the antioxidant defense capacity of PC12 cells against oxidative stress damages, suggesting the possible potential of extracts from the plant as sources of bioactive molecules in the treatment of neurodegenerative disorders.

Cordycepin protects PC12 cells against 6-hydroxydopamine induced neurotoxicity via its antioxidant properties.

Parkinson's disease (PD) is a progressive neurodegenerative disorder that is characterized by degeneration and loss of dopaminergic neurons of the substantia nigra. Increasing evidence has indicated that oxidative stress plays a pivotal role in the pathogenesis of Parkinson's disease (PD). Therapeutic options that target the antioxidant machinery may have potential in the treatment of PD. Cordycepin, a nucleoside isolated from Cordyceps species displayed potent antioxidant, anti-inflammatory and anticancer properties. However, its neuroprotective effect against 6-OHDA neurotoxicity as well as underlying mechanisms is still unclear. In this present study, we investigated the protective effect of cordycepin against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity and its underlying mechanism. We observed that cordycepin effectively inhibited 6-OHDA-induced cell death, apoptosis and mitochondrial dysfunction. Cordycepin also inhibited cell apoptosis induced by 6-OHDA as observed in the reduction of cytochrome c release from the mitochondrial as well as the inhibition of caspase-3. In addition cordycepin markedly reduced cellular malondialdehyde (MDA) content and intracellular reactive oxygen species (ROS) level. Cordycepin also significantly increased the antioxidant enzymes; superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in 6-OHDA-treated cells. The results obtained unambiguously demonstrated that cordycepin protects PC12 cells against 6-OHDA-induced neurotoxicity through its potent antioxidant activity.

Polysaccharides purified from Cordyceps cicadae protects PC12 cells against glutamate-induced oxidative damage.

Two polysaccharides CPA-1 and CPB-2 were isolated purified from Cordyceps cicadae by hot water extraction, ethanol precipitation and purification using anion exchange and gel filtration chromatography. Preliminary structural characterization of CPA-1 and CPB-2 were performed. The protective effect of CPA-1 and CPB-2 against glutamate-induced oxidative toxicity in PC12 cells was analyzed. The results indicated that pretreatment of PC12 cells with CPA-1 and CPB-2 significantly increased cell survival, Ca(2+) overload and ROS generation. CPA-1 and CPB-2 also markedly up-regulated the antioxidant status of pretreated PC12 cells. Our results suggested that Cordyceps cicadae polysaccharides can protect PC12 cells against glutamate excitotoxicity and might serve as therapeutic agents for neuronal disorders.

Neuroprotective effects of adenosine isolated from Cordyceps cicadae against oxidative and ER stress damages induced by glutamate in PC12 cells.

Glutamate has been proven to induce oxidative stress through the formation of reactive oxygen species (ROS) and increased calcium overload which results in neuronal injury, development of neurodegenerative diseases and death. Adenosine is one of the bioactive nucleosides found in Cordyceps cicadae and it has displayed several pharmacological activities including neuroprotection. In this study, the protective effects of adenosine from C. cicadae against glutamate-induce oxidative stress in PC12 cells were evaluated. The exposure of PC12 cells to glutamate (5mM) induced the formation of ROS, increased Ca(2+) influx, endoplasmic reticulum (ER) stress and up regulated the expression of pro-apoptotic factor Bax. However, pretreatment with adenosine markedly increased cell viability, decreased the elevated levels of ROS and Ca(2+) induced by glutamate. Furthermore adenosine increased the activities of GSH-Px and SOD, as well as retained mitochondria membrane potential (MMP), increased Bcl-2/Bax ratio, and reduced the expression of ERK, p38, and JNK. Overall, our results suggest that adenosine may be a promising potential therapeutic agent for the prevention and treatment of neurodegenerative disorders.

Bromotyrosine Alkaloids with Acetylcholinesterase Inhibitory Activity from the Thai Sponge Acanthodendrilla sp.

Twenty bromotyrosine alkaloids, including a new compound, 13-oxosubereamolline D (5), were isolated from the Thai sponge Acanthodendrilla sp. Their structures were determined by analyses of 1D- and 2D-NMR, high-resolution mass, and circular dichroism data. The complete 1H and 13C NMR assignments of 5,7ß-dichlorocavernicolin (19) and 5,7α-dichlorocavernicolin (20) are described herein for the first time. The acetylcholinesterase (AChE) inhibitory activity of all isolated compounds was evaluated. Only homoaerothionin (7) and fistularin 1 (10) exhibited inhibitory activity against human recombinant AChE (hrAChE) with IC50s of 4.5 and 47.5 µM, respectively. The hrAChE inhibition kinetics of 7, the most potent alkaloid, showed increased Km and unchanged Vmaxvalues, suggesting its competitive mode of inhibition. The spirocyclohexadienylisoxazole and the length of the alkyl diamine linkage were proposed as the crucial parts for its strong inhibitory activity. This finding indicates a therapeutic potential for 7 in acetylcholine-related diseases, most importantly Alzheimer's disease.

Non-competitive inhibition of acetylcholinesterase by bromotyrosine alkaloids.

Fifteen bromotyrosine-derived alkaloids were isolated from the sponge Pseudoceratina cf. purpurea. The acetylcholinesterase-inhibiting activity of all the isolated compounds were examined; to purealidin Q, isoanomoian A, aplyzanzine A, and aplysamine 2 were active with IC50 values of 1.2, 70, 104, and 1.3 µM, respectively. On the other hand, antiproliferative activity against MCF-7 cells of aerophobin 1 gave an IC50 value of 0.8 µM. The Michaelis-Menten plots of the active alkaloids indicated that all the four compounds inhibited acetylcholinesterase in a non-competitive manner. The structures of the active compounds suggested that the N,N-dimethylaminopropyloxydibromotyramine moiety may play an important role in the enzyme-inhibiting activity, presumably on the anionic and hydrophobic binding sites.