Clinical and experimental studies on polyherbal formulations for diabetes: current status and future prospective / 中西医结合学报

Diabetes is a leading cause of morbidity and mortality in the world. There is currently an active search for antidiabetic drugs with greater effectiveness with fewer and less adverse side effects. Although numerous individual herbs have been experimentally or clinically reported to possess antidiabetic effects, considerably less research has been conducted on polyherbal compounds. It is believed that herbal compounds containing multiple plant products have synergistic antidiabetic effects and could enhance the desired actions. Several polyherbal formulations have been studied as therapeutic agents in diabetes management. To describe the current state of research on polyherbal compounds in the treatment of diabetes, an extensive review of literature was undertaken on several major databases. This paper presents what is known about the efficacy of these polyherbal formulations and compare their antidiabetic effects with those of current oral hypoglycemic drugs as reference. The percent decrease in blood glucose, lipids and other biochemical parameters achieved by each product in diabetic animals and patients is reported. Also, the possible mechanisms responsible for hypoglycemic action of polyherbal formulations are discussed.

Clinical and experimental studies on polyherbal formulations for diabetes: current status and future prospective / 中西医结合学报

Diabetes is a leading cause of morbidity and mortality in the world. There is currently an active search for antidiabetic drugs with greater effectiveness with fewer and less adverse side effects. Although numerous individual herbs have been experimentally or clinically reported to possess antidiabetic effects, considerably less research has been conducted on polyherbal compounds. It is believed that herbal compounds containing multiple plant products have synergistic antidiabetic effects and could enhance the desired actions. Several polyherbal formulations have been studied as therapeutic agents in diabetes management. To describe the current state of research on polyherbal compounds in the treatment of diabetes, an extensive review of literature was undertaken on several major databases. This paper presents what is known about the efficacy of these polyherbal formulations and compare their antidiabetic effects with those of current oral hypoglycemic drugs as reference. The percent decrease in blood glucose, lipids and other biochemical parameters achieved by each product in diabetic animals and patients is reported. Also, the possible mechanisms responsible for hypoglycemic action of polyherbal formulations are discussed.

Effect of zirconium dioxide nanoparticles on glutathione peroxidase enzyme in PC12 and N2a cell lines

Today, special attention is paid to the use of zirconium dioxide nanoparticle [nano-ZrO[2]], a neutral bioceramic metal, particularly for drug and gene delivery in medicine. However, there are some reports implying that use of nano-ZrO[2] is associated with cytotoxic effects like inhibiting the cell proliferation, DNA damage and apoptosis. In the present study, we examined whether nano-ZrO[2] alters cell viability and glutathione peroxidase [GPx] activity in two neuronal cell lines. The PC12 and N2a cells were cultured in the absence or presence of varying concentrations [31.25-2000 micro g/mL] of nano-ZrO[2] for 12, 24 or 48 h. The cell viability was evaluated using 3-[4, 5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium [MTS] assay and GPx activity was determined by quantifying the rate of oxidation of the reduced glutathione to the oxidized glutathione. Nano-ZrO[2] caused a significant reduction in cell viability and GPx activity after 12, 24 and 48 h, as compared with control group. These effects were concentration dependent and started from 250 micro g/mL. The present study demonstrated that nano-ZrO[2], at concentrations of > 250 micro g/mL, has antiproliferative effects via reducing the cell defense mechanism against oxidative stress

Potentiating effects of Lactuca sativa on pentobarbital-induced sleep

Traditionally, Lactuca sativa [lettuce] has been recommended for its hypnotic property. The present study was planned to investigate sleep-prolonging effect of this plant. The hydro-alcoholic extract [HAE] of lettuce and its water fraction [WF], ethyl acetate fraction [EAF], and n-butanol fraction [NBF] were administrated [IP] to mice 30 min before the pentobarbital injection. Moreover, both in-vivo and in-vitro toxicity of the extracts were determined. The quality of HAE and NBF was also evaluated using HPLC fingerprint. The HAE prolonged the pentobarbital-induced sleep duration at dose of 400 mg/Kg. The NBF was the only fraction which could increase the sleep duration and decrease sleep latency. The effects of NBF were comparable to those of induced by diazepam. The LD[50]-value for HAE was found to be 4.8 g/Kg. No neurotoxic effect was observed either by HAE or by its fractions in cultured PC12 neuron-like cells. The results suggest that lettuce potentiates pentobarbital hypnosis without major toxic effect. The main component[s] responsible for this effect is most likely to be non-polar agent[s] which found in NBF of this plant

Effect of Ganoderma lucidum hydroalcoholic extract on insulin release in rat-isolated pancreatic islets

Ganoderma Lucidum [G. Lucidum] has been suggested to increase serum insulin level. This study was undertaken to investigate its direct effect on the islets of Langerhans. Male albino Wistar rats were anesthetized and the islets were isolated after digestion of the pancreas with collagenase. The islets were incubated for 60 min in Krebs bicarbonate buffer containing 3 or 10 mM glucose in the presence of hydroalcoholic extract of G. Lucidum [1 mg/ml], 3-isobutyl-1-methylxanthine [IBMX, 100 micro M] or vehicle. Exposure of islets to the extract increased insulin secretion at basal [3 mM] glucose concentration. Increase of glucose concentration to 10 mM resulted in a significant increase in the rate of insulin secretion. While the IBMX could augment insulin release evoked by 10 mM glucose, the extract failed to modify it. Our results demonstrate that G. lucidum acts directly on the Langerhans islets to increase basal insulin release

Effects of Coriandrum sativum extracts on glucose/serum deprivationinduced neuronal cell death

This study was planned to investigate whether Coriandrum sativum [C. sativum] is capable of protecting neurons against glucose/serum deprivation [GSD]-induced cytotoxicity. The PC12 cells were cultivated for 24 h in standard media [high-glucose DMEM containing Fetal Bovine Serum] or for 6 h in GSD condition [glucose-free DMEM, without serum] in the absence or presence of various concentrations [0.1, 0.2, 0.4, 0.8 and 1.6 mg/ml] of hydro-alcoholic extract [HAE], water fraction [WF], ethyl acetate fraction [EAF] or N-butanol fraction [NBF] of this plant. At the end of the treatments, the cell viability was determined using MTT assay. With the exception of 1.6 mg/ml of EAF or NBF which decreased cell survival, the HAE and its fractions exhibited no cytotoxicity under standard condition. Exposure of the cells to GSD condition showed 52% decrease in the viability. In this condition, the HAE, EAF and NBF not only failed to increase cell viability but also increased the toxicity. On the other hand, WF at 0.4, 0.8 and 1.6 mg/ml significantly attenuated the GSD-induced decrease in cell survival. The present study revealed that C. sativum bearing water-soluble compound[s] could induce neuroprotective activity. Also, we showed that some constituents from this plant may serve as cytotoxic agents under stressful conditions like hypoglycemia and serum limitation

Antimicrobial activity of aqueous and methanolic extracts of pomegranate fruit skin

Punica granatum, commonly known as pomegranate, has emerged as a medicinal plant with potential antimicrobial activity. The present study was planned to evaluate this activity against both Gram positive Staphylococcus aureus [S. aureus] and negative Pseudomonas aeruginosa [P. aeruginosa] bacteria as well as against pathogenic yeast, Candida albicans [C. albicans]. The aqueous and methanolic extracts of pomegranate fruit skin were prepared using a Soxhalet apparatus. Antimicrobial effect of the extracts was studied and compared with commercial antibiotics using three different methods; agar dilution, cylinder plate, and disk inhibition zone techniques. Both extracts showed good antibacterial activity against S. aureus and P. aeruginosa. Also the methanolic extract presented strong antifungal effect on C. albicans. The antimicrobial activities against S. aureus, P. aeruginosa and C. albicans were comparable with those of cloxacillin, gentamycin and clotrimazole, respectively. The methanolic extract was found to be more effective than aqueous one against all the tested microorganisms. The extracts from pomegranate fruit skin possess strong antimicrobial activity against the tested microorganisms. Therefore this plant could be an important source of new antimicrobial compounds to treat bacterial and fungal infections