Ethnopharmacologic investigation of ginger (Zingiber officinale)

An ethanolic extract of the rhizomes of Zingiber officinale was investigated for anti-inflammatory, analgesic, antipyretic, antimicrobial and hypoglycaemic activities. In rats, the extract reduced carrageenan-induced paw swelling and yeast-induced fever but was ineffective in suppressing the writhing induced by intraperitoneal acetic acid. The extract produced blood glucose lowering in rabbits. The growth of both Gram-positive and Gram-negative bacteria was significantly inhibited. A dose-dependent inhibition of prostaglandin release effect was observed using rat peritoneal leucocytes.     

The effects of Ananas comosus L. leaves on diabetic-dyslipidemic rats induced by alloxan and a high-fat/high-cholesterol diet

The aim of this study is to demonstrate the effects of Ananas comosus L. leaves on diabetic-dyslipidemic rats. Hypoglycemic and hypolipidemic activities of the ethanolic extract of Ananas comosus L. leaves (EEACL) were evaluated in normal and alloxan-induced diabetic rats by oral glucose tolerance test and an olive oil load test. Anti-diabetic, anti-hyperlipidemic and anti-oxidative activities of EEACL were also investigated in diabetic-dyslipidemic rats induced by alloxan and a high-fat/high-cholesterol diet. EEACL at the dose of 0.40 g/kg significantly inhibited the increase in blood glucose in diabetic rats in oral glucose tolerance test, but did not cause any hypoglycerimic activity in normal rats. It also significantly inhibited the increase in postprandial triglycerides (TG) levels in both normal and diabetic rats in olive oil load test. After 15 days of treatment of diabetic dyslipidemic rats, EEACL significantly decreased blood glucose (-51.0%, P < 0.01), TG (-50.1%, P < 0.01), TC (-23.3%, P < 0.01), LDL-c (-47.9%, P < 0.01) and glycated albumin (-25.4%, P < 0.01) levels, significantly increased serum high-density lipoprotein cholesterol levels (66.2%, P < 0.01) and prevented lower body weight of diabetes (11.8%, P < 0.05), significantly lowered lipid peroxidation productions of blood (-27.8%, P < 0.01), brain (-31.6%, P < 0.05), liver (-44.5%, P < 0.01) and kidneys (-72.2%, P < 0.05) compared with those in untreated diabetic dyslipidemic rats. These data suggest that EEACL has anti-diabetic, anti-dyslipidemic and anti-oxidative activities, which may be developed into a new plant medicine for treatment of diabetes and its complications.     

Comparative evaluation of hypoglycaemic activity of some Indian medicinal plants in alloxan diabetic rats

In our experiments 30 hypoglycaemic medicinal plants (known and less known) have been selected for thorough studies from indigenous folk medicines, Ayurvedic, Unani and Siddha systems of medicines. In all the experiments with different herbal samples (vacuum dried 95% ethanolic extracts), definite blood glucose lowering effect within 2 weeks have been confirmed in alloxan diabetic albino rats. Blood glucose values are brought down close to normal fasting level using herbal samples at a dose of 250 mg/kg once, twice or thrice daily, as needed. While evaluating comparative hypoglycaemic activity of the experimental herbal samples, significant blood glucose lowering activities are observed in decreasing order in the following 24 samples-Coccinia indica, Tragia involucrata, G. sylvestre, Pterocarpus marsupium, T. foenum-graecum, Moringa oleifera, Eugenia jambolana, Tinospora cordifolia, Swertia chirayita, Momordica charantia, Ficus glomerata, Ficus benghalensis, Vinca rosea, Premna integrifolia, Mucuna prurita, Terminalia bellirica, Sesbenia aegyptiaca, Azadirachta indica, Dendrocalamus hamiltonii, Zingiber officinale, Aegle marmelos, Cinnamomum tamala, Trichosanthes cucumerina and Ocimum sanctum. Present studies besides confirming hypoglycaemic activities of the experimental herbal samples, help identify more potent indigenous hypoglycaemic herbs (in crude ethanolic extract) from the comparative study of the reported experimental results.     

Reversal of cisplatin-induced delay in gastric emptying in rats by ginger (Zingiber officinale)

Cisplatin causes nausea, vomiting and inhibition of gastric emptying. We have demonstrated the antiemetic effect of the acetone and ethanolic extract of ginger (Zingiber officinale, Roscoe, Zingiberacae) against cisplatin-induced emesis in dogs. In the present study, the acetone and 50% ethanolic extract of ginger in the doses of 100, 200 and 500 mg/kg (p.o.) and ginger juice, in the doses of 2 and 4 ml/kg, were investigated against cisplatin effect on gastric emptying in rats. All three ginger preparations significantly reversed cisplatin-induced delay in gastric emptying. The ginger juice and acetone extract were more effective than the 50% ethanolic extract. The reversal produced by the ginger acetone extract was similar to that caused by the 5-HT₃ receptor antagonist ondansetron; however, ginger juice produced better reversal than ondansetron. Therefore, ginger, an antiemetic for cancer chemotherapy, may also be useful in improving the gastrointestinal side effects of cancer chemotherapy.     

Antihyperglycaemic and Insulin Release Effects of Aegle marmelos Leaves in Streptozotocin–Diabetic Rats

An aqueous extract of Aegle marmelos leaves exhibited significant hypoglycaemic and antihyperglycaemic effects in normoglycaemic and streptozotocin-diabetic rats, respectively. It also significantly ( p <0.05) increased the plasma insulin levels of diabetic rats. The extract did not show any signs of toxicity and the LD₅₀ was greater than 10.0 g/kg when given orally in rats.     

Analgesic, antiinflammatory and hypoglycaemic effects of ethanol extract of Zingiber officinale (Roscoe) rhizomes (Zingiberaceae) in mice and rats

The present study was undertaken to investigate the analgesic, antiinflammatory and hypoglycaemic effects of Zingiber officinale dried rhizomes ethanol extract (ZOE) in mice and rats. The analgesic effect of ZOE was evaluated by 'hot-plate' and 'acetic acid' analgesic test methods in mice; while the antiinflammatory and hypoglycaemic effects of the plant extract were investigated in rats, using fresh egg albumin-induced pedal oedema, and streptozotocin (STZ)-induced diabetes mellitus models. Morphine (MPN, 10 mg/kg), diclofenac (DIC, 100 mg/kg) and chlorpropamide (250 mg/kg) were used as reference drugs for comparison. ZOE (50-800 mg/kg i.p.) produced dose-dependent, significant (p < 0.05-0.001) analgesic effects against thermally and chemically induced nociceptive pain in mice. The plant extract (ZOE, 50-800 mg/kg p.o.) also significantly (p < 0.05-0.001) inhibited fresh egg albumin-induced acute inflammation, and caused dose-related, significant (p < 0.05-0.001) hypoglycaemia in normal (normoglycaemic) and diabetic rats. The findings of this experimental animal study indicate that Zingiber officinale rhizomes ethanol extract possesses analgesic, antiinflammatory and hypoglycaemic properties; and thus lend pharmacological support to folkloric, ethnomedical uses of ginger in the treatment and/or management of painful, arthritic inflammatory conditions, as well as in the management and/or control of type 2 diabetes mellitus in some rural Africa communities.     

Effects of ethanolic extract of Iris germanica on lipid profile of rats fed on a high-fat diet

Ethanolic extract of Iris germanica rhizomes was investigated for hypolipidemic activity. I. germanica belong to the family Irdaceae and has been used to treat liver and spleen ailments in traditional system of medicine. Two groups of Wistar rats were fed with high-fat diet and ethanolic extract of I. germanica were administered orally in one group of rats, while other received saline for 10 weeks. Complete lipid profiles of experimental animals were determined by assessing serum levels of total lipids, triglycerides, cholesterol, high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol. Results indicate that ethanolic extract of I. germanica significantly lowered the lipid components especially, the cholesterol and triglycerides.     

Cholesterol and triglycerides lowering activities of caraway fruits in normal and streptozotocin diabetic rats

The purpose of this study was to examine the effect of single and repeated oral administration of the aqueous extract of Carum carvi L. fruits at a dose of (20mg/kg) on lipid metabolism in normal and streptozotocin-induced diabetic rats (STZ). After a single oral administration, Carum carvi extract produced a significant decrease on triglycerides levels in normal rats (p<0.05). In STZ diabetic rats, cholesterol levels were decreased significantly 6h after Carum carvi treatment (p<0.05). On the other hand, repeated oral administration of Carum carvi extract exhibited a significant hypotriglyceridemic and hypocholesterolemic activities in both normal (p<0.01 and <0.001 respectively) and STZ diabetic rats (p<0.001) 15 days after Carum carvi treatment. We conclude that the aqueous extract of Carum carvi (20mg/kg) exhibits a potent lipid lowering activity in both normal and severe hyperglycemic rats after repeated oral administration of Carum carvi aqueous extract.     

Glutathione S-transferases and malondialdehyde in the liver of NOD mice on short-term treatment with plant mixture extract P-9801091

Changes in the concentration of glutathione S-transferases (GSTs) and malondialdehyde (MDA) were assessed in the liver of normal and diabetic NOD mice with and without treatment with the plant extract P-9801091. The plant extract P-9801091 is an antihyperglycaemic preparation containing Myrtilli folium (Vaccinium myrtillus L.), Taraxaci radix (Taraxacum of fi cinale Web.), Cichorii radix (Cichorium intybus L.), Juniperi fructus (Juniperus communis L.), Centaurii herba (Centaurium umbellatum Gilib.), Phaseoli pericarpium (Phaseolus vulgaris L.), Millefoliiherba (Achillea millefolium L.), Mori folium (Morus nigra L.), Valerianae radix (Valeriana of ficinalis L.) and Urticae herba et radix (Urtica dioica L). Hyperglycaemia in diabetes mellitus is responsible for the development of oxidative stress (via glucose auto-oxidation and protein glycation), which is characterized by increased lipid peroxide production (MDA is a lipid peroxidation end product) and/or decreased antioxidative defence (GST in the liver is predominantly an alpha enzyme, which has antioxidative activity). The catalytic concentration of GSTs in the liver was significantly reduced in diabetic NOD mice compared with normal NOD mice (p < 0.01), while the concentration of MDA showed a rising tendency (not significant). The results showed that statistically significant changes in antioxidative defence occurred in the experimental model of short-term diabetes mellitus. A 7-day treatment with P-9801091 plant extract at a dose of 20 mg/kg body mass led to a significant increase in the catalytic concentration of GSTs in the liver of diabetic NOD mice (p < 0.01) and a decrease in MDA concentration (not significant), which could be explained by its antihyperglycaemic effect.     

Antidiabetic activity of Paspalum scrobiculatum Linn. in alloxan induced diabetic rats

Ethnopharmacological relevance

Paspalum scrobiculatum Linn. (Poaceae) is traditionally used to treat diabetes mellitus. The grains of Paspalum scrobiculatum are having potential in the development of drug for diabetes due to their antidiabetic activity.

Aim of the study

To evaluate the antidiabetic activity of aqueous and ethanolic extracts of grains of Paspalum scrobiculatum Linn. (Poaceae) in alloxan induced diabetic rats.

Materials and methods

Aqueous and ethanolic extracts (250 and 500 mg/kg body weight), were administered orally to male Wistar albino rats. Alloxan monohydrate was used to induce diabetes mellitus. Total phenolic content was estimated in the extracts. The parameters studied included oral glucose tolerance test, fasting blood glucose, serum insulin and glycated haemoglobin levels, liver glycogen content, serum lipid profile, and changes in body weights.

Results

In oral glucose tolerance test, reduction of fasting blood glucose levels took place from 60 min of extract administration. The extracts produced a dose-dependent fall in fasting blood glucose (FBG). After 15 days of treatment with extracts the maximum reduction in FBG (35.14%) was observed in diabetic rats treated with ethanolic extract 500 mg/kg dose. A significant increase in serum insulin level was observed in the treated rats. Serum lipid levels were reversed towards near normal and a control in the loss of body weight was observed in treated rats as compared to diabetic control. The extract treatment also showed a significant increase in the liver glycogen and a significant decrease in glycated haemoglobin levels. The results demonstrate that Paspalum scrobiculatum possesses significant antidiabetic activity in diabetic rats.

Conclusion

The results suggest that Paspalum scrobiculatum has antidiabetic activity, thereby justifying its traditional claim and augmenting it into the present day systems of medicine.     

Comparison between ethanolic and aqueous extracts from Chinese juniper berries for hypoglycaemic and hypolipidemic effects in alloxan-induced diabetic rats

AIM OF THE STUDY: Hypoglycaemic and hypolipidemic properties of the ethanolic and aqueous extracts, respectively, from Chinese juniper (Juniperus chinensis L.) berries were investigated in alloxan-induced diabetic rats. MATERIALS AND METHODS: After oral administration of each extract singly or repeatedly to alloxan-induced diabetic rats, the blood glucose, glutamate-pyruvate transferase (GPT), glutamate-oxaloacetate transaminase (GOT), total cholesterol (TC) and triglyceride (TG) levels were assayed. RESULTS: The blood glucose levels after a single oral administration of the ethanolic extract significantly reduced in a time-dependent manner, which is much faster and more than that of glibenclamide. The blood glucose levels of alloxan-induced diabetic rats treated with the ethanolic extract were reduced to 94, 81%, 66%, 45% and 40% at 1, 3, 5, 7 and 9h, respectively (p<0.05), while the aqueous extract had no effect at all. Repeated oral administration of the ethanolic extract also effectively reduced the GPT value to 58% of the diabetic rats, but slightly reduced the GOT value to 87% of the diabetic rats (p<0.05). On the other hand, the repeated oral administration of aqueous extract effectively reduced the GOT value to 43% of the diabetic rats, without affecting the GPT level. Effects of both extracts on the TC and TG levels were different. There was no significant difference in the TC and TG levels between diabetic control and diabetic groups when repeatedly administered orally with ethanolic extract. On the other hand, the aqueous extract brought down the TC value to 57% and the TG value to 37% of the diabetic control rats (p<0.05). CONCLUSIONS: The results suggested that the ethanolic extract of Chinese juniper berries possesses a potential hypoglycaemic effect while the aqueous extract has a potential hypolipidemic effect.     

Effect of soluble dietary fibre fraction of Trigonella foenum graecum on glycemic,insulinemic, lipidemic and platelet aggregation status of Type 2 diabetic model rats

The soluble dietary fibre (SDF) fraction of Trigonella foenum graecum (Tf-sdf) has previously been shown to reduce postprandial elevation in blood glucose level of Type 2 model diabetic rats by delaying the digestion of sucrose. The Tf-sdf has now been investigated for its chronic effect on serum fructosamine, insulin and lipid levels, and on platelet aggregation in Type 2 diabetic rats. Tf-sdf was administered orally twice daily at a dose of 0.5 g kg(-1) for 28 days. It lowered the serum fructosamine level (P<0.05) with no significant change in the insulin level as compared with the control. Atherogenic lipids, i.e. triglycerides, cholesterol and LDL-cholesterol were found to decrease significantly in Tf-sdf fed rats (P<0.01). HDL-cholesterol showed an opposite trend (P=0.024), but serum non-esterified fatty acid (NEFA) values paralleled the atherogenic lipids (P=0.001). No significant effect on platelet aggregation (%) was found although there was a tendency to lower the aggregation (P=0.069). It is concluded that Tf-sdf has a beneficial effect on dyslipidemia and has a tendency to inhibit platelet aggregation in Type 2 model diabetic rats.     

Hypolipidemic activity of aqueous extract of Capparis spinosa L. in normal and diabetic rats

The purpose of this study was to examine the effect of single and repeated oral administrations of the aqueous extract of Capparis spinosa L. (CS) at a dose of 20mg/kg on lipid metabolism in normal and streptozotocin-induced diabetic rats. In normal rats, the aqueous extract of CS induced a significant decrease on plasma triglycerides concentrations 1 week (p<0.05) and 2 weeks (p<0.01) after once daily repeated oral administration. A significant decrease of plasma cholesterol levels was also observed 4 days (p<0.05) and 1 week (p<0.05) after repeated oral administration. In diabetic rats, CS treatment caused a significant decrease of plasma triglycerides levels after repeated oral administration. Four days after repeated oral administration of aqueous CS extract, the plasma cholesterol levels were significantly decreased (p<0.05) and still dropped after 2 weeks (p<0.01). On the other hand, the repeated oral administration of CS aqueous extract caused a significant decrease of body weight 4 days after repeated oral treatment in diabetic rats (p<0.05). We conclude that the aqueous extract of CS (20 mg/kg) exhibits a potent lipid lowering activity in both normal and severe hyperglycemic rats after repeated oral administration of CS aqueous extract.     

In vivo assessment of antidiabetic and antioxidant activities of rosemary (Rosmarinus officinalis) in alloxan-diabetic rabbits

Rosemary (Rosmarinus officinalis), used in traditional Turkish folk medicine for the treatment of hyperglycaemia, is widely accepted as one of the medicinal herb with the highest antioxidant activity. Accordingly, the present study was designed to investigate the possible actions of ethanolic extract of the leaves of Rosmarinus officinalis on glucose homeostasis and antioxidant defense in rabbits. In the first set of experiments, hypoglycaemic effects of oral administration of various doses (50, 100 and 200 mg/kg) of the extract were examined in normoglycaemic and glucose-hyperglycaemic rabbits. Optimal effect was observed in both of the animal groups with a dose of 200 mg/kg of the extract and this activity was independent from the effects of insulin. In another part of experiments, acute effect of various doses of the Rosmarinus officinalis extract on blood glucose and serum insulin levels was studied in alloxan-induced diabetic rabbits. Of the three doses of extract, the highest dose (200 mg/kg) significantly lowered blood glucose level and increased serum insulin concentration in alloxan-diabetic rabbits. The last set of experiments designed to investigate the subacute effect of the Rosmarinus officinalis extract on repeated administration in alloxan-diabetic rabbits. At the doses of 100 and 200 mg/kg, antihyperglycaemic effect of extract was accompanied by a significant increase in serum insulin levels in diabetic rabbits. Furthermore, during 1 week of treatment of diabetic rabbits with a dose of 200 mg/kg of the extract showed that the extract possessed a capability to inhibit the lipid peroxidation and activate the antioxidant enzymes. It was concluded that probably, due to its potent antioxidant properties, the Rosmarinus officinalis extract exerts remarkable antidiabetogenic effect.     

Lipid lowering activity of Phyllanthus niruri in hyperlipemic rats

The lipid lowering activity (LLA) of Phyllanthus niruri has been studied in triton and cholesterol fed hyperlipemic rats. Serum lipids were lowered by P. niruri extract orally fed (250 mg/kg b.w.) to the triton WR-1339 induced hyperlipemic rats. Chronic feeding of this drugs (100 mg/kg b.w.) in animals simultaneously fed with cholesterol (25 mg/kg b.w.) for 30 days caused lowering in the lipids and apoprotein levels of VLDL and LDL in experimental animals. The LLA of this drug is mediated through inhibition of hepatic cholesterol biosynthesis, increased faecal bile acids excretion and enhanced plasma lecithin: cholesterol acyltransferase activity.     

Antihyperglycemic and antilipidperoxidative effects of Pongamia pinnata (Linn.) Pierre flowers in alloxan induced diabetic rats

Our aim was to evaluate the antihyperglycemic and antilipid peroxidative effect of ethanolic extract of Pongamia pinnata (Linn.) Pierre (Leguminosae) flowers (PpEt) in normal rats and alloxan induced diabetic rats. Hyperglycemia, elevated lipid peroxidation [thiobarbituric acid reactive substances (TBARS)] and disturbed nonenzymatic [Vitamin E, Vitamin C and glutathione] and enzymatic antioxidants status were noticed in alloxan induced diabetic rats. The oral administration of ethanolic extract of Pongamia pinnata flowers (300 mg/kg bw) showed significant antihyperglycemic, and antilipidperoxidative effects and enhancement in antioxidants defense system in alloxan induced diabetic rats. However, no significant characteristic changes were noticed in blood glucose level as well as in lipid peroxidation and antioxidant status in normal rats treated with "PpEt" alone. We have also observed that the "PpEt" considerably reduced the blood glucose concentration in a similar extent to that of the reference drug glibenclamide (600 microg/kg bw) in alloxan induced diabetic rats. Our results thus suggested that the "PpEt" could be used as a safe alternative antihyperglycemic drug for diabetic patients.     

Protective effects of Zingiber officinale (Zingiberaceae) against carbon tetrachloride and acetaminophen-induced hepatotoxicity in rats

The effect of the ethanol extract of the rhizome of Zingiber officinale was tested against carbon tetrachloride (CCl(4)) and acetaminophen-induced liver toxicities in rats. Increases in serum and liver marker enzymes such as alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase as well as sorbitol and glutamate dehydrogenases were produced in normal rats that were not pretreated with the extract. However, extract-pretreated rats attenuated in a dose-dependent manner, CCl(4) and acetaminophen-induced increases in the activities of ALT, AST, ALP, LDH and SDH in the blood serum. The protective effect of the extract on CCl(4) and acetaminophen-induced damage was confirmed by histopathological examination of the liver. These results indicate that the oil from the rhizome of Zingiber officinale could be useful in preventing chemically induced acute liver injury.     

Protective effect of ginger volatile oil against acetic acid-induced colitis in rats: a light microscopic evaluation

OBJECTIVE: Ulcerative colitis is a chronically recurrent infl ammatory bowel disease of unknown origin. In the present study, the effect of ginger(rhizome of Zing iber officinale Roscoe) volatile oil on a rat model of colitis was evaluated. METHODS: Volatile oil of ginger with doses of 100, 200, and 400 mg/kg, prednisolone(4 mg/kg), or vehicle were administered orally to groups of male Wistar rats(n = 6) for 5 d. Animals were randomly divided into 6 groups, each group consisting of 6 rats. Colitis was induced by intracolonic instillation of 2 mL of 4%(v/v) acetic acid solution. All rats were sacrificed 24 h later and the tissue injuries were assessed macroscopically and histopathologically. RESULTS: Ginger volatile oil with all doses reduced colon weight/length ratio(P 0.01) and the effects were similar to the reference drugs. Higher oral doses of volatile oil(200 and 400 mg/kg) reduced ulcer severity(P 0.05 and P 0.01), ulcer area(P 0.01) and ulcer index(P 0.01). On the other hand, evaluation of microscopic scores showed that the dose of 400 mg/kg of volatile oil was effective to reduce infl ammation severity(P 0.01) and infl ammation extent(P 0.05) compared to the control group.CONCLUSION: It is concluded that ginger volatile oil could effectively reduce symptoms of experimental colitis in a dose-dependent manner.     

The effect of Chinese medicinal herb Zingiberis rhizoma extract on cytokine secretion by human peripheral blood mononuclear cells

The ethanolic extract of the Chinese medicinal herb Zingiberis rhizoma, the rhizome of Zingiber officinale Roscoe (Zingiberaceae), was found to show biphasic effects on secretion of cytokines by human peripheral blood mononuclear cells in vitro. In this study, the augmentative effect of Zingiberis rhizoma extract on cytokine secretion was shown to be time dependent. No significant secretion of cytokine was noted when the reaction time was 1 or 3 h. Secretion of interleukin-1β (IL-1β), interleukin-6 (IL-6), and granulocyte-macrophage colony-stimulating factor (GM-CSF) by the mononuclear cells was markedly increased in the presence of a low concentration of Zingiberis rhizoma extract, varying from 10–30 mg/ml, when the reaction time was 18 or 24 h. A higher concentration of the herbal extract did not show similar or stronger augmentative effect as did low concentration of the herbal extract.     

Mosquito larvicidal activity of isolated compounds from the rhizome of Zingiber officinale

The larvicidal activity of a petroleum ether extract of Zingiber officinale Roscoe (Zingiberaceae) was evaluated against Aedes aegypti L. and Culex quinquefasciatus Say (Diptera). Bioassay-guided fractionation led to the isolation of 4-gingerol (1), (6)-dehydrogingerdione (2) and (6)-dihydrogingerdione (3); the latter has not previously been reported from Z. officinale. The structures were established from infrared (IR), ultraviolet (UV), (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectral data. Following a 24 h exposure, compounds 1-3 exhibited larvicidal activities against fourth instar larvae of A. aegypti (LC(50) 4.25, 9.80, 18.20 ppm) and C. quinquefasciatus (LC50 5.52, 7.66, 27.24 ppm), respectively. The results show that the most effective compound was 4-gingerol.