Protective Effects of Annona Muricata Linn. (Annonaceae) Leaf Aqueous Extract on Serum Lipid Profiles and Oxidative Stress in Hepatocytes of Streptozotocin-Treated Diabetic Rats

Extracts from various morphological parts of Annona muricata Linn. (Annonaceae) are widely used medicinally in many parts of the world for the management, control and/or treatment of a plethora of human ailments, including diabetes mellitus (DM). The present study was undertaken to investigate the possible protective effects of A. muricata leaf aqueous extract (AME) in rat experimental paradigms of DM. The animals used were broadly divided into four (A, B, C and D) experimental groups. Group A rats served as ‘control’ animals and received distilled water in quantities equivalent to the administered volumes of AME and reference drugs'' solutions intraperitoneally. Diabetes mellitus was induced in Groups B and C rats by intraperitoneal injections of streptozotocin (STZ, 70 mg kg⁻¹). Group C rats were additionally treated with AME (100 mg kg⁻¹ day⁻¹, p.o.) as from day 3 post STZ injection, for four consecutive weeks. Group D rats received AME (100 mg kg⁻¹ day⁻¹ p.o.) only for four weeks. Post-euthanization, hepatic tissues were excised and processed biochemically for antioxidant enzymes and lipid profiles, such as catalase (CAT), reactive oxygen species (ROS), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), thiobarbituric acid reactive substances (TBARS), triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL) and low density lipoprotein (LDL), respectively. Treatment of Groups B and C rats with STZ (70 mg kg⁻¹ i. p.) resulted in hyperglycaemia, hypoinsulinaemia, and increased TBARS, ROS, TC, TG and LDL levels. STZ treatment also significantly decreased (p<0.05) CAT, GSH, SOD, GSH-Px activities, and HDL levels. AME-treated Groups C and D rats showed significant decrease (p<0.05) in elevated blood glucose, ROS, TBARS, TC, TG and LDL. Furthermore, AME treatment significantly increased (p<0.05) antioxidant enzymes'' activities, as well as serum insulin levels. The findings of this laboratory animal study suggest that A. muricata extract has a protective, beneficial effect on hepatic tissues subjected to STZ-induced oxidative stress, possibly by decreasing lipid peroxidation and indirectly enhancing production of insulin and endogenous antioxidants.     

Modulation of Penile Erection in Rabbits by Mondia Whitei: Possible Mechanism of Action

Mondia whitei root was evaluated to validate its anecdotal use and determine its possible mode of action in the management of erectile dysfunction. Rabbits were administered with daily oral doses of 100–400 mg kg⁻¹ crude ethanolic extract of M. whitei and sildenafil (50 mg kg⁻¹) as positive control for 6 weeks. Cavernosal tissue NOS activity and levels of NO and cGMP, and NOS and PDE protein expressions were investigated. The effect of the crude extract, chloroform and petroleum ether fractions in vitro on cavernosal tissue NOS activity and levels of NO and cGMP at 0.01 and 0.10 mg g⁻¹ tissue were also investigated. Results indicate that the crude extract increased NOS activity by 7% at 200 mg kg⁻¹ with corresponding increases in NO (88%) and cGMP (480%) levels. No significant changes in these measurements were observed with the 100 and 400 mg kg⁻¹ doses whilst sildenafil slightly reduced them (15.9–37.5%). NOS and PDE protein expressions in test animals were not different from controls. Pre-incubation of cavernosal tissue in vitro with the crude extract of M. whitei and its chloroform fraction markedly increased NOS activity (26–132%) and levels of NO (25%) and cGMP (50–400%) at 0.01 mg g⁻¹ tissue but these were reduced to near control levels when their concentrations were increased to 0.10 mg g⁻¹ tissue whilst the petroleum ether fraction had no effect. These findings suggest that M. whitei may influence erectile function through activation/stimulation of NOS with corresponding increases in tissue NO and cGMP levels and that certain chemical constituents present in the chloroform fraction may be responsible for biological activity.     

Role of Wormwood (Artemisia Absinthium) Extract on Oxidative Stress in Ameliorating Lead Induced Haematotoxicity

Effects of ROS generation have been postulated to be major contributors to lead-exposure related disease. The aim of the study was to investigate the effect of aqueous extract of wormwood (Artemisia absinthium) on oxidative stress in rats protractedly exposed to lead. Aqueous extract of wormwood plant was administered orally (200 mg.kg⁻¹ body weight). Plasma vitamin C, E and non-protein thiol concentrations, red blood cells (RBC) thiobarbituric acid reactive substances, reduced glutathione levels and haemolysis test were evaluated. In addition, RBC antioxidant enzymes activities such as superoxide dismutases, catalase, glutathione peroxidase, glutathione reductase were also estimated. After 11-weeks, significant decreases of plasma vitamin C, E, non protein-thiol (NP-SH) and RBC-reduced glutathione levels were observed in Pb compared to control group (−32.9%, −57.1%, −53.1%, −33.9%, respectively); superoxide dismutase, glutathione peroxidase, uric aminolevulinic acid and haemolysis test significantly increased in Pb compared to control group (+64.3%, +40.3%, +145%, +44.3%, respectively). In our investigation, after 4-weeks of treatment all treated groups did not show any difference compared to the control group, except for glutathione peroxidase and RBC-superoxide dismutase activity (−15.7% and +16.4%, respectively). The findings of this study suggest that wormwood (Artemisia absinthium) extract restored the enzymes activities perturbed by exposure to lead, and had a protective role against lipid peroxidation     

Biochemical and Toxicological Studies of Aqueous Extract of Syzigium Aromaticum (L.) Merr. & Perry (Myrtaceae) in Rodents

The effects of long-term administration of boiled aqueous extract of Syzigium aromaticum (SYZ), commonly known as clove (which has been locally employed for treating gastrointestinal tract diseases and also used as food spices), on some biochemical indices, such as body weight, liver functions and blood parameters were studied in adult albino rats of both sexes. Selected doses of 300 and 700 mg kg⁻¹ were given orally through cannular to groups of animals for a period of 90 days, while the control group received distilled water throughout the duration of study via the same route. Blood samples collected after therapy and assayed for activities of some liver enzymes recorded a significant (p<0.05) and prominent effect on ALP and AST. Measurement of haematological parameters also revealed significant effects (p<0.05; p<0.001) on Hb, RBC (p<0.05), PCV (p<0.001), platelets (p<0.001) and granulocytes (p<0.001). An insignificant reduction was recorded for total WBC. The histopathological study conducted was in consonance with the results of the biochemical investigations that the aqueous extract of SYZ even at moderate doses, significantly affects body organs, their enzymes as well as the various functions. LD₅₀ for both intraperitoneal and oral routes of SYZ were 263 and 2500 mg kg⁻¹ respectively. The present work has revealed the toxicity of sub chronic administration of SYZ, which suggests that its prolonged usage must be avoided.     

Absence of Organ Specific Toxicity in Rats Treated with Tonica, an Aqueous Herbal Haematinic Preparation

The sub-chronic toxicity of Tonica, an aqueous herbal haematinic prepared from the stem barks of Khaya senegalensis, Mitragyna stipulosa and Kigelia africana, was investigated in male Sprague-Dawley rats at 28, 280 and 560 mg kg⁻¹ day⁻¹, representing the normal human dose, 10x and 20x that dose, respectively for 6 weeks. The growth rate of animals over the period of treatment and certain serum biochemical and haematological indices as well as urinalysis and weight of selected organs at termination, were determined. Results show that the extract did not affect the weight gain of the animals with time or the mean wet weights of selected organs. Although there were slight but insignificant (p>0.05) elevations in WBC (16–27%) and PLT (8–11%) counts in Tonica-treated animals compared to controls at 10x and 20x the normal dose, most serum biochemical, haematological and urinalysis data indicated no significant differences (p>0.05) between tests and control rats. There were also no changes in the morphology of liver, kidney, lung and heart tissues as a result of Tonica treatment. These findings suggest that Tonica is safe at the dosage regimens administered to the animals in this study, and there appears to be no overt organ specific toxicity associated with it.     

Anti-Inflammatory and Antioxidant Effects of an Ethanolic Extract of the Aerial Parts of Hilleria Latifolia (Lam.) H. Walt. (Phytolaccaceae)

Various parts of the perennial herb Hilleria latifolia (Lam.) H. Walt. (Family: Phytolaccaceae) are used in Ghanaian traditional medicine for the treatment of several inflammatory-related disorders. The present study examined the anti-inflammatory effect of an ethanolic extract of the aerial parts of Hilleria latifolia (HLE) in acute and chronic inflammation models. Since free radicals and reactive oxygen species are implicated in inflammatory diseases, the antioxidant potential of HLE was also investigated in in vitro experimental models. HLE (10–300 mg kg⁻¹, p.o.), either preemptively or curatively, significantly inhibited carrageenan-induced foot oedema in 7-day old chicks. Similarly, the NSAID diclofenac (10–100 mg kg⁻¹, i.p.) and the steroidal anti-inflammatory agent dexamethasone (0.3–3 mg kg⁻¹, i.p.) dose-dependently reduced the oedema in both pre-emptive and curative treatments. In the Freund''s adjuvant induced-arthritis model in rats, HLE as well as the positive controls, dexamethasone and methotrexate, showed significant anti-arthritic properties when applied to established adjuvant arthritis. HLE (10–300 mg kg⁻¹, p.o.) significantly reduced oedema in the ipsilateral paw of rats but failed to prevent systemic arthritic spread. The DMARD methotrexate (0.1–1 mg kg⁻¹, i.p.) and dexamethasone (0.3–3 mg kg⁻¹, i.p.) reduced significantly the total polyarthritic oedema as well as the spread of the arthritis from the ipsilateral to the contralateral paws of the treated animals. The extract (0.03–1.00 mg ml⁻¹) exhibited Fe³⁺ reducing activity, scavenged DPPH and prevented lipid peroxidation. These findings suggest that the extract exerts in vivo anti-inflammatory activity after oral administration and also has antioxidant properties which may contribute to its activity.     

Antidiabetic Effect of Ceiba Pentandra Extract on Streptozo-tocin-induced Non-insulin-dependent Diabetic (NIDDM) Rats

The aim of this work was to investigate the effect of daily oral administration of root bark methylene chloride/methanol extract of Ceiba pentandra (Linn) in streptozotocin-induced type-2 diabetic rats, and the effect of this treatment on the physiological and metabolic parameters that are related in diabetic animals. The diabetic rats were separated into four groups and each given the following samples by gavage, daily for 28 days: vehicle (diabetic control), Ceiba pentandra extract at the dose of 40 mg/kg, Ceiba pentandra extract at the dose of 75 mg/kg and glibenclamide (5 mg/kg). All the parameters were also determined in healthy (non diabetic) rats for comparison. The methylene chloride/methanol extract of Ceiba pentandra treatment significantly reduced the intake of both food and water as well as the levels of blood glucose, serum cholesterol, triglyceride, creatinine and urea, in comparison with diabetic controls. The treatment also improves impaired glucose tolerance but no effect was observed in the level of hepatic glycogen. The effect of Ceiba pentandra (40 mg/kg) was more prominent when compared to glibenclamide in lowering blood glucose, with the added benefit of considerably reducing serum cholesterol and triglyceride concentrations. The results of this experimental animal study indicated that Ceiba pentandra possesses antidiabetic activity; and thus is capable of ameliorating hyperglycaemia in streptozotocin-induced type-2 diabetic rats and is a potential source for isolation of new orally active agent(s) for anti-diabetic therapy.     

Hypoglycaemic and Biochemical Properties of Cnestis Ferruginea

Increasing incidences of diabetes in Africa has prompted the search for safe and readily available alternative herbal remedies for the treatment of diabetes mellitus. Cnestis ferruginea was extracted with methanol and ethylacetate and the extracts obtained were tested for hypoglycaemic activities in streptozotocin (STZ)-induced diabetic rats and mice. The extracts (250mg/kg body weight) were administered orally for 10 consecutive days to STZ-induced diabetic rats while a single dose (250mg/kg body weight) of the extracts were administered to STZ-induced diabetic mice. Fasting blood glucose (FBG) levels were determined in the two groups of animals after extract administration. There was significant reduction in FBG (P< 0.005) by MCF and ECF within 4 hrs of extract administration in a time- dependent manner. Furthermore, administration of MCF and ECF for 10 days significantly lowered FBG in STZ diabetic rats (P<0.005) by 74% and 68%, respectively, whereas, glibenclamide - a standard antidiabetic drug reduced FBG by 60%. The levels of serum creatinine, urea, triglyceride, total cholesterol, total protein and level of lipid peroxidation were also evaluated. The extracts reduced significantly (P<0.005) the elevated levels of serum ALT and AST in diabetic treated rats. Similarly, both extracts significantly lowered (P<0.005) the levels of serum creatinine, urea, total cholesterol, triglyceride and thiobarbituric acid reactive species (TBARS).These results suggest that Cnestis ferruginea leaves contain a highly potent hypoglycaemic principle and could be a potential source for isolation of new orally active antihyperglycaemic compounds for attenuating secondary complications of diabetes such as atherosclerosis, liver and renal dysfunction.     

In vivo hypoglycemic effect of methanolic fruit extract of Momordica charantia L

Background

Momordica charantia L. is a medicinal plant commonly used in the management of diabetes mellitus.

Objectives

We investigated the blood glucose lowering effect of the methanolic fruit extract of the Ugandan variety of M. charantia L. in alloxan-induced diabetic albino rats.

Methods

500g of M. charantia powder were macerated in methanol and the extract administered to two groups of alloxan-induced diabetic rats. The first group received 125mg/kg, the second 375mg/kg and a third group 7mg/kg of metformin. A fourth group received 1ml normal saline. Fasting blood glucose (FBG) levels were measured at 0.5,1,2,3,5,8 and 12 hours and compared using one-way ANOVA.

Results

There was an initial rise in FBG for 1 hour after administration of extracts followed by steep reductions. Significant reduction in FBG occurred at 2 hours for 125mg/kg of extract (−3.2%, 313±25.9 to 303±25.0mg/dL, p = 0.049), 375mg/kg of extract (−3.9%, 356±19.7 to 342±20.3mg/dL, p = 0.001), and metformin (−2.6%, 344±21.7 to 335±21.1mg/dL, p = 0.003) when compared to normal saline. The maximum percentage reduction in FBG by both extracts occurred between 3 and 12 hours post dose.

Conclusions

The methanolic fruit extract of M. charantia exhibits dose dependent hypoglycaemic activity in vivo.     

Evaluation of the Chemical Composition of Dacryodes Edulis and Raphia Hookeri Mann and Wendl Exudates used in Herbal Medicine in South Eastern Nigeria

The phytochemical contents and medicinal values of Dacroydes edulis and Raphia hookeri exudates were investigated. Phytochemical screening of the plant showed that they contain the presence of bioactive compounds comprising saponins (2.08–3.98mg 100g⁻¹), alkaloids (0.28–0.49 mg 100g⁻¹), tannins (0.47–0.72 mg 100g⁻¹), flavonoids (0.26–0.39 mg 100g⁻¹), and phenolic compounds (0.01–0.05 mg 100g⁻¹). The carbohydrates, lipids and protein content were 77.42–78.90%, 2.02–4.185% and 16.63–18.38% respectively. The exudates are a good source of water soluble vitamins; ascorbic acid (7.04–26.40 mg 100g⁻¹), niacin (3.12–4.00 mg 100g⁻¹), riboflavin (0.14–0.54 mg 100g⁻¹) and thiamine (0.15–0.22 mg 100g⁻¹),). Both plants exudates are good sources of minerals such as Ca, Mg, P, Fe, Zn, Cu and Mn while Cr and Co were trace. These results indicate that exudates can be potential sources of feedstock for the pharmaceutical industry.     

Effects of Tephrosia Purpurea Aqueous Seed Extract on Blood Glucose and Antioxidant Enzyme Activities in Streptozotocin Induced Diabetic Rats

The aim of the present study was to evaluate the effects of aqueous seed extract of Tephrosia purpurea (TpASet) on blood glucose and antioxidant status in streptozotocin induced diabetic rats. Hyperglycemia associated with an altered hexokinase and glucose-6-phosphatase activities, elevated lipid peroxidation, disturbed enzymatic [Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] and non enzymatic [Glutathione, vitamin C and vitamin E] antioxidant status were observed in streptozotocin induced diabetic rats. Oral administration of “TpASet” at a dose of 600mg/kg body weight showed significant improvement in above mentioned parameters. Our results clearly indicate that “TpASet” has potent antihyperglycemic and antioxidant effects in streptozotocin-induced diabetic rats and therefore further studies are warranted to isolate and characterize the bioactive principles from “TpASet”.     

Antihyperlipidemic Effect of Peucedanum Pastinacifolium Extract in Streptozotocin-Induced Diabetic Rats

INTRODUCTION:

Dyslipidemia is one of the most common complications of diabetes mellitus, significantly contributing to cardiovascular morbidity and mortality in diabetic patients. Peucedanum pastinacifolium Boiss. & Hausskn. is commonly used as an antihyperlipidemic vegetable in Iranian folk medicine.

MATERIAL AND METHODS:

In this study, we examined a hydroalcoholic extract of the aerial parts of Peucedanum pastinacifolium to determine its lipid-lowering activity in normal and streptozotocin (STZ)-induced diabetic rats. Experimental diabetes mellitus was induced by a single intraperitoneal administration of streptozotocin. Normal and streptozotocin-induced diabetic rats were separated into four groups. The groups were fed with 0, 125, 250 or 500 mg/kg body weight of Peucedanum Pastinacifolium hydroalcoholic Extract (PPE) in aqueous solution for 30 days.

RESULTS:

The results show that there were significant (P < 0.05) increases in total serum cholesterol, triglyceride and low-density lipoprotein cholesterol (LDL-C) and a decrease in high-density lipoprotein cholesterol (HDL-C) in streptozotocin-induced diabetic rats. Treatment of diabetic rats with PPE over a period of a month returned these levels close to control levels.

CONCLUSION:

These results suggest that PPE has hypolipidemic effects in streptozotocin-induced diabetic rats.     

The Effects of Crude Aqueous and Alcohol Extracts of Aloe Vera on Growth and Abdominal Viscera of Suckling Rats

The gastrointestinal tract of neonates is sensitive to dietary manipulations. When nursing mothers use Aloe vera, their babies are at risk of indirect exposure to Aloe vera via breast feeding or directly as health supplements. The effects of orally administered extracts of Aloe vera in unweaned rats were investigated. Six day old Sprague-Dawley rats were gavaged with aqueous or alcohol extracts of Aloe vera (low dose 50mg. kg⁻¹ or high dose 500mg. kg⁻¹) daily for eight days. All data were expressed as mean ± SD and analyzed by one way ANOVA. Pups receiving high doses of either extract had a significantly higher body mass gain than the group receiving lower dose (p < 0.05). Tibial length was significantly increased in the high dose aqueous extract group (15–26 %). The differences in growth could not be attributed to circulating insulin-like growth factor-1 as the levels were not significantly different. The caecum was significantly enlarged in the rats that received the high doses of both extracts. Although, there was no significant difference in the non-fasting plasma concentration of glucose and triglycerides, the hepatic lipid and glycogen content were significantly higher (p < 0.001) for the high dose aqueous extract group. The plasma alanine transaminase was not affected by the treatments, however the high doses of the extracts significantly increased plasma alkaline phosphatase activity. Short term administration of Aloe vera extracts resulted in growth promotion, enhanced hepatic storage of metabolic substrates, increased ALP possibly in relation to bone growth and caused hypertrophy of the caecum of neonatal rats. These effects need to be explored further to enhance animal production and health.     

Effect of C-peptide administration on whole body glucose utilization in STZ-induced diabetic rats

Recent studies suggest that C-peptide stimulates glucose transport in isolated skeletal muscle. In order to determine the effect of C-peptide on whole body glucose utilization, streptozotocin (60 mg kg^-1) (STZ)-induced diabetic and normal rats were studied using the euglycaemic clamp procedure and continuous infusion of somatostatin (1.0 μg kg^-1 min^-1) in pentobarbital-anaesthetized rats. Plasma insulin levels during the 6.0- and 30.0-mU kg^-1 min^-1 insulin infusions rose to 70–90 μU mL^-1 and 500–700 μU mL^-1, respectively. Blood glucose concentrations were clamped at 7.5–7.9 mmol L^-1 in the diabetic rats and at basal levels or 7.7 mmol L^-1 in the non-diabetic (normal) rats. Biosynthetic human C-peptide (0.5 nmol kg^-1 min^-1) was infused in 12 diabetic and 11 normal rats, resulting in concentrations of 26–41 nmol L^-1. The metabolic clearance rate of glucose (MCR) for the diabetic rats receiving C-peptide (12.0±1.0 mL kg^-1 min^-1) was significantly (P<0.01) higher than that in the diabetic rats given saline (6.3±0.7 mL kg^-1 min^-1) or a randomly scrambled C-peptide (7.8±1.3 mL kg^-1 min^-1) at low-dose insulin infusion but not at the high-dose insulin infusion. In normal rats C-peptide did not significantly increase the MCR for glucose. These results thus demonstrate that C-peptide has the capacity to increase glucose utilization in STZ-induced diabetic rats.     

Methanol Fractionations of Catha Edulis Frosk (Celastraceae) Contracted Lewis Rat Aorta In Vitro: A Comparison Between Crimson and Green Leaves

The study investigated the effect of methanol extract and its fractionations obtained from Yemeni khat on the smooth muscle isometric tension in Lewis rat aortal ring preparations and compared the effects of the crimson and green leaves. Khat leaves were sorted into green (khat Light; KL) and crimson (khat Dark; KD) leaves, extracted with methanol, followed with solvent-solvent extraction (benzene, chloroform and ethylacetate). The contractile activity of the fractions was tested using aortal ring preparations. The control (phenylepherine contraction) methanol extracts contracted aortas at concentrations 250, 125 and 67.5 µg /1 ml buffer by 80.2%, 57.3%, 26.4% and 81.5%, 65.6%, 24.6% for KL and KD, respectively. Fractions of benzene (BF) and ethylacetate (EaF) contracted the aorta with 2µgm, whereas, chloroform (ChF) with 1 µgm / 1 ml buffer was less potent. The shape of contraction curve produced by EaF differed from that of ChF and BF of both (KL and KD). The EaF induced-contraction peaked after 3.3 ± 0.94 mins, whereas those of BF and CHF peaked after 18.0 ± 2.2, 19.7 ± 0.94 mins, respectively. Pre-incubation with nifedipine (10⁻⁶ M) insignificantly reduced the contraction induced by all fractionations, but prazosin (10⁻⁶ M) reduced the contraction by 81.9%, 63.1%, 71.8% with p= 0.23, 0.09, 0.15 for BF, ChF and EaF of KL, respectively. It significantly reduced contraction of ChF, 64.1%; p= 0.02, and of EaF, 73.5%; p= 0.04 of KD, while the reduction in contraction of BF was 63.1%; p= 0.06. In conclusion, fractions of green and crimson Yemeni khat leaves contracted aortas of Lewis rats. Both leaves behave almost similarly. Contraction induced by chloroform fraction produced alpha-sympathetic activity.     

Chlorophytum borivilianum Root Extract Maintains near Normal Blood Glucose,Insulin and Lipid Profile Levels and Prevents Oxidative Stress in the Pancreas of Streptozotocin-Induced Adult Male Diabetic Rats

The effect of C. borivilianum root on blood glucose, glycated hemoglobin (HbAIc), insulin and lipid profile levels in diabetes mellitus are not fully understood. This study therefore investigated the effect of C. borivilianum root on the above parameters and oxidative stress of the pancreas in diabetes. Methods: C. borivilianum root aqueous extract (250 and 500 mg/kg/day) was administered to streptozotocin (STZ)-induced male diabetic rats for 28 days. Body weight, blood glucose, HbA1c, insulin, lipid profile levels and glucose homeostasis indices were determined. Histopathological changes and oxidative stress parameters i.e. lipid peroxidation (LPO) and antioxidant enzymes activity levels of the pancreas were investigated. Results: C. borivilianum root extract treatment to diabetic rats maintained near normal body weight, blood glucose, HbA1c, lipid profile and insulin levels with higher HOMA-β cell functioning index, number of Islets/pancreas, number of β-cells/Islets however with lower HOMA-insulin resistance (IR) index as compared to non-treated diabetic rats. Negative correlations between serum insulin and blood glucose, HbA1c, triglyceride (TG) and total cholesterol (TC) levels were observed. C. borivilianum root extract administration prevented the increase in lipid peroxidation and the decrease in activity levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) with mild histopathological changes in the pancreas of diabetic rats. Conclusions: C. borivilianum root maintains near normal levels of these metabolites and prevented oxidative stress-induced damage to the pancreas in diabetes.     

Antihyperglycemic and Antinociceptive Activity Evaluation of ‘Khoyer’ Prepared from Boiling the Wood of Acacia Catechu in Water

‘Khoyer’ is prepared by boiling the wood of Acacia catechu in water and then evaporating the resultant brew. The resultant hard material is powdered and chewed with betel leaves and lime with or without tobacco by a large number of the people of Bangladesh as an addictive psycho-stimulating and euphoria-inducing formulation. There are folk medicinal claims that khoyer helps in the relief of pain and is also useful to diabetic patients to maintain normal sugar levels. Thus far no scientific studies have evaluated the antihyperglycemic and antinociceptive effects of khoyer. The present study was carried out to evaluate the possible glucose tolerance efficacy of methanolic extracts of khoyer using glucose-induced hyperglycemic mice, and antinociceptive effects with acetic acid-induced gastric pain models in mice. In antihyperglycemic activity tests, the extract at different doses was administered one hour prior to glucose administration and blood glucose level was measured after two hours of glucose administration (p.o.) using glucose oxidase method. The statistical data indicated the significant oral hypoglycemic activity on glucose-loaded mice at all doses of the extracts tested. Maximum anti-hyperglycemic activity was shown at 400 mg extract per kg body weight, which was less than that of a standard drug, glibenclamide (10 mg/kg body weight). In antinociceptive activity tests, the extract also demonstrated a dose-dependent significant reduction in the number of writhing induced in mice through intraperitoneal administration of acetic acid. Maximum antinociceptive activity was observed at a dose of 400 mg extract per kg body weight, which was greater than that of a standard antinociceptive drug, aspirin, when administered at a dose of 400 mg per kg body weight. The results validate the folk medicinal use of the plant for reduction of blood sugar in diabetic patients, as well as the folk medicinal use for alleviation of pain.     

Antidiabetic effects of Corni Fructus extract in streptozotocin-induced diabetic rats

Purpose

Diabetes is the leading cause of end-stage renal failure. The present study was undertaken to characterize the effects of Corni Fructus on diabetic nephropathy in streptozotocin-induced diabetic rats and their mechanisms.

Materials and Methods

Streptozotocin-diabetic rats were orally administrated with Corni Fructus at a dose of 100, 200 or 400 mg/kg body mass for 40 days.

Results

Corni Fructus-treated diabetic rats showed significant decreases of blood glucose, urinary protein levels and water consumption. Corni Fructus also reduced serum total cholesterol, total triglyceride and low-density lipoprotein cholesterol levels, and showed a tendency of enhancing high-density lipoprotein cholesterol level. Levels of serum albumin and creatinine in diabetic rats were also significantly reduced by Corni Fructus administration at a dose of 200 and 400 mg/kg body mass compared with non-treated diabetic rats. Corni Fructus increased catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidose (GSH-px) activities in the kidneys of diabetic rats. Furthermore, Corni Fructus treatment enhanced renal peroxisome proliferator-activated receptor-γ (PPARγ) expression in diabetic rats.

Conclusion

These results demonstrated that Corni Fructus may have the potential to protect the animals from diabetic nephropathy by amelioration of oxidative stress and stimulation of PPARγ expression.     

Spasmogenic effect of the Aqueous Extract of Tamarindus Indica L. (Caesalpiniaceae) on the Contractile Activity of Guinea-Pig Taenia Coli

The effect of aqueous extract of Tamarindus indica (AETI) was studied on the guinea pig taenia coli, due to its use for treatment of constipation in traditional medicines. AETI, at concentrations ranging from 10⁻⁸ mg/ml to 10⁻² mg/ml, increased the spontaneous contractile activity of guinea pig taenia coli in a dose-dependent manner (EC50= 4×10⁻⁶ mg/ml). This activity was unaffected by atropine. In high K⁺, Ca²⁺-free solution containing EDTA, AETI as well as acetylcholine, used as a control, induced tonic contraction. These results suggest that the plant extract exert a spasmogenic effect that would not involve cholinergic mechanism of action. However, these active principles could mobilize both extra cellular calcium and intracellular calcium from internal stores.