High-dose Extract Research Articles

Effects of the High Doses ofUrginea maritima(L.) Baker Extract on Chromosomes

The effects of high doses of extracts of Urginea maritima bulbs which can be used as bio-pesticides were investigated with the Allium test method. The bulbs of Allium cepa were rooted in solutions including 8%, 10%, 12%, 14%, 16% and 100% (v/v) U. maritima extracts for 48, 72 and 144 hours. Moreover, the bulbs were rooted in a solution including 2% of a chemical pesticide (Vydate ® ) and in tap water (as control). A. cepa root tip meristem cells were prepared according to Feulgen squash procedure and the chromosomal aberrations and cell anomalies were determined. The data were evaluated with statistical analyses. Chromosome aberrations oc- curring in all solutions including U. maritima extract and vydate solution were found to be signifi cantly related to the increasing dose and period of the treatment. Moreover, a statistically signifi cant decrease was observed in the mitotic index (MI) when compared to the control. It was found that even the high doses of U. maritima extract are less genotoxic and cytotoxic than vydate.

Acute toxicity study of the standardized methanolic extract of Mitragyna speciosa Korth in Rodent

Ethnopharmacological relevance: Mitragyna speciosa Korth (ketum) is widely used in Malaysia as a medicinal agent for treating diarrhea, worm infestations and also acts as an analgesic and antipyretic. Aim The aim of the study is to determine the acute toxicity of Mitragyna speciosa Korth standardized methanol extract in vivo in 4-weeks-old Sprague–Dawley rats. Methodology Rats were orally administrated single dose of 100, 500 and 1000 mg/kg Mitragyna speciosa Korth standardized methanol extract and the control group received 430 mg/kg of morphine orally. There were 10 rats in each group. All animals were sacrificed after 14 days of treatment. Eight parameters were tested: cage side observation, body weight measurement, food and water consumption, blood pressure, absolute and relative organ weight, hematology, biochemical analysis and histopathology, to look for evidence of toxicity. Result No mortality was noted after 14 days of treatment. In general, behavior, food and water consumption, hematological studies and organ weights showed no significant changes. The standardized methanol extraction of Mitragyna speciosa Korth increased rat blood pressure (systolic: 147.4 ± 1.01, 131.64 ± 4.94 and 137.8 ± 4.46) after an hour of 100, 500 and 1000 mg/kg doses, respectively. Biochemical studies showed significant elevation of ALT, AST, albumin, triglycerides, cholesterol and albumin ( p > 0.05), at all levels of doses. But, nephrotoxicity evidenced by elevated creatinine was seen only at a dose of 1000 mg/kg. Histological examination showed congestion of sinusoids, hemorrhage hepatocytes, fatty change, centrilobular necrosis and increased number of Kuppfer cells in the liver of all Mitragyna speciosa Korth standardized methanol extract treated groups. Conclusion Oral administration of standardized methanolic extraction of Mitragyna speciosa Korth resulted in increasing rat blood pressure after an hour of drug administration. The highest dose of extract also induced acute severe hepatotoxicity and mild nephrotoxicity. However, Mitragyna speciosa Korth shows no effects on body weight, food and water consumption, absolute and relative organ weight and also hematology parameters.

Anticonvulsant potential of Anisomeles malabarica leaves against experimentally induced convulsions in rats

Anisomeles malabarica (AM) R.Br. (Lamiaceae) is an aromatic perennial herb, the leaves of which are traditionally used to treat convulsions in southern India. The present study has been designed to investigate the anticonvulsant potential of chloroform, ethyl acetate and methanol extracts of leaves of AM against pentylenetetrazole (PTZ) and maximal electroshock (MES) induced convulsions. All the three extracts were administered (i.e. 100, 200, 400 mg/kg, p.o.) for 7 days and at the end of the treatment convulsions were induced experimentally. Diazepam and phenytoin (1 mg/kg, i.p. and 25 mg/kg, i.p., respectively) were used as reference anticonvulsant drugs against experimentally induced convulsions. High doses (400 mg/kg, p.o.) of chloroform and ethyl acetate extracts both significantly decreased the extent of MES- and PTZ-induced convulsions. On the other hand, ethyl acetate extract at lowest and medium selected doses (i.e. 100 mg/kg, p.o. and 200 mg/kg, p.o., respectively, for 7 days) had also significantly attenuated PTZ-induced convulsions. However, methanol extract at any of the doses used (i.e. 100, 200 and 400 mg/kg, p.o.) did not show any significant effect on PTZ- and MES-induced convulsions. None of the extracts at doses used in the present study have altered locomotor activity and motor coordination. Hence, it may be concluded that chloroform and ethyl acetate extracts of AMleaves are effective against PTZ- and MES induced-convulsions in rats. Key words: Anisomeles malabarica leaves, chloroform extract and ethyl acetate extract, convulsions, maximal electroshock, pentylenetetrazole

Erythrina variegata extract exerts osteoprotective effects by suppression of the process of bone resorption

Our previous study showed that Erythrina variegata L. (EV) inhibited bone loss and improved bone properties in ovariectomised rats. The purpose of the present study is to investigate the potential mechanism involved in mediating the osteoprotective actions of EV. Female Sprague-Dawley rats were fed a phyto-oestrogen-free diet and subjected to either ovariectomy or a sham operation. Ovariectomised rats were treated with genistein (40 mg/kg) as well as low (200 mg/kg), medium (500 mg/kg) or high (1000 mg/kg) doses of EV extract. Bone properties and mRNA expressions were evaluated by micro-computed tomography and quantitative RT-PCR, respectively. Osteoclast differentiation in RAW 264.7 cells was studied by tartrate-resistant acid phosphatase (TRAP) staining. High doses of EV could decrease urinary Ca and P excretion, maintain serum Ca and P level, and exert beneficial effects on the micro-structure and morphology of trabecular bone and cortical bone in ovariectomised rats. EV suppressed the up-regulation of cathepsin K mRNA and the down-regulation of osteoprotegrin mRNA in the tibia of ovariectomised rats. TRAP-positive cell numbers were significantly decreased in receptor activator of nuclear factor-κB ligand (RANKL)-induced RAW 264.7 cells when co-cultured with EV extracts. The present study indicated that the protective effects of EV on bone properties in ovariectomised rats are likely to be mediated by its inhibitory actions on the process of bone resorption via the suppression of osteoclast differentiation and maturation.

Reindeer bone extract can heal the critical-size rat femur defect

Bone extract from reindeer induces new ectopic bone formation (BF) in muscle pouches, but its feasibility in experimental bone lesions has not been evaluated. We investigated the effects of implants, containing 2, 5, 15, 20 or 50 mg of reindeer bone extract in a collagen carrier, on the healing of 8-mm femur defects in 78 rats. We used 30 µg of recombinant human bone morphogenetic protein-2 (rhBMP-2) in a collagen carrier, collagen and untreated defects as controls. Bone healing was evaluated with radiographs, peripheral quantitative computed tomography (pQCT), biomechanics and histology. In comparison with empty defects, the groups receiving bone extracts showed more BF at three weeks and had better bone union (BU), larger mean cross-sectional bone area at the defect site in groups receiving higher doses of extract, showed greater torsional stiffness of the bones and higher maximum breaking load of bones at six weeks. In comparison to all other groups, in the rhBMP-2 group, BF and BU were best at the three- and six-week follow-up, bone area was largest and mechanical test results were best. Although rhBMP-2 is superior for new bone regeneration, native reindeer bone extract is also effective in the six-week follow-up period.

Study of the mechanisms by which Sambucus williamsii HANCE extract exert protective effects against ovariectomy-induced osteoporosis in vivo

The purpose of this study is to investigate the dose-dependent effects of SWH on bone properties and the mechanism involved in mediating the osteoprotective actions of SWH. The results indicated that SWH could improve bone properties by inhibiting the process of bone resorption and stimulating the process of bone formation. Our previous study showed that Sambucus williamsii HANCE (SWH) improved trabecular bone mass and cortical bone strength in ovariectomized (OVX) rats. The purpose of this study is to investigate the dose-dependent effects of SWH on bone properties and the mechanism involved in mediating the osteoprotective actions of SWH. Three-month-old C57BL/6J mice were fed a phytoestrogen-free diet and subjected to either ovariectomy or sham operation. OVX mice were treated with genistein (50 mg/kg), or a low (200 mg/kg), medium (500 mg/kg), or high (1,000 mg/kg) dose of SWH extract. SWH could dose-dependently decrease urinary Ca excretion and increase serum Ca level in OVX mice. It could increase tibial bone mineral density and exert beneficial effects on the microarchitecture of trabecular bone in the OVX mice. SWH suppressed the ovariectomy-induced expression of Cbfa1 mRNA and cathepsin K mRNA and enhanced the ratio of OPG/RANKL mRNA expression in the tibia. In vitro study showed that SWH dramatically reduced the number of TRAP-positive cells in RANKL-induced RAW 264.7 cells. The present study indicated that SWH could improve bone properties by inhibiting the process of bone resorption and stimulating the process of bone formation.

Beans and Diabetes:Phaseolus vulgarisPreparations as Antihyperglycemic Agents

Bean pods (Phaseolus vulgaris) are among the most widely used traditional remedies against diabetes mellitus. Historical knowledge is summarized and compared to recent study results. Reports dating from the first half of the 20(th) century as well as recent publications show contradictory results. It seems that Phaseolus preparations should not be considered the first choice in phytopharmaceutical treatment of diabetes or lead structure research. To be effective, fairly high doses of aqueous extracts need to be given. Because of their fiber content and an alpha-amylase inhibitory effect, beans might be more useful as food components in preventing or ameliorating type 2 diabetes.

Evaluation of Myrtus communis Linn. berries (common myrtle) in experimental ulcer models in rats

The present study was conducted to investigate the protective effect of the dried berries of Myrtus communis L. in gastric ulcer against ethanol, indomethacin and pyloric ligation induced models in Wistar rats. Two doses of aqueous extracts of M. communis (AE( 1) and AE(2)) at the dose 105 and 175 mg/kg, respectively, and methanolic extracts (ME(1) and ME(2)) at the dose of 93 and 154 mg/kg, respectively, were administered orally to animals prior to the exposure of ulcerogens. The parameters taken to assess anti-ulcer activity were ulcer index, gastric juice volume, gastric pH, total acidity, gastric wall mucus and histopathological studies. Oral administration of AE(1) and AE(2) significantly reduced the ulcer index in all models of ulcers. Low dose of aqueous extract and high dose of methanolic extract of M. communis exhibited more significant effect in comparison to omeprazole (standard drug) in ethanol-induced ulcer model. Both the doses of aqueous and methanolic extracts also reduced the gastric juice volume, total acidity and increased the gastric pH and gastric wall mucus content in all the models of ulcers used in the present study. Histopathological examinations of gastric tissues of rats treated with the aqueous and methanolic extracts in indomethacin-induced ulcer exhibited significant ulcer-protective effect at both the dose levels.

Comparative Effect of Green Tea, Chokeberry and Honeysuckle Polyphenols on Nutrients and Mineral Absorption and Digestibility in Rats

Background/Aims: Natural polyphenols are chemically and biologically active. This study aimed at examining the physiological effects of high doses of polyphenol extracts from green tea and new polyphenol-rich sources (chokeberry and honeysuckle fruits) on nutrient absorption. Methods: 32 male Wistar rats were divided into four groups and fed a diet supplemented with one of the three polyphenolic extracts (at 0.4%) or a control diet for 4 weeks. A perfusion technique was used to study the effects at intestinal level. Pure polyphenols from the three sources were introduced into perfusion fluid at a concentration of 0.4% and allowed to cross the intestinal tract in 1.5 h. Results: In the perfusion experiment, addition of the extracts caused a strong and statistically significant reduction in absorption of the selected nutrients (water, glucose, cholesterol, amino acids and minerals) compared to control animals. In the nutritional experiment, we recorded a slight decrease in diet utilization and growth in rats on polyphenolic diets relative to control group. In the same experiment, we observed a reduction of Zn and Cu absorption, but this was not accompanied by diminished concentrations in the bone femur. Conclusions: The presence of the polyphenolic extracts in the perfusion liquids significantly reduced absorption from the small intestine, but the nutritional experiment did not confirm deleterious consequences of the consumption of high extract doses.

Anticonvulsant potential of Anisomeles malabarica leaves against experimentally induced convulsions in rats

Anisomeles malabarica (AM) R.Br. (Lamiaceae) is an aromatic perennial herb, the leaves of which are traditionally used to treat convulsions in southern India. The present study has been designed to investigate the anticonvulsant potential of chloroform, ethyl acetate and methanol extracts of leaves of AM against pentylenetetrazole (PTZ) and maximal electroshock (MES) induced convulsions. All the three extracts were administered (i.e. 100, 200, 400 mg/kg, p.o.) for 7 days and at the end of the treatment convulsions were induced experimentally. Diazepam and phenytoin (1 mg/kg, i.p. and 25 mg/kg, i.p., respectively) were used as reference anticonvulsant drugs against experimentally induced convulsions. High doses (400 mg/kg, p.o.) of chloroform and ethyl acetate extracts both significantly decreased the extent of MES- and PTZ-induced convulsions. On the other hand, ethyl acetate extract at lowest and medium selected doses (i.e. 100 mg/kg, p.o. and 200 mg/kg, p.o., respectively, for 7 days) had also significantly attenuated PTZ-induced convulsions. However, methanol extract at any of the doses used (i.e. 100, 200 and 400 mg/kg, p.o.) did not show any significant effect on PTZ- and MES-induced convulsions. None of the extracts at doses used in the present study have altered locomotor activity and motor coordination. Hence, it may be concluded that chloroform and ethyl acetate extracts of AMleaves are effective against PTZ- and MES induced-convulsions in rats. Key words: Anisomeles malabarica leaves, chloroform extract and ethyl acetate extract, convulsions, maximal electroshock, pentylenetetrazole

Comparative study of teratogenic potentials of crude ethanolic root bark and leaf extract of Rauwolfia vomitoria (apocynaceae) on the fetal heart.

Background:Rauwolfia vomitoria, a tropical shrub, is a medicinal plant used in the treatment of a variety of ailments. It is popular to the locals because of its anti-hypertensive and sedative properties.Aim:This is to find the probable teratogenic effects of ethanolic leaf and root bark extracts of Rauwolfia vomitoria on the morphological and histological features of the fetal heart.Material and Methods:Twenty five female rats weighing between 170-200g were used for this study. The rats were divided into five groups labeled A, B, C, D and E, with each group consisting of five rats. Pregnancy was induced by caging the female rats with sexually matured males. The presence of vaginal plug and tail structures in the vaginal smear the following morning confirmed coition, and it was regarded as day 0 of pregnancy. Group A was given sham treatment of distilled water. Group B and C received respectively 150mg/kg and 250mg/kg body weight doses of ethanolic leaf extract of Rauwolfia vomitoria, and those in groups D and E received respectively 150mg/kg and 250mg/kg body weight doses of ethanolic root bark extract of Rauwolfia vomitoria. These treatments were on days 7-11 of gestation (5 days) with the aid of an orogastric tube. On the day 20 of gestation, the rats were sacrificed and the fetuses examined for gross anomalies, preserved and latter process for histological studies.Results:There were no mortality in this study, and no obvious gross malformations in the fetuses. Histological observations of the fetal heart showed marked distortion of the cardiac muscle nuclei and myocardial fibers in the treated groups particularly those whose mothers received 250mg/kg of the extracts. These effects were more pronounced in the groups whose mothers received the root extract when compared with the control and the groups whose mothers received the leaf extract.Conclusion:This result suggests that high doses of ethanolic leaf and root extracts of Rauwolfia vomitoria may be cardiotoxic to the developing rat's heart.

Fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats

Ethnopharmacological relevance The aerial parts of Coccinia cordifolia L. are used to treat female infertility in West Bengal state of India. Aim of the study The present study was undertaken to evaluate the fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats. Materials and methods The effect of aqueous extract of Coccinia cordifolia L. on hyperprolactinemia induced infertility, endometriosis induced infertility and androgen-induced infertility was studied. The effect on serum estrogen level, serum progesterone level and reproductive tract was also evaluated in normal healthy female rats. The extract was administered orally at two different doses of 500 mg/kg and 1000 mg/kg. Results In hyperprolactinemia induced infertility model, the numbers of uterine implants were almost 10 times more in the extract treated groups as compared to control. The high dose of extract also produced a significant increase in serum estrogen levels ( p < 0.01) and number of corpus luteum ( p < 0.05) in healthy female rats. The extract at both doses was effective in reducing the weight of endometrial implants by 70–80%, but failed to induce fertility in rats with endometriosis. The extract was ineffective in inducing fertility in androgen-induced infertility model. Conclusions The aqueous extract of Coccinia cordifolia L. induces fertility in hyperprolactinemia induced infertility model in female rats.

Hypocholesteremic and Antioxidant Effects of Garlic (Allium sativum L.) Extract in Rats Fed High Cholesterol Diet

The present study is designed to evaluate the effect of garlic extract on lipid profiles and oxidative stress in male albino rats fed a high cholesterol diet (HCD). A group of 24 male albino rats each weighing 125±5.0g, was divided into four groups. Group I was used as negative control and fed on standard diet and orally administered 1 ml distilled water. Group II was used as positive control and fed on high cholesterol diet and orally administered 1ml distilled water. Groups III and IV were fed on high cholesterol diet and orally administered garlic extract (0.2 and 0.4g/kg body weight/day, respectively). Garlic extract significantly increased (p < 0.05) plasma HDL-Cholesterol and decreased plasma TC, LDL-Cholesterol and TG as well as liver TC and TG as compared with positive control (group II). No significant difference was observed in plasma LDL-Cholesterol, HDL-Cholesterol as well as plasma and liver TG between the rats ingested with high or low dose of garlic extracts. However, there was a significant (p < 0.05) decrease in plasma and liver TC in rats ingested with a high dose of garlic extract (Group IV) as compared to low dose ingestion. Garlic extract significantly increased (p < 0.05) total antioxidant capacity, SOD and GSH-Px activities as compared to negative or positive control (group I and group II, respectively). No significant difference was observed in total antioxidant capacity, SOD and GSH-Px activities between the rats ingested with high or low dose of garlic extract. There was a significant decrease (p < 0.05) in plasma malondialdehyde in rats ingested with a high or low dose of garlic extract as compared to negative or positive control rats.

Anti-Inflammatory and Antinociceptive Effects of Mitragyna speciosa Korth Methanolic Extract

Objectives: To determine the anti-inflammatory and antinociceptive activities of Mitragyna speciosa Korth methanol extract in rodents. Materials and Methods: Anti-inflammatory activity was evaluated using carrageenan-induced paw edema and cotton pellet-induced granuloma tests in rats. Antinociceptive activity was measured using the writhing test and the hot plate test in mice, and the formalin test in rats. All drugs and extracts were diluted in dH₂O and administered through the intraperitoneal route. Results were analyzed using one-way ANOVA followed by Dunnett’s test for multiple comparisons among groups. Results: Results showed that intraperitoneal administration of the extract at doses of 100 and 200 mg/kg produced significant dose-dependent activity in all of the nociceptive models evaluated (p < 0.05). With the formalin test, the antinociceptive activity in mice was inhibited only at the highest dose of the extract (200 mg/kg). The study also showed that intraperitoneal administration of the methanol extract of M. speciosa (100 and 200 mg/kg) significantly and dose-dependently suppressed the development of carrageenan-induced rat paw edema (p < 0.05). In the chronic test, however, significant reduction in granulomatous tissue formation in rats was observed only at the highest dose of the methanol extract of M. speciosa (200 mg/kg, p < 0.05). Conclusion: The present study suggests the presence of potent antinociceptive and anti-inflammatory principles in the extract, supporting its folkloric use for the treatment of these conditions.

Effects of soy isoflavone extracts on the growth of estrogen-dependent human breast cancer (MCF-7) tumors implanted in ovariectomized nude mice

In this study, we explored the effects of soy isoflavone extracts on the growth of estrogen-dependent human breast cancer (MCF-7) tumors implanted in ovariectomized athymic mice. The ovariectomized athymic mice were implanted with MCF-7 cells. They were fed with low, moderate and high doses of soy isoflavone extracts, at dietary concentrations of 6.25, 12.5 and 25 g/kg, respectively. The expression of ki-67 was detected by immunohistochemistry. The pS2 expression in tumors was analyzed by real-time PCR. Estrogen level in the serum was measured by chemiluminescence enzyme immunoassay. Compared with the control group, dietary soy isoflavone extracts had a significant stimulatory effect on MCF-7 tumor growth in mice (P 0.05). In conclusion, in the tested dietary concentration range soy isoflavone extracts had a stimulatory effect on tumor growth. 6.25 and 12.5 g/kg doses of soy isoflavone extracts can increase the cell proliferation in tumors and induce estrogen-responsive pS2 expression.

Green tea extract selectively activates peroxisome proliferator-activated receptor β/δ in cultured cardiomyocytes

Hypoxia/reoxygenation is one of the causes of the increased expression of inducible NO synthase in cardiomyocytes. In a recent study we demonstrated that a single, high dose of green tea extract (GT) supplemented to the medium of cultured cardiomyocytes just before hypoxia/reoxygenation is able to prevent the increased expression of inducible NO synthase, therefore reducing NO overproduction. In the present study we investigated the mechanism by which GT reduces NO production. Since a molecular mechanism for polyphenol activity has been postulated, and PPAR activation is related to the transcription of the inducible NO synthase gene, we evaluated the activation of PPAR by GT. A moderate GT concentration, supplemented to the cardiomyocyte medium since the initial seeding, selectively activated the PPAR-beta/delta isoform. Furthermore, we observed a reduction in NO production and an increase in total antioxidant activity, indicating that GT components may act on both reactive oxygen species, via an antioxidant mechanism, and NO overproduction. PPAR-beta/delta activation could represent the key event in the reduction of NO production by GT. Although PPAR activation by GT was lower than activation by fenofibrate, it is very interesting to note that it was selective for the beta/delta isoform, at least in neonatal cardiomyocytes.

Evaluation of Direct-Oxidative DNA Damage on Human Lung Epithelial Cells Exposed to Urban Airborne Particulate Matter

Airborne particulate matter (PM) extracts were investigated for their content of organic compounds and for the direct and oxidative DNA damage induced on lung epithelial cells A549. PM10 was seasonally collected at two monitoring sites (Stations 1 and 2), characterized by different traffic loads. The cells were exposed for 30 min to extracts of PM10 diluted at 0.025%, 0.05%, and 0.1% for summer samples, and at 0.05%, 0.1%, and 0.15% for winter samples. Oxidative and direct DNA damage were evaluated by formamidopyrimidine glycosylase (fpg) comet assay analyzing tail moment (TM) values from fpg-enzyme-treated cells (TMenz) and enzyme untreated cells (TM) respectively and by comet percentage analysis. Measurements relating to Station 2 showed higher levels of polycyclic aromatic hydrocarbons (PAHs), and their methyl-(methyl-PAHs) and nitro-(nitro-PAHs) derivatives in both the seasons. Nitro-PAH concentrations were higher in summer than in winter at both the stations. We found a significant increase of comet percentages at the highest dose of extract from both stations in summer and from Station 2 in winter. The TM and TMenz values relative to the summer sampling showed an early oxidative DNA damage induction also followed by direct DNA damage more evident at Station 2, that seems to correlate with the presence of higher nitro-PAH concentrations during the warm season. At both monitoring stations, the results from winter sampling campaign showed a direct DNA damage induction at 0.1% of extract and oxidative-direct DNA damage at the highest dose (0.15%).

Repeat-dose effects of Zanthoxylum chalybeum root bark extract: A traditional medicinal plant used for various diseases in Uganda

Zanthoxylum chalybeum is a traditional medicinal plant used in the treatment of various ailments in the African region. In sickle cell disease a decoction of the root bark extract is administered for life. The safety of long term use of this plant is not documented. This study investigated the systemic effects of daily administration of low and high oral doses of the root bark extract of this plant in rodents. Three groups of six young Albino Wister rats each were used. The first and second groups received a daily dose of 100 and 4000 mg/kg of the extract respectively orally for 4 weeks. Animal weight, renal, liver function tests, heamatological indices, plasma electrolytes and tissue pathology were used to assess safety. No serious adverse event was observed with both study doses in the experimental animals. Histology revealed presence of squamous cell growth in the small and large intestines of the rats that received the dose of 4000 mg/kg. This group also showed significant elevations in plasma creatinine, sodium and potassium levels (p< 0.05). Long term administration of low doses of the root bark extract of Z. chalybeum is safe in experimental animals. High doses however may be associated with impaired renal function and intestinal neoplasms. We recommend cautious dosing in traditional use of the root bark extracts of Z. chalybeum as there is a possibility of dose-dependant toxicity. There is need for further studies to document the effectiveness of these extracts in sickle cell disease Key words: Zanthoxylum chalybeum, safety, repeat dose.

Effects of single daily khat ( Catha edulis) extract on spatial learning and memory in CBA mice

This study investigated the effects of fresh khat extract on learning and memory in CBA mice. A total of 20 male CBA mice, weighing 20–30 g, 5–6 weeks old were administered intraperitoneally with a single daily dose of khat extract for 5 days. The animals were divided into four groups, each comprising five animals. The first three groups were administered three doses (40, 120 and 360 mg/kg body weight) of khat extract, respectively. The last group served as controls and was administered with 0.5 ml normal saline intraperitoneally. The animals were then subjected to Morris water maze (MWM) task performance. Moderate and high doses (120 and 360 mg/kg body weight) of khat extract significantly impaired ( P < 0.05) while low dose (40 mg/kg body weight) of khat extract did not have a significant effect on CBA mice acquisition learning. The high dose of khat extract significantly ( P < 0.05) improved while moderate and low doses impaired accuracy for spatial memory of the platform location. This study has shown that khat extract has selective effect on spatial learning and memory, with low dose having no effect on learning but impairing memory, whereas high dose impairs learning but improves memory.

Onion and garlic extracts lessen cadmium-induced nephrotoxicity in rats

Cadmium (Cd) is a well-known nephrotoxicant inducing kidney damage via oxidative stress. Since kidney is the critical target organ of Cd toxicity, this study was designed to evaluate the protective effects of onion (Allium cepa L.) and garlic (Allium sativum L.) aqueous extracts on Cd-induced renal oxidative stress in male Wistar rats. The control group received double distilled water alone and Cd group was challenged with 3CdSO4 x 8H2O (as Cd) (1.5 mg/100 g bw/day per oral) alone. Extract-treated groups were pre-treated with varied doses (0.5 ml and 1.0 ml/100 g bw/day per oral) of onion and/or garlic extract for 1 week after which they were co-treated with Cd (1.5 mg/100 g bw/day per oral) for 3 weeks. The results showed that the levels of renal lipid peroxidation (LPO) and glutathione-S transferase (GST) were significantly (P < 0.001) increased in rats that received Cd alone relative to the control group. More so, the levels of renal glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and Na+/K+-ATPase were significantly (P < 0.001) decreased in rats that received Cd alone. Treatment of Cd-intoxicated rats with varied doses of onion and/or garlic extract significantly (P < 0.05) restored the alterations in these parameters relative to the group that received Cd alone. While treatment with high dose of onion extract exerted a significant dose-dependent restoration of these parameters, treatment with high dose of garlic elicited a pro-oxidant effect, relative to their respective low dose. Our study suggests that onion and garlic extracts may exert their protective effects via reduction in LPO and enhanced antioxidant defense. These extracts may, therefore, be useful nutritional option in alleviating Cd-induced renal damage.