Effect of rhynchophylline on central neurotransmitter levels in amphetamine-induced conditioned place preference rat brain

The effects of rhynchophylline on expression of amphetamine reward using a conditioned place preference (CPP) paradigm and central neurotransmitter levels in rat brain was investigated. Rats were injected with amphetamine (2 mg/kg, per day for 4 consecutive days) and treated with rhynchophylline (60 mg/kg, per day for the later 3 days). Control rats were administered with rhynchophylline (60 mg/kg) instead of amphetamine to evaluate whether rhynchophylline by itself produced CPP. Glutamic acid, γ-aminobutyric acid, endorphin, acetylcholine, norepinephrine, dopamine, and 5-hydroxytryptamine contents were examined by encephalofluogram technology. Rhynchophylline reversed the expression of amphetamine-induced CPP and itself did not produce a CPP. Glutamic acid, dopamine, and norepinephrine contents in amphetamine-CPP rat brain were significantly higher; while γ-aminobutyric acid, endorphin, and acetylcholine contents were significantly lower than those of control rats. Rhynchophylline reversed those central neurotransmitter levels induced by amphetamine to control levels; rhynchophylline by itself had no effect on central neurotransmitter in control rats. These findings show that rhynchophylline reverses the expression of amphetamine-induced rewarding effect which is partly mediated by regulation of central neurotransmitter levels in the rat brain.     

Evaluation of central nervous system effects of iso-6-cassine isolated from Senna spectabilis var. excelsa (Schrad) in mice

The depressant and anticonvulsant activities of iso-6-cassine (ISO) from Senna spectabilis (0.5, 1.0 and 1.5 mg/kg) injected by oral route in mice caused a significant decrease in the motor activity of animals when compared with the control group, up to 30 days after the administration and at dose of 1.5 mg/kg, it reduced the remaining time of animals on Rota-rod apparatus. Additionally, ISO at doses tested was also capable to promote an increase of latency for development of convulsions induced by pentylenetetrazole and picrotoxin. These results suggest possible depressant and anticonvulsant activities in mice that need further investigation.     

Anti-diabetic effect of American ginseng may not be linked to antioxidant activity: Comparison between American ginseng and Scutellaria baicalensis using an ob/ob mice model

Antioxidants have been considered as a useful remedy in diabetes therapeutics, and thus, herbal medicines with antioxidant properties may play major role in treating diabetes. In this report, we performed a comparative study using American ginseng and Scutellaria baicalensis to test whether the anti-diabetic effect of American ginseng is associated with its antioxidant activity. We used a simple water extraction procedure to prepare American ginseng root extract (AGE) and S. baicalensis extract (SbE), and utilized these two antioxidant herbs to evaluate their anti-diabetic effect in obese diabetic ob/ob mice. HPLC analysis was used to identify major constituents in the AGE and SbE. After 12 days of daily intraperitoneal injection, AGE at 300 mg/kg showed significant effects on fasting blood glucose levels (P < 0.01) and glucose tolerance test (P < 0.01) compared to vehicle-treated mice. Animal body weights also reduced significantly after 12-day treatment (P < 0.01). However, SbE, a very strong antioxidant extract, administered at 5–50 mg/kg (based on our previous studies without adverse events) for 12 days did not show any significant effects on blood glucose and body weight changes. No effects were shown when baicalein, an effective antioxidant constituent in SbE, was administered at 1–5 mg/kg. It appears that the anti-diabetic effect of American ginseng may not be linked to its antioxidant actions. The mechanisms of American ginseng's effects on reducing high blood glucose levels and body weight remain to be investigated in future experiments.     

Evaluation of analgesic, anti-inflammatory and hepatoprotective effects of lycorine from Sternbergia fisheriana (Herbert) Rupr

The present study reports the potential antinociceptive, anti-inflammatory and hepatoprotective activities of lycorine from Sternbergia fischeriana (Herbert) Rupr. (Amaryllidaceae). Lycorine was evaluated on mice by using acetic-acid induced writhing and tail-flick tests. Lycorine exhibited stronger inhibition than aspirin in acetic-acid induced abdominal stretching at 1.0 mg/kg dose. Lycorine also showed antinociceptive activity at 1.0 mg/kg dose in tail-flick test. The anti-inflammatory activity of lycorine was not found to be significant at dose of 0.5 mg/kg. However, at doses of 1.0 mg/kg and 1.5 mg/kg, i.p. showed a significant reduction with 53.45% and 36.42%, respectively in rat paw oedema induced by carrageenan against the reference anti-inflammatory drug indomethacin (3 mg/kg, i.p.) (95.70%). The ED₅₀ of lycorine was determined as 0.514 mg/kg. Hepatoprotective activity of lycorine on carbon tetrachloride (CCl₄) induced acute liver toxicity following biochemical parameters were also evaluated. Rats were treated with lycorine at doses of 1.0 mg/kg and 2.0 mg/kg, i.p. Results of biochemical tests were confirmed by histopathological examination. Lycorine exhibited significant hepatoprotective effect at dose of 2.0 mg/kg i.p. dose.     

Hypoglycemic effect of protopanaxadiol-type ginsenosides and compound K on Type 2 diabetes mice induced by high-fat diet combining with streptozotocin via suppression of hepatic gluconeogenesis

Compound K (CK) is a final intestinal metabolite of protopanaxadiol-type ginsenosides (PDG) from Panax ginseng. Although anti-diabetic activity of CK have been reported with genetic mouse models (db/db mice) in recent years, the therapeutic usefulness of CK and PDG in type 2 diabetes, a more prevalent form of diabetes, remains unclear. In the present investigation, we developed a mouse of non-insulin-dependent diabetes mellitus that closely simulated the metabolic abnormalities of the human disease. For this purpose, type 2 diabetes was induced in male ICR mice by combining of streptozotocin. The male ICR mice fed with HFD for 4 weeks received 100 mg/kg of STZ injected intraperitoneally. After 4 weeks, mice with fasting (12 h) blood glucose levels (FBG) above 7.8 mmol/L were divided into 3 groups (n = 12) and treated with vehicle (diabetes model, DM), 300 mg/kg/day of PDG and 30 mg/kg/day of CK for 4 weeks while continuing on the high-fat diet. Hypoglycemic effects of CK and PDG were consistently demonstrated by FBG levels, and insulin-sensitizing effects were seen during oral glucose tolerance testing (OGTT). Moreover, the mechanism of hypoglycemic effect in type 2 diabetic mice was examined. Gluconeogenic genes, Phosphoenolpyruvate carboxykinase (PEPCK) and Glucose-6-phosphatase (G6Pase), were decreased in two treatment groups with CK showing greater effects. These findings demonstrated the hypoglycemic and insulin-sensitizing capabilities of CK on type 2 diabetes induced by HFD/STZ via down-regulation of PEPCK and G6Pase expression in liver.     

Theacrine,a purine alkaloid with anti-inflammatory and analgesic activities

The anti-inflammatory and analgesic effects of theacrine (1, 3, 7, 9-tetramethyluric acid), a purine alkaloid which is abundantly present in Camellia kucha, were investigated. Xylene-induced ear edema, acetic acid-induced vascular permeability and λ-carrageenan-induced paw edema were used to investigate anti-inflammatory activity, and acetic acid-induced writhing and hot-plate tests were used to determine analgesic effect. Oral administration of theacrine (8–32 mg/kg) induced dose-related anti-inflammatory and analgesic effects. On the other hand, oral caffeine administration (8–32 mg/kg) did not show an inhibitory effect on the inhibition of inflammatory response or cause analgesia. Additionally, the result of the acute toxicity test showed that the LD₅₀ of theacrine was 810.6 mg/kg (769.5–858.0 mg/kg). The data obtained suggest theacrine possessed analgesic and anti-inflammatory activities.     

Effects of Butea superba on reproductive systems of rats

The effects of Butea superba on the reproductive system in male Wistar rats were investigated. The animals were fed daily with the powdered crude drug suspended in distilled water by a gastric tube at the dose of 2, 25, 250 and 1250 mg/kg body weight for 8 weeks. Rats fed with 1 ml of distilled water were used as a negative control. The weights of all vital organs in all treated groups were not different from the control. The percentage weight ratios of body weights of seminal vesicles and prostate glands were not different from the control, except that the testis of the group fed with 1250 mg/kg was significantly different from the control and the other treated groups. In addition, the sperm counts in this group showed about 16% more than the control group. Hematology as well as the liver and kidney function of all treated groups showed no difference from the control. B. superba, drug at 250 mg/kg which was 100 times more than the Thai FDA recommended dose for humans appeared to be safe in rats. The crude drug has demonstrated an increase tendency on testis weight and sperm counts in rat. The information from the present study can be used to explain the Thai folklore application of this plant in Thailand.     

A postmenopause-like model of ovariectomized Wistar rats to identify active principles of Erythrina lysistemon (Fabaceae)

To determine whether the two major compounds of Erythrina lysistemon are active principles accounting for Erythrina estrogenic effects, we used a postmenopause-like model of ovariectomized Wistar rats to evaluate their effects on some menopausal problems. Ovariectomized rats were orally treated either with compound 1 or compound 2 at 1 and 10 mg/kg BW for 28 days. Estradiol valerate served as the reference substance. As results, compounds 1 and 2 displayed estrogen-like effects on the uterus and the vagina, and reduced atherogenic risks by decreasing the two assessed atherogenic parameters, the total cholesterol/HDL-cholesterol ratio and the atherogenic index of plasma.     

Gingkoselect alleviates chronic corticosterone-induced spatial memory deficits in rats

The preventive effects of Gingkoselect (100 mg/kg/day, orally, 21 days) on spatial memory deficits induced by a chronic restraint stress (2 h daily, 21 days) or chronic corticosterone treatment (5 mg/kg, subcutaneously, 21 days) were investigated using the Barnes maze.     

Effect of Satureja khuzestanica essential oil on male rat fertility

This study was undertaken to study the effect of Satureja khuzestanica essential oil (SKEO) in male rat fertility. SKEO was administered orally at doses of 75, 150, and 225 mg/kg/day for 45 days through drinking water. Treated and control rats were mated with female on day 45 of treatment. SKEO significantly improved all the parameters evaluated such as potency, fecundity, fertility index, and litter size. Moreover, concentrations of FSH and testosterone were significantly increased in SKEO-treated groups. Also the weights of testes, seminal vesicles, and ventral prostate weights were increased by SKEO (225 mg/kg). Histopathological analysis showed that in male rats treated with SKEO (150, 225 mg/kg) the number of spermatogonium, spermatid cords, Leydig cells, and spermatozoids was increased. Also in these groups, the Sertoli cells were hypertrophic.     

Antidiabetic properties of aqueous barks extract of Parinari excelsa in alloxan-induced diabetic rats

The aqueous extract of the Parinari excelsa barks at doses of 100 and 300 mg/kg/day for 7 days has a significant antihyperglycemic effect on alloxan-induced diabetic rats. At the same dose the acute oral administration of aqueous extract of the P. excelsa barks (100 and 300 mg/kg) induced a significant decrease of blood glucose on glucose-loaded normoglycaemic rats. Our results seem to confirm the rational bases for its use in traditional medicine.     

Effect of Urtica dioica extract intake upon blood lipid profile in the rats

Aqueous (150 mg/kg/day) and to a lesser extent petroleum ether (20 mg/kg/day) extract of Urtica dioica given for 30 days to rats fed with normal or high-fat diet, improved the blood lipid profile. Significant decreases in total cholesterol, LDL cholesterol, LDL/HDL cholesterol ratio and plasma total apo B were observed. Assessment of GOT, GPT and LDH activities showed that no liver damage has occurred during the study period.     

Hypoglycemic activity of Nymphaea stellata leaves ethanolic extract in alloxan induced diabetic rats

The ethanolic extract of leaves of Nymphaea stellata given by oral route to diabetic rats at dose of 100 and 200 mg/kg/day for seven days reduced significantly by 31.6 and 42.6 % the plasma glucose level increased by intraperitoneal injection of 120 mg/day of alloxan. Moreover, the treatment significantly affected the plasma level of cholesterol and triglyceride.     

Antioxidant flavonoid glycosides from Evolvulus alsinoides

Oxidative damage is an established outcome of chronic stress. Thus, the present study was designed to investigate the modulatory role of ethanolic extract of Evolvulus alsinoides (EA) in terms of oxidative alterations at peripheral and central level in rats subjected to chronic unpredictable stress (CUS). CUS exposure for 7 days reduced Cu, Zn superoxide dismutase and catalase activity with increase in glutathione peroxidase activity and lipid peroxidation, while decrease in reduced glutathione level in blood plasma, frontal cortex and hippocampus regions of brain. Oral administration of EA extract at 200 mg/kg p.o. normalized these stress induced oxidative alterations with an efficacy similar to that of melatonin. Further, EA extract was taken up for detailed chemical investigation. Two new flavonol-4′-glycoside, kaempferol 4′-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (3) and kaempferol 4′-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside (5) were isolated, along with eight known compounds (1, 2, 4 and 6–10). The structures of new compounds were established by detailed spectroscopic studies, while known compounds were characterized by direct comparison of their reported NMR data. All these compounds were evaluated for their in vitro antioxidant activity. Compounds 3, 5, 9 and 10 at 100 and 200 μg/ml showed significant in vitro antioxidant activity. Therefore, EA may hold great potential in preventing clinical deterioration in stress induced oxidative load and related disorders.     

The effect of aqueous extract of gross and commercial yerba mate (Ilex paraguariensis) on intra-abdominal and epididymal fat and glucose levels in male Wistar rats

This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1 mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5 mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups.     

Ocotea quixos Lam. essential oil: In vitro and in vivo investigation on its anti-inflammatory properties

Here we investigated the anti-inflammatory properties of Ocotea quixos essential oil and of its main components, trans-cinnamaldehyde and methyl cinnamate, in in vitro and in vivo models. Ocotea essential oil and trans-cinnamaldehyde but not methyl cinnamate significantly reduced LPS-induced NO release from J774 macrophages at non-toxic concentrations, inhibited LPS-induced COX-2 expression and increased forskolin-induced cAMP production. The essential oil (30–100 mg/kg os) and trans-cinnamaldehyde (10 mg/kg os) in carrageenan-induced rat paw edema showed anti-inflammatory effect without damaging gastric mucosa. In conclusion we provide the first evidence of a significant anti-inflammatory gastro-sparing activity of O.quixos essential oil.     

Comparative pharmacokinetics of baicalin in plasma after oral administration of Huang-Lian-Jie-Du-Tang or pure baicalin in MCAO and sham-operated rats

A sensitive and specific HPLC method was developed to analyze baicalin in rat plasma. The author had compared the pharmacokinetics of baicalin after oral administration of HLJDT decoction or pure baicalin in MCAO and sham-operated rats. All the rats were divided into two groups, MCAO and sham-operated rats. Each group contained two subgroups: HLJDT decoction and pure baicalin subgroup. The HLJDT subgroup oral administration of HLJDT decoction extract 10.00 g/kg according to body weight (containing baicalin 400.00 mg/kg according to body weight), the pure baicalin subgroup received a gavages at a dosage of baicalin 400.00 mg/kg according to body weight too. The pharmacokinetics parameters were analyzed by kinetica. The results indicated that the pharmacokinetics of baicalin in rat plasma was non-linear and there were significant differences between different groups. No matter in MCAO or sham-operated rats, pure baicalin had shown better absorption than HLJDT decoction. Whether administration of pure baicalin or HLJDT decoction, the MCAO rats show better, quicker absorption of baicalin than sham-operated rats. It was good for baicalin to exert pharmacological effects on healed cerebrovascular diseases. The method had been applied successfully to pharmacokinetics of baicalin in rat plasma after oral administration of pure baicalin or HLJDT decoction.     

沙棘叶子提取物对白化病白鼠由铬诱导氧化胁迫的抗氧化活性评估

本研究报道沙棘(胡颓子科)对雄性白化病白鼠由铬诱导氧化胁迫的抗氧化活性。氧化胁迫通过对小白鼠进行强制性喂养30 d,以浓度为30 m g/kg的铬相对体重比例的重铬酸钾盐实现。铬促使体重下降,而却明显增加了器官与体重比例。铬处理明显减少了谷胱甘肽的降低,增加了丙二醛和肌氨酸磷酸激酶的水平;而且它还加强了血清中谷氨酸草酰乙酸转移酶和谷氨酸丙酮酸转移酶的浓度。用不同剂量的沙棘叶子提取物(乙醇提取)对保护铬元素诱导的氧化胁迫进行了评估,结果表明叶子提取物在浓度为100到250 m g/kg铬与体重比的情况下可以明显保护动物避免由铬所诱导的氧化伤害。     

Antinociceptive and antiplasmodial activities of cassane furanoditerpenes from Caesalpinia volkensii H. root bark

The chloroform and ethyl acetate extract (100 mg/kg) of Caesalpinia volkensii H. exhibited significant (P ≤ 0.05) antinociceptive activities using hot plate and writhing tests in mice while the later showed antiplasmodial activity (IC₅₀ 0.23 ± 0.07 and 4.39 ± 2.49 μg/ml) against chloroquine sensitive (D6) and chloroquine-resistant (W2), respectively. Two new furanoditerpenes [rel. 1β,5α-dihydroxyvoucapane (1) and rel. 1β,6β-dihydroxyvoucapane; 19β-methyl ester (2)] together with seven known compounds [voucapane (3), voucapan-5-ol (4), deoxycaesaldekarin C (5), caesaldekarin C (6), 5-hydroxyvinhaticoic acid (7), triacontanyl-(E)-ferulate (8), triacontanyl-(E)-caffaete (9) and 30′-hydroxytriacontanyl-(E)-ferulate (10)] were isolated from the two extracts. The administration of 3, 4, 5 and 6 (100 mg/kg i.p) caused a significant (P ≤ 0.05) reduction in the number of writhing episodes induced by acetic acid and (P ≤ 0.01) increased pain latency threshold in hot-plate test compared to control. However, the pure compounds indicated relatively (P ≤ 0.05) low antiplasmodial activity. The phytochemical constituents from the root bark of C. volkensii had better analgesic properties than antimalarial properties, justifying the use of the plant root bark as a remedy for pain.