Chronic intrathecal infusion of gabapentin prevents nerve ligation-induced pain in rats.

BACKGROUND: Gabapentin is an anticonvulsant and adjuvant analgesic. It is effective in several pain studies. Neuropathic pain is the most difficult type of pain to treat. In this study, we examined if intrathecal gabapentin could prevent nerve injury-induced pain. METHODS: Under isoflurane anaesthesia, male Sprague-Dawley rats (200-250 g) underwent right L5/6 spinal nerve ligation and placement of an intrathecal catheter connected to an infusion pump. After surgery, intrathecal saline or gabapentin (20 µg h(-1)) was given for 7 days (n=8 per group). The right hind paw withdrawal threshold to von Frey filament stimuli and withdrawal latency to radiant heat were determined before (baseline) and once daily for 7 days after surgery. Haematoxylin and eosin and toluidine blue staining were used to evaluate the neurotoxicity of gabapentin (40 µg h(-1)). RESULTS: Seven days after nerve ligation, the affected paw withdrawal threshold and latency of saline-treated rats decreased from the baseline 11.7 (11.7-22.2) [median (inter-quartile range)] to 1.6 (0.9-3.2) g and 10.8 (10.5-11.2) to 4.3 (4.2-7) s, respectively. Rats receiving gabapentin (20 µg h(-1)) had higher withdrawal threshold [9.9 (9.9-19.3) g] and latency [11.5 (9.7-11.9) s] on day 7 after ligation. No obvious histopathological change or growth retardation was detected after intrathecal gabapentin (40 µg h(-1)) infusion. CONCLUSIONS: We showed a preventative effect of intrathecal gabapentin on the development of nerve injury-induced mechanical allodynia and thermal hyperalgesia. Our data suggest that continuous intrathecal gabapentin may be considered as an alternative for the prevention of nerve injury-induced pain.

L-type calcium channels are involved in mediating the anti-inflammatory effects of magnesium sulphate.

BACKGROUND: Magnesium sulphate (MgSO(4)) has potent anti-inflammatory capacity. It is a natural calcium antagonist and a potent L-type calcium channel inhibitor. We sought to elucidate the possible role of calcium, the L-type calcium channels, or both in mediating the anti-inflammatory effects of MgSO(4). METHODS: RAW264.7 cells, an immortalized murine macrophage-like cell line, were treated with phosphate buffered saline, MgSO(4), lipopolysaccharide (LPS), LPS plus MgSO(4), LPS plus MgSO(4) plus extra-cellular supplement with calcium chloride (CaCl(2)), or LPS plus MgSO(4) plus the L-type calcium channel activator BAY-K8644. After harvesting, the production of inflammatory molecules was evaluated. Because the production of endotoxin-induced inflammatory molecules is regulated by the crucial transcription factor nuclear factor (NF)-kappaB, we also evaluated the expression of NF-kappaB. RESULTS: LPS significantly induced the production of inflammatory molecules, including macrophage inflammatory protein-2, tumour necrosis factor-alpha, interleukin (IL)-1beta, IL-6, nitric oxide/inducible nitric oxide synthase, and prostaglandin E(2)/cyclo-oxygenase-2. LPS also induced NF-kappaB activation, as inhibitor-kappaB degradation, NF-kappaB nuclear translocation, and NF-kappaB-DNA binding activity were significantly increased in LPS-treated RAW264.7 cells. MgSO(4), in contrast, significantly inhibited the LPS-induced inflammatory molecules production and NF-kappaB activation. Moreover, the effects of MgSO(4) on inflammatory molecules and NF-kappaB were reversed by extra-cellular calcium supplement with CaCl(2) and L-type calcium channel activator BAY-K8644. CONCLUSIONS: MgSO(4) significantly inhibited endotoxin-induced up-regulation of inflammatory molecules and NF-kappaB activation in activated RAW264.7 cells. The effects of MgSO(4) on inflammatory molecules and NF-kappaB may involve antagonizing calcium, inhibiting the L-type calcium channels, or both.

Protection of tea melanin on hydrazine-induced liver injury.

The protective activity of melanin derived from tea (MDFT) was studied using hydrazine as a DNA-reactive chemical agent. Intra-peritoneal administration of MDFT at the doses of 5 or 20 mg/kg dose-dependently prevented liver toxicity induced by hydrazine in rats. It normalized rises in serum alanine transferase activity and a decrease in the glutathione level in the liver. It also reduced the hepatic malondialdehyde concentration. Monitoring the intensity of chemiluminescence showed that MDFT could prevent the production of free radicals that are generated owing to metabolic transformation of hydrazine. It also prevented the formation 8-hydroxy-deoxyguanosine (8-OH-dG) DNA adducts. The results obtained in vivo and in vitro suggest that MDFT confers marked protection of the liver against hydrazine-induced oxidative toxicity.

Some chemical and physical properties of bambara groundnut (Voandzeia subterranea Thouars) seed and products.

Some chemical and physical properties of bambara groundnut seed were determined. The proximate composition of the bambara groundnut seed was found to be 9.7% moisture, 16.6% protein, 5.9% fat, 2.9% ash, 4.9% crude fibre and 64.9% carbohydrate. Maximum water absorption was attained after soaking for 11, 9, 6, and 4 h at 25, 40, 50, and 60 degrees C, respectively. Maximum dehulling efficiency was attained when the seeds absorbed 54.7% water and drying for 9 h at 60 degrees C. Study of the microstructure of the raw flour and seed showed that they contained differently shaped and sized starch granules and protein materials within the cell wall in the cotyledon. Milling disorganised the arrangement of these components in the cotyledons. In the steamed moin-moin ('okpa'), all components in the seed had lost their identity and integrity.

Identification of ent-16 beta, 17-dihydroxykauran-19-oic acid as an anti-HIV principle and isolation of the new diterpenoids annosquamosins A and B from Annona squamosa.

Phytochemical analysis of the fruits of Annona squamosa yielded 12 known kaurane derivatives (1-11, 13) and two new kaurane diterpenoids, which have been named annosquamosin A (16 beta-hydroxy-17-acetoxy-ent-kauran-19-al) (12) and annosquamosin B (19-nor-ent-kaurane-4 alpha,16 beta,-17-triol) (14). The structures of the new compounds were established by spectral analyses and chemical evidence. Among these 14 compounds, 16 beta, 17-dihydroxy-ent-kauran-19-oic acid (2) showed significant activity against HIV replication in H9 lymphocyte cells with an EC50 value of 0.8 microgram/mL (therapeutic index > 5).

Treatment effect of "ryu-wei-ti-huang-wan" (a Chinese herbal prescription) on the sexual performance of male rats with streptozotocin-induced diabetes.

The treatment effect of "ryu-wei-ti-huang-wan', a Chinese prescription composed of extracts from six plants, on diabetic impotence was evaluated in the present study. Adult male Wistar rats were divided into three groups: (1) rats rendered diabetic with a single intraperitoneal injection of streptozotocin (60 mg/kg body weight); (2) rats with streptozotocin-induced diabetes treated with a ryu-wei-ti-huang-wan powder preparation at a dose of 30 mg powder/kg body weight twice a day, and (3) control rats. A male rat was caged with an adult ovariectomized female rat during the dark cycle. Infra-red-light-illuminated video recording was utilized to evaluate the sexual performance. The diabetic rats exhibited depressed mounting activity and no intromission or ejaculation. After ryu-wei-ti-huang-wan treatment either for 1 day or 2 weeks, the diabetic rats showed significant improvement in mounting performance with preservation of intromission and ejaculation. No significant difference in the blood sugar level was noted between the treatment and non-treatment groups. In conclusion, the diabetic rats showed impairment in sexual arousal, erectile as well as ejaculatory functions. Ryu-wei-ti-huang-wan was effective in preserving these functions with a rapid onset. It is evident that the extracts exert the therapeutic effects not through a lowering of blood sugar. These substances are potentially useful in the clinical treatment of male diabetic impotence.

Evaluation of substrates and storage conditions for preparing and maintaining starter cultures for tempeh fermentation.

Heat-pasteurized cassava root, cowpeas, partially defatted peanuts, rice and soybeans were evaluated for their suitability to support growth and sporulation of the tempeh mold, Rhizopus microsporus var. oligosporus, and the oncom mold, Neurospora intermedia, at 25, 30 and 37 degrees C. The molds grew best and sporulated most luxuriantly on cassava and rice incubated at 37 degrees C. Viability of molds remained high for up to 30 weeks when dried (a(w) 0.48), powdered substrates on which the molds had been cultured, were stored at 5, 25 and 37 degrees C. Survival was best when powders were stored at 5 degrees C, although storage at 25 degrees C did not cause a marked decline in CFU/g. R. microsporus var. oligosporus starter cultures produced on rice and then stored for 20 weeks at these temperatures compared most favorably with commercial starter cultures for preparing high-quality soybean tempeh. The simple technology required to prepare these starter cultures enhances the potential for their application in developing countries where the introduction of nontraditional fermented legume foods to low-protein diets could help to ameliorate malnutrition.