Antimicrobial and brine shrimp toxicity of some plants used in traditional medicine in Bukoba District, north-western Tanzania.

Tanzan J Health Res. 2009 Jan; 11(1): 23-8Moshi MJ, Innocent E, Masimba PJ, Otieno DF, Weisheit A, Mbabazi P, Lynes M, Meachem K, Hamilton A, Urassa IHerbal medicines constitute a potentially important resource for new and safe drugs for the management of microbial infections and other diseases. In this study, dichloromethane, ethylacetate and ethanol extracts of Canarium schweinfurthii Engl., Dissotis brazzae Cong., Iboza urticifolia (Bak) E.A.Bruce, Isoglosa lacteal Lindau, Strombosia Scheffleri Engl., and Whitfieldia elongate T. Anders were tested for antimicrobial activity and brine shrimp toxicity. The objective was to validate claims that they are used to treat bacterial infections, diarrhoea and heal wounds among the Haya tribe of north-western Tanzania. At least one extract of each plant showed antibacterial activity. Dichloromethane extracts were the most active while ethanol extracts were the least active. Extracts of Whitfieldia elongate and Isoglossa lacteal were the most and least active with MICs in the range 0.08-0.62 mg/ml and 15.6-62.5 mg/ml, respectively. The dichloromethane extract of Whitfieldia elongate exhibited strong antifungal activity against Cryptococcus neoformans. Against brine shrimp larvae, the extracts from the six plants exhibited a low to very low toxicity with LC50 values ranging from 15.35-374.0 microg/ml. However, ethanol extracts of Dissotis brazzae and Strombosia scheffleri had LC50 values of >1000 microg/ml. The seemingly innocuous nature and relatively good antibacterial activity against skin infections and gastrointestinal pathogenic bacteria support the traditional uses of the plants and deserve more detailed studies.

Use of physiologically based biokinetic (PBBK) modeling to study estragole bioactivation and detoxification in humans as compared to male rats.

Toxicol Sci. 2009 May 15; Punt A, Paini A, Boersma MG, Freidig AP, Delatour T, Scholz G, Schilter B, van Bladeren PJ, Rietjens IMThe extent of bioactivation of the herbal constituent estragole to its ultimate carcinogenic metabolite, 1'-sulfooxyestragole depends on the relative levels of both bioactivation and detoxification pathways. The present study investigated the kinetics of the metabolic reactions of both estragole and its proximate carcinogenic metabolite 1'-hydroxyestragole in humans in incubations with relevant tissue fractions. Based on the kinetic data obtained a PBBK model for estragole in human was defined to predict the relative extent of bioactivation and detoxification at different dose levels of estragole. The outcomes of the model were subsequently compared to those previously predicted by a PBBK model for estragole in male rat to evaluate the occurrence of species differences in metabolic activation. The results obtained reveal that formation of 1'-oxoestragole, which represents a minor metabolic route for 1'-hydroxyestragole in rat, is the main detoxification pathway of 1'-hydroxyestragole in humans. Due to a high level of this 1'-hydroxyestragole oxidation pathway in human liver, the predicted species differences in formation of 1'-sulfooxyestragole remain relatively low, with the predicted formation of 1'-sulfooxyestragole being 2-fold higher in human compared to male rat, even though the formation of its precursor 1'-hydroxyestragole was predicted to be 4-fold higher in human. Overall, it is concluded that in spite of significant differences in the relative extent of different metabolic pathways between human and male rat there is a minor influence of species differences on the ultimate overall bioactivation of estragole to 1'-sulfooxyestragole.

The Effects of Ginkgo Biloba Extract EGb 761 on Mechanical and Cold Allodynia in a Rat Model of Neuropathic Pain.

Anesth Analg. 2009 Jun; 108(6): 1958-63Kim YS, Park HJ, Kim TK, Moon DE, Lee HJBACKGROUND: Neuropathic pain is chronic pain that is caused by an injury to the peripheral or central nervous system. The symptoms of neuropathic pain are continuing pain, hyperalgesia, and allodynia. Ginkgo biloba extract is an oriental herbal medicine that has various pharmacological actions. We examined the effect of Ginkgo biloba extract, EGb 761, on the mechanical and cold allodynia in a rat model of neuropathic pain. METHODS: Male Sprague-Dawley rats were prepared by tightly ligating the left L5 and L6 spinal nerves. All the rats developed mechanical and cold allodynia 7 days after surgery. Fifty neuropathic rats were assigned into five groups for the intraperitoneal administration of drugs. The study was double-blind and the order of the treatments was randomized. Normal saline and EGb 761 (50, 100, 150, and 200 mg/kg) were administered, respectively, to the individual groups. We examined mechanical and cold allodynia at preadministration and at 15, 30, 60, 90, 120, 150, and 180 min after intraperitoneal drug administration. Mechanical allodynia was quantified by measuring the paw withdrawal threshold to stimuli with von Frey filaments of 1.0, 1.4, 2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 15.0, and 26.0 g. Cold allodynia was quantified by measuring the frequency of foot lift with applying 100% acetone. We measured the locomotor function of the neuropathic rats by using the rotarod test to reveal if EGb 761 has side effects, such as sedation or reduced motor coordination. RESULTS: The control group showed no differences for mechanical and cold allodynia. For the EGb 761 groups, the paw withdrawal thresholds to mechanical stimuli and withdrawal frequencies to cold stimuli were significantly reduced versus the preadministration values and versus the control group. The duration of antiallodynic effects increased in a dose-dependent fashion, and these were maintained for 120 min at the highest dose (P < 0.05). Only at the highest dose (200 mg/kg) did EGb 761 reduce the rotarod performance time. CONCLUSION: We conclude that Ginkgo biloba extract, EGb 761, attenuates mechanical and cold allodynia in a rat model of neuropathic pain, and it may be useful for the management of neuropathic pain.

MotherSafe: Review of three years of counselling by an Australian teratology Information Service.

Aust N Z J Obstet Gynaecol. 2009 Apr; 49(2): 168-72Lim JM, Sullivan E, Kennedy DBACKGROUND: MotherSafe was established in January 2000 at the Royal Hospital for Women as Australia's first 'purpose-built' Teratogen Information Service and since then has received over 75,000 calls regarding exposures during pregnancy and lactation. AIM: To describe the patterns of use of MotherSafe over a three-year period. METHODS: Retrospective descriptive epidemiological study using data from the database established at MotherSafe. Records from all the calls logged at MotherSafe between January 2005 and December 2007 were analysed to determine total number of calls, demographic characteristics of callers, including age, caller category and postcode, reason for call, source of referral and type of exposure. RESULTS: A total of 47,138 calls were recorded to the MotherSafe service from January 2005 to December 2007. The majority of calls were regarding exposures in pregnancy (55%) and breast-feeding (38%). Average age of patients was 32.3 years. Of the calls made, 81.9% (38,485 of 46,968) were by consumers (the pregnant or lactating woman herself or a relative). The most common primary exposure categories were: over-the-counter medications (11.3%), psychotropic medication (9.0%), herbal or vitamin products (8.2%), antibiotics (7.0%), gastrointestinal medications (6.8%) and topical products (6.6%). Forty per cent of callers enquired about multiple exposures. CONCLUSIONS: The utilisation of MotherSafe by consumers and general practitioners continues to increase, reflecting the strong demand for a teratogen counselling service that provides high-quality, evidence-based information on exposures during pregnancy and lactation.