Guinea-pig Test Research Articles

Protection efficacy and immunogenicity of Clostridium chauvoei proteins as a subunit blackleg vaccine or an adjuvant for Clostridium perfringens epsilon toxoid

Potential application of Clostridium chauvoei proteins was studied as a subunit blackleg vaccine or a biological adjuvant for Clostridium perfringens epsilon toxoid vaccine. Extracellular and cell surface proteins were extracted from C. chauvoei culture, and their protective efficacy was evaluated by potency test in guinea pigs. In order to investigate the effect of cell surface proteins on C. perfringens epsilon toxoid immunogenicity, rabbits were inoculated subcutaneously twice with: C. perfringens type D toxoid supernatant + 200 μg C. chauvoei cell surface proteins (PR-200), toxoid supernatant + 400 μg cell surface proteins (PR-400), inactivated C. perfringens type D vaccine (Vac), toxoid supernatant (Tox), or PBS. Isolation of cell surface proteins yielded about 2.5 mg/L culture protein with a sharp band at 43 kDa probably corresponding to flagellin. Potency test demonstrated the protection ability of both cellular and extracellular proteins of C. chauvoei. ELISA showed that the highest antibody titers against epsilon toxoid belonged to PR-400 and Vac groups. The effect of days post immunization on antibody response was not significant. No significant difference was observed between PR-400 and Vac, as well as PR-200 and Tox groups. Clostridium chauvoei cell surface proteins may have the potential for application as a blackleg disease vaccine and an adjuvant for clostridial toxoids.

Evaluating the ability of non-tuberculous mycobacteria to induce non-specific reactions in bovine tuberculosis diagnostic tests in guinea pigs and cattle

Limitations in diagnostic test performance are one of the major challenges hampering the eradication of bovine tuberculosis (bTB). Non-tuberculous mycobacteria (NTM) are considered one of the main causes of non-specific reactions in the intradermal tuberculin test, the most widely used bTB diagnostic test. To determine the role of NTMs in bTB misdiagnosis in Spain, an experimental study including the NTM species most commonly found in bTB-positive animals from bTB-free farms in the country (M. avium subsp. avium (Maa), “Mycobacterium avium subsp. hominissuis” (Mah), M. bourgelatii, M. intermedium, M. kansasii and M. nonchromogenicum) was carried out on guinea pigs and cattle. First, guinea pigs were sensitized with the selected NTMs, and six weeks post-sensitization four antigen mixtures (bovine-PPD, avian-PPD, P22 and ESAT6-CFP10) were inoculated intradermally and their effect was measured 24- and 48-h post-inoculation. Larger erythematous reactions were observed in guinea pigs sensitized with Mah, M. kansasii, and Maa, with significant differences in the reactions measured at the bovine-PPD inoculation site for the two first bacteria compared with other NTMs. The sensitization process was repeated in cattle, and five months post-sensitization the same antigen mixtures were inoculated in the cervical region and responses were measured at 48- and 72-h post-inoculation. A significantly higher increase in the skinfold thickness measured at the bovine-PPD inoculation site was observed in calves sensitized with Mah, Maa, M. intermedium and M. kansasii. These results demonstrate that certain NTM species may play a more significant role in bTB diagnostic interferences and show that results obtained in guinea pig and bovine models do not always coincide.

Evaluation of long-term immune response in cattle to botulism using a recombinant E. coli bacterin formulated with Montanide™ ISA 50 and aluminum hydroxide adjuvants

Botulism is a severe disease caused by potent botulinum neurotoxins (BoNTs) produced by Clostridium botulinum. This disease is associated with high-lethality outbreaks in cattle, which have been linked to the ingestion of preformed BoNT serotypes C and D, emphasizing the need for effective vaccines. The potency of current commercial toxoids (formaldehyde-inactivated BoNTs) is assured through tests in guinea pigs according to government regulatory guidelines, but their short-term immunity raises concerns. Recombinant vaccines containing the receptor-binding domain have demonstrated potential for eliciting robust protective immunity. Previous studies have demonstrated the safety and effectiveness of recombinant E. coli bacterin, eliciting high titers of neutralizing antibodies against C. botulinum and C. perfringens in target animal species. In this study, neutralizing antibody titers in cattle and the long-term immune response against BoNT/C and D were used to assess the efficacy of the oil-based adjuvant compared with that of the aluminum hydroxide adjuvant in cattle. The vaccine formulation containing Montanide™ ISA 50 yielded significantly higher titers of neutralizing antibody against BoNT/C and D (8.64 IU/mL and 9.6 IU/mL, respectively) and induced an immune response that lasted longer than the response induced by aluminum, extending between 30 and 60 days. This approach represents a straightforward, cost-effective strategy for recombinant E. coli bacterin, enhancing both the magnitude and duration of the immune response to botulism.

Dendrobium officinale polysaccharides-chemical properties and pharmacodynamic effects on the airways in experimental conditions.

The study aimed to analyze the effects of Dendrobium polysaccharides on the cough and airway reactivity and compare them with the effects of clinically used antitussives (codeine phosphate and butamirate citrate) and bronchodilators (salbutamol), using the guinea pig test system. Dendrobium officinale polysaccharides contained proteins (4.0 wt%) and phenolic compounds (1.7 wt%) with a molecular weight of 25,000 g/mol. The sugar analysis revealed a dominance of glucose (93.7 wt%) and a lesser amount of mannose (5.1 wt%) while other sugar quantities were negligible. Methylation analysis indicated the presence of highly branched polysaccharides. Glucose was found mainly as terminal, 1,4- and 1,6-linked. Furthermore, some 1,4- and 1,6-linked glucose units were found branched at O2, O3, and O6/O4. Mannose was terminal and 1,4-linked. NMR spectra signals indicate the presence of the (1→4)-linked α-d-glucan, (1→4)-linked β-d-glucan branched at position O6, (1→6)-linked β-d-glucan branched at position O3 and (1→4)-linked glucomannan. Pharmacological studies showed statistically significant antitussive activity of Dendrobium polysaccharides, exceeding the effect of clinically used antitussives, which may be partially associated with confirmed bronchodilation and the ability of polysaccharides to increase the threshold of cough receptor activation. Dendrobium polysaccharides may increase the possibility of symptomatic treatment of cough, especially in asthmatics.

Protective immunization against Enterohemorrhagic Escherichia coli and Shigella dysenteriae Type 1 by chitosan nanoparticle loaded with recombinant chimeric antigens comprising EIT and STX1B-IpaD

Increasing evidence demonstrated that Enterohemorrhagic Escherichia coli (EHEC) and Shigella dysenteriae type 1 (S. dysenteriae1) are considered pathogens, that are connected with diarrhea and are still the greatest cause of death in children under the age of five years, worldwide. EHEC and S. dysenteriae 1 infections can be prevented and managed using a vaccination strategy against pathogen attachment stages. In this study, the chitosan nanostructures were loaded with recombinant EIT and STX1B-IpaD polypeptides. The immunogenic properties of this nano-vaccine candidate were investigated. The EIT and STX1B-IpaD recombinant proteins were heterologous expressed, purified, and confirmed by western blotting. The chitosan nanoparticles, were used to encapsulate the purified proteins. The immunogenicity of recombinant nano vaccine candidate, was examined in three groups of BalB/c mice by injection, oral delivery, and combination of oral-injection. ELISA and antibody titer, evaluated the humoral immune response. Finally, all three mice groups were challenged by two pathogens to test the ability of the nano-vaccine candidate to protect against bacterial infection. The Sereny test in guinea pigs was used to confirm the neutralizing effect of immune sera in controlling S. dysenteriae 1, infections. SDS-PAGE and western blotting, confirmed the presence and specificity of 63 and 27 kDa recombinant EIT and STX1B-IpaD, respectively. The results show that the nanoparticles containing recombinant proteins could stimulate the systemic and mucosal immune systems by producing IgG and IgA, respectively. The challenge test showed that, the candidate nano-vaccine could protect the animal model from bacterial infection. The combination of multiple recombinant proteins, carrying several epitopes and natural nanoparticles could evocate remarkable humoral and mucosal responses and improve the protection properties of synthetic antigens. Furthermore, compared with other available antigen delivery methods, using oral delivery as immune priming and injection as a booster method, could act as combinatorial methods to achieve a higher level of immunity. This approach could present an appropriate vaccine candidate against both EHEC and S. dysenteriae 1.

Studies on safety and efficacy of particles containing a mixture of hydroxyapatite–argentum–titanium oxide (HAT) and sheets coated with HAT particles to be used in masks to improve nasal allergy: II. Cellular, in vivo, and clinical studies

PurposeWe report the manufacture of particles containing a mixture of hydroxyapatite–argentum–titanium oxide (HAT), followed by attachment to nonwoven polyester fabrics to produce HAT-coated sheets (HATS) for use in masks. The purpose of the present study was to perform cellular, in vivo, and clinical studies to further examine the safety of HATS for use in masks to improve nasal allergy.MethodsReverse mutation tests for HAT were performed using five bacterial strains. A cellular toxicity test was performed using a Chinese hamster cell line incubated with the HATS extracts. Skin reactions after intradermal administration were examined in rabbits. Skin sensitization tests in guinea pigs were performed using the HATS extracts. HAT was administered to the nasal cavity and conjunctival sac of the rabbits. An oral administration study was performed in rats. Finally, a human skin patch test was performed using the HATS.ResultsReverse mutation tests showed negative results. The cellular toxicity test showed that the HATS extract had moderate cytotoxicity. The intradermal skin reaction and skin sensitization tests were all negative. The administration of HAT to the nasal cavity and intraocular administration showed negative results. No toxicity was observed after oral administration of HAT powder up to a dose of 2000 mg/kg. Finally, the skin patch test result was negative.ConclusionAlthough HAT showed moderate cytotoxicity, in vivo results indicated that HAT is safe because it does not come in direct contact with cells in normal usage, and HATS is safe when used in masks.

Local lymph node assay: 5-bromo-d-deoxyuridine-ELISA method for comparative study in assessing chemical potencies and skin sensitization in BALB/c and CBA/J strains

Local lymph node assay (LLNA) is a predictive in vivo method to provide estimates of relative potency and to contribute to risk assessment/risk management regarding skin sensitizing potency of chemicals and formulations as a stand-alone alternative test. In addition, LLNA is relatively rapid and cost-effective compared to the Buehler method (Guinea pig test), and confers important animal welfare benefits. CBA/J and BALB/c strains are widely commercially available and have been evaluated by formal LLNA validation studies. However, the LLNA method using BrdU with ELISA, unlike other LLNA methods (OECD TG 429, 442 A, 442B), has not been previously validated. Therefore, in this study a validation method was performed to evaluate if the LLNA:BrdU-ELISA method could also be used to identify sensitizers among chemicals listed in OECD TG 429 using CBA/J and BALB/c strains. Here, we newly found that the LLNA:BrdU-ELISA validation method correctly identified 12 of 13 sensitizers in the BALB/c, 11 of 13 sensitizers in the CBA/J, and 3 of 5 non-sensitizers were identified in the two strains. Collectively, we found that the results of LLNA:BrdU-ELISA method provide a similar level of performance for accuracy and sensitivity in two mouse strains BALB/c and CBA/J.

In vitro and in vivo assessments for developing an oral BCG vaccine formulation

The aim of this study was to establish in vitro analytical methods for assessing an investigated oral BCG vaccine formulation. In addition, in vivo immune response was also evaluated in guinea pigs by determining the potentially protective effect of the investigated formulation on tuberculosis. The bicinchoninic acid (BCA) method for BCG protein quantitation was developed for rapid measuring the content of BCG vaccine in the investigated formulation. The analytical method was conducted at 45°C to offer good precision (coefficient of variation <3.5%) and accuracy (error: -3.6∼2.6%) in the range of 150∼4000 μg/mL of BCG vaccine concentrations. In the simulation study of drug release from the investigated formulation in the gastrointestinal tract under physiological conditions, the investigated oral formulation could protect active component at lower pH (0.1 N HCl) and completely release active component at higher pH (phosphate buffer, pH 6.8). Although the investigated oral BCG vaccine formulation showed weak immune response to elicit IgG titer, the PPD (purified protein derivative) skin test in guinea pigs by oral dosing of 4 mg BCG vaccine formulation acquired about equal or higher response than that by 0.5 mg dose by subcutaneous vaccination. The analytical method and in vivo approach could be further applied in the development of oral BCG vaccine formulations.

Design and In Vivo Verification of a CMOS Bone-Guided Cochlear Implant Microsystem.

To develop and verify a CMOS bone-guided cochlear implant (BGCI) microsystem with electrodes placed on the bone surface of the cochlea and the outside of round window for treating high-frequency hearing loss. The BGCI microsystem consists of an external unit and an implanted unit. The external system-on-chip is designed to process acoustic signals through an acquisition circuit and an acoustic DSP processor to generate stimulation patterns and commands that are transmitted to the implanted unit through a 13.56 MHz wireless power and bidirectional data telemetry. In the wireless power telemetry, a voltage doubler/tripler (2X/3X) active rectifier is used to enhance the power conversion efficiency and generate 2 and 3 V output voltages. In the wireless data telemetry, phase-locked loop based binary phase-shift keying and load-shift keying modulators/demodulators are adopted for the downlink and uplink data through high-Q coils, respectively. The implanted chip with four-channel high-voltage-tolerant stimulator generates biphasic stimulation currents up to 800 μA. Electrical tests on the fabricated BGCI microsystem have been performed to verify the chip functions. The in vivo animal tests in guinea pigs have shown the evoked third wave of electrically evoked auditory brainstem response waveforms. It is verified that auditory nerves can be successfully stimulated and acoustic hearing can be partially preserved. Different from traditional cochlear implants, the proposed BGCI microsystem is less invasive, preserves partially acoustic hearing, and provides an effective alternative for treating high-frequency hearing loss.

A New Model to Calibrate a Reference Standard for Bovine Tuberculin Purified Protein Derivative in the Target Species.

Since 1986, use of a Bovine International Standard (BIS) for bovine tuberculin has been required to ensure national and international uniformity regarding the potency designation of bovine tuberculin Purified Protein Derivative (PPDb) preparations produced by multiple manufacturers. The BIS is the unique golden standard in the guinea pig potency assay, representing 100% potency, where potencies of production batches are calculated as relative potencies in comparison with the potency of the BIS which was set at 32,500 international Unit (IU) per mg. The stock supply and lifetime of the BIS is limited.The aim of this study was to develop a model to determine the potency of a newly produced in-house Reference Standard (RS) for PPDb with great accuracy in the target species (cattle) and to prove its precision and accuracy in the guinea pig potency test. First simulations were done to estimate the required number of cattle needed. Then, 30 naturally bTB infected cattle were subjected to a tuberculin skin test using multiple injections of both the RS and the BIS. Both were applied randomly in the same volume and concentration (1 dose). The potency of the RS against the BIS was directly derived from the least square means (LSMEANS) and was estimated as 1.067 (95% CI: 1.025–1.109), equal to a potency of 34,700 ± 1,400 IU/mg. In six guinea pig potency assays the RS was used to assign potencies to production batches of PPDb. Here, precision and accuracy of the RS was determined according to the parallel-line assay. Relative potencies were estimated by exponentiation of the common slope. The corresponding 95% confidence intervals were obtained according to Fieller's theorem. In sensitized guinea pigs, the relative potency of the RS against the BIS was 1.115 (95% CI: 0.871–1.432), corresponding to an absolute potency of 36,238 IU/mg (95% CI: 28,308–46,540).In conclusion: the method used to determine the potency of the RS against the BIS in naturally bTB infected cattle, resulted in a highly accurate potency estimate of the RS. The RS can be used in the guinea pig test to assign potencies to PPDb production batches with high precision and accuracy.

Comparison of humoral neutralizing antibody response in rabbits, guinea pigs, and cattle vaccinated with epsilon and beta toxoids from Clostridium perfringens and C. botulinum types C and D toxoids

Rabbits and guinea pigs are used in the official control and validation of clostridial vaccines, but it is unknown whether the antitoxin titers obtained in these animals corroborate with the humoral response in bovine. The objective of the study was to compare the humoral antibody response of guinea pig and rabbits to those obtained in cattle vaccinated with a commercial vaccine containing Clostridium perfringens epsilon and beta, and Clostridium botulinum types C and D toxoids. This study revealed the same level of humoral response in rabbits and cattle for all four toxoids tested, including C. botulinum types C and D toxoids. In contrast, the titers of neutralizing antibodies against C. botulinum type C toxin in guinea pigs differed from those obtained in cattle. Thus, the present work suggests that the potency test for C. botulinum types C in rabbits agrees more with the humoral response in cattle than the potency test in guinea pigs, thereby making it possible to use only rabbits as models in the official control and validations of clostridial vaccines.

Systemic and Local Anaphylaxis is Not Induced by Korean Red Ginseng Mixture in Guinea Pigs

Currently, injuries to customers due to health functional foods are annually increasing. To evaluate the antigenicity of Korean red ginseng mixture (KRGM), we tested for systemic anaphylactic shock and passive cutaneous anaphylaxis in guinea pigs. Based on a comparison of measured body weights, there were no changes in body weight for the KRGM treatment group compared with the control group. In the ovalbumin treated group, however, there was a statistically significant decrease in body weight. For the active systemic anaphylaxis test, after the induction, there were no symptoms that suggested anaphylactic shock in the control and KRGM treatment group. In the ovalbumin treated group, there were symptoms that suggested severe anaphylaxis, and those symptoms included restlessness, piloerection, tremor, rubbing or licking the nose, sneezing, coughing, hyperpnea, dyspnea, staggering gait, jumping, gasping and writhing, convulsion, side position and Cheyne-stokes respiration. All animals died within thirty minutes in the ovalbumin treated group. For the passive cutaneous anaphylaxis test in guinea pigs sensitized to KRGM, each anti-serum was diluted in a stepwise manner. This was followed by an intravenous injection of a mixture of KRGM and Evans blue. The results of the test showed that all the responses were negative in the control and the low-dose and high-dose administration groups. However, in the ovalbumin treated group, all the responses were positive. Based on the above results, there were no anaphylactic responses for up to 12 times the amount of human intake of KRGM in Hartley Guinea-pigs. The results suggest that KRGM is safe as measured by the systemic and local antigenicity in guinea pigs.

ANTI DIARRHEA EFFECT OF ETHANOL EXTRACT KECAPI BARK (SANDORICUM KOETJAPE MERR) ON MALE GUINEA PIG INDUCED WITH CASTOR OIL AND BACTERIA ESCHERICHIA COLI

Objective: Kecapi bark (Sandoricum koetjape Merr.) is a plant of the Meliaceae family that is often used by people to treat diarrhea and abdominal pain. This study aims to determine the effects of antidiarrheal from the ethanol extract of the Kecapi stem bark on induced with castor oil and bacteria Escherichia coli.Methods: Before the in vivo on male guinea pig test was switched first, then 10 ml of castor oil was induced and 7.7 ml of E. coli male guinea pig was induced, then each male guinea was given a variation of dose ethanol extract kecapi stem bark and loperamide as the comparison. Parameters measured in this study were the start time of diarrhea, consistency of feces, frequency, and duration of diarrhea.Result: The results obtained showed that ethanol extract of kecapi bark antidiarrheal effect on guinea pigs induced castor oil (dose of 800 mg/kg body weight) and E. coli.Conclusion: Ethanol extract of Kecapi bark has an activity of antidiarrheal..

REGULATORY AND METHODOLOGICAL ASPECTS OF STUDYING ALLERGENIC PROPERTIES OF NEW MEDICINES AT THE PRECLINICAL STAGE

The assessment of allergic risk at the preclinical stage of drug development has been a debatable issue due to the integration of national requirements for medicines authorisation with those of the Eurasian Economic Union (EAEU). The article summarises mechanisms and factors involved in the development of drug hypersensitivity, as well as the main national and foreign regulatory requirements. It also cites the results of allergic risk assessment studies involving standard guinea pig tests, such as systemic anaphylactic reactions and active cutaneous anaphylaxis, for a number of medicines with the molecular weight of the active substance of more than 1000 Da and less than 1000 Da. Data analysis confirms that the number of positive reactions for high molecular weight compounds (&gt;1000 Da) is significantly higher than the number of positive reactions for low molecular weight compounds (&lt;1000 Da). There were some false-positive results detected. The results of foreign studies confirm the lack of correlation between the experimental data obtained in similar tests in guinea pigs and the clinical data. Thus, standard tests in guinea pigs cannot adequately predict the risk of immediate hypersensitivity reactions to new medicines in clinical practice. Negative or positive results should not be regarded as confirmation of potential absence or presence of anaphylactic reactions in clinical practice.

Adverse reaction and screening of sensitizing substance of Shuxuening injection

In this study, by the means of the active systemic allergy test in guinea pigs, passive skin allergy test in rats and pseudoallergic test in mice, it was determined that the "allergic reaction" of Shuxuening injection(SXNI) may not be a true IgE-mediated allergic reactions, but mainly of pseudoallergic reaction. Further pseudoallergic test proved that the pseudoallergic reactions of SXNI had difference between batches and showed dose dependence, so it was recommended to establish SXNI pseudoallergic reaction detection method for timely detecting and controlling the product risk of each batch products. In addition, as the pseudoallergic reactions of SXNI were dose-dependent, the dose and concentration of SXNI should be strictly controlled in clinical use. Then the main pseudoallergenic reaction test was conducted for the main monomer components in SXNI and the different fractions of Ginkgo biloba extract in mice, and the results showed that the sensitizing substances may mainly exist in YXY-3 fractions containing flavonol glycosides. By further chemically separating YXY-3, we got four chemical components. Among these four components, YXY-3-1 and YXY-3-2 were testified as the main allergenic components in SXNI through pseudoallergic test in mice. To make sure the specific chemical constituent that is responsible for the pseudoallergic reaction, in-depth study in follow-up experiments should be needed.

Preclinical safety and efficacy evaluation of ‘BioCaS’ bioactive calcium sulfate bone cement

A new bioactive calcium sulfate-based formulation (named ‘BioCaS’) has been developed for bone filler applications. This is a self-setting injectable cement where the preset form comprises bassanite obtained from the uniform submicron-sized precursor crystals of gypsum, modified with hydrogen orthophosphate ions. The results of the safety and efficacy evaluation of BioCaS cement, done as per the International Standards and guidelines, are presented in this paper. The study plan consisted of in vitro screening tests of cytotoxicity and haemolysis and in vivo biocompatibility evaluation, including an acute systemic toxicity test (in mice), an intracutaneous reactivity test (in rabbits), a pyrogen test (in rabbits) and a maximization sensitization test (in guinea pigs). The efficacy of the material in healing bone defects was investigated by implanting it in artificially created defects in rabbit femora, with clinically established hydroxyapatite porous ceramic as the control, followed by histological analysis at 12, 26 and 52 weeks. Set BioCaS cement consisted of hydrogen orthophosphate incorporating low-dimensional gypsum crystal lattices, the bioactivity of which has been identified by immersion in simulated body fluid. BioCaS was proved to be non-cytotoxic and non-haemolytic in the screening tests. In the live/dead assay, human osteoblast-like human osteosarcoma cells adhered well and spread on the surface of the material, attaining typical morphology and affirming the bone cell compatibility of the material. In the biocompatibility evaluation there were no acute systemic effects and the material proved non-pyrogenic. There was no intracutaneous erythemic or oedematous reactivity and no hypersensitivity observed in the Magnusson–Kligman method. The material satisfied the biocompatibility requirements. Bone implantation study revealed BioCaS to be osteoconductive and its efficacy of healing the experimental bone defects in rabbit femora is on a par with that of hydroxyapatite ceramic. The material resorbed at a pace matching that of new bone formation. This property of osteotransductivity will help the defect to heal and gain strength faster.

CRF1 but not glucocorticoid receptor antagonists reduce separation-induced distress vocalizations in guinea pig pups and CRF overexpressing mouse pups. A combination study with paroxetine

RationaleGiven the large number of patients that does not respond sufficiently to currently available treatment for anxiety disorders, there is a need for improved treatment. ObjectivesWe evaluated the anxiolytic effects of corticotropin releasing factor (CRF)1 receptor antagonists and glucocorticoid receptor (GR) antagonists in the separation-induced vocalization test in guinea pigs and transgenic mice with central CRF overexpression. Furthermore, we explored effects of these drugs when given in combination with a suboptimal dose of a selective serotonin re-uptake inhibitor (SSRI). MethodsIn guinea pig pups, the CRF1 receptor antagonists CP-154,526 and DMP695, and the GR antagonists mifepristone and Org34517 (all at 2.5, 10 and 40mg/kg intraperitoneally (IP)) were tested alone or in combination with 0.63mg/kg paroxetine IP. In CRF overexpressing mouse pups and wild type littermates, effects of CP-154,526 (10, 20 and 40mg/kg subcutaneously (SC)) and mifepristone (5, 15, 45mg/kg SC) were studied alone or in combination with 0.03mg/kg paroxetine SC. ResultsCRF1 but not GR antagonists reduced the number of calls relative to vehicle in guinea pigs and mice, independent of genotype. Treatment of CRF1 receptor or GR antagonists with paroxetine had no combined effect in guinea pigs, wild type or CRF overexpressing mice. ConclusionsCurrent results indicate robust anxiolytic properties of CRF1 receptor antagonists in guinea pigs and mice overexpressing CRF, and lack thereof of GR antagonists. Although no combined treatment effects were observed, it would be interesting to study combined treatment of CRF1 receptor antagonists with SSRIs following chronic drug administration.

Local Anaesthetic Effect of Methanolic Leaves Extract of Lannea schimperi (Hoschst. Ex Rich) Eng.

Local anaesthetics provide relief from pain when applied locally to nerve tissue by blocking conduction of sensory nerve impulse from the receptor to the brain cortex. This study aimed at evaluating local anaesthetic activity of the methanolic leaves extract of Lannea schimperi. Six groups of five animals were used; groups I-IV were used for intracutaneous wheal test in guinea pigs for infiltration anaesthesia, while group V and VI were used for guinea pig corneal reflex method of surface anaesthesia. The result indicated a significant ( 0.05) dose dependent local anaesthetic activity of the methanolic leaves extract of Lannea schimperi with faster onset and longer duration of action at 24 mg/ml than at 12 mg/ml of the extract. Additions of 5 μg of adrenaline into the 24 mg/ml preparation also prolonged the duration of local anaesthetic activity of the extract. The extract at 24 mg/ml significantly (0.05) inhibited corneal reflex, lidocaine was used as a standard drug in positive control group, while normal saline was used as negative control in all the treated groups. The patent data therefore revealed that the methanolic leaves extract Lannea schimperi possess local anaesthetic principles that may require further scientific elucidation.

Oral Toxicity Study and Skin Sensitization Test of a Cricket.

Crickets have been attracting considerable interest in the field of nutrition and toxicology due to the global exhaustion of food resulting from a growing population. The cricket is normally eaten in several countries after roasting, similar to the grasshopper; however, safety evaluation data on cricket powder is limited. Here, we performed general toxicity studies of cricket powder including a single, 2-week repeated dose range evaluation test, a 13-week repeated oral dose toxicity test in Sprague-Dawley rats, a single oral dose toxicity test in Beagle dogs, and a skin sensitization test in guinea pigs following the Organization for Economic Cooperation and Development test guidelines 406 and 408 in addition to Good Laboratory Practice. To investigate the NOAEL and target organs of cricket powder, Sprague-Dawley rats were allocated to 4 groups: vehicle control, 1,250 mg/kg, 2,500 mg/kg, 5,000 mg/kg dose test groups and cricket powder was administered over 13 weeks after single dose and dose range finding studies in rats based on the results of the single oral administration toxicity study in rats and Beagle dogs. The results of the study showed that the NOAEL of cricket powder was over 5,000 mg/kg for both sexes of rats without adverse effects in a 13-week repeated oral toxicity study and there was no skin hypersensitivity reaction. Therefore, our results reveal that crickets can be widely used as a new substitute food or nutrient resource.

Evaluasi Uji Iritasi Dan Uji Sifat Fisik Sediaan Emulgel Minyak Atsiri Bunga Cengkeh (Syzigium Aromaticum)

Inflammation is the human body's response to a tissue damage as indicated by an increase of vascular permeability. One of the natural substances that can be used to treat inflammation is clove oil (MABC). This study aimed to evaluate the physical properties and MABC emulgel irritation test ( S yzygium aromaticum ). This experimental study was initiated by the emulgel formulation with three kinds of formula, with each formula contains MABC levels of 10% (F1), 12.5% (F2), and 15% (F3). The physical tests for emulgel was done including pH, spreading test and adhesive test and irritation test in guinea pigs using Draize test method. Statistical analysis by t test with a level of confidence 95% was conducted to detect a significant differences between the treatment groups. The emulgel formula with a concentration of 10%, 12.5% and 15% were physically stable, moreover the dispersive power test for each formula showed normal distribution data (p>0.05) and homogeneous (p>0.05), ANOVA test results obtained significantly different results in each formula (p<0.05), whereas the stickiness test results for each formula more than 30 minutes with pH 6. The results of irritation test by using Draize test method, indicated that each formula did not show any irritant effect.