Assuring safety without animal testing: Unilever's ongoing research programme to deliver novel ways to assure consumer safety

Assuring consumer safety without the generation of new animal data is currently a considerable challenge. However, through the application of new technologies and the further development of risk-based approaches for safety assessment, we remain confident it is ultimately achievable. For many complex, multi-organ consumer safety endpoints, the development, evaluation and application of new, non-animal approaches is hampered by a lack of biological understanding of the underlying mechanistic processes involved. The enormity of this scientific challenge should not be underestimated. To tackle this challenge a substantial research programme was initiated by Unilever in 2004 to critically evaluate the feasibility of a new conceptual approach based upon the following key components: 1.Developing new, exposure-driven risk assessment approaches. 2.Developing new biological (in vitro) and computer-based (in silico) predictive models. 3.Evaluating the applicability of new technologies for generating data (e.g. "omics", informatics) and for integrating new types of data (e.g. systems approaches) for risk-based safety assessment. Our research efforts are focussed in the priority areas of skin allergy, cancer and general toxicity (including inhaled toxicity). In all of these areas, a long-term investment is essential to increase the scientific understanding of the underlying biology and molecular mechanisms that we believe will ultimately form a sound basis for novel risk assessment approaches. Our research programme in these priority areas consists of in-house research as well as Unilever-sponsored academic research, involvement in EU-funded projects (e.g. Sens-it-iv, Carcinogenomics), participation in cross-industry collaborative research (e.g. Colipa, EPAA) and ongoing involvement with other scientific initiatives on non-animal approaches to risk assessment (e.g. UK NC3Rs, US "Human Toxicology Project" consortium).

Non-Animal Approaches for Consumer Safety Risk Assessments: Unilever's Scientific Research Programme

Non-animal based approaches to risk assessment are now routinely used for assuring consumer safety for some endpoints (such as skin irritation) following considerable investment in developing and applying new methods over the past 20 years. Unilever's research programme into non-animal approaches for safety assessment is currently focused on the application of new technologies to risk assessments in the areas of skin allergy, cancer and general toxicity (including inhalation toxicity). In all of these areas, a long-term investment is essential to increase the scientific understanding of the underlying biological and chemical processes that we believe will ultimately form a sound basis for novel risk assessment approaches. Our research programme in these priority areas consists of in-house research as well as Unilever-sponsored academic research, involvement with EU-funded projects (e.g. Sens-it-iv, carcino-GENOMICS), participation in cross-industry collaborative research (e.g. COLIPA, EPAA) and ongoing involvement with other scientific initiatives on non-animal approaches to risk assessment (e.g. UK NC3Rs, US ‘Human Toxicology Project’ consortium).

Identification of transcriptional biomarkers induced by SERMS in human endometrial cells using multivariate analysis of DNA microarrays

Functional genomic tools such as DNA microarrays are having a major impact on the drug-discovery process. Potentially, compounds with toxic responses can be identified and removed at a relatively early stage in the drug-development process before tests on animals or humans, solely on the gene expression profiles produced in cell culture. The study examined the expression profiles of primary cultured human endometrial cells treated with 17beta-oestradiol and the SERMs (selective oestrogen receptor modulators) tamoxifen and raloxifene. Primary cultures from three individuals were split into glandular epithelial cells and stromal cell types. Principal components and partial least-squares-discriminate analyses were employed to examine the transcript profile as a whole, identifying genes responsible for patient separation and those that might have an important role in tamoxifen-associated carcinogenesis. Using multivariate data analysis, transcriptional responses were identified in epithelial cells but not in stromal cells for the three SERMs examined. However, it was demonstrated that a major problem associated with using primary cultures derived from human patients is the large transcriptional differences that might exist between the different cultures.

Evaluation of an automated in vitro micronucleus assay in CHO-K1 cells

In this paper, we describe the evaluation of an automated in vitro micronucleus assay using CHO-K1 cells in 96-well plates. CHO-K1 cells were pre-loaded with a cell dye that stains the cytoplasm, after which the cells were treated with the test compounds for either 3h (for the +S9 condition) or 24h (for the -S9 condition). A total of 10 concentrations were tested, of which the top five concentrations were scored (limited by either cytotoxicity or solubility). At the end of the incubation period the cells were fixed and their DNA was stained with Hoechst. The visualization and scoring of the cells was done using an automated fluorescent microscope coupled with proprietary automated image analysis software provided by Cellomics (Pittsburg, PA). A total of 46 compounds were used in this evaluation, including 8 aneugens and 25 clastogens with varied mechanisms of action. Thirteen non-genotoxic compounds were also included. The automated scoring had a sensitivity of 88% and a specificity of 100%, with a predictive value positive of 100% and a predictive value negative of 76%, compared to data from the literature that was obtained with manual scoring. We also describe the incorporation of a metabolic activation system using rat liver S9 homogenates, and the use of cell number counts as a cytotoxicity index which is complementary to the CBPI- (cytokinesis-block proliferation index) based index. Finally, we also discuss the potential for artefactual findings due to fluorescent precipitate, which should be carefully monitored to prevent false positive results. In conclusion, the automated in vitro micronucleus scoring is a valid alternative to the manual scoring of slides, and it has the advantage of generating data in a rapid and consistent manner, and with low compound requirements, which makes it well suited as a screening assay in the early stages of compound development.

In vitro approaches to develop weight of evidence (WoE) and mode of action (MoA) discussions with positive in vitro genotoxicity results

A recent analysis by Kirkland et al. [Kirkland, D., Aardema, M., Henderson, L. and Müller, L. (2005) Evaluation of the ability of a battery of 3 in vitro genotoxicity tests to discriminate rodent carcinogens and non-carcinogens. I. Sensitivity, specificity and relative predictivity. Mutat. Res. 584, 1-256] demonstrated an extremely high false positive rate for in vitro genotoxicity tests when compared with carcinogenicity in rodents. In many industries, decisions have to be made on the safety of new substances, and health risk to humans, without rodent carcinogenicity data being available. In such cases, the usual way to determine whether a positive in vitro genotoxicity result is relevant (i.e. indicates a hazard) for humans is to develop weight of evidence (WoE) or mode of action (MoA) arguments. These are based partly on further in vitro investigations, but usually rely heavily on tests for genotoxicity in one or more in vivo assays. However, for certain product types in the European Union, the use of animals for genotoxicity testing (as well as for other endpoints) will be prohibited within the next few years. Many different examples have been described that indicate DNA damage and genotoxic responses in vitro can arise through non-relevant in vitro events that are a result of the test systems and conditions used. The majority of these non-relevant in vitro events can be grouped under a category of 'overload of normal physiology' that would not be expected to occur in exposed humans. However, obtaining evidence in support of such MoAs is not easy, particularly for those industries prohibited from carrying out in vivo testing. It will become necessary to focus on in vitro studies to provide evidence of non-DNA, threshold or in vitro-specific processes and to discuss the potential for such genotoxic effects to occur in exposed humans. Toward this end, we surveyed the published literature for in vitro approaches that may be followed to determine whether a genotoxic effect observed in vitro will occur in humans. Unfortunately, many of the approaches we found are based on only a few published examples and validated approaches with consensus recommendations often do not exist. This analysis highlights the urgent need for developing consensus approaches that do not rely on animal studies for dealing with in vitro genotoxins.

Wegener's Granulomatosis of the Breast

A 60-year-old woman presented with a painless self-detected breast lump. After wide local excision, the histology of this radiologically suspicious lump turned out to be an inflammatory lesion with granulomatous foci, suggesting a diagnosis of granulomatous mastitis. Prior to the excision biopsy, this woman had suffered from and been treated for anterior uveitis, secretory otitis media, and proximal myopathy. Four weeks later, a skin biopsy of a rapidly developing widespread petechial rash, mainly affecting the lower limbs, confirmed the diagnosis as Wegener's granulomatosis. Treatment with intravenous steroids and later cyclophosphamide produced rapid remission.

Gene expression profiling of p53(+/-) knockout and wild-type mice following diethylstilbestrol administration

Studies with clastogenic carcinogen diethylstilbestrol (DES) resulted in a broad of spectrum of toxic and carcinogenic effects in humans and rodents, but the cellular and molecular mechanism(s) by which it induces cancer is not clear. To identify putative genetic targets for p53 in vivo, we applied the cDNA macroarray gene expression profiles associated with apoptosis by comparing p53+/- knockout mice and wild-type mice on the kidney and uterus of female mice. p53+/- knockout mice and wild-type mice were treated with DES (500 micromole kg(-1)) or vehicle i.p once daily for 4 days. Total RNAs were obtained from kidney and uterus of both control and DES-treated. The signal intensities of individual gene spots on the membrane were quantified and normalized to the expression level of the GAPDH gene as an internal control. Our results demonstrated that 16 genes; bad, bax, bcl-2, bcl-w, bcl-x, caspase-3, caspase-7, caspase-8, c-myc, E124, GADD45, mdm2, NKkappab1, p53, p21, Rb and trail were up-regulated and six genes; caspase-1, caspase-2, DR5, E2F1, FasL and iNOS did not changed in response to DES treatment in wild-type mice compared to p53+/- knockout mice. Most genes are involved in cell cycle regulation, signal transduction, apoptosis, or transcription. The greatest changes were seen in bad, bcl-x, mdm2, p53 and p21 gene expression in wild-type mice compared to p53+/- knockout mice. In comparing p53 and p21 gene expression in wild-type mice and p53+/- knockout mice, there was an 4.4-fold vs. 1.8-fold; 8-fold vs. 5.2-fold for kidney and 16-fold vs. 5.5-fold; 2.1-fold vs. 8.3-fold for uterus samples increase in induction (respectively). RT-PCR and densitometric analysis was used to confirm the biggest changes of p21, p53 and bax genes. Using this approach, we have identified apoptosis associated genes regulated in response to DES and have revealed putative differences between the isogenic parent strain and p53+/- knockout mice, which will contribute to a better understanding of toxicity/carcinogenicity mechanisms in this model.

The protean face of renal sarcoid

Sarcoidosis is a multisystem disorder of unknown etiology, which may occur in all tissues and organs of the body. Clinical presentation may be quite variable and affected by race. The most commonly affected system is the lungs with >95% of patients displaying such involvement. Renal involvement is uncommon (<2%) and may occur in the absence of pulmonary involvement resulting in diagnostic difficulties. Here we describe a sequential cohort of patients with differing presentations of renal sarcoid with and without additional organ involvement. The clinical course and treatment are described.

Acute renal failure in the surgical setting

Acute renal failure (ARF) is an unwelcome complication of major surgical procedures that contributes to surgical morbidity and mortality. Acute renal failure associated with surgery may account for 18-47% of all cases of hospital-acquired ARF. The overall incidence of ARF in surgical patients has been estimated at 1.2%, although is higher in at-risk groups. Mortality of patients with ARF remains disturbingly high, ranging from 25% to 90%, despite advances in dialysis and intensive care support. Appreciation of at-risk surgical populations coupled with intensive perioperative care has the capacity to reduce the incidence of ARF and by implication mortality. Developments in understanding the pathophysiology of ARF may eventually result in newer therapeutic strategies to either prevent or accelerate recovery from ARF. At present the best form of treatment is prevention. In this review the epidemiology, pathophysiology, diagnosis, treatment and possible prevention of ARF will be discussed.

Metabonomics and medicine: the Biochemical Oracle

Occasionally, a new idea emerges that has the potential to revolutionize an entire field of scientific endeavour. It is now within our grasp to be able to detect subtle perturbations within the phenomenally complex biochemical matrix of living organisms. The discipline of metabonomics promises an all-encompassing approach to understanding total, yet fundamental, changes occurring in disease processes, drug toxicity and cell function.

Non-specialist management of acute renal failure

In a 12-month prospective study of the initial management of patients with acute renal failure (ARF) in East Kent (population 593 000), we evaluated the initial management of ARF and assessed what proportion of ARF may have been preventable. Patients were seen and assessed on a daily basis, and were followed until discharge from hospital or death; survivors were subsequently followed for 3 years. Overall, 288 patients developed ARF (486 per million population/year). Mean age at presentation was 73 years (range 14-96). Initial assessment was often suboptimal, and key features in investigation and initial management were often lacking. In 108 cases, ARF was iatrogenic and/or potentially preventable (53 preventable, 99 iatrogenic, 44 both). Overall survival was 56% at discharge from hospital, 35% at 1-year follow-up, 31% at 2 years, and 28% at 3 years. In discharged patients, recovery of function was complete in 69%. A significant proportion of ARF is preventable. Clear guidelines, easily accessible at the point of care, could aid the diagnostic evaluation of the patient with ARF and indicate where referral for a specialist opinion is appropriate.