Pre-clinical safety assessment of biotechnologically produced lacto-N-tetraose (LNT).

Lacto-N-tetraose (LNT) is a human milk oligosaccharide with average concentrations ranging from 0.74 to 1.07 g/L in breastmilk, depending on the lactation stage. In this study, the preclinical safety of LNT produced by the Escherichia coli K-12 E2083 production strain was assessed. LNT was negative in both the bacterial reverse mutation assay and the in vitro micronucleus assay, demonstrating the absence of genotoxic potential for this substance. In the OECD 408 guideline compliant 90-day oral toxicity study rat, LNT did not induce any adverse effects in any treatment group up to and including the highest dose tested, and no LOAEL could be determined. Therefore, the no-observed-adverse effect level (NOAEL) is set at the highest dose level tested, i.e. a dietary level of 5 % (w/w), corresponding to ≥2856 mg/kg bw/day and ≥3253 mg/kg bw/day for males and females, respectively. This might be an underestimation of the NOAEL, caused by the range of dose levels tested. The results obtained in the current study are in good agreement with available data generated using other biotechnologically produced LNT batches and therefore support its safe use as a food ingredient.

A critical evaluation of thyroid hormone measurements in OECD test guideline studies: Is there any added value?

Recently several OECD test guidelines were updated to include thyroid hormone measurements for assessing endocrine disruptor potency, which led to an imperative need to align interpretation of these results by the different stakeholders. We therefore evaluated 124 repro screening studies, which showed in 38% of the studies a statistical significant finding for T4 in at least one treatment group, probably due to disturbances of normal homeostasis causing high variation. Consequently, for a thorough evaluation it is extremely important to take the historical control range into account. In conclusion, the current testing approach is not providing specific information needed to assess endocrine disruption, as too often a statistical significant finding is noted and as down-stream adverse effects are not evaluated. Therefore, major modifications are urgently needed. Instead of extending the in vivo experiments, it should be investigated if in vitro assessments will provide more relevant information on human endocrine disruptor potential.

REACH alternative testing strategy for skin sensitization in practice: Fact or fiction?

From October 2016 the REACH Regulation requires an alternative testing strategy for skin sensitization. The current paper describes our experience when putting into practice the REACH alternative testing strategy with a modification for 50 industrial chemicals in total, including mono-constituents, multi-constituents and UVCBs. For mono- and multi-constituents, a tiered approach was followed starting with an in silico (Derek Nexus) assessment, DPRA and KeratinoSens™ assay, followed by a weight of evidence conclusion based on the generated data, or further testing using the U-SENS™ assay. For UVCBs testing started with the KeratinoSens™ assay followed by the U-SENS™ assay if additional relevant information could be gained for an overall conclusion. From the 50 substances tested, for 46% a conclusion on skin sensitization potential and potency could be drawn based on the non-animal testing strategy; however, 54% of the substances still needed to be studied in vivo due to discordant results from non-animal testing or the need for reliable potency data. Important issues with the currently available, validated non-animal methods are the lack or comparability of skin metabolism and lack of potency indication, which is present in the in vivo assays. Skin sensitization testing for UVCBs and multi-constituents is still in a grey area, as neither the in chemico, in vitro assays, and in vivo LLNA have been validated for UVCBs and multi-constituents.

Assessment of health claims, content, and safety of herbal supplements containing Ginkgo biloba.

BACKGROUND: European Regulation 1924/2006 states that all health claims made on foods need to be substantiated scientifically. OBJECTIVE: To apply the PASSCLAIM criteria for the scientific substantiation of health claims on foods to herbal supplements containing Ginkgo biloba. Evaluation of three selected claimed health effects for G. biloba (improvement of blood circulation, improvement of symptoms of old age, and improvement of memory) was achieved through review of publicly available scientific data. A total of 35 human intervention studies were evaluated. Commercially available products claimed to contain mainly G. biloba (N=29) were randomly sampled in the Netherlands and analyzed for their content on ginkgo extract. Also, a toxicological risk assessment was performed. RESULTS: The three selected health claims investigated could not be substantiated. This was mainly because of a lack of data from studies in healthy volunteers. In most studies results performed with a 24% standardized G. biloba extract were described. However, our chemical analysis showed that 25 of the 29 sampled products did not contain the required minimum 24% standardized extract. Moreover, in most preparations the content of substances typical for G. biloba did not conform to what was declared on the label. Since toxicity data for G. biloba are very limited, a safety limit could not be established. CONCLUSIONS: Evidence is lacking for three health claims of herbal products with G. biloba. Neither safety nor efficacy can be guaranteed at the recommended daily dose. The multidisciplinary approach described in this paper provides good insight into issues that are relevant for the evaluation of health claims for herbal food supplements.