Juvenile and mature tilapia {O reochrom is m ossam bicus) were exposed to a range o f sublethal copper (Cu) concentrations for 6 days to examine the mechanisms underlying the acclimation to the toxic effects o f the metal. The study focuses on the gills, the primary target for waterborne pollutants. To obtain a comprehensive picture o f the branchial acclimation processes operating, multiple biochemical and m orphological parameters were studied. A t all concentrations tested, Cu exposure resulted in the accum ulation o f the metal in mature fish. A t 100 and 200 jug C u I-1 only, chloride cell proliferation was observed, which was accompanied by an increase in aver age cell diameter in these groups. W hole body flux measurements in juvenile fish demonstrated a decrease in N a influx in fish exposed to 200 jug I' 1 Cu, in the absence o f an effect on Ca influx. G ill N a + / K + -ATPase activity was also decreased in the crude branchial homogenates o f the mature fish exposed to the highest C u concentration only, but not in the purified branchial vesicle preparations o f these fish, which may indicate reactivation o f in vivo Cu-inhibited ATPase activity during the isolation process. Plasma pH , Na, Cl, K, glucose and ceruloplasmin concentrations were also affected in the 200 jug Cu l_l group exclusively. In accordance with the gill accum ulation data, plasma C u levels were clearly elevated in all groups exposed to the metal. The results underscore the integrated response o f the gills to Cu, which, however, does not come into play until challenged by relatively high ambient concentrations. These results indicate that, in comparison to the Cu-sensitive rainbow trout, tilapia is more Cu-tolerant. The most sensitive parameters affected by Cu are gill and plasma metal levels, followed by chloride cell num ber and diameter. Pelgrom et al. IA quatic Toxicology 32 (1995) [303][304][305][306][307][308][309][310][311][312][313][314][315][316][317][318][319][320]

Sexually mature female tilapia were exposed to sublethal concentrations of waterborne Cu and/or Cd over 6 days, and

Aquatic Toxicology 30 (1994) 117-135 ; Interactions between copper and cadmium during single and combined exposure in juvenile tilapia O r e o c h r o m i s m o s s a m b i c u s :Influence of feeding condition on whole body metal accumulation and the effect of the metals on tissue water and ion content AbstractJuvenile tilapia (Oreochromis mossamhicus) were exposed for 96 h to ranges of sublethal concentrations of Cu or Cd, under both fed and non-fed conditions. Exposure to one metal (Cu or Cd) not only resulted in an increased whole body content of the metal exposed to, but also influenced the concentration of the other metal present in the fish. Furthermore, the total amount of Cu and Cd accumulated during exposure to heavy metals was influenced by the nutritional state of the fish. Besides exposure to either Cu or Cd, fish were also exposed to mixtures of Cu and Cd. Results indicated that accumulation during Cu/Cd co-exposure cannot be predicted by simple addition of the effects of single metal exposures. Obviously, complex interaction mechanisms are involved, as was concluded e.g. from the significantly decreased whole body Cd-content of Cu/Cd-co-exposed fish compared to the Cd-content of Cd-exposed fish. This phenomenon was observed in both fed and non-fed fish. Because ionic homeostasis is known to be affected by heavy metals, in this study also whole body water, calcium and sodium content in Cu and/or Cd-exposed fish were determined. The results indicate that also with respect to these parameters the two metals interact. The effects on water and ion appear to be dissociated. The data reveal previously unrecognized effects of interaction of the metals on whole body metal content, water and ion regulation.

BackgroundEuropean Regulation 1924/2006 states that all health claims made on foods need to be substantiated scientifically.ObjectiveTo 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.ResultsThe 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.ConclusionsEvidence 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.

Plasma ions and cortisol levels were studied in immature tilapia for 6 days to a range of sublethal concentrations of Cu (50, 100 and 200 pg Cu I-1), Cd (20, 35 and 70 p g Cd I-1) and to combinations of these metals (50/ig Cu I-1 + 2 0 /*g Cd I ' 1, 100/ig Cu I-1 + 35 /ig Cd I-1 and 200 p g Cu I" 1 -f 70 p g Cd 1 " 1 ). Our data show that Na and Ca were markedly, although not exclusively, affected by Cu and Cd, respectively. Plasma Na concentrations were most prominently decreased in Cu-exposed fish, with less pronounced effects in Cd-exposed fish. In fish exposed to 10 pg Cd I-1, the plasma Ca concentration was half of the control value. Cu-induced changes of plasma Ca concentrations were less strongly marked. In combined Cu/Cd exposed fish, Na, Ca and Cl concentrations were significantly changed. Important in the present study was the notion that, in combined Cu/Cd exposed fish, the changes in Na and Ca levels could not be explained by synergism of addition of the effects observed in single metal exposed fish. Plasma cortisol levels were increased in Cu-exposed fish, but an increase was not observed in the Cu/Cd co-exposed fish. It is argued that the absence of this cortisol response contributes to an inadequate recovery of ionic disturbances in the Cu/Cd co-exposed fish.