Cytokine profile and natural killer cell activity in Listeria monocytogenes infected mice treated orally with Petiveria alliacea extract.

In this work, we investigated the effects of Petiveria alliacea extract on the production of Th1-type and Th2-type cytokines and on NK cells activity in normal and Listeria monocytogenes infected mice. Our results demonstrated that in normal/non-infected mice P. alliacea administration led to increased levels of Interleukin-2 (IL-2). The infection alone enhanced INF-gamma levels and NK cell activity at 48 and 72 hours of infection. The treatment with five consecutive doses of 1000 mg/kg/day of P. alliacea extract, given previously to infection, led to further increases in IL-2 levels, in relation to normal/non-infected/P. alliacea treated controls, and in INF-gamma levels at 72 h of infection, compared to infected mice. On the other hand, the production of IL-4 and IL-10 were not altered either by the infection or by the treatment with P. alliacea extract. NK cells activity increased at 48 h and 72 h following the inoculation of the bacteria. When mice were treated with P. alliacea previously to infection, NK activity was higher than that observed at 48 h, 72 h and 120 h of infection in the infected animal. Based on these findings we suggest that P. alliacea up-regulates anti-bacterial immune response by enhancing both Th1 function and the activity of NK cells.

Petiveria alliacea L. extract protects mice against Listeria monocytogenes infection--effects on bone marrow progenitor cells.

In this study we have investigated the effects of Petiveria alliacea on the hematopoietic response of mice infected with Listeria monocytogenes. Our results demonstrate a protective effect of the crude extract of P. alliacea since the survival of the treated/infected was higher than that in the infected group. Moreover, the number of granulocyte/macrophage colonies (CFU-GM) and the serum colony stimulating activity levels were increased in the treated/infected mice in relation to the infected group. These results suggest an immunomodulation of Petiveria alliacea extract on hematopoiesis, which may be responsible, at least in part, for the increased resistance of mice to Listeria monocytogenes infection.

Presence of micronuclei in lymphocytes of mercury exposed workers.

We have investigated the presence of micronuclei in mercury exposed workers. The study group consisted of 15 workers from a mercury-producing plant, mean age 39.5 years and a mean exposed period of 12 years. At the time of testing and for the six previous months, the exposed population had urinary mercury levels below the currently accepted limit of 50 ug/g creatinine. A significant increase in the percentage of micronuclei was observed in the mercury exposed individuals when compared to the non exposed group. We have not found any correlation between the percentage of micronuclei and age, length of exposure or urinary mercury concentrations. Our results suggest a genotoxic effect of mercury, which is observed in workers exposed chronically to levels considered biologically safe for the exposed population.

Polymorphonuclear phagocytosis and killing in workers occupationally exposed to hexachlorobenzene.

Phagocytosis and intracellular killing of Candida albicans and Candida pseudotropicalis by neutrophils from 66 workers exposed to chlorinated compounds were studied. Phagocytosis with both antigens was normal in all the workers studied. However, lytic activity of the neutrophils in the presence of both antigens, C. albicans and C. pseudotropicalis was impaired. These findings might be related to a derangement in the antioxidant mechanisms and to some interference with GSH levels that might lead to the abnormal functions observed in neutrophils.

Immunoglobulin levels in workers exposed to hexachlorobenzene.

The serum immunoglobulin (IgG, IgM and IgA) concentrations of 52 chlorinated-exposed workers were examined and compared with those of non-exposed, age- and sex-matched individuals. At the time of testing, the exposed population had mean hexachlorobenzene (HCB) blood levels of 3.84 micrograms/dl with a range of 0.1 to 16 micrograms/dl. Increased IgG and IgM levels were found in the HCB-exposed workers (P < 0.05 and P < 0.01, respectively). Hepatic function was evaluated by serum aspartate (AST) and alanine aminotransferase (ALT) activities, as well as by bilirubin levels. IgM concentrations were positively correlated with three of the studied parameters, namely, length of exposure (r = 0.367) and the activities of both AST (r = 0.367) and ALT (r = 0.507).

Renal tubular sodium handling determined by lithium clearance in partially hepatectomized rats.

Decreased renal sodium excretion was observed 2 to 5 days after a two-thirds hepatectomy (Hx) in male Wistar-Hannover rats (200-300 g; N = 10 per group). This fall occurred after normalization of serum liver enzymes by the second day. Hepatocellular dysfunction was demonstrated by a pronounced and transient increase of about 1150% in plasma alanine aminotransferase (ALT), 500% in aspartate aminotransferase (AST), 250% in alkaline phosphatase (ALP) and in serum direct bilirubin levels, which were about six-fold higher than in sham-operated (SH) animals on the first and second days after hepatectomy. On the basis of the renal clearance of lithium in partially hepatectomized rats, there was a sustained decrease in fractional sodium excretion between the second (SH: 0.053 +/- 0.008% vs Hx: 0.023 +/- 0.008%) and fifth days (SH: 0.040 +/- 0.006% vs Hx: 0.027 +/- 0.009%) post-hepatectomy. This decrease was accompanied by a rise in the absolute (68 +/- 5.2 mumol min-1 100 g body weight-1) and fractional (85.2 +/- 1.4%) proximal sodium reabsorption rates compared to sham-operated rats (53 +/- 3.5 mumol min-1 100 g body weight-1 and 80.6 +/- 1.1%), but a return to baseline excretion levels was observed by the tenth experimental day. These changes occurred in the absence of any alterations in creatinine clearance, sodium filtered load, hematocrit and total blood volume. Further studies are required to establish the mechanisms of interaction between renal tubule sodium handling and liver function.

Renal tubular sodium handling determined by lithium clearance in partially hepatectomized rats

Decreased renal sodium excretion was observed 2 to 5 days after a two-thirds hepatectomy (Hx) in male Wistar-Hannover rats (200-300 g; N = 10 per group). This fall occurred after normalization of serum liver enzymes by the second day. Hepatocellular dysfunction was demonstrated by a pronounced and transient increase of about 1150 per cent in plasma alanine aminotransferase (ALT), 500 per cent in aspartate aminotransferase (AST), 250 per cent in alkaline phosphatase (ALP) and in serum direct bilirubin levels, which were about six-fold higher than in sham-operated (SH) animals on the first and second days aft hepatectomy. On the basis of the renal clearance of lithium in partially hepatectomized rats, there was a sustained decrease in fractional sodium excretion between the second (SH: 0.053 ñ 0.008 per cent vs Hx: 0.023 ñ 0.008 per cent) and fifth days (SH: 0.040 ñ 0.006 per cent vs Hx: 0.027 ñ 0.009 per cent) post-hepatectomy. This decrease was accompanied by a rise in the absolute (68 ñ 5.2 mumol min-1 100 g body weight-l) an fractional (85.2 ñ 1.4 per cent) proximal sodium reabsorption rates compared to sham-operated rats (53 ñ 3.5 mumol min-1 100 g body weigh-1 and 80.6 ñ 1.1 per cent), but a return to baseline excretion levels was observed by the tenth experimental day. These changes occurred in the absence of any alterations in creatinine clearance, sodium filtered load, hematocrit and total blood volume. Further studies are required to establish the mechanisms of interaction between renal tubule sodium handling and liver function.