Inhibitory Activity of Marine Sponge-Derived Natural Products against Parasitic Protozoa

In this study, thirteen sponge-derived terpenoids, including five linear furanoterpenes: furospinulosin-1 (1), furospinulosin-2 (2), furospongin-1 (3), furospongin-4 (4), and demethylfurospongin-4 (5); four linear meroterpenes: 2-(hexaprenylmethyl)-2-methylchromenol (6), 4-hydroxy-3-octaprenylbenzoic acid (7), 4-hydroxy-3-tetraprenyl-phenylacetic acid (8), and heptaprenyl-p-quinol (9); a linear triterpene, squalene (10); two spongian-type diterpenes dorisenone D (11) and 11β-acetoxyspongi-12-en-16-one (12); a scalarane-type sesterterpene; 12-epi-deoxoscalarin (13), as well as an indole alkaloid, tryptophol (14) were screened for their in vitro activity against four parasitic protozoa; Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Plasmodium falciparum. Cytotoxic potential of the compounds on mammalian cells was also assessed. All compounds were active against T. brucei rhodesiense, with compound 8 being the most potent (IC₅₀ 0.60 μg/mL), whereas 9 and 12 were the most active compounds against T. cruzi, with IC₅₀ values around 4 μg/mL. Compound 12 showed the strongest leishmanicidal activity (IC₅₀ 0.75 μg/mL), which was comparable to that of miltefosine (IC₅₀ 0.20 μg/mL). The best antiplasmodial effect was exerted by compound 11 (IC₅₀ 0.43 μg/mL), followed by compounds 7, 10, and 12 with IC₅₀ values around 1 μg/mL. Compounds 9, 11 and 12 exhibited, besides their antiprotozoal activity, also some cytotoxicity, whereas all other compounds had low or no cytotoxicity towards the mammalian cell line. This is the first report of antiprotozoal activity of marine metabolites 1–14, and points out the potential of marine sponges in discovery of new antiprotozoal lead compounds.     

Chemical Composition of Green Tea (<Emphasis Type="Italic">Camellia sinensis</Emphasis>) Infusions Commercialized in Portugal

To evaluate the potential benefits and risks associated with tea consumption it is important to identify the constituents of this beverage. Levels of some minerals, caffeine and catechins in green tea samples commercialized in Portugal were evaluated. Potassium is the metal present in larger amount (92–151 mg/l). The content of sodium, calcium, fluoride, aluminium, manganese and iron were 35–69, 1.9–3.5, 0.80–2.0, 1.0–2.2, 0.52–1.9, 0.020–0.128 mg/l, respectively. Chromium and selenium were not detected. The resulting data showed considerable variability in catechins content. The levels of epigallocatechin gallate (EGCG) ranged from 117 to 442 mg/l, epicatechin 3-gallate (EGC) from 203 to 471 mg/l, epigallocatechin (ECG) from 16.9 to 150 mg/l, epicatechin (EC) from 25 to 81 mg/l and catechin (C) from 9.03 to 115 mg/l. Caffeine contents in the green tea infusions studied were between 141–338 mg/l. Green tea infusions provide significant amounts of catechins and could be an important source of some minerals.     

Host cell specific activity of RTX toxins from haemolytic Actinobacillus equuli and Actinobacillus suis

We assessed and compared host cell specificity of the haemolytic and cytotoxic activity of the RTX toxins from Actinobacillus equuli, an equine pathogen, and Actinobacillus suis, which is pathogenic for pigs. The two bacterial species are closely related, phenotypically as well as phylogenetically, sharing the same 16S rRNA gene sequence. Both species contain specific protein toxins from the family of pore-forming RTX toxins, however, the two species differ in their RTX toxin profiles. Haemolytic A. equuli contains the operon for the Aqx toxin, whereas A. suis harbours genes for ApxI and ApxII. We tested the toxic activity of the corresponding proteins on erythrocytes as well as on lymphocytes isolated from horse and pig blood. The strength of the haemolytic activity for each of the toxins was independent of the origin of erythrocytes. When testing cytotoxic activity, the Aqx protein showed a higher toxic effect for horse lymphocytes than for porcine lymphocytes. On the other hand, ApxI and ApxII showed a strong cytotoxic effect on porcine lymphocytes and a reduced toxicity for horse lymphocytes; the toxicity of ApxII was generally much lower than ApxI. Our results indicate a host species specificity of the toxic activity of RTX toxins Aqx of A. equuli and ApxI and ApxII of A. suis.     

Prevalence of hereditary diseases in three-year-old Swiss Warmblood horses

The objective of this study was to investigate clinical signs indicating hereditary diseases like equine sarcoid, osteochondrosis (OC) and the idiopathic laryngeal hemiplegia (ILH), and to demonstrate relationships between environment, feeding habits and conformation ("exterieur" evaluation) of the horses. For this purpose, we analyzed veterinary examinations of 403 stallions at the approvals since 1994 examined 493 three-year-old Swiss Warmblood horses, which were shown at the Swiss-Field-Tests in 2005.With the help of the owners a questionnaire on health, environment and feeding habits of the animals was completed. At the same time, the horses were assessed and graded for their "exterieur" (type, conformation, gaits) by judges of the Swiss Sporthorse breeding association. In 11.5% of horses sarcoids were found, 8.7% showed one and 2.8% several tumors.The prevalence of sarcoids in offspring of sires with known sarcoids was not significantly higher than in descendants from stallions without a known history of sarcoids. We found distended joints as a possible symptom of OC in 11.4% of the horses, 3.9% (n = 19) in both tarsal joints.We did not find a relationship between enlarged joints in the offspring and the presence of OC in the sires. Abnormal respiratory noise at work, as a possible sign for ILH, was heard only in 1.2% (n = 6). It is important to note that while we found a high number of sarcoid affected horses compared to other studies, presence of enlarged joints was not very frequent and very few horses showed abnormal respiratory noise. Additionally, we found no correlation between "exterieur" marks and the horse's general health.     

Growth performance, energy, and nitrogen balance of weanling pigs fed a cereal-based diet supplemented with Chinese rhubarb

Forty Swiss Large White piglets of 4 weeks of age were used to determine the effect of dietary Chinese rhubarb on growth performance, as well as on energy and nitrogen metabolism by means of indirect respiration calorimetry studies. A cereal-based diet, supplemented with four different dosages of Chinese rhubarb (0.0%, 0.25%, 0.5%, 1%), was offered ad libitum to the piglets. Gaseous exchange was measured, and urine, faeces, and blood samples were taken. The addition of 0.25% dietary rhubarb increased feed intake (+32%) and daily weight gain (+67%) compared to the diet containing the greatest amount of rhubarb (1%). The piglets fed diet supplemented with 0.25% rhubarb digested and metabolised more energy and nitrogen relative to the animals of treatment 1%. As a consequence, the same group (0.25%) converted more energy and nitrogen into body protein than piglets receiving diet supplemented with 1% rhubarb. However, compared to the control group, the addition of 0.25% rhubarb to the diet resulted in not significantly alter growth performance, energy, and nitrogen metabolism of the animals.Blood parameters were not affected by the rhubarb supplementation. The dose-responding effect of Chinese rhubarb was reflected by the dry matter content of faecal samples. According to the laxative effect of higher doses of rhubarb, the addition of 1% rhubarb to the diet reduced dry matter content of faeces. This effect was well visible in practice, although not relevant in statistical terms. The addition of 0.5% dietary rhubarb had no relevant effect on growth performance or on energy and nitrogen metabolism of treated animals.     

Serum troponin I levels in hyperthyroid cats before and after treatment with radioactive iodine

A raised concentration of serum cardiac troponin I (cTnI) is a sensitive marker of cardiac myocyte injury in the cat and assays developed for its measurement in human patients have been validated in the cat. Raised levels have been associated with a number of cardiac insults including hypertrophic cardiomyopathy and trauma. Hyperthyroidism is a common disease of older cats and excess thyroid hormone is known to produce significant cardiovascular effects in this species. This study evaluated the effect of treatment for hyperthyroidism with radioactive iodine on cTnI concentration, assessed the association between thyroxin levels and glomerular filtration rate (GFR) and cTnI concentration in cats treated for hyperthyroidism and described changes in echocardiographic parameters following treatment. Prior to the treatment serum cTnI was measured and echocardiography performed, thyroxin, cTnI, and echocardiography were then repeated at various time points following radioisotope therapy. The results show that higher thyroxin levels were significantly (P=0.002) associated with a higher likelihood of the cat presenting with detectable levels of cTnI. No significant association was found between GFR and presence of detectable levels of cTnI. Furthermore the results indicate that the effects of hyperthyroidism on echocardiographic parameters appear considerably less in this study than in previous studies and that the main outcome of treatment on these parameters is a significant reduction in fractional shortening (P=0.006). These results suggest that chronic exposure to excess thyroid hormone may induce myocyte damage of sufficient severity to raise serum cTnI concentration in a proportion of cats that resolves following establishment of a euthyroid state.