Influence of red pepper and capsaicin on body composition and lipogenesis in rats

Inclusion of red pepper or its active principle ‘capsaicin’ in the diet led to a lowering of total lipids, particularly triglycerides in the liver. The total body fat was lowered in animals fed red pepper or capsaicin but not in animals fed paprika powder which had negligible capsaicin content. Hyperlipogensis and hypertriglyceridemia caused by fructose feeding were significantly were decreased in capsaicin-fed animals. Activities of the key lipogenic enzymes were reduced as reflected by decreased lipogenesis.     

Influence of capsaicin,curcumin and ferulic acid in rats fed high fat diets

Three compounds capsaicin, curcumin and ferulic acid showing hypolipidemic activity have been tested in adult Wistar rats fed high fat diets. Capsaicin (0.20 mg%) fed to female rats along with a 30% saturated fat diet lowered the rate of weight gain, liver and serum triglycerides. In male rats it lowered only the liver and serum total and very low density and low density lipoprotein triglycerides whether fed continuously for 13 or 8 weeks after interchanging the control and test diets from the 5th week onwards. Capsaicin fed to female rats in 30% mixed fat diet increased the rate of weight gain, lowered liver and serum triglycerides, lowered adipose tissue lipoprotein lipase, elevated the hormone sensitive lipase and serum free fatty acids. Capsaicin in 30% saturated fat diet lowered both the enzyme activities to a much lesser extent. Curcumin and ferulic acid (both at 25 mg%) in 30% saturated fat diet tended to lower the rate of weight gain, liver total lipids and serum triglycerides. It is of significance that a common dietary compound ‘capsaicin’ in the range of human intake triggers lipid lowering action in rats fed high fat diets. This paper was presented at the 55th Annual Meeting of the Society of Biological Chemists (India) held at Trivandrum during December 15–17th, 1986.     

Characterization of poly(ADP-ribosyl)ated domains of rat pachytene chromatin.

Poly(ADP-ribosyl)ation of nuclear proteins was several-fold higher in the pachytene spermatocytes than in the premeiotic germ cells of the rat. Among the histones of the pachytene nucleus, histone subtypes H2A, H1 and H3 were poly(ADP-ribosyl)ated. Based on the immunoaffinity fractionation procedure of Malik, Miwa, Sugimara & Smulson [(1983) Proc. Natl. Acad. Sci. U.S.A. 80, 2554-2558] we have fractionated DNAase-II-solubilized chromatin into poly(ADP-ribosyl)ated chromatin (PAC) and non-poly(ADP-ribosyl)ated chromatin (non-PAC) domains on an anti-[poly(ADP-ribose)] IgG affinity matrix. Approx. 2.5% of the pachytene chromatin represented the PAC domains. A significant amount of [alpha-32P]dATP-labelled pachytene chromatin (labelled in vitro) was bound to the affinity matrix. The DNA of pachytene PAC domains had internal strand breaks, significant length of gaps and ligatable ends, namely 5'-phosphoryl and 3'-hydroxyl termini. On the other hand, the PAC domains from 18 h regenerating liver had very few gaps, if any. The presence of gaps in the pachytene PAC DNA was also evident from thermal denaturation studies. Although many of the polypeptides were common to the PAC domains of both pachytene and regenerating liver, the DNA sequences associated with these domains were quite different. A 20 kDa protein and the testis-specific histone H1t were selectively enriched in the pachytene PAC domains. The pachytene PAC domains also contained approx. 10% of the messenger coding sequences present in the DNAase-II-solubilized chromatin. The pachytene PAC domains, therefore, may represent highly enriched DNA-repair domains of the pachytene nucleus.     

Hormonal sex reversal of wild-spawned tilapia in India

The effectiveness of methyltestosterone (MT) for sex reversal and growth promotion in Oreochromis mossambicus was studied in culture experiments in India. Wild-spawned fry were treated with 30 μg MT g⁻¹ diet for 30 or 60 days at two feeding levels (initially 20% or 10% of body weight daily). The fish were grown on for 66–96 days after the hormone treatment period in fertilized cement ponds without supplementary feeding. Tilapia treated with MT for 60 days attained an average weight of 29.0 g compared to 18.8 g for untreated fish reared under similar conditions. The percentage of males among the untreated tilapia was 58%, MT treatment for 30 days significantly increased this percentage at the higher feeding level (79% male), but not at the lower feeding level (51%). More than 90% of the tilapia in both 60 day MT treatment groups were male; 3% of all the fish reared showed an intersex condition. The experiments demonstrated that the anabolic and sex reversal effects of MT on tilapia are proportional to the duration of treatment and quantity of hormone administered. The possible application of monosex tilapia culture in tropical countries is noted.     

Biosynthesis of branched-chain amino acids in yeast: regulation of leucine biosynthesis in prototrophic and leucine auxotrophic strains

The first enzyme in the biosynthesis of leucine in yeast, alpha-isopropylmalate synthetase, is inhibited by l-leucine. In a mutant resistant to the analogue 5',5',5'-trifluoroleucine, the enzyme is markedly resistant to inhibition by l-leucine. Growth ing the presence of exogenous l-leucine results in repression of the second and third enzymes of the pathway. The first enzyme is not repressed unless both l-leucine and l-threonine are supplied in the medium. Comparison of levels of the remaining two enzymes in leucine auxotrophs grown under conditions of leucine excess and leucine limitation reveals deviations from the wild-type derepression pattern in some mutants. In some, repression of the synthetase by leucine alone was observed. In others, the repressibility of the dehydrogenase was lost. It is unlikely that these deviations were due to the same primary mutational event that caused leucine auxotrophy. No mutants were found in which an altered gene was recognized to be clearly responsible for the level of the leucine-forming enzymes.     

Studies onGesonula punctifrons Stål (Orthoptera: Acrididae: Cyrtacanthacridinae) attacking water-hyacinth in India

Résumé L'AcridienGesonula punctifrons St?l attaque la Jacinthe d'eau (Eichhornia crassipes) dans plusieurs parties de l'Inde et est adapté à un habitat aquatique ou semi-aquatique. Les œufs, pondus dans les pétioles des feuilles, éclosent en 3 à 4 semaines. Les larves se développent en 4 à 5 semaines et demi, avec 5 mues. Les adultes vivent au maximum 4 à 5 mois en s'alimentant seulement de Jacinthe d'eau. En essais de laboratoire cet Acridien se nourrit activement deCanna orientalis dont les tiges sont percées de trous pour la ponte par les femelles, mais aucun œuf n'est déposé. Quarante trois autres plantes d'intérêt économique ont été expérimentées: plusieurs d'entre elles ont été l'objet d'attaques légères à modérées. L'analyse de la littérature concernant les plantes-h?tes du genreGesonula et la distribution deG. punctifrons montrent que cette espèce s'est adaptée secondairement àE. crassipes. Bien que cet Acridien s'observe en grand nombre dans quelques régions, l'ensemble de ses dégats à la mauvaise herbe n'est pas suffisant pour assurer le contr?le de celle-ci.

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This research has been financed in part by a grant made by the United States Department of Agriculture under P. L. 480.     

Neither delta- nor lambda-tris(phenanthroline)ruthenium(II) binds to DNA by classical intercalation.

Equilibrium binding studies and viscosity experiments are described that characterize the interaction of delta- and lambda-[Ru(o-phen)3]2+ with calf thymus DNA. The mode of binding of these compounds to DNA is a matter of controversy. Both isomers of [Ru(o-phen)3]2+ were found to bind but weakly to DNA, with binding constants of 4.9 (+/- 0.3) x 10(4) M-1 and 2.8 (+/- 0.2) x 10(4) M-1 determined for the delta and lambda isomers, respectively, at 20 degrees C in a solution containing 5 mM Tris-HCl (pH 7.1) and 10 mM NaCl. We determined that the quantity delta log K/delta log [Na+] equals 1.37 and 1.24 for the delta and lambda isomers, respectively. Application of polyelectrolyte theory allows us to use these values to show quantitatively that both the delta and lambda isomers are essentially electrostatically bound to DNA. Viscosity experiments show that binding the lambda isomer does not alter the relative viscosity of DNA to any appreciable extent, while binding of the delta isomer decreases the relative viscosity of DNA. From these viscosity results, we conclude that neither isomer of [Ru(o-phen)3]2+ binds to DNA by classical intercalation.