Melanogenesis‐Inhibitory and Cytotoxic Activities of Chemical Constituents from the Leaves of Sauropus androgynus L. Merr. (Euphorbiaceae)

A new steroid, 20‐hydroxyisofucosterol (stigmasta‐5,24(28)‐diene‐3β,20β‐diol) ( 7 ), along with six known compounds 1 – 6 were isolated from the MeOH extract of the leaves of Sauropus androgynus L. Merr . (Euphorbiaceae). The structure of new steroid was determined by HR‐APCI‐MS and various NMR techniques in combination with literature data. Subsequently, their anti‐inflammatory, cytotoxic activities against five human cell lines, as well as inhibitory activities against the α‐MSH induced melanogenesis on the B16 cell line were evaluated. As the results, steroid compounds, 6 and 7 exhibited moderate cytotoxic to HL60, AZ521, SKBR3, and A549 tumor cell lines (IC₅₀ 26.9 – 45.1 μm ) with high tumor selectivity for A549 relative to WI38 cell lines (SI 2.6 and 3.0, resp.). And, flavonoid compounds, 4 and 5 exhibited superior inhibitory activities against melanogenesis (67.0 – 94.7% melanin content), even with no or low toxicity to the cells (90.1 – 99.6% cell viability) at the concentrations from 10 to 100 μm . Furthermore, Western blot analysis suggested that compound 5 could inhibit melanogenesis by suppressing the protein expressions of MITF, TRP‐1, TRP‐2, and tyrosinase.     

New method for determination of fecal sterols in urine using non-chlorinated solvents

A new method has been developed to determine a number of sterols in urine using non-chlorinated solvents, namely methyl tert.-butyl ether and methanol (the MTB method). The method involves liquid–liquid extraction, saponification, reextraction, silylation and final identification and quantification by GC–FID. The sterols determined were coprostanol, epicoprostanol, cholesterol and dihydrocholesterol. 5α-Cholestane was used as internal standard. The limit of detection for the sterols in this experiment was 2 μg l⁻¹ urine. Recovery of coprostanol over the range 5–100 μg l⁻¹ urine by this method was between 80 and 92%.     

Reduction of 4-androstene-3,17-dione by growing cucumber plants

4-[4-¹⁴C]Androstene-3,17-dione was applied to the leaves of growing cucumber plants, Cucumis sativus, twice a week. Four weeks after the first     

Nitrogen and energy loss in the marine teleost Lithognathus mormyrus (Linnaeus)

Nitrogen excretion and assimilation efficiencies in Lithognathus mormyrus (Linnaeus), a marine teleost present in high-energy surf zones in Algoa Bay, South Africa, were determined under controlled laboratory conditions at 15, 20 and 25 °C. Ammonia was the major form of nonfaecal nitrogen excreted by starved and fed L. mormyrus. Urea and amino acids were secondary excretory products. Ammonia excretion rates were temperature independent and the excretion rates of fed fish were significantly higher than starved fish at 20 and 25 °C but not at 15 °C. The mass component (b) of the mass/ammonia excretion equation was temperature independent and ranged from 0.590 to 0.669 and from 0.670 to 0.767 for starved and fed fish, respectively. The mean percentage of food energy lost via the dissolved nonfaecal excretory products (exogenous plus endogenous) was 4.12%. Assimilation efficiencies ranged from 71.89 to 98.78% for dry matter and from 96.89 to 99.88% on an energy basis. The combined nonfaecal and faecal energy loss was calculated at 10.11% of the ingested energy. The omnivorous ichthyofauna present in the surf zone ecosystem recycle 33 g N · m strip · yr⁻¹. This constitutes < 1 % of total phytoplankton nitrogen requirements.     

Cold-induced phase separation for the simple and reliable extraction of sex hormones for subsequent LC-MS/MS analysis

Sex hormones, including androgens, estrogens, and progestogens, are important biomarkers for various diseases. Quantification of sex hormones is typically conducted by LC-MS/MS. At present, most methods require liquid-liquid extraction or solid phase extraction for sample preparation. However, these pretreatments are prone to compromise LC-MS/MS throughput. To improve on the current standard practices, we investigated cold-induced phase separation for sex hormone extraction. After protein precipitation with acetonitrile and adjusting the solution constitution with water, samples were stored at ?30°C for 10 min to generate two distinct phases: an acetonitrile-rich layer on top of a water-rich layer. During this process, the hydrophobic sex hormones spontaneously separate into the upper layer. This simple and reliable cold-induced phase separation-based LC-MS/MS methodology was used here to simultaneously detect estrone, estradiol, estriol, testosterone, androstenedione, dehydroepiandrosterone, progesterone, and 17-hydroxyprogesterone in serum. Validation of this method indicated satisfactory performance, including acceptable linearity, accuracy, precision, and tractability. Compared with the mainstream liquid-liquid extraction-based method, this new method exhibits significant progress in throughput, which shortens the time cost of sample preparation from 90 to 40 min. We propose that this method can be an excellent alternative for sex hormone analysis in routine clinical laboratories.     

The regulation of maternal behaviour in marmosets and tamarins

This article reviews a long-term investigation into the roles of (1) experience obtained with infants during development and postnatally, and (2) levels of reproductive-steroid hormones during late pregnancy, in the regulation of maternal caregiving motivation and behaviour in the red-bellied tamarin (Saguinus labiatus) and the common marmoset (Callithrix jacchus) (family Callitrichidae, Order Primates). Both observational studies, e.g. post hoc analysis of the relationship between developmental caregiving experience and infant-rearing success, and manipulative studies, e.g. direct analysis of the effects of sex-steroid administration on maternal motivation, were performed. In red-bellied tamarins, a breeding female's infant-rearing success was related to its caregiving experience obtained during development and postpartum/postnatally. In multiparous females lacking developmental caregiving experience, postpartum maternal caregiving behaviour and infant-rearing success were related to prepartum urinary oestradiol levels. In nulliparous common marmosets, caregiving of infant-siblings increased as a consequence of physical interaction with parent-infant dyads, late pregnancy, and exposure to late pregnancy-like levels of progesterone and oestradiol. The evidence for a dual mechanism of endocrine and experiential regulation of caregiving in these monkeys is discussed in terms its evolution and function.     

Monoamines and reproduction in Pecten maximus,a preliminary approach

Summary

The distribution of serotonin-like immunoreactivity was studied in the central nervous system and the gonad of Pecten maximus. Cerebral and pedal ganglia contain a well developed serotonin-immunoreactive neuronal subpopulation, whereas positive neurons are scarce in the visceral ganglion. The distribution pattern of immunoreactive elements in the gonad indicate that serotonin is involved in peripheral neurotransmission of this organ. Seasonal variations of monoamines (serotonin, dopamine and noradrenaline) have been investigated in the nervous system using HPLC. Lower concentrations of serotonin are observed during winter in the central nervous system; dopamine levels of the visceral ganglion are correlated to gonadal growth.     

Mechanism Based Inhibition of Hydroxysteroid Dehydrogenases

Abstract

Steroid hormone action can be regulated not only at the receptor level but also by the enzymes that are responsible for the synthesis and degradation of biologically active steroids. Traditionally the pharmacological intervention of steroid hormone action has focused on the development of steroidal and nonsteroidal hormone receptor agonists and antagonists with appropriate pharmacokinetics. Recently, the development of selective inhibitors/inactivators of steroid metabolizing enzymes has gained momentum. This review will concentrate on the development of mechanism-based inhibitors for one class of steroid hormone transforming enzymes, the hydroxysteroid dehydrogenases.     

Metagenomics analysis of the fecal microbiota in Ring-necked pheasants (Phasianus colchicus) and Green pheasants (Phasianus versicolor) using next generation sequencing

Pheasant reintroduction and conservation efforts have been in place in Pakistan since the 1980 s, yet there is still a scarcity of data on pheasant microbiome and zoonosis. Instead of growing vast numbers of bacteria in the laboratory, to investigate the fecal microbiome, pheasants (green and ring neck pheasant) were analyzed using 16S rRNA metagenomics and using IonS5TMXL sequencing from two flocks more than 10 birds. Operational taxonomic unit (OTU) cluster analysis and phylogenetic tree analysis was performed using Mothur software against the SSUrRNA database of SILVA and the MUSCLE (Version 3.8.31) software. Results of the analysis showed that firmicutes were the most abundant phylum among the top ten phyla, in both pheasant species, followed by other phyla such as actinobacteria and proteobacteria in ring necked pheasant and bacteroidetes in green necked pheasant. Bacillus was the most relatively abundant genus in both pheasants followed by Oceanobacillus and Teribacillus for ring necked pheasant and Lactobacillus for green necked pheasant. Because of their well-known beneficial characteristics, these genus warrants special attention. Bird droppings comprise germs from the urinary system, gut, and reproductive sites, making it difficult to research each anatomical site at the same time. We conclude that metagenomic analysis and classification provides baseline information of the pheasant fecal microbiome that plays a role in disease and health.     

Endocrine monitoring of the ovarian cycle and pregnancy in the saddle-back tamarin (Saguinus fuscicollis) by measurement of steroid conjugates in urine

Direct measurements of urinary immunoreactive estrone conjugates (E1C) and pregnanediol glucuronide (PdG), were applied to monitoring the ovarian cycle (n = 9) and pregnancy (3 full term pregnancies, 2 mid-term abortions) in Saguinus fuscicollis. During the ovarian cycle, urinary E1C concentrations revealed a high degree of day-to-day variability and appeared to be uninformative in reflecting cyclic ovarian function. In contrast, PdG was a reliable indicator of ovarian cyclicity with excretion patterns corresponding well with plasma progesterone profiles. Luteal phase PdG concentrations were on average 4–7–fold higher than corresponding follicular phase values. On the basis of changes in circulating progesterone, a mean cycle length of 25.7 ±1.0 days with an average follicular phase of 7.1 ± 0.6 days and a mean luteal phase of 18.6 ± 0.7 days, was found (n = 14 cycles). Following conception, both urinary steroid conjugate concentrations increased and elevated levels were maintained beyond the normal luteal phase length, allowing pregnancy to be determined at around day 25–30. During mid- to late pregnancy, PdG levels declined while E1C concentrations continued to be elevated until approximately 6 weeks before parturition when a decrease occurred. Both hormones showed a clear and rapid fall to follicular phase values following termination of pregnancy at either parturition or mid-term abortion. Post partum ovulations (n = 5) occurred on average 17–18 days following birth with four ovulations leading to conceptions. The results demonstrate the potential of urinary steroid conjugate analysis as a practical and reliable method for non-invasive monitoring of reproductive status in the female saddle-back tamarin. © 1995 Wiley-Liss, Inc.