Androgenic effect of honeybee drone milk in castrated rats: roles of methyl palmitate and methyl oleate.

ETHNOPHARMACOLOGICAL RELEVANCE: Numerous honeybee (Apis mellifera) products have been used in traditional medicine to treat infertility and to increase vitality in both men and women. Drone milk (DM) is a relatively little-known honeybee product with a putative sexual hormone effect. The oestrogenic effect of a fraction of DM has recently been reported in rats. However, no information is available on the androgenic effects of DM. The purpose of the present study was to determine the androgen-like effect of DM in male rats and to identify effective compounds. MATERIALS AND METHODS: A modified Hershberger assay was used to investigate the androgenic effect of crude DM, and the plasma level of testosterone was measured. The prostatic mRNA and protein expression of Spot14-like androgen-inducible protein (SLAP) were also examined with real-time PCR and Western blot techniques. GC-MS and NMR spectroscopic investigations were performed to identify the active components gained by bioactivity-guided fractionation. RESULTS: The crude DM increased the relative weights of the androgen-dependent organs and the plasma testosterone level in castrated rats and these actions were flutamide-sensitive. DM increased the tissue mRNA and protein level of SLAP, providing further evidence of its androgen-like character. After bioactivity-guided fractionation, two fatty acid esters, methyl palmitate (MP) and methyl oleate (MO), were identified as active compounds. MP alone showed an androgenic effect, whereas MO increased the weight of androgen-sensitive tissues and the plasma testosterone level only in combination. CONCLUSION: The experimental data of DM and its active compounds (MO and MP) show androgenic activity confirming the traditional usage of DM. DM or MP or/and MO treatments may project a natural mode for the therapy of male infertility.

Metabolic effects of mulberry leaves: exploring potential benefits in type 2 diabetes and hyperuricemia.

The leaves of Morus alba L. have a long history in Traditional Chinese Medicine and also became valued by the ethnopharmacology of many other cultures. The worldwide known antidiabetic use of the drug has been suggested to arise from a complex combination effect of various constituents. Moreover, the drug is also a potential antihyperuricemic agent. Considering that type 2 diabetes and hyperuricemia are vice-versa in each other's important risk factors, the use of mulberry originated phytotherapeutics might provide an excellent option for the prevention and/or treatment of both conditions. Here we report a series of relevant in vitro and in vivo studies on the bioactivity of an extract of mulberry leaves and its fractions obtained by a stepwise gradient on silica gel. In vivo antihyperglycemic and antihyperuricemic activity, plasma antioxidant status, as well as in vitro glucose consumption by adipocytes in the presence or absence of insulin, xanthine oxidase inhibition, free radical scavenging activity, and inhibition of lipid peroxidation were tested. Known bioactive constituents of M. alba (chlorogenic acid, rutin, isoquercitrin, and loliolide) were identified and quantified from the HPLC-DAD fingerprint chromatograms. Iminosugar contents were investigated by MS/MS, 1-deoxynojirimycin was quantified, and amounts of 2-O-alpha-D-galactopyranosyl-1-deoxynojirimicin and fagomine were additionally estimated.

5-Alpha- and 5-beta-2-deoxyintegristerone A, a 5-alpha and 5-beta isomer pair of ecdysteroids isolated from the Silene genus.

5-Alpha-2-deoxyintegristerone A and 5-beta-2-deoxyintegristerone A were isolated from the aerial parts of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman using a specific combination of absorption column chromatography, preparative thin-layer chromatography and preparative HPLC. Both normal-phase and reversed-phase modes of HPLC were employed for isolation. Structural elucidation of 5-alpha-2-deoxyintegristerone A was completed by X-ray diffraction. Both 5-alpha-2-deoxyintegristerone A and 5-beta-2-deoxyintegristerone A were firstly isolated from this plant. We propose that 5-alpha-2-deoxyintegristerone A is not an artifact but an integral part of the ecdysteroid spectrum of Silene italica ssp. nemoralis (Waldst. and Kit.) Nyman.

[Structural diversity of ecdysteroids of Lychnis flos-cuculi]. / A Lychnis flos-cuculi ekdiszteroidjainak szerkezeti diverzitása.

Eleven ecdysteroids have been isolated from Lychnis floscuculi; we are the first who report eight ecdysteroids of the eleven compounds in this plant. Two of these ecdysteroids, dihydrorubrosterone and 20-hydroxyecdysone 3-acetate are newly discovered natural products. The success of isolation of these new ecdysteroids has been based on the use of separation methods in a proper order; these separation procedures were completing each others. At the beginning steps of isolation simple separation methods were used, such a solvent-solvent distribution and fractionated precipitation. Two third of the contaminants were removed thereby. High capacity low resolution methods were used then, such as classical adsorption column chromatography and preparative thin-layer chromatography. The major component (20-hydroxyecdyssone) and certain minor ecdysteroids (polypodine B and rubrosterone) were isolated in pure form here. Purification of the further minor components (poststerone, 2-deoxy-20-hydroxyecdysone, vitikosterone E, dihydrorubrosterone, makisterone A, taxisterone, 20-hydroxyecdysone 2-acetate, 20-hydroxyecdysone 3-acetate) required HPLC and other absorption chromatographic methods. Our recent separation scheme means a generally applicable guiding principle for isolation of any plant ecdysteroid, major and minor alike. Structural identification of the known ecdysteroids was based on their spectral data and that of their literature information. Structural elucidation of 20-hydroxyecdysone 3-acetate was done by the help of a standard component prepared by acetylation of 20-hydroxyecdysone. From the mixture of seven acetates the corresponding compound (20-hydroxyecdysone 3-acetate) was isolated, and used for identification. Structural diversity of ecdysteroids of Lychnis flos-cuculi is evaluated, and a tentative explanation is introduced for the formation and biosynthesis of the versatility of phytoecdysteroids.

Isolation of 5 alpha- and 5 beta-dihydrorubrosterone from Silene otites L. (Wib).

5 alpha-Dihydrorubrosterone (2 beta, 3 beta, 14 alpha, 17 beta-tetrahydroxy-5 alpha-androst-7-ene-6-one), a new 19-carbon 5 alpha-ecdysteroid, was isolated together with its 5 beta counterpart from the aerial parts of Silene otites L. (Wib.) (Caryophyllaceae) by a combination of solvent partition, low-pressure column chromatography, thin-layer chromatography (normal-phase and reversed-phase) and finally HPLC. Mass spectrometry and nuclear magnetic resonance spectroscopic procedures were used for compound characterization.

The analysis and crystallographic characterization of 20-hydroxyecdysone.

20-Hydroxyecdysone (20E) is an insect molting hormone that is also widely spread in various plants. Many chromatographic methods can be used to identify and/or determine 20E content in samples of biological origin and various spectroscopic methods serve to identify its structural elements. We have utilized X-ray crystallography to reveal the stereostructures of 20E. Our data demonstrates that 20E exists in two different crystalline forms that are both orthorhombic modifications. One form is homo-molecular, with a limited freedom of internal rotation of the side chain around the C23-C24 bond and the other, which is a clathrate formed with methanol and water, which minimize the conformational freedom of the side chain.

[Components of Serratula species; screening for ecdysteroid and inorganic constituents of some Serratula plants]. / Serratula fajok 20-hidroxiekdizon és szervetlen elem tartalmának vizsgálata.

Ecdysteroid and inorganic components were analyzed from several plant species belonging to Caryophyllaceae family, such as in the cases of Serratula tinctoria, Serratula wolffii, Serratula coronata (20-hydroxyecdysone and inorganic components) and Jurinea mollis, Serratula gmellinii and Leuzea carthamoides (inorganic components, only). The 20-hydroxyecdysone content was determined using thin-layer chromatography after a simple clean up that had been performed by solid-phase extraction. Inorganic constitutents were determined using either ICP or flame photometry. Vegetation dependence of both 20-hydroxyecdysone and inorganic elements was studied. Serratula coronata shows remarkable high 20-hydroxyecdysone (2.3%, in April) and the studied Serratula plants gave a minimum of 20-hydroxyecdysone in June. Favorable period for harvesting is suggested as July and August, through the blossoming of these plants. Potassium and 20-hydroxyecdysone content gave a similar tendency considering their vegetation dependence, while the magnesium content moved toward opposite direction. The calcium contents of Serratula tinctoria, Serratula wolffii and Serratula coronata were found between 2.2% and 3.8%, which values are high relative to the other medicinal plants. At the same time, the Cu content of the ecdysteroid producing (and screened) Caryophyllaceae plants is low. The Fe, Mn and Mg contents of Serratula coronata are high, even higher than that of the Leuzea carthamoides. Our results have suggested the importance of analysis and control of inorganic constituents of crude plant extracts used for medicinal and recreational purposes.

Gas-chromatographic study on the stereoselectivity of deprenyl metabolism.

The metabolism and urinary elimination of both (-)-deprenyl and (+)-deprenyl have been studied. Gas-chromatographic analysis with mass specific detection indicated that the metabolism of (-)-deprenyl results in a large excess of methamphetamine compared to amphetamine, while the metabolism of (+)-deprenyl gave nearly equal amounts of amphetamine and methamphetamine. A novel deprenyl metabolite, phenylacetone, was also identified in our studies.

Isolation and Structural Elucidation of Two Plant Ecdysteroids, Gerardiasterone and 22-Epi-20-hydroxyecdysone

Two minor plant ecdysteroids, 22-epi-20-hydroxyecdysone (1) and gerardiasterone (2), were isolated from Serratula tinctoria L. (Compositae). The first compound, a new natural product, was characterized by an unusual stereochemistry at C-22 (i.e., 22S). The second compound was identified as (20R,23S)-20,23-dihydroxyecdysone, a compound previously isolated from the Zooanthid Gerardia savaglia.

Formaldehyde generation by N-demethylation.

Microsomal oxidation of exogenic compounds yields efferent metabolites with small molecular size. N-demethylation results in formaldehyde generation in addition to the nor-compound. Interesting changes in the level of formaldehyde elimination were observed after a single dose of either ( )-deprenyl or (+)-deprenyl. Urine elimination of the generated formaldehyde was determined using thin-layer chromatography after derivatization with dimedone.

New minor ecdysteroids from Silene otites (L.) Wib.

Six minor new ecdysteroid components have been isolated from Silene otites (L.) Wib. by a combination of chromatographic methods. Three of them (2-deoxy-20-hydroxyecdysone 3,22-diacetate, 5 alpha-2-deoxy-20-hydroxyecdysone 3-acetate, and 2-deoxy-20-hydroxyecdysone 3-crotonate) are new natural products.

Urinary excretion of deprenyl metabolites.

(+)-Deprenyl metabolites in rat's urine, such as nordeprenyl. methamphetamine amphetamine and p-hydroxy. methamphetamine were identified by HPLC-MS. After oral administration of 10 mg of pure (-)- and (+)-deprenyl to human volunteers, their urine was analyzed by gas chromatography. The concentration of methamphetamine was found to be overwhelming in the case of the (-)-isomer, while amphetamine and methamphetamine were excreted in equal amounts when (+)-deprenyl was administered. The metabolic processes of deprenyl resulted in metabolites possessing different lipophilicity, as it has been shown by planar displacement chromatography.

[Droplet countercurrent chromatography to isolate ecdysteroids from the herb Silene tatarica (L>)]. / Ellenáramú cseppmegoszlásos kromatorgáfia alkalmazása ekdiszteroidok izolálására.

Our research project was to isolate ecdysteroids from Silene tatarica (L.) Pers., which plant belongs to Caryophyllaceae family. This plant as a species of the Silence genus has been considered as a good potential source of ecdysteroids, including new, hitherto never identified natural product(s). The raw material of isolation was the herba of Silene tatarica (L.) Pers. that was cultivated in the fields of the Ecological and Botanical Research Institute of the Hungarian Academy of Sciences (Vácrátót, Hungary) and the plants were collected in June of 1994. The isolation procedure started with methanol extraction of the ground and milled herba. To improve the recovery, the extraction was done with boiling methanol under reflux for 20 minutes. The crude extract was purified using simple techniques, such as fractioned precipitation (with acetone), solvent-solvent partition (benzene-aqueous methanol). Further purification includes droplet counter-current chromatography (chloroform-methanol-water, 65:20:20, v/v/v) and straight-phase HPLC (silica stationary phase, dichloromethane-150 propanol-water. 125:25:2 v/v/v, mobile phase). Structural identification was done by using mass spectrometry and NMR spectroscopy. Three of the isolated ecdysteroids were identified as 20-hydroxyecdysone, 2-deoxy-20-hydroxyecdysone and 20-hydroxyecdysone-22-benzoate these compounds have never been detected in Silene tatarica (L.) Pers. Structural elucidation of the fourt isolated ecdysteroid resulted in a new natural product with the chemical structure of 2-deoxy-20-hydroxyecdysone 22-benzoate.

New Ecdysteroids from Serratula tinctoria.

Six new ecdysteroids have been isolated from SERRATULA TINCTORIA; these are: the 2,22- and 3,22-diacetates of 20-hydroxyecdysone, 5beta-hydroxyrubrosterone, 3-epi-poststerone, 3-epi-rubrosterone, and 22-oxo-20-hydroxyecdysone. These minor compounds were found together with the known ecdysteroids, 20-hydroxyecdysone, its 2-, 3-, and 22-monoacetates, rubrosterone, poststerone, polypodine B (5beta,20-dihydroxyecdysone), pterosterone (25-deoxy-20,24-dihydroxyecdysone), and makisterone C (24-ethyl-20-hydroxyecdysone). All these ecdysteroids were isolated by a combination of several chromatographic techniques (liquid chromatography on alumina, DCCC, and HPLC), then identified using standard mass spectrometric and 2D (1)H-NMR techniques.