Clinical evaluation of purified Shilajit on testosterone levels in healthy volunteers.

Purified Shilajit, an Ayurvedic rasayana, was evaluated in healthy volunteers of age between 45 and 55 years for its effect on male androgenic hormone viz. testosterone in a randomised, double-blind, placebo-controlled clinical study at a dose of 250 mg twice a day. Treatment with Shilajit for consecutive 90 days revealed that it has significantly (P < 0.05) increased total testosterone, free testosterone and dehydroepiandrosterone (DHEAS) compared with placebo. Gonadotropic hormones (LH and FSH) levels were well maintained.

A novel Gymnema sylvestre extract stimulates insulin secretion from human islets in vivo and in vitro.

Many plant-based products have been suggested as potential antidiabetic agents, but few have been shown to be effective in treating the symptoms of Type 2 diabetes mellitus (T2DM) in human studies, and little is known of their mechanisms of action. Extracts of Gymnema sylvestre (GS) have been used for the treatment of T2DM in India for centuries. The effects of a novel high molecular weight GS extract, Om Santal Adivasi, (OSA(R)) on plasma insulin, C-peptide and glucose in a small cohort of patients with T2DM are reported here. Oral administration of OSA(R) (1 g/day, 60 days) induced significant increases in circulating insulin and C-peptide, which were associated with significant reductions in fasting and post-prandial blood glucose. In vitro measurements using isolated human islets of Langerhans demonstrated direct stimulatory effects of OSA(R) on insulin secretion from human ß-cells, consistent with an in vivo mode of action through enhancing insulin secretion. These in vivo and in vitro observations suggest that OSA(R) may provide a potential alternative therapy for the hyperglycemia associated with T2DM.

Clinical evaluation of spermatogenic activity of processed Shilajit in oligospermia.

The safety and spermatogenic activity of processed Shilajit (PS) were evaluated in oligospermic patients. Initially, 60 infertile male patients were assessed and those having total sperm counts below 20 million ml(-1) semen were considered oligospermic and enrolled in the study (n = 35). PS capsule (100 mg) was administered twice daily after major meals for 90 days. Total semenogram and serum testosterone, luteinising hormone and follicle-stimulating hormone were estimated before and at the end of the treatment. Malondialdehyde (MDA), a marker for oxidative stress, content of semen and biochemical parameters for safety were also evaluated. Twenty-eight patients who completed the treatment showed significant (P < 0.001) improvement in spermia (+37.6%), total sperm count (+61.4%), motility (12.4-17.4% after different time intervals), normal sperm count (+18.9%) with concomitant decrease in pus and epithelial cell count compared with baseline value. Significant decrease of semen MDA content (-18.7%) was observed. Moreover, serum testosterone (+23.5%; P < 0.001) and FSH (+9.4%; P < 0.05) levels significantly increased. HPLC chromatogram revealed inclusion of PS constituents in semen. Unaltered hepatic and renal profiles of patients indicated that PS was safe at the given dose. The present findings provide further evidence of the spermatogenic nature of Shilajit, as attributed in Ayurvedic medicine, particularly when administered as PS.

Chemical and pharmacological evaluation of different ayurvedic preparations of iron.

Ayurvedic preparations of metallic iron commonly categorised as different 'putas' of 'Louha Bhasma' was chemically analysed and pharmacologically investigated in iron deficiency anemia. Atomic absorption spectral (AAS) study of different putas of Louha Bhasma revealed the presence of various proportions of important metals along with varied concentration of iron in it. The effect of a representative puta viz. 50 puta of Louha Bhasma in the management of agar gel diet and phlebotomy induced iron deficiency anemia in animal model was found to be statistically highly significant (P < 0.001) in comparison to the control and standard drug Fefol treated groups.

Purification and characterization of human NTH1, a homolog of Escherichia coli endonuclease III. Direct identification of Lys-212 as the active nucleophilic residue.

The human endonuclease III (hNTH1), a homolog of the Escherichia coli enzyme (Nth), is a DNA glycosylase with abasic (apurinic/apyrimidinic (AP)) lyase activity and specifically cleaves oxidatively damaged pyrimidines in DNA. Its cDNA was cloned, and the full-length enzyme (304 amino acid residues) was expressed as a glutathione S-transferase fusion polypeptide in E. coli. Purified wild-type protein with two additional amino acid residues and a truncated protein with deletion of 22 residues at the NH2 terminus were equally active and had absorbance maxima at 280 and 410 nm, the latter due to the presence of a [4Fe-4S]cluster, as in E. coli Nth. The enzyme cleaved thymine glycol-containing form I plasmid DNA and a dihydrouracil (DHU)-containing oligonucleotide duplex. The protein had a molar extinction coefficient of 5.0 x 10(4) and a pI of 10. With the DHU-containing oligonucleotide duplex as substrate, the Km was 47 nM, and kcat was approximately 0.6/min, independent of whether DHU paired with G or A. The enzyme carries out beta-elimination and forms a Schiff base between the active site residue and the deoxyribose generated after base removal. The prediction of Lys-212 being the active site was confirmed by sequence analysis of the peptide-oligonucleotide adduct. Furthermore, replacing Lys-212 with Gln inactivated the enzyme. However, replacement with Arg-212 yielded an active enzyme with about 85-fold lower catalytic specificity than the wild-type protein. DNase I footprinting with hNTH1 showed protection of 10 nucleotides centered around the base lesion in the damaged strand and a stretch of 15 nucleotides (with the G opposite the lesion at the 5'-boundary) in the complementary strand. Immunological studies showed that HeLa cells contain a single hNTH species of the predicted size, localized in both the nucleus and the cytoplasm.

Specific interaction of wild-type and truncated mouse N-methylpurine-DNA glycosylase with ethenoadenine-containing DNA.

N-Methylpurine-DNA glycosylase (MPG), a ubiquitous DNA repair enzyme, is responsible for the removal of a wide variety of alkylated base lesions in DNA, e.g., N-alkylpurines and cyclic ethenoadducts of adenine, guanine, and cytosine. These lesions, some of which are mutagenic and toxic, are generated endogenously or by genotoxic agents such as N-alkylnitrosamines and vinyl chloride. Wild-type mouse MPG, expressed from recombinant baculovirus, was purified to near homogeneity for studying its specific interaction with substrate, 1,N6-ethenoadenine- (epsilonA-) containing DNA. Electrophoretic mobility shift assays (EMSA) indicated that MPG formed a specific complex with a 50-mer epsilonA-containing duplex oligonucleotide. This complex was shown to be a transient reaction intermediate, because it could be formed only with the unreacted substrate and contained active enzyme molecules. DNA footprinting studies confirmed the specific binding of the protein to the epsilonA-containing duplex oligonucleotide; eight nucleotides on the epsilonA-containing strand and 16-17 nucleotides in the complementary strand spanning the base adduct were protected from DNase I digestion. A systematic deletion analysis of MPG was carried out in order to determine the minimally sized polypeptide capable of forming a stable substrate complex that is also suitable for characterization by NMR spectroscopy and X-ray crystallography. A truncated polypeptide (NDelta100CDelta18) lacking 100 and 18 amino acid residues from the amino and carboxyl termini, respectively, was found to be the minimal size that retained activity. The truncated and wild-type enzymes have similar kinetic properties. Moreover, both EMSA and DNase I footprinting studies indicated identical pattern of specific binding by the truncated and full-length polypeptides. Removal of five and nine additional residues from the amino- and carboxyl-termini of this polypeptide, respectively, resulted in a complete loss of activity. These results suggest that minimal structural change occured as a result of truncation in the NDelta100CDelta18 mutant, which may thus be suitable for elucidating the structure and mechanism of MPG.

Purification of acid phosphatase I from germinating seeds of Vigna sinensis.

Acid phosphatase I (AP-I) is the major isoform of Vigna acid phosphatase. It is constitutively expressed in seed cotyledons during germination. AP-I was separated from other isoforms and purified to homogeneity by three simple purification steps; (NH4)2SO4 precipitation, and phosphocellulose and DEAE-cellulose column chromatography. The activity of AP-I was not affected by 1 mM Mg2+, Mn2+, Ca2+, Co2+ or Pb2+, but severely inhibited by 1 mM Cu2+, Fe3+, Hg2+, Mo6+ or Zn2+. AP-I has both phosphatase and pyrophosphatase activities, and is highly stable even at 50 degrees.