Effects of Aqueous Extract of Fresh Leaves of Abroma augusta L. on Oral Absorption of Glucose and Metformin Hydrochloride in Experimental Rats.

To get better control in disease conditions, many people take herbs with conventional medicines, therefore, posing a risk of potential pharmacokinetic interactions between herbs and conventional drugs. The aqueous extract of the fresh leaves of Abroma augusta L. (Family: Sterculiaceae, Bengali name: Ulatkambal, English name: Devil's cotton, DC) is viscous and used traditionally to treat diabetes mellitus. This study was done to investigate the probable mechanism by which the aqueous extract of Abroma augusta L. is beneficial in managing type 2 DM and to observe the effects of this extract on absorption of metformin hydrochloride from the gastrointestinal tract. Studies were conducted in healthy Long Evans rats using Na-carboxymethyl cellulose (CMC) as positive control. Both Na-CMC and WSF of DC significantly (P < 0.05) reduced the absorption of glucose administered orally in fasted rats. On the other hand, WSF of DC significantly (P < 0.05) reduced the absorption of metformin hydrochloride in alloxan-induced diabetic rats. The results of this study suggest that WSF of DC may be beneficial in diabetic patients to improve glycemic control but should not be coadministered with metformin HCl for management of type 2 diabetes mellitus.

Water-soluble Fraction of Abelmoschus esculentus L Interacts with Glucose and Metformin Hydrochloride and Alters Their Absorption Kinetics after Coadministration in Rats.

This study was done to investigate the effects of water-soluble fraction (WSF) of the fruits of Abelmoschus esculentus L (okra/lady's fingers) on absorption of oral glucose as well as metformin from the gastrointestinal tract in the Long Evans rats. WSF of A. esculentus significantly (P < 0.05) reduced the absorption of glucose as studied in the 24 hrs fasting rats. The effect of WSF of A. esculentus on metformin absorption was studied in alloxan-induced diabetic rats. Significant differences (P < 0.05) were observed in the average blood glucose level from 2 to 24 hours after metformin therapy in presence (33.6 to 34.2 mmol/L) or absence (15.2 to 20.2 mmol/L) of oral WSF of A. esculentus. In both of the experiments, Na-carboxymethylcellulose (CMC) was used as positive control. The results of this study indicate that A. esculentus may improve glycemic control but should not be taken concurrently with metformin hydrochloride in controlling diabetes mellitus.

Enzyme-linked immunosorbent assay to detect urinary antibody against recombinant rKRP42 antigen made from Leishmania donovani for the diagnosis of visceral leishmaniasis.

We recently reported the production of the recombinant kinesin-related protein of Leishmania donovani with a molecular weight of 42 kd (rKRP42) and the value of the antigen in serum-based ELISA for the diagnosis of visceral leishmaniasis (VL). In this study, the rKRP42 antigen was validated with ELISA using urine samples (rKRP42 urine ELISA). The urine-based ELISA showed 94% sensitivity (108 positives among 115 VL samples) and 99.6% specificity (239 negatives among 240 non-VL samples). The sensitivity and specificity are almost similar to our previous results by ELISA with acetone-treated L. donovani promastigote antigen and direct agglutination test, both methods being done by use of urine samples. A comparison of the rKRP42 urine ELISA with the commercially available urinary antigen detection kit (KAtex) using 108 VL samples showed much higher sensitivity of the ELISA (96.3%) than KAtex (55.6%). The use of the rKRP42 antigen with urine samples will facilitate epidemiologic studies.

Short report: production of recombinant kinesin-related protein of Leishmania donovani and its application in the serodiagnosis of visceral leishmaniasis.

To detect IgG antibody in the serodiagnosis of visceral leishmaniasis (VL), a recombinant antigen rK39, which is part of a Leishmania chagasi kinesin-related protein, has been used successfully and showed high sensitivity and specificity. We report production of a recombinant protein rKRP42, which is part of an L. donovani kinesin-related protein and a homolog of rK39, and its application in an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of VL. When rKRP42 and rK39 were compared, amino acid sequence analysis showed 89.3% identity and 98.7% homology, with rKRP42 having 39 more amino acids than rK39. The ELISA using rKRP42 showed a sensitivity of 94.6% (70 positive samples among 74 from VL patients) and a specificity of 99.3% (148 negative samples among 149 samples from Japanese controls), whereas the sensitivity of the commercial rK39 dipstick test was 93.2% (69 positive samples among 74 from patients with VL). The rKRP42 is a promising new antigen in developing immunodiagnostic methods for VL.