P. Gopalakrishna Bhat

Enzyme inhibitors from plants: Enterokinase inhibitors in tubers and seeds

Of the 22 tubers and 9 pulses screened for inhibitors of enterokinase activity, the following 12 tubers,Curcuma amada, Kyllinga monocephala, Solanum tuberosum, Canna indica, Helianthus tuberosus, Coleus parviformis, Mirabilis jalapa, Colocasia antiquorum (red variety),Alium cepa, Amorphophalus companulatus, Maranta arundinacea, Daucus carota, and 9 pulses namely,Vigna sinensis, Arachis hypogea, Pisum sativum, Phaseolus vulgaris (white bean),Phaseolus vulgaris (kidney bean),Phaseolus mungo, Cicer arietinum, Dolichos lablab and Cajonus cajan contained inhibitory activity. Three tubers,Amorphophalus companulatus, Maranta arundinacea andDaucus carota and all the nine pulses exhibited endogenous esterase activity towards benzoyl arginine ethyl ester. Among the 8 pulses and 3 tubers processed by affinity chromatography on trypsin-sepharose, to separate trypsin inhibitor from enterokinase inhibitor,Phaseolus vulgaris (kidney bean),Phaseolus vulgaris (white bean) andDolichos lablab contained distinct enterokinase inhibitors. These fractions were devoid of trypsin inhibitor activity. The trypsin inhibitor fromColeus parviformis tubers alone did not bind to trypsinsepharose and was recovered in the unbound fraction along with the enterokinase inhibitor.

Estimation of serum α2-macroglobulin based on the esterolytic activity of bound α-chymotrypsin

A colorimetric method to estimate α2-macroglobulin (MG) in human serum is described which is based on the capacity of MG: α-chymotrypsin complex to hydrolyze N-acetyl l-tyrosine ethyl ester in the presence of excess crude preparation of a trypsin/chymotrypsin inhibitor from redwood seed. Acetyltyrosine formed was measured using Folins reagent (7). The method was found to be as reliable as, but at least five times more sensitive than the procedures described using trypsin and soybean trypsin inhibitor. MG level is expressed in terms of micrograms of bovine α-chymotrypsin bound. Serum from healthy males had a lower value (150.5 ± 31.9 μg/ml, n = 20) than in females (196.8 ± 40.4, n = 20). No significant difference between the levels in fasting and postprandial conditions was observed.

Effect of varying durations of pyramid exposure — an indication towards a possibility of overexposure

Miniature replicas modeled after the Great Pyramid of Giza are believed to concentrate geoelectromagnetic energy within their cavities and hence act as antistressors in humans and animals. Although there are not many reports of adverse effects of ‘overexposure’ in the pyramid, subjects have claimed to feel uneasy after certain duration of staying in the pyramid. The present study was aimed to analyze the effects of prolonged pyramid exposure on plasma cortisol level, markers of oxidative damage and antioxidant defense in erythrocytes of adult female Wistar rats. Rats were divided into three groups, normal controls (NC, n=6) that were maintained under standard laboratory conditions in their home cages, pyramid exposed group-2 (PE-2, n=6) & pyramid exposed group-4 (PE-4, n=6) where the rats were housed under the pyramid for 6 hours/day for 2 weeks and 4 weeks respectively. Plasma cortisol and erythrocyte TBARS levels were significantly lower in both PE-2 and PE-4 rats and erythrocyte GSH levels and GSH-Px activity were significantly higher in them as compared to the NC rats. There was no significant difference in the results for these parameters between the PE-2 and PE-4 rats except for erythrocyte GSH-Px activity which was significantly more in the PE-2 rats than in the PE-4 rats. Although these results don’t confirm any adverse effects of prolonged exposure in pyramids, they indicate a possibility of such adverse effects.

CAN SERUM GLUTATHIONE-S-TRANSFERASE LEVELS IN CARCINOMA CERVIX BE A PREDICTOR OF RADIATION RESPONSE?

We conducted a pilot study wherein serum Glutathione-S-transferase levels were measured before and after radiotherapy in carcinoma cervix patients and correlated with response to treatment during a two-year follow-up period. Out of 17 patients who received radiotherapy, 9 showed a significant decrease (p<0.005) while 8 showed significant increase (p<0.004) in post radiotherapy glutathione-S-transferase values as compared to pre treatment values respectively. These patients were followed up for two years and we observed that 71% who had significant increase in post radiotherapy values had relapse of cancer within 2 years where as 66% of those who had significant decrease in post radiotherapy values had no evidence of relapse. This shows that alterations in serum Glutathione-S-transferase levels may help us to predict radiation response