Cellulase enzyme was purified and characterized from termite soldiers (Ametermes eveuncifer) using 70% ammonium sulphate precipitation, ion exchange chromatography and affinity chromatography. The enzyme isolated had a specific activity of 5.04 U/mg with a percentage yield of 11.7%. The enzyme showed maximum activity at 50 0 C and pH 8. The enzyme was not inhibited by Ba 2+ at a concentration of 1mM and Pb 2+ at 10 mM concentration but was inhibited by other metal ions at 1 mM and 10 mM concentrations of their salts (NaCl, KCl, MnCl 2 , and NiCl 2 ) ,

Rhodanese, a cyanide detoxifying enzyme, was isolated from soldier termite using ammonium sulphate fractionation, reactive blue affinity chromatography and gel filtration on Sephadex G-150. The enzyme had a specific activity of 7.9 RU per milligram of protein. The K m values of the substrates (KCN and Na 2 S 2 O 3 ) were 7.0 mM and 5.3 mM respectively. The results of substrate specificity showed that the enzyme was specific for thiosulphate (S 2 O 3 2-) when compared with other sulphur compounds. The native and subunit molecular weight of the enzyme was found to be 37,154 and 32,210 dalton respectively. The optimum pH and temperature of the enzyme activity were 8.0 and 55 o C respectively. NH 4 + , Mn 2+ , and Ba 2+ had about 50 % effect on the activity of the enzyme. However, Hg 2+ , Zn 2+ and Mg 2+ inhibited the enzyme considerably (≤ 20 %). The half-life of the enzyme at 40 o C, 50 o C, 60 o C, 70 o C and 80 o C were found to be 150.7, 60.3, 43.0, 37.7 and 37.0 respectively.

In the present study, the hot and cold aqueous extracts of Digitaria exilis and Pentadiplandra brazzeana (Baill) as well as the ethanolic extract of Monodora myristica were screened for their anti diabetic activity via inhibition of α-amylase. The root of Pentadiplandra brazzeana Baill and the grains of Acha (Digitaria exilis) were extracted by Soaking in hot and cold water while the seed of Monodora myristica was extracted using 70% ethanol. α-amylase was significantly inhibited by Digitaria exilis, Pentadiplandra brazzeana Baill and Monodora myristica. Results showed that the three plants can act as potent α-amylase inhibitor. The cold aqueous extract of Pentadiplandra brazzeana Baill showed the highest inhibition against pancreatic α-amylase among the plants studied with IC 50 value of 197.63±1.450 µg/ml while the ethanolic extract of Monodora myristica showed the least with IC 50 value of 408.17±2.945. α-amylase inhibitors from herbal sources offer an attractive therapeutic approach to the treatment of postprandial hyperglycemia by decreasing glucose release from starch and may have potential for use in the treatment/management of diabetes mellitus and obesity.

The paper reports the tissue distribution of the enzyme arginase in three different Cichlids: Tilapia zilli, Sarotherodon galilaeus and Oreochromis niloticus, from the Aiba and Osinmo reservoirs, located in the southwestern Nigeria. The tissues of S. galilaeus showed very high activity of arginase as compared with the other two species. The liver of O. niloticus and the gut of T. zillii showed very high activity of arginase in the Osinmo reservoir. The high arginase activity observed in the tissues of these organisms is attributed to ureotelism and is similar to the result obtained for tilapia, Alcolapia grahami, from lake Magadi, Kenya.

Arginase (EC 3.5.3.1) catalyzes the hydrolysis of arginine to ornithine and urea. Arginase was purified and characterized from the gut of Zonocerus variegatus through DEAE-cellulose and biogel-P100 gel filtration chromatography. The specific activity of the enzyme was 3.7 µmoles/min per mg of protein and a yield of 14.7%. An apparent molecular weight of 143,000 daltons was estimated by gel filtration on biogel P-100. The Michaelis constant (K m) of the enzyme was 40 mM with arginine as substrate. The optimum pH was 8.0 and the optimum temperature was 40 o C for Z. variegatus arginase. The enzyme was stable up to 40 o C for 20 min and lost all of its activity at 80 o C. The enzyme was specific for arginine as substrate. The enzyme was strongly enhanced in the presence of Mn 2+ , Na + , NH 4 + and Hg 2+ showed similar activation. Ni 2+ and Zn 2+ slightly inhibited Z. variegatus. Chelating (EDTA, citrate, ascorbic acid and urea) and thio (2-mercaptoethanol and cystein) compounds inhibited the activity of arginase in Z. variegatus. While amino acids (proline, lysine, aspartate and valine) showed no inhibition on arginase activity. The presence of arginase in the gut of Zonocerus variegatus could be for other functions rather than urea production in urea cycle.

Arginase, rhodanese and thiaminase are enzymes often encountered and that play crucial roles in different metabolic pathways. These enzymes were found to be present in different fruits: avocado pear (Persea americana), water melon (Citrullu slanatus), green exotic apple (Malus domestica), red exotic apple (Malus pumila), red local apple (Syzygium malaccense); pink local apple (Syzygium samarangense); sweet orange (Citrus sinensis), tangerine (Citrus tangerina), lime (Citrus aurantifolia), pawpaw (Carica papaya), banana (Musa acuminata), pineapple (Ananas comosus) and grape (Citrus paradisi). It was found that avocado pear has highest activity of arginase, rhodanese and thiaminase than the rest of the fruits investigated. The specific activity of rhodanese was however highest in water melon while that of arginase was more or less the same in red local apple and avocado pear. Arginase was also seen to vary significantly in the different plant samples with orange having the highest mean value of activity while sweet potato showed no activity. The study provides information on the presence of thiaminase, arginase and rhodanese in the different plants for nutritional purpose.

No abstract

Anaphe venata entomophagy has previously been implicated in the aetiopathogenesis of seasonal ataxia in humans and altered motor function in rodents. Thus, we investigated the effect of A. venata Phosphate Buffer Saline (PBS) extract on stretching, ataxia and the possible mechanism(s) of action. Animals were divided into four groups (n = 6-12 per group) and graded doses of extract (100, 200 or 400 mg/kg) were administered intraperitoneally (i.p.) while the control group received saline. Behavioral scores were recorded for a period of 30 min immediately after the administration of saline or extract. The role of various receptors in the extract induced stretching and ataxia was evaluated using known receptor antagonists in other groups of rats. The in-vitro cholinesterase inhibition assay of the extract was also performed. The protein profile of the extract was evaluated using the Sodium Dodecyl Sulphate (SDS)-Polyacrylamide gel electrophoresis. Results showed that the extract induced significant (p<0.01) stretching and ataxia behavioural effects dose-dependently when compared to vehicle-treated rats. Pretreatment with the non-selective muscarinic antagonist, scopolamine, significantly (p<0.05) reversed both stretching and ataxia-induced behaviour of PBS extract at all dose levels however both flumazenil and naloxone did not show any significant effects. Anticholinesterase assay also provided evidence that the extract has inhibitory effect on acetylcholinesterase enzyme. Electrophoresis assay suggested that the major proteins in the extract are probably of small molecular weight. In conclusion, the A. venata PBS extract induced-behaviours are probably mediated via the activation of cholinergic-muscarinic receptor systems.