Kalavathy Ramasamy

Effects of dietary prebiotics, probiotic and synbiotics on performance, caecal bacterial populations and caecal fermentation concentrations of broiler chickens

BACKGROUND In view of a worldwide attempt to restrict or ban the use of antibiotics as growth promoters in animal production, probiotics, prebiotics and combinations of both, as synbiotics, have been suggested as potential alternatives. In this study, the effects of a prebiotic (isomalto-oligosaccharides, IMO), a multi-strain probiotic (consisting of 11 Lactobacillus strains), and a combination of these dietary additives as a synbiotic on the performance, caecal bacterial populations and concentrations of caecal volatile fatty acids and non-volatile fatty acids of broiler chickens were evaluated. RESULTS Supplementation of 1g kg⁻¹ probiotic (PRO); 5 g kg⁻¹ prebiotic IMO (PRE05); 10 g kg⁻¹ prebiotic IMO (PRE10); synbiotic consisting of 1g kg⁻¹ probiotic + 5 g kg⁻¹ prebiotic IMO (SYN05); or synbiotic consisting of 1 g kg⁻¹ probiotic + 10 g kg⁻¹ prebiotic IMO (SYN10) significantly (P < 0.05) improved weight gain of broiler chickens at 22-42 and 1-42 days of age, and feed conversion rate from 1 to 21, 22-42 and 1-42 days of age. The supplementation of probiotic (PRO), prebiotics (PRE05 and PRE10) or synbiotics (SYN05 and SYN10) also significantly (P < 0.05) increased the caecal populations of lactobacilli and bifidobacteria, and decreased the caecal Escherichia coli at 21 days of age, and increased the caecal VFA at 21 and 42 days of age. In all parameters studied, synbiotics did not show a two-fold synergistic effect, when compared to those of probiotic or prebiotic alone. CONCLUSION The results of the study indicated that prebiotic IMO (5 g kg⁻¹ or 10 g kg⁻¹), probiotic and their combinations as synbiotics were effective in improving the performance of broiler chickens and in increasing the caecal beneficial bacteria and fatty acids.

Bile salt deconjugation and cholesterol removal from media by Lactobacillus strains used as probiotics in chickens

BACKGROUND Bile salt deconjugation by Lactobacillus strains is often closely linked to bile tolerance and survival of the strains in the gut and lowering of cholesterol in the host. The present study investigated the deconjugation of bile salts and removal of cholesterol by 12 Lactobacillus strains in vitro. The 12 strains were previously isolated from the gastrointestinal tract of chickens. RESULTS The 12 Lactobacillus strains could deconjugate sodium glycocholate (GCA, 16.87-100%) and sodium taurocholate (TCA, 1.69-57.43%) bile salts to varying degrees, with all strains except L. salivarius I 24 having a higher affinity for GCA. The 12 Lactobacillus strains also showed significant (P < 0.05) differences in their ability to remove cholesterol from the growth medium (26.74-85.41%). Significant (P < 0.05) correlations were observed between cholesterol removal and deconjugation of TCA (r = 0.83) among the L. reuteri strains (C1, C10 and C16) and between cholesterol removal and deconjugation of TCA (r = 0.38) and GCA (r = 0.70) among the L. brevis strains (I 12, I 23, I 25, I 211 and I 218). In contrast, although L. gallinarum I 16 and I 26 and L. panis C 17 showed high deconjugating activity, there was no correlation between cholesterol removal and deconjugation of bile salts in these strains. CONCLUSION The results showed that the 12 Lactobacillus strains were able to deconjugate bile salts and remove cholesterol in vitro, but not all strains with high deconjugating activity removed cholesterol effectively.

Cytotoxic and antibacterial activities of endophytic fungi isolated from plants at the National Park, Pahang, Malaysia

BackgroundEndophytes, microorganisms which reside in plant tissues, have potential in producing novel metabolites for exploitation in medicine. Cytotoxic and antibacterial activities of a total of 300 endophytic fungi were investigated.MethodsEndophytic fungi were isolated from various parts of 43 plants from the National Park Pahang, Malaysia. Extracts from solid state culture were tested for cytotoxicity against a number of cancer cell lines using the MTT assay. Antibacterial activity was determined using the disc diffusion method.ResultsA total of 300 endophytes were isolated from various parts of plants from the National Park, Pahang. 3.3% of extracts showed potent (IC50 < 0.01 μg/ml) cytotoxic activity against the murine leukemic P388 cell line and 1.7% against a human chronic myeloid leukemic cell line K562. Sporothrix sp. (KK29FL1) isolated from Costus speciosus showed strong cytotoxicity against colorectal carcinoma (HCT116) and human breast adenocarcinoma (MCF7) cell lines with IC50 values of 0.05 μg/ml and 0.02 μg/ml, respectively. Antibacterial activity was demonstrated for 8% of the extracts.ConclusionResults indicate the potential for production of bioactive agents from endophytes of the tropical rainforest flora.

Design, synthesis, antimicrobial, anticancer evaluation, and QSAR studies of 4-(substituted benzylidene-amino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-ones

A series of 4-(substituted benzylidene-amino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-ones (1–17) was synthesized and tested in vitro for its antimicrobial and anticancer potentials. The biological screening results indicated that compounds having m-chloro substituent on benzaldehyde portion showed antimicrobial potential, whereas compounds having chloro, methoxy, and hydroxyl groups showed anticancer potential. The quantitative structure activity relationship (QSAR) studies indicated the importance of topological parameter, valence first order molecular connectivity index in describing antifungal activity. The developed QSAR models, however, were statistically insignificant with reference to anticancer activity of the synthesized compounds.

Chitosan coated alginate-xanthan gum bead enhanced pH and thermotolerance of Lactobacillus plantarum LAB12.

The vulnerability of probiotics at low pH and high temperature has limited their optimal use as nutraceuticals. This study addressed these issues by adopting a physicochemical driven approach of incorporating Lactobacillus plantarum LAB12 into chitosan (Ch) coated alginate-xanthan gum (Alg-XG) beads. Characterisation of Alg-XG-Ch, which elicited little effect on bead size and polydispersity, demonstrated good miscibility with improved bead surface smoothness and L. plantarum LAB12 entrapment when compared to Alg, Alg-Ch and Alg-XG. Sequential incubation of Alg-XG-Ch in simulated gastric juice and intestinal fluid yielded high survival rate of L. plantarum LAB12 (95%) at pH 1.8 which in turn facilitated sufficient release of probiotics (>7 log CFU/g) at pH 6.8 in both time- and pH-dependent manner. Whilst minimising viability loss at 75 and 90 °C, Alg-XG-Ch improved storage durability of L. plantarum LAB12 at 4 °C. The present results implied the possible use of L. plantarum LAB12 incorporated in Alg-XG-Ch as new functional food ingredient with health claims.

Antimicrobial and cytotoxic activities of Malaysian endophytes

Endophytes, which are receiving increasing attention, have been found to be potential sources of bioactive metabolites following the discovery of paclitaxel producing endophytic fungi. In the present study, a total of 348 endophytes were isolated from different parts of 24 Malaysian medicinal plants. Three selected endophytes (HAB10R12, HAB11R3 and HAB21F25) were investigated for their antimicrobial and cytotoxic activities. For antimicrobial activity, HAB10R12 and HAB11R3 were found to be most active against bacteria and fungi, respectively. Their antimicrobial effects were comparable to, if not better than, a number of current commercial antibacterial and antifungal agents. Both HAB10R12 and HAB21F25 were found to be potential anticancer drug candidates, having potent activity against MCF‐7 and HCT116 cell lines and warrant further investigation. Copyright

Reversal of memory deficits by Coriandrum sativum leaves in mice

BACKGROUND Coriandrum sativum L., commonly known as coriander and belonging to the family Apiaceae (Umbelliferae), is cultivated throughout the world for its nutritional value. The present study was undertaken to investigate the effects of fresh Coriandrum sativum leaves (CSL) on cognitive functions, total serum cholesterol levels and brain cholinesterase activity in mice. In this study, CSL (5, 10 and 15% w/w of diet) was fed orally with a specially prepared diet for 45 days consecutively to experimental animals. Elevated plus-maze and passive avoidance apparatus served as the exteroceptive behavioral models for testing memory. Diazepam, scopolamine and ageing-induced amnesia served as the interoceptive behavioral models. RESULTS CSL (5, 10 and 15% w/w of diet) produced a dose-dependent improvement in memory scores of young as well as aged mice. CSL also reversed successfully the memory deficits induced by scopolamine (0.4 mg kg(-1), i.p.) and diazepam (1 mg kg(-1), i.p.). Interestingly, brain cholinesterase activity and serum total cholesterol levels were considerably reduced by CSL administration in daily diets concomitantly for 45 days. CONCLUSION CSL may be a useful remedy in the management of Alzheimers disease on account of its multifarious effects such as, memory-improving property, cholesterol-lowering property and anticholinesterase activity.

Probiotics for the management of type 2 diabetes mellitus: A systematic review and meta-analysis

AIMS To systematically review evidence of probiotic interventions against type 2 diabetes mellitus (T2DM) and analyse the effects of probiotics on glycaemic control among T2DM patients. METHODS Electronic search using five electronic databases was performed until October 2015. Relevant studies were identified, extracted and assessed for risk of bias. The primary outcomes of this review were glycated haemoglobin (HbA1c) and fasting blood glucose (FBG). Fasting plasma insulin, homeostasis model assessment-insulin resistance, C-reactive protein, interleukin-6 and malondialdehyde, were identified as the secondary outcomes. Mean differences (MD) between probiotics and control groups for all outcomes were pooled using either Fixed- or Random-Effect Model. Statistical heterogeneity was assessed using I(2) and Chi(2) tests. RESULTS Six randomised controlled trials (RCTs) were included in the systematic review, whereas only five were included in meta-analysis. Most RCTs were presented with low or unclear risk of bias. When compared to placebo, FBG was significantly lower with probiotic consumption (MD=-0.98mmol/L; 95% CI: -1.17, 0.78, p<0.00001), with moderate but insignificant heterogeneity noted. Insignificant changes between the groups were also noted for HbA1c and other secondary outcomes. CONCLUSIONS A moderate hypoglycaemic effect of probiotics, with a significantly lower FBG was noted. Findings on HbA1c, anti-inflammatory and anti-oxidative effects of probiotics in the clinical setting, however, remain inconsistent. The findings imply the need for well-designed clinical studies to further assess the potential beneficial effects of probiotics in management of T2DM.

Protective effects of total alkaloidal extract from Murraya koenigii leaves on experimentally induced dementia.

Dementia is a syndrome of gradual onset and continuous decline of higher cognitive functioning. It is a common disorder in older persons and has become more prevalent today. The fresh leaves of Murraya koenigii are often added to various dishes in Asian countries due to the delicious taste and flavor that they impart. These leaves have also been proven to have health benefits. In the present study, the effect of total alkaloidal extract from M. koenigii leaves (MKA) on cognitive functions and brain cholinesterase activity in mice were determined. In vitro β-secretase 1 (BACE1) inhibitory activity was also evaluated. The total alkaloidal extract was administered orally in three doses (10, 20 and 30 mg/kg) for 15 days to different groups of young and aged mice. Elevated plus maze and passive avoidance apparatus served as the exteroceptive behavioral models for testing memory. Diazepam-, scopolamine-, and ageing-induced amnesia served as the interoceptive behavioral models. MKA (20 and 30 mg/kg, p.o.) showed significant improvement in memory scores of young and aged mice. Furthermore, the same doses of MKA reversed the amnesia induced by scopolamine (0.4 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.). Interestingly, the brain cholinesterase activity was also reduced significantly by total alkaloidal extract of M. koenigii leaves. The IC50 value of MKA against BACE1 was 1.7 μg/mL. In conclusion, this study indicates MKA to be a useful remedy in the management of Alzheimers disease and dementia.

Total isoflavones from soybean and tempeh reversed scopolamine-induced amnesia, improved cholinergic activities and reduced neuroinflammation in brain

The present study was undertaken to compare the neuroprotective effects between total isoflavones from soybean and tempeh against scopolamine-induced cognitive dysfunction. Total isoflavones (10, 20 and 40mg/kg) from soybean (SI) and tempeh (TI) were administered orally to different groups of rats (n=6) for 15days. Piracetam (400mg/kg, p.o.) was used as a standard drug while scopolamine (1mg/kg, i.p.) was used to induce amnesia in the animals. Radial arm and elevated plus mazes served as exteroceptive behavioural models to measure memory. Brain cholinergic activities (acetylcholine and acetylcholinesterase) and neuroinflammatory activities (COX-1, COX-2, IL-1β and IL10) were also assessed. Treatment with SI and TI significantly reversed the scopolamine effect and improved memory with TI group at 40mg/kg, p.o. exhibiting the best improvement (p<0.001) in rats. The TI (10, 20 and 40mg/kg, p.o.) significantly increased (p<0.001) acetylcholine and reduced acetylcholinesterase levels. Meanwhile, only a high dose (40mg/kg, p.o.) of SI showed significant improvement (p<0.05) in the cholinergic activities. Neuroinflammation study also showed that TI (40mg/kg, p.o.) was able to reduce inflammation better than SI. The TI ameliorates scopolamine-induced memory in rats through the cholinergic neuronal pathway and by prevention of neuroinflammation.