Population Dynamics of the Rubber Plantation Litter Beetle Luprops tristis, in Relation to Annual Cycle of Foliage Phenology of Its Host, the Para Rubber Tree, Hevea brasiliensis

The population dynamics of the rubber plantation litter beetle, Luprops tristis Fabricius 1801 (Coleoptera: Tenebrionidae) was assessed in relation to the phenology of leaf shedding and defoliation pattern of para rubber trees, Hevea brasiliensis Müll. Arg (Malpighiales: Euphorbiaceae), during a two year study period. The abundance of adults, larvae and pupae per 1m2 of litter sample was recorded. Post dormancy beetles appeared in leaf litter following annual leaf shedding, whereas larvae, pupae and teneral adults were present after leaf flush. No stages were recorded from plantations following the summer rains until the annual litter fall in the next season. Parental adults peaked at the time of leaf sprouting and tender leaf fall. Larvae and teneral adults peaked at the time of premature fall of green leaves and flowers. Teneral adults of six age classes were recorded and all entered dormancy irrespective of the feeding time available to each age class. Females outnumbered males in the parent generation, while the sex ratio of new generation adults was not biased towards either sex. The phenological stages of rubber trees included leaf fall in late December and early January, leaf sprouting and new leaf production in January and flowering in February. All feeding stages of L. tristis peaked in abundance when premature leaves are most abundant in the leaf litter. Prediction of the timing of appearance of various developmental stages of L. tristis in plantations, invasion into buildings and intensity of population build up in rubber belts is possible by tracking the phenology of leaf fall in rubber plantations, time of return of post dormancy adults and the onset of summer rainfall. Perfect synchrony was recorded between the field return of parental adults with annual leaf shedding, the oviposition phase of parental adults with tender leaf fall at the time of leaf sprouting, and larval and teneral adult stages with premature fall of leaves. Premature leaf availability is suggested as contributing to the reproductive efficiency of parental adults, the survival of early developmental stages and of new generation adults during dormancy

Comparative study of the antioxidant and reactive oxygen species scavenging properties in the extracts of the fruits of Terminalia chebula, Terminalia belerica and Emblica officinalis

<p>Abstract</p> <p>Background</p> <p>Cellular damage caused by reactive oxygen species (ROS) has been implicated in several diseases, and hence natural antioxidants have significant importance in human health. The present study was carried out to evaluate the <it>in vitro </it>antioxidant and reactive oxygen species scavenging activities of <it>Terminalia chebula</it>, <it>Terminalia belerica </it>and <it>Emblica officinalis </it>fruit extracts.</p> <p>Methods</p> <p>The 70% methanol extracts were studied for <it>in vitro </it>total antioxidant activity along with phenolic and flavonoid contents and reducing power. Scavenging ability of the extracts for radicals like DPPH, hydroxyl, superoxide, nitric oxide, hydrogen peroxide, peroxynitrite, singlet oxygen, hypochlorous acid were also performed to determine the potential of the extracts.</p> <p>Results</p> <p>The ability of the extracts of the fruits in exhibiting their antioxative properties follow the order <it>T. chebula </it>><it>E. officinalis </it>><it>T. belerica</it>. The same order is followed in their flavonoid content, whereas in case of phenolic content it becomes <it>E. officinalis </it>><it>T. belerica </it>><it>T. chebula</it>. In the studies of free radicals' scavenging, where the activities of the plant extracts were inversely proportional to their IC₅₀values, <it>T. chebula </it>and <it>E. officinalis </it>were found to be taking leading role with the orders of <it>T. chebula </it>><it>E. officinalis </it>><it>T. belerica </it>for superoxide and nitric oxide, and <it>E. officinalis </it>><it>T. belerica </it>><it>T. chebula </it>for DPPH and peroxynitrite radicals. Miscellaneous results were observed in the scavenging of other radicals by the plant extracts, viz., <it>T. chebula </it>><it>T. belerica </it>><it>E. officinalis </it>for hydroxyl, <it>T. belerica </it>><it>T. chebula </it>><it>E. officinalis </it>for singlet oxygen and <it>T. belerica </it>><it>E. officinalis </it>><it>T. chebula </it>for hypochlorous acid. In a whole, the studied fruit extracts showed quite good efficacy in their antioxidant and radical scavenging abilities, compared to the standards.</p> <p>Conclusions</p> <p>The evidences as can be concluded from the study of the 70% methanol extract of the fruits of <it>Terminalia chebula</it>, <it>Terminalia belerica </it>and <it>Emblica officinalis</it>, imposes the fact that they might be useful as potent sources of natural antioxidant.</p

Antidiabetic and renoprotective effects of the chloroform extract of Terminalia chebula Retz. seeds in streptozotocin-induced diabetic rats

BACKGROUND: Terminalia chebula (Combretaceae) has been widely used in Ayurveda for the treatment of diabetes. In the present investigation, the chloroform extract of T. chebula seed powder was investigated for its antidiabetic activity in streptozotocin-induced diabetic rats using short term and long term study protocols. The efficacy of the extract was also evaluated for protection of renal functions in diabetic rats. METHODS: The blood glucose lowering activity of the chloroform extract was determined in streptozotocin-induced (75 mg/kg, i.p.; dissolved in 0.1 M acetate buffer; pH 4.5) diabetic rats, after oral administration at the doses of 100, 200 and 300 mg/kg in short term study. Blood samples were collected from the eye retro-orbital plexus of rats before and also at 0.5, 1, 2, 4, 6, 8 and 12 h after drug administration and the samples were analyzed for blood glucose by using glucose-oxidase/peroxidase method using a visible spectrophotometer. In long term study, the extract (300 mg/kg) was administered to streptozotocin-induced diabetic rats, daily for 8 weeks. Blood glucose was measured at weekly intervals for 4 weeks. Urine samples were collected before the induction of diabetes and at the end of 8 weeks of treatments and analyzed for urinary protein, albumin and creatinine levels. The data was compared statistically using one-way ANOVA with post-hoc Dunnet's t-test. RESULTS: The chloroform extract of T. chebula seeds produced dose-dependent reduction in blood glucose of diabetic rats and comparable with that of standard drug, glibenclamide in short term study. It also produced significant reduction in blood glucose in long term study. Significant renoprotective activity is observed in T. chebula treated rats. The results indicate a prolonged action in reduction of blood glucose by T. chebula and is probably mediated through enhanced secretion of insulin from the β-cells of Langerhans or through extra pancreatic mechanism. The probable mechanism of potent renoprotective actions of T. chebula has to be evaluated. CONCLUSION: The present studies clearly indicated a significant antidiabetic and renoprotective effects with the chloroform extract of T. chebula and lend support for its traditional usage. Further investigations on identification of the active principles and their mode of action are needed to unravel the molecular mechanisms involved in the observed effects

EVALUATION OF HEPATOPROTECTIVE ACTIVITY OF DRACAENA TERNIFLORA ROXB. AGAINST ETHANOL INDUCED HEPATIC INJURY IN WISTAR ALBINO RATS

Objectives: The objectives of the study were to investigate hepatoprotective activity of ethanolic root extract of Dracaena terniflora Roxb. (DTR-E) in alcohol-induced hepatotoxicity in rats. Methods: Hepatotoxicity was induced in albino Wistar rats by oral administration of 40% ethanol (2 mL/100 g body weight). DTR-E root extract was administered at a dose level of 100 mg/kg and 200 mg/kg orally for 21 days. On the 22nd day blood was taken by puncturing retro orbital plexus and used for the estimation of biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, creatinine, urea, triglycerides, total cholesterol, albumin, and total protein. Animals were sacrificed by cervical dislocation and liver was dissected out and histopathological analysis of liver and kidney was carried out. Results: Obtained results revealed that administration of ethanol caused a significant increase in liver weight, plasma ALT, AST, ALP, bilirubin creatinine, urea, triglycerides,and total cholesterol compared to the control group, while total protein and albumin concentration are significantly declined which were effectively prevented by the DTR-E extract. The histopathological observations supported the biochemical evidence of hepatoprotection. Conclusions: The findings suggest that DTR-E root extract protects the liver cell from ethanol induced liver damages due to its antioxidative effect on hepatocytes. The results of the present investigation indicated that roots of D. terniflora Roxb. possesses significant hepatoprotective activity.</jats:p

Antioxidant activity of different extracts from leaves of Pereskia bleo (Cactaceae)

The present study was conducted to assess the antioxidant properties of ethanol, ethyl acetate, methanol and hexane extracts from leaves of Pereskia bleo using 2,2-diphenyl-1-picrylhydrazyl method (DPPH assay), ferric reducing antioxidant power (FRAP assay) and β-Carotene-Linoleic acid methods. Total phenolic compounds (TPC) and flavonoids of the leaves of P. bleo were measured using Folin-Ciocalteu and HPLC methods respectively. Results of the present study showed that Ethyl acetate extract of P. bleo leaf exhibited significantly (p < 0.05) higher antioxidant activity as measured using DPPH free radical (IC50), FRAP and β-carotene-linoleic assays than that of hexane extract, methanol extract and ethanol extract. Pereskia bleo leaf was also found to contain high amounts of bioactive compounds including total phenolic compounds (109.43 ±0.84 mg GAE/g), epicatechin (575± 0.04 mg/100g), quercetin (110.94 ±0.12 mg/100g), catechin (918 ± 0.01 mg/100 g) and myricetin (9.49±0.55 mg/100g) while the concentrations of α- tocopherol, β-carotene and lycopene were found to be higher (69±0.25, 51.97±1.18 mg/100 g, 92.46±0.41 μg/g), respectively