Objective: To evaluate the toxicological and psychotropic properties of Calotropis(C.) procera. Methods: C. procera leaves and root-bark aqueous extracts were evaluated for their toxic and behavioral effects using adu...Objective: To evaluate the toxicological and psychotropic properties of Calotropis(C.) procera. Methods: C. procera leaves and root-bark aqueous extracts were evaluated for their toxic and behavioral effects using adult mice. Toxicity studies were carried out using Organisation for Economic Cooperation and Development guidelines 423 and 407 for acute and subacute evaluation. Behavioral studies were performed using traction test, fireplace test, hole-board test and forced-swimming test to evaluate the sedative, anxiety and depressive-like activities of the extracts. Results: Very low acute toxicity was observed in mice that received both leaves and rootbark extracts. The subacute test showed some morphological, biochemical and hematological changes in the treated groups. Behavioral assessment demonstrated anxiety effects on mice for C. procera leaf extract(400 mg/kg of body weight). Conclusions: The acute use of C. procera(leaves and root-barks) aqueous extracts could be considered as low toxic. However, their repeated uses could have harmful effect on some organs. Likewise, a single dose up to 400 mg/kg body weight of these extracts produce no sedative or depressive-like effect, but they possess possible dose dependent anxiety effect. Yet, more studies are necessary to relate these results to the chemical profile of the plant extracts.展开更多
The study on arsenopyrite and realgar of bacterial oxidation shows that the chemical behaviors of different arsenic-bearing sulphides oxidated by thermophilic bacteria are quite distinct. Arsenopyrite is active and qu...The study on arsenopyrite and realgar of bacterial oxidation shows that the chemical behaviors of different arsenic-bearing sulphides oxidated by thermophilic bacteria are quite distinct. Arsenopyrite is active and quickly eroded in bacteria-bearing solution. With a high leaching rate over 95%, the arsenopyrite phase cannot be detected by X-ray diffraction(XRD). Arsenopyrite is highly toxic to bacteria that at the initial stage of bio-oxidation, bacterial growth is inhibited and the number of bacterium cell drops from 2.26 × 108/mL to the lowest 2.01 × 105/mL. At the later stages of bio-oxidation, bacteria grow fast and reach 2.23 × 108/mL. Comparably, realgar is inertial and resistive to bacterial corrosion and oxidation. Arsenic in realgar crystal is hard to be leached and the residue is still realgar phase, as indicated by XRD. The cell number of bacteria varies a little, decreasing from 2.26 × 108/mL to 2.01 × 107/mL, during the bacterial oxidation. The results show that the crystal structure and arsenic valency of arsenic-bearing sulphides play a vital role during the leaching process of bacterial oxidation.展开更多
Toxicological Impact of Benzenehexachloride on the Behaviour and Neuropathology of Heteropneustes fossilis.Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Runoffs from treate...Toxicological Impact of Benzenehexachloride on the Behaviour and Neuropathology of Heteropneustes fossilis.Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Runoffs from treated fields contaminates nearby bodies of water with organochlorine componds, which are neurotoxic to the ichthyofouna. The present work was designed to study the effect of bezenehexachloride on the behaviour and histopathology of Heteropneustes fossilis, as an experimental model.The experimental fish were exposed to different concentraions of the pesticide for 72 hoare. After exposure, the fish exhibited various behavioural changes. Histopathological exndnation of brain tis-sue revealed cytopathic and gross histopaholopcal alteratios, including necrosis and infrationalchanges. These results are consistent with the finding that organochlorides cause neurotoxic effects.展开更多
为探讨卤代酚复合污染对水生生物的联合毒性效应,探究较为可靠的检测方法,根据所选6种卤代酚化学结构的相似程度和48 h LC50值,将其分为3组二元混合物进行急性暴露实验,毒性单位比为1∶1,每组分2个浓度级别观察金鱼生物学行为的变化,同...为探讨卤代酚复合污染对水生生物的联合毒性效应,探究较为可靠的检测方法,根据所选6种卤代酚化学结构的相似程度和48 h LC50值,将其分为3组二元混合物进行急性暴露实验,毒性单位比为1∶1,每组分2个浓度级别观察金鱼生物学行为的变化,同时检测金鱼肝脏中3种抗氧化酶(SOD,CAT和GSH-Px)活性以及酶活性影响率的变化.结果表明:3组卤代酚对金鱼肝脏中3种抗氧化酶的酶活性影响率变化均有显著性差异(P<0.01);3种抗氧化酶中仅SOD在1/2LC50剂量暴露组中均表现为明显升高的酶活性激活率或酶活性抑制率,提示SOD较适合作为卤代酚低浓度复合水污染情况监测的生物化学检测指标.展开更多
文摘Objective: To evaluate the toxicological and psychotropic properties of Calotropis(C.) procera. Methods: C. procera leaves and root-bark aqueous extracts were evaluated for their toxic and behavioral effects using adult mice. Toxicity studies were carried out using Organisation for Economic Cooperation and Development guidelines 423 and 407 for acute and subacute evaluation. Behavioral studies were performed using traction test, fireplace test, hole-board test and forced-swimming test to evaluate the sedative, anxiety and depressive-like activities of the extracts. Results: Very low acute toxicity was observed in mice that received both leaves and rootbark extracts. The subacute test showed some morphological, biochemical and hematological changes in the treated groups. Behavioral assessment demonstrated anxiety effects on mice for C. procera leaf extract(400 mg/kg of body weight). Conclusions: The acute use of C. procera(leaves and root-barks) aqueous extracts could be considered as low toxic. However, their repeated uses could have harmful effect on some organs. Likewise, a single dose up to 400 mg/kg body weight of these extracts produce no sedative or depressive-like effect, but they possess possible dose dependent anxiety effect. Yet, more studies are necessary to relate these results to the chemical profile of the plant extracts.
文摘The study on arsenopyrite and realgar of bacterial oxidation shows that the chemical behaviors of different arsenic-bearing sulphides oxidated by thermophilic bacteria are quite distinct. Arsenopyrite is active and quickly eroded in bacteria-bearing solution. With a high leaching rate over 95%, the arsenopyrite phase cannot be detected by X-ray diffraction(XRD). Arsenopyrite is highly toxic to bacteria that at the initial stage of bio-oxidation, bacterial growth is inhibited and the number of bacterium cell drops from 2.26 × 108/mL to the lowest 2.01 × 105/mL. At the later stages of bio-oxidation, bacteria grow fast and reach 2.23 × 108/mL. Comparably, realgar is inertial and resistive to bacterial corrosion and oxidation. Arsenic in realgar crystal is hard to be leached and the residue is still realgar phase, as indicated by XRD. The cell number of bacteria varies a little, decreasing from 2.26 × 108/mL to 2.01 × 107/mL, during the bacterial oxidation. The results show that the crystal structure and arsenic valency of arsenic-bearing sulphides play a vital role during the leaching process of bacterial oxidation.
文摘Toxicological Impact of Benzenehexachloride on the Behaviour and Neuropathology of Heteropneustes fossilis.Organochlorine pesticides are widely used in the vast agricultural fields of Assam, India. Runoffs from treated fields contaminates nearby bodies of water with organochlorine componds, which are neurotoxic to the ichthyofouna. The present work was designed to study the effect of bezenehexachloride on the behaviour and histopathology of Heteropneustes fossilis, as an experimental model.The experimental fish were exposed to different concentraions of the pesticide for 72 hoare. After exposure, the fish exhibited various behavioural changes. Histopathological exndnation of brain tis-sue revealed cytopathic and gross histopaholopcal alteratios, including necrosis and infrationalchanges. These results are consistent with the finding that organochlorides cause neurotoxic effects.
文摘为探讨卤代酚复合污染对水生生物的联合毒性效应,探究较为可靠的检测方法,根据所选6种卤代酚化学结构的相似程度和48 h LC50值,将其分为3组二元混合物进行急性暴露实验,毒性单位比为1∶1,每组分2个浓度级别观察金鱼生物学行为的变化,同时检测金鱼肝脏中3种抗氧化酶(SOD,CAT和GSH-Px)活性以及酶活性影响率的变化.结果表明:3组卤代酚对金鱼肝脏中3种抗氧化酶的酶活性影响率变化均有显著性差异(P<0.01);3种抗氧化酶中仅SOD在1/2LC50剂量暴露组中均表现为明显升高的酶活性激活率或酶活性抑制率,提示SOD较适合作为卤代酚低浓度复合水污染情况监测的生物化学检测指标.
