Objective: To investigate the toxicity of aqueous extract of Guibourtia tessmannii(Harms) J. Leonard(G. tessmannii) and evaluate its safety.Methods: NMRI mice were used to determine the acute toxicity of G. tessmannii...Objective: To investigate the toxicity of aqueous extract of Guibourtia tessmannii(Harms) J. Leonard(G. tessmannii) and evaluate its safety.Methods: NMRI mice were used to determine the acute toxicity of G. tessmannii.Increasing concentrations of the plant extracts were administered intraperitoneally or by force-feeding. General behavior and death were monitored and recorded daily for 7 days.In order to determine the sub-acute toxicity of the extract, several doses were administered by oral gavage daily for 28 days in adult Wistar rats. Different parameters were assessed including body weight, food and water intake, biochemical parameters and several vital organ weights.Results: LD50 of 328.78 mg/kg was obtained by i.p. route and more than 5 000 mg/kg was obtained in acute toxicity by oral route. In sub-acute toxicity, no significant alteration was observed in body weight or vital organs, food and water intake, and biochemical parameters.Conclusions: The results showed that the aqueous extract of G. tessmannii has low toxicity intraperitoneally and no sub-acute toxicity via oral intake.展开更多
Triumfetta cordifolia and Bridelia thermifolia are two shrubs from tropical region of Africa. Their gums are traditionally extracted from fresh barks and used in traditional recipes (thickening and aromatization of sa...Triumfetta cordifolia and Bridelia thermifolia are two shrubs from tropical region of Africa. Their gums are traditionally extracted from fresh barks and used in traditional recipes (thickening and aromatization of sauces, improvement of the swelling of maize and bean cakes) and in the process of decantation of traditional beer. In order to valorize these barks in dried form, study of the effect of drying temperature on the rheological properties of their gums was carried out. In this respect, the fresh barks were dried at 40℃, 50℃, 60℃, 70℃ and 80℃ and the viscosity of their extracts was measured. The drying kinetic of the barks showed two falling rate periods represented by two drying constants?k1 and k2. The absolute viscosity of the extracts decreased beyond drying temperatures higher than 70℃ and 80℃respectively for T cordifolia and B. Thermifolia. The decreasing viscosity is attributed mainly to a reorganization of polysaccharide chains. The temperatures range lower than 70℃ could be retained to dry the barks and to extract gums without deteriorating their properties.展开更多
Factor analysis and expert scoring methods were used to rank flammability of 16 major species of trees and shrubs in Daxing'anling area of northeastern China,based on 6 flammability variables,i.e.,air dry moisture...Factor analysis and expert scoring methods were used to rank flammability of 16 major species of trees and shrubs in Daxing'anling area of northeastern China,based on 6 flammability variables,i.e.,air dry moisture content,absolute dry moisture content,ignition point,ash content,heat of combustion and extractive content measured on leaves,barks and twigs.Out of 16 species evaluated,for leaves' flammability,Larix gmelini was the smallest and Pinus sylvestris var.mongolica was the biggest;for barks' flammability,Salix koreensis was the smallest and P.sylvestris var.mongolica was the biggest;and for twigs' flammability,Populus davidiana was the smallest and Ledum palustre var.dilatatum was the biggest.The flammability ranking based on the integrated scores of leaves,barks and twigs suggested that Prunus padus,Betula dahurica,and L.gmelini were the top 3 less flammable species and that L.palustre var.dilatatum,P.sylvestris var.mongolica,and R.simsii were the top 3 more flammable species.This ranking agreed well with current standards and experience and should help the species selection for building fire-break forest belts in the study region.展开更多
基金Supported by the doctoral training funds no.84722652USTM/4802 AC-USTM,of the University of Sciences and Technique of Masuku
文摘Objective: To investigate the toxicity of aqueous extract of Guibourtia tessmannii(Harms) J. Leonard(G. tessmannii) and evaluate its safety.Methods: NMRI mice were used to determine the acute toxicity of G. tessmannii.Increasing concentrations of the plant extracts were administered intraperitoneally or by force-feeding. General behavior and death were monitored and recorded daily for 7 days.In order to determine the sub-acute toxicity of the extract, several doses were administered by oral gavage daily for 28 days in adult Wistar rats. Different parameters were assessed including body weight, food and water intake, biochemical parameters and several vital organ weights.Results: LD50 of 328.78 mg/kg was obtained by i.p. route and more than 5 000 mg/kg was obtained in acute toxicity by oral route. In sub-acute toxicity, no significant alteration was observed in body weight or vital organs, food and water intake, and biochemical parameters.Conclusions: The results showed that the aqueous extract of G. tessmannii has low toxicity intraperitoneally and no sub-acute toxicity via oral intake.
文摘Triumfetta cordifolia and Bridelia thermifolia are two shrubs from tropical region of Africa. Their gums are traditionally extracted from fresh barks and used in traditional recipes (thickening and aromatization of sauces, improvement of the swelling of maize and bean cakes) and in the process of decantation of traditional beer. In order to valorize these barks in dried form, study of the effect of drying temperature on the rheological properties of their gums was carried out. In this respect, the fresh barks were dried at 40℃, 50℃, 60℃, 70℃ and 80℃ and the viscosity of their extracts was measured. The drying kinetic of the barks showed two falling rate periods represented by two drying constants?k1 and k2. The absolute viscosity of the extracts decreased beyond drying temperatures higher than 70℃ and 80℃respectively for T cordifolia and B. Thermifolia. The decreasing viscosity is attributed mainly to a reorganization of polysaccharide chains. The temperatures range lower than 70℃ could be retained to dry the barks and to extract gums without deteriorating their properties.
基金financially supported by National Natural Science Foundation of China(No.30900189)National Key Technology R&D Program(2011BAD32B05)+2 种基金Projects of Jilin Provincial Sci-tech Department(20100582and20121820)Project of Jilin Provincial Education Department(2009-402)SHAN Yanlong was supported by the Program for New Century Excellent Talents in University
文摘Factor analysis and expert scoring methods were used to rank flammability of 16 major species of trees and shrubs in Daxing'anling area of northeastern China,based on 6 flammability variables,i.e.,air dry moisture content,absolute dry moisture content,ignition point,ash content,heat of combustion and extractive content measured on leaves,barks and twigs.Out of 16 species evaluated,for leaves' flammability,Larix gmelini was the smallest and Pinus sylvestris var.mongolica was the biggest;for barks' flammability,Salix koreensis was the smallest and P.sylvestris var.mongolica was the biggest;and for twigs' flammability,Populus davidiana was the smallest and Ledum palustre var.dilatatum was the biggest.The flammability ranking based on the integrated scores of leaves,barks and twigs suggested that Prunus padus,Betula dahurica,and L.gmelini were the top 3 less flammable species and that L.palustre var.dilatatum,P.sylvestris var.mongolica,and R.simsii were the top 3 more flammable species.This ranking agreed well with current standards and experience and should help the species selection for building fire-break forest belts in the study region.
