In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experime...In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experiment and orthogonal experiment.The results showed that the optimum extraction condition was:the ration of ethanol and acetone 1∶1(v/v,containing 0.1%BHT),solid-liquid ratio 1∶30(g/mL),extraction time 7 min,ultrasonic power 240 W,extraction frequency 3 times.Under the above condition,the extraction rate of carotenoids was 85.98%.展开更多
The unicellular green alga Dunaliella is outstanding for its ability of massive accumulation of carotenoids. To elucidate the carotenoids synthesis pathway in this alga,phytoene desaturase(pds) gene cDNA together with...The unicellular green alga Dunaliella is outstanding for its ability of massive accumulation of carotenoids. To elucidate the carotenoids synthesis pathway in this alga,phytoene desaturase(pds) gene cDNA together with its DNA sequences were isolated and their structures and functions analyzed. The full-length pds cDNA of 2290 bp(GenBank Accession No. DQ243892) was de-duced from RACE results,including untranslated 21 bp 5'-and 520 bp 3'-flanking regions and an open reading frame of 582 amino acids,coding a protein of 64.196 kDa. The DNA sequence of 2908 bp(GenBank Accession No. DQ845248) including five introns was obtained. The fifth intron was uncompleted and complex,including two bases' perfect repeats(GT) 10 and large different-sized repeats within the last 400 bp. The Southern blot hybridization result demonstrated that this gene occurred as a single copy in this species,and the quantitative RT-PCR result showed that the transcription of this gene was constitutive. The evolutional significance of pds was discussed.展开更多
Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-relat...Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin （TG）, which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG （1 μmol/L） treatment for 24 h, following PQS pre-treatment （160 μg/mL） for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase （Si-PERK） for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 （GRP78）, calreticulin, PERK, eukaryotic translation initiation factor 2α （elF2c0, activating transcription factor 4 （ATF4）, and C/EBP homologous protein （CHOP） were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.展开更多
Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga expose...Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a probable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.展开更多
Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for...Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for the nutrition of sick people and domestic animals. This study aimed at encouraging the consumption of squash pulp to contribute to vitamin A needs. The contents of a-carotene, all-trans-β-carotene and ascorbic acid were determined respectively by HPLC and titration with 2.6 dichlorophenol-indophenol in five landraces of raw, steamed, steam-dried and fried squash pulp from Cameroon. Moisture and total lipid content were also determined. Peeled pulp squash of 5 cm slice was steamed at 90℃ for 30 min or at 85℃ for 30 min, sliced again at 5 mm thickness and dried at 80℃ during 4 h to obtained steamed or steam-dried squashes. To have fried squashes, 40 g of 1 mm thickness slices pulp were fried in boiling refined palm oil （free of carotenoids） bath at 150℃ during 7 and 10 min. The results obtained showed that steam-drying and frying of squashes leaded to water losses （89%-95%）. As a consequence of this, the a-carotene, all-trans-β-carotene and ascorbic acid contents （expressed in g （100 g）-1 fresh portion） of steam-dried and fried squashes were significantly higher （P 〈 0.05） than those of steamed and raw pulp. However, the retention rate of provitamins A and ascorbic acid was more elevated in steamed than in steam-dried and fried squashes. These results suggest that steam-dried and fried squashes could contribute to fight against vitamin A deficiency while increasing availability of squashes.展开更多
文摘In order to explore the extraction method of carotenoids from citrus leaves,the extraction effect of carotenoids from leaves of Honey pomelo by ultrasonic-assisted extraction was investigated by single factor experiment and orthogonal experiment.The results showed that the optimum extraction condition was:the ration of ethanol and acetone 1∶1(v/v,containing 0.1%BHT),solid-liquid ratio 1∶30(g/mL),extraction time 7 min,ultrasonic power 240 W,extraction frequency 3 times.Under the above condition,the extraction rate of carotenoids was 85.98%.
文摘The unicellular green alga Dunaliella is outstanding for its ability of massive accumulation of carotenoids. To elucidate the carotenoids synthesis pathway in this alga,phytoene desaturase(pds) gene cDNA together with its DNA sequences were isolated and their structures and functions analyzed. The full-length pds cDNA of 2290 bp(GenBank Accession No. DQ243892) was de-duced from RACE results,including untranslated 21 bp 5'-and 520 bp 3'-flanking regions and an open reading frame of 582 amino acids,coding a protein of 64.196 kDa. The DNA sequence of 2908 bp(GenBank Accession No. DQ845248) including five introns was obtained. The fifth intron was uncompleted and complex,including two bases' perfect repeats(GT) 10 and large different-sized repeats within the last 400 bp. The Southern blot hybridization result demonstrated that this gene occurred as a single copy in this species,and the quantitative RT-PCR result showed that the transcription of this gene was constitutive. The evolutional significance of pds was discussed.
基金Acknowledgements This work was supported by International Science and Technology Cooperation Project （2010DFA31690）, National Natural Science Foundation of China （81030063 and 81170140） and China Postdoctoral Science Foundation （2014M562608）. The authors declare no conflict of interests regarding the publication of this paper.
文摘Background Endoplasmic reticulum （ER） stress-related apoptosis is involved in the pathophysiology of many cardiovascular diseases, and Panax quinquefolium saponin （PQS） is able to inhibit excessive ER stress-related apoptosis of cardiomyocytes following hypoxia/reoxygenation and myocardial infarction. However, the pathway by which PQS inhibits the ER stress-related apoptosis is not well understood. To further investigate the protective effect of PQS against ER stress-related apoptosis, primary cultured eardiomyocytes were stimulated with thapsigargin （TG）, which is widely used to model cellular ER stress, and it could induce apoptotic cell death in sufficient concentration. Methods Primary cultured cardiomyocytes from neonatal rats were exposed to TG （1 μmol/L） treatment for 24 h, following PQS pre-treatment （160 μg/mL） for 24 h or pre-treatment with small interfering RNA directed against protein kinase-like endoplasmic reticulum kinase （Si-PERK） for 6 h. The viability and apoptosis rate of cardiomyocytes were detected by cell counting kit-8 and flow cytometry respectively. ER stress-related protein expression, such as glucose-regulated protein 78 （GRP78）, calreticulin, PERK, eukaryotic translation initiation factor 2α （elF2c0, activating transcription factor 4 （ATF4）, and C/EBP homologous protein （CHOP） were assayed by western blotting. Results Both PQS pre-treatment and PERK knockdown remarkably inhibited the cardiomyocyte apoptosis induced by TG, increased cell viability, decreased phosphorylation of both PERK and eIF2α, and decreased protein levels of both ATF4 and CHOP. There was no statistically significant difference between PQS pre-treatment and PERK knockdown in the cardioprotective effect. Conclusions Our data indicate that the PERK-eIF2α-ATF4-CHOP pathway of ER stress is involved in the apoptosis induced by TG, and PQS might prevent TG-induced cardiomyocyte apoptosis through a mechanism involving the suppression of this pathway. These findings provide novel data regarding the molecular mechanisms by which PQS inhibits cardiomyocyte apoptosis.
文摘Parietochloris incisa is an arachidonic acid rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a probable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.
文摘Vitamin A deficiency still remains a nutritional concern in Cameroon. Squashes pulp is rich in provitamins A and could help to reduce this deficiency. Unfortunately, in Cameroon, squash pulp is more often reserved for the nutrition of sick people and domestic animals. This study aimed at encouraging the consumption of squash pulp to contribute to vitamin A needs. The contents of a-carotene, all-trans-β-carotene and ascorbic acid were determined respectively by HPLC and titration with 2.6 dichlorophenol-indophenol in five landraces of raw, steamed, steam-dried and fried squash pulp from Cameroon. Moisture and total lipid content were also determined. Peeled pulp squash of 5 cm slice was steamed at 90℃ for 30 min or at 85℃ for 30 min, sliced again at 5 mm thickness and dried at 80℃ during 4 h to obtained steamed or steam-dried squashes. To have fried squashes, 40 g of 1 mm thickness slices pulp were fried in boiling refined palm oil （free of carotenoids） bath at 150℃ during 7 and 10 min. The results obtained showed that steam-drying and frying of squashes leaded to water losses （89%-95%）. As a consequence of this, the a-carotene, all-trans-β-carotene and ascorbic acid contents （expressed in g （100 g）-1 fresh portion） of steam-dried and fried squashes were significantly higher （P 〈 0.05） than those of steamed and raw pulp. However, the retention rate of provitamins A and ascorbic acid was more elevated in steamed than in steam-dried and fried squashes. These results suggest that steam-dried and fried squashes could contribute to fight against vitamin A deficiency while increasing availability of squashes.
