Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1998
The levels of acidic and basic proline-rich proteins in the camel tick Hyalomma dromedarii has be... more The levels of acidic and basic proline-rich proteins in the camel tick Hyalomma dromedarii has been followed throughout embryogenesis. The developmental profiles of proline content in the crude protein fractions showed significant changes which would have to be of greater physiological consequences. During purification of FIIa to homogeneity the ion exchange chromatography step lead to separation of nine peaks where
Polygalacturonase-inhibitor proteins (PGIPs)
are important plant defense proteins which modulate ... more Polygalacturonase-inhibitor proteins (PGIPs) are important plant defense proteins which modulate the activity of microbial polygalacturonases (PGs) leading to elicitor accumulation. Very few studies have been carried out towards understanding the role of PGIPs in monocot host defense. Hence, present study was taken up to characterize a native PGIP from pearl millet and understand its role in resistance against downy mildew.
Traditionally several species of Memecylon are used to cure skin problems. However, scientific va... more Traditionally several species of Memecylon are used to cure skin problems. However, scientific validation of the plant as a modern medicine is lacking. Therefore, in the present study methanolic extracts of three species of Memecylon i.e., M. umbellatum, M. talbotianum and M. malabaricum were assessed for their antioxidant, anti-microbial, DNA protection capacities, 5-lipoxygenase and human cyclooxygenase (COX-2) inhibition. Methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) ABTS radical scavenging capacities for extracts in dose range of 50 μg/mL - 10 mg/mL were measured. 15-Lipoxygenase inhibition for these extracts at 10 - 200 μg/mL dose was studied. Human cyclooxygenase-2 was recorded for doses 10 and 50 μg/mL. DNA-nicking assay at 10 μg was recorded. Cell cytotoxicity was recorded by colorimetric MTT assay using doxorubicin as control for extracts (50 - 500 μg/mL). Results: The IC50 values for scavenging the DPPH radical ranged from 0.11 to 0.17 mg/mL and those for the ABTS radical cation from 2.1 to 3.7 mg/mL for the extracts. M. malabaricum leaf extract exhibited highest lipoxygenase inhibition capacity with an IC50 value of 29.87 μg/mL. It also inhibited human COX-2 (80.6 % at 50 μg/mL). Methanolic leaf extracts could prevent DNA nicking by hydroxyl radicals, produced in the Fenton reaction. M. malabaricum leaf extracts inhibited growth of Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Conclusion: This study forms initial screening of these plants with further studies directed towards identification of bioactive molecules as potential lead candidates.
Methanol extracts of Elaeocarpus, E. serratus, E. tuberculatus
(Elaeocarpaceae), Catunaregam ulig... more Methanol extracts of Elaeocarpus, E. serratus, E. tuberculatus (Elaeocarpaceae), Catunaregam uliginosa, C. spinosa (Rubiaceae), Elaeagnus conferta (Elaeagnaceae), Evodia lunu-ankenda (Rutaceae), Glycosmis arborea (Rutaceae), Melastoma malabathricum. (Melastomataceae), and Smilax zeylanica (Liliaceae) leaves were screened for antioxidant, anti-inflammatory, and cytotoxicity to Vero cell lines. 1,1-diphenyl-2-picrylhydrazyl and 2-2-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid radical scavenging capacities were identified C. spinosa and E. tuberculatus. Anti-inflammatory capacity with lipoxygenase and human cyclooxygenase-2 inhibition for E. tuberculatus and E. serratus was recorded. The extracts prevented DNA damage by hydroxyl radicals produced by Fenton reagent. Cell cytotoxicity studies revealed S. zeylanica and E. tuberculatus with potent cytotoxicity to Vero cells.
p-Coumaric acid (p-CA), an ubiquitous plant phenolic
acid, has been proven to render protection a... more p-Coumaric acid (p-CA), an ubiquitous plant phenolic acid, has been proven to render protection against pathological conditions. In the present study, p-CAwas evaluated for its capacity to induce cytotoxic effect to neuroblastoma N2a cells and we report here the possible mechanism of its action. p-CA at a concentration of 150 μmol/L, upon exposure for 72 h, stimulated 81.23 % of cells to apoptosis, as evidenced by flow cytometer studies mediated through elevated levels of ROS (7.5-fold over control). Excess ROS production activated structural injury to mitochondrial membrane, observed as dissipation of its membrane potential and followed by the release of cytochrome c (8.73-fold). Enhanced generation of intracellular ROS correlated well with the decreased levels (~60 %) of intracellular GSH. Sensitizing neuroblastoma cells for induction of apoptosis by p-CA identified p53- mediated upregulated accumulation of caspase-8 messenger RNA (2.8-fold). Our data report on autophagy, representing an additional mechanism of p-CA to induce growth arrest, detected by immunoblotting and fluorescence, correlated with accumulation of elevated levels (1.2-fold) of the LC3-II protein and acridine orange-stained autophagosomes, both autophagy markers. The present study indicates p-CA was effective in production of ROS-dependent mitochondrial damage-induced cytotoxicity in N2a cells.
The present study was carried out to investigate
the antioxidant and neuroprotective effects of H... more The present study was carried out to investigate the antioxidant and neuroprotective effects of Hyptis suaveolens methanol extract (HSME) using various in vitro systems. The total phenol and flavonoids contents of the HSME were quantified by colorimetric methods. The HSME extract exhibited potent antioxidant activity as determined by 2,20-azino-bis(3-ethylbenzothiazoline-6- sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl, and ferric reducing antioxidant power assays. The neuroprotective activity of HSME was determined on mouse N2A neuroblastoma cells using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase, intracellular ROS assays, and upregulation of brain neuronal markers at genetic level. The N2A cells were pretreated with different concentrations (0.5, 1, 1.5, and 2 mg/ml) of the extract and then exposed to H2O2 to induce oxidative stress and neurotoxicity. The survival of the cells treated with different concentrations of HSME and H2O2 increased as compared to cells exposed only to H2O2 (47.3 %) (p\0.05). The HSME also dose-dependently reduced LDH leakage and intracellular ROS production (p\0.05). Pretreatment with HSME promotes the upregulation of tyrosine hydroxylase (2.41-fold, p\0.05), and brain-derived neurotrophic factor genes (2.15-fold, p\0.05) against H2O2-induced cytotoxicity in N2A cells. Moreover, the HSME showed antioxidant activity and decreased neurotoxicity. These observations suggest that HSME have marked antioxidant and neuroprotective activities.
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1998
The levels of acidic and basic proline-rich proteins in the camel tick Hyalomma dromedarii has be... more The levels of acidic and basic proline-rich proteins in the camel tick Hyalomma dromedarii has been followed throughout embryogenesis. The developmental profiles of proline content in the crude protein fractions showed significant changes which would have to be of greater physiological consequences. During purification of FIIa to homogeneity the ion exchange chromatography step lead to separation of nine peaks where
Polygalacturonase-inhibitor proteins (PGIPs)
are important plant defense proteins which modulate ... more Polygalacturonase-inhibitor proteins (PGIPs) are important plant defense proteins which modulate the activity of microbial polygalacturonases (PGs) leading to elicitor accumulation. Very few studies have been carried out towards understanding the role of PGIPs in monocot host defense. Hence, present study was taken up to characterize a native PGIP from pearl millet and understand its role in resistance against downy mildew.
Traditionally several species of Memecylon are used to cure skin problems. However, scientific va... more Traditionally several species of Memecylon are used to cure skin problems. However, scientific validation of the plant as a modern medicine is lacking. Therefore, in the present study methanolic extracts of three species of Memecylon i.e., M. umbellatum, M. talbotianum and M. malabaricum were assessed for their antioxidant, anti-microbial, DNA protection capacities, 5-lipoxygenase and human cyclooxygenase (COX-2) inhibition. Methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) ABTS radical scavenging capacities for extracts in dose range of 50 μg/mL - 10 mg/mL were measured. 15-Lipoxygenase inhibition for these extracts at 10 - 200 μg/mL dose was studied. Human cyclooxygenase-2 was recorded for doses 10 and 50 μg/mL. DNA-nicking assay at 10 μg was recorded. Cell cytotoxicity was recorded by colorimetric MTT assay using doxorubicin as control for extracts (50 - 500 μg/mL). Results: The IC50 values for scavenging the DPPH radical ranged from 0.11 to 0.17 mg/mL and those for the ABTS radical cation from 2.1 to 3.7 mg/mL for the extracts. M. malabaricum leaf extract exhibited highest lipoxygenase inhibition capacity with an IC50 value of 29.87 μg/mL. It also inhibited human COX-2 (80.6 % at 50 μg/mL). Methanolic leaf extracts could prevent DNA nicking by hydroxyl radicals, produced in the Fenton reaction. M. malabaricum leaf extracts inhibited growth of Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Conclusion: This study forms initial screening of these plants with further studies directed towards identification of bioactive molecules as potential lead candidates.
Methanol extracts of Elaeocarpus, E. serratus, E. tuberculatus
(Elaeocarpaceae), Catunaregam ulig... more Methanol extracts of Elaeocarpus, E. serratus, E. tuberculatus (Elaeocarpaceae), Catunaregam uliginosa, C. spinosa (Rubiaceae), Elaeagnus conferta (Elaeagnaceae), Evodia lunu-ankenda (Rutaceae), Glycosmis arborea (Rutaceae), Melastoma malabathricum. (Melastomataceae), and Smilax zeylanica (Liliaceae) leaves were screened for antioxidant, anti-inflammatory, and cytotoxicity to Vero cell lines. 1,1-diphenyl-2-picrylhydrazyl and 2-2-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid radical scavenging capacities were identified C. spinosa and E. tuberculatus. Anti-inflammatory capacity with lipoxygenase and human cyclooxygenase-2 inhibition for E. tuberculatus and E. serratus was recorded. The extracts prevented DNA damage by hydroxyl radicals produced by Fenton reagent. Cell cytotoxicity studies revealed S. zeylanica and E. tuberculatus with potent cytotoxicity to Vero cells.
p-Coumaric acid (p-CA), an ubiquitous plant phenolic
acid, has been proven to render protection a... more p-Coumaric acid (p-CA), an ubiquitous plant phenolic acid, has been proven to render protection against pathological conditions. In the present study, p-CAwas evaluated for its capacity to induce cytotoxic effect to neuroblastoma N2a cells and we report here the possible mechanism of its action. p-CA at a concentration of 150 μmol/L, upon exposure for 72 h, stimulated 81.23 % of cells to apoptosis, as evidenced by flow cytometer studies mediated through elevated levels of ROS (7.5-fold over control). Excess ROS production activated structural injury to mitochondrial membrane, observed as dissipation of its membrane potential and followed by the release of cytochrome c (8.73-fold). Enhanced generation of intracellular ROS correlated well with the decreased levels (~60 %) of intracellular GSH. Sensitizing neuroblastoma cells for induction of apoptosis by p-CA identified p53- mediated upregulated accumulation of caspase-8 messenger RNA (2.8-fold). Our data report on autophagy, representing an additional mechanism of p-CA to induce growth arrest, detected by immunoblotting and fluorescence, correlated with accumulation of elevated levels (1.2-fold) of the LC3-II protein and acridine orange-stained autophagosomes, both autophagy markers. The present study indicates p-CA was effective in production of ROS-dependent mitochondrial damage-induced cytotoxicity in N2a cells.
The present study was carried out to investigate
the antioxidant and neuroprotective effects of H... more The present study was carried out to investigate the antioxidant and neuroprotective effects of Hyptis suaveolens methanol extract (HSME) using various in vitro systems. The total phenol and flavonoids contents of the HSME were quantified by colorimetric methods. The HSME extract exhibited potent antioxidant activity as determined by 2,20-azino-bis(3-ethylbenzothiazoline-6- sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl, and ferric reducing antioxidant power assays. The neuroprotective activity of HSME was determined on mouse N2A neuroblastoma cells using 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase, intracellular ROS assays, and upregulation of brain neuronal markers at genetic level. The N2A cells were pretreated with different concentrations (0.5, 1, 1.5, and 2 mg/ml) of the extract and then exposed to H2O2 to induce oxidative stress and neurotoxicity. The survival of the cells treated with different concentrations of HSME and H2O2 increased as compared to cells exposed only to H2O2 (47.3 %) (p\0.05). The HSME also dose-dependently reduced LDH leakage and intracellular ROS production (p\0.05). Pretreatment with HSME promotes the upregulation of tyrosine hydroxylase (2.41-fold, p\0.05), and brain-derived neurotrophic factor genes (2.15-fold, p\0.05) against H2O2-induced cytotoxicity in N2A cells. Moreover, the HSME showed antioxidant activity and decreased neurotoxicity. These observations suggest that HSME have marked antioxidant and neuroprotective activities.
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Papers by Shailasree Sekhar
are important plant defense proteins which modulate the
activity of microbial polygalacturonases (PGs) leading to
elicitor accumulation. Very few studies have been carried
out towards understanding the role of PGIPs in monocot
host defense. Hence, present study was taken up to characterize
a native PGIP from pearl millet and understand its
role in resistance against downy mildew.
Methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) ABTS radical scavenging capacities for extracts in dose range of 50 μg/mL - 10 mg/mL were measured. 15-Lipoxygenase inhibition for these extracts at 10 - 200 μg/mL dose was studied. Human cyclooxygenase-2 was recorded for doses 10 and 50 μg/mL. DNA-nicking assay at 10 μg was recorded. Cell cytotoxicity was recorded by colorimetric MTT assay using doxorubicin as control for extracts (50 - 500 μg/mL).
Results: The IC50 values for scavenging the DPPH radical ranged from 0.11 to 0.17 mg/mL and those for the ABTS radical cation from 2.1 to 3.7 mg/mL for the extracts. M. malabaricum leaf extract exhibited highest lipoxygenase inhibition capacity with an IC50 value of 29.87 μg/mL. It also inhibited human COX-2 (80.6 % at 50 μg/mL). Methanolic leaf extracts could prevent DNA nicking by hydroxyl radicals, produced in the Fenton reaction. M. malabaricum leaf extracts inhibited growth of Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli.
Conclusion: This study forms initial screening of these plants with further studies directed towards identification of bioactive molecules as potential lead candidates.
(Elaeocarpaceae), Catunaregam uliginosa, C. spinosa (Rubiaceae),
Elaeagnus conferta (Elaeagnaceae), Evodia lunu-ankenda
(Rutaceae), Glycosmis arborea (Rutaceae), Melastoma malabathricum.
(Melastomataceae), and Smilax zeylanica (Liliaceae)
leaves were screened for antioxidant, anti-inflammatory, and
cytotoxicity to Vero cell lines. 1,1-diphenyl-2-picrylhydrazyl
and 2-2-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid radical
scavenging capacities were identified C. spinosa and E. tuberculatus.
Anti-inflammatory capacity with lipoxygenase and human
cyclooxygenase-2 inhibition for E. tuberculatus and E. serratus
was recorded. The extracts prevented DNA damage by hydroxyl
radicals produced by Fenton reagent. Cell cytotoxicity studies
revealed S. zeylanica and E. tuberculatus with potent cytotoxicity
to Vero cells.
acid, has been proven to render protection against pathological
conditions. In the present study, p-CAwas evaluated
for its capacity to induce cytotoxic effect to neuroblastoma
N2a cells and we report here the possible mechanism of its
action. p-CA at a concentration of 150 μmol/L, upon exposure
for 72 h, stimulated 81.23 % of cells to apoptosis, as evidenced by flow cytometer studies mediated through elevated levels of ROS (7.5-fold over control). Excess ROS production
activated structural injury to mitochondrial membrane, observed
as dissipation of its membrane potential and followed
by the release of cytochrome c (8.73-fold). Enhanced generation
of intracellular ROS correlated well with the decreased
levels (~60 %) of intracellular GSH. Sensitizing neuroblastoma
cells for induction of apoptosis by p-CA identified p53-
mediated upregulated accumulation of caspase-8 messenger RNA (2.8-fold). Our data report on autophagy, representing
an additional mechanism of p-CA to induce growth arrest,
detected by immunoblotting and fluorescence, correlated with
accumulation of elevated levels (1.2-fold) of the LC3-II protein
and acridine orange-stained autophagosomes, both autophagy
markers. The present study indicates p-CA was effective
in production of ROS-dependent mitochondrial
damage-induced cytotoxicity in N2a cells.
the antioxidant and neuroprotective effects of Hyptis
suaveolens methanol extract (HSME) using various in vitro
systems. The total phenol and flavonoids contents of the
HSME were quantified by colorimetric methods. The
HSME extract exhibited potent antioxidant activity as
determined by 2,20-azino-bis(3-ethylbenzothiazoline-6-
sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl,
and ferric reducing antioxidant power assays. The
neuroprotective activity of HSME was determined on
mouse N2A neuroblastoma cells using 3-(4,5-dimethylthiazol-
2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase,
intracellular ROS assays, and upregulation of
brain neuronal markers at genetic level. The N2A cells
were pretreated with different concentrations (0.5, 1, 1.5,
and 2 mg/ml) of the extract and then exposed to H2O2 to
induce oxidative stress and neurotoxicity. The survival of
the cells treated with different concentrations of HSME and
H2O2 increased as compared to cells exposed only to H2O2
(47.3 %) (p\0.05). The HSME also dose-dependently
reduced LDH leakage and intracellular ROS production
(p\0.05). Pretreatment with HSME promotes the upregulation
of tyrosine hydroxylase (2.41-fold, p\0.05),
and brain-derived neurotrophic factor genes (2.15-fold,
p\0.05) against H2O2-induced cytotoxicity in N2A cells.
Moreover, the HSME showed antioxidant activity and
decreased neurotoxicity. These observations suggest that
HSME have marked antioxidant and neuroprotective
activities.
are important plant defense proteins which modulate the
activity of microbial polygalacturonases (PGs) leading to
elicitor accumulation. Very few studies have been carried
out towards understanding the role of PGIPs in monocot
host defense. Hence, present study was taken up to characterize
a native PGIP from pearl millet and understand its
role in resistance against downy mildew.
Methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) ABTS radical scavenging capacities for extracts in dose range of 50 μg/mL - 10 mg/mL were measured. 15-Lipoxygenase inhibition for these extracts at 10 - 200 μg/mL dose was studied. Human cyclooxygenase-2 was recorded for doses 10 and 50 μg/mL. DNA-nicking assay at 10 μg was recorded. Cell cytotoxicity was recorded by colorimetric MTT assay using doxorubicin as control for extracts (50 - 500 μg/mL).
Results: The IC50 values for scavenging the DPPH radical ranged from 0.11 to 0.17 mg/mL and those for the ABTS radical cation from 2.1 to 3.7 mg/mL for the extracts. M. malabaricum leaf extract exhibited highest lipoxygenase inhibition capacity with an IC50 value of 29.87 μg/mL. It also inhibited human COX-2 (80.6 % at 50 μg/mL). Methanolic leaf extracts could prevent DNA nicking by hydroxyl radicals, produced in the Fenton reaction. M. malabaricum leaf extracts inhibited growth of Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli.
Conclusion: This study forms initial screening of these plants with further studies directed towards identification of bioactive molecules as potential lead candidates.
(Elaeocarpaceae), Catunaregam uliginosa, C. spinosa (Rubiaceae),
Elaeagnus conferta (Elaeagnaceae), Evodia lunu-ankenda
(Rutaceae), Glycosmis arborea (Rutaceae), Melastoma malabathricum.
(Melastomataceae), and Smilax zeylanica (Liliaceae)
leaves were screened for antioxidant, anti-inflammatory, and
cytotoxicity to Vero cell lines. 1,1-diphenyl-2-picrylhydrazyl
and 2-2-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid radical
scavenging capacities were identified C. spinosa and E. tuberculatus.
Anti-inflammatory capacity with lipoxygenase and human
cyclooxygenase-2 inhibition for E. tuberculatus and E. serratus
was recorded. The extracts prevented DNA damage by hydroxyl
radicals produced by Fenton reagent. Cell cytotoxicity studies
revealed S. zeylanica and E. tuberculatus with potent cytotoxicity
to Vero cells.
acid, has been proven to render protection against pathological
conditions. In the present study, p-CAwas evaluated
for its capacity to induce cytotoxic effect to neuroblastoma
N2a cells and we report here the possible mechanism of its
action. p-CA at a concentration of 150 μmol/L, upon exposure
for 72 h, stimulated 81.23 % of cells to apoptosis, as evidenced by flow cytometer studies mediated through elevated levels of ROS (7.5-fold over control). Excess ROS production
activated structural injury to mitochondrial membrane, observed
as dissipation of its membrane potential and followed
by the release of cytochrome c (8.73-fold). Enhanced generation
of intracellular ROS correlated well with the decreased
levels (~60 %) of intracellular GSH. Sensitizing neuroblastoma
cells for induction of apoptosis by p-CA identified p53-
mediated upregulated accumulation of caspase-8 messenger RNA (2.8-fold). Our data report on autophagy, representing
an additional mechanism of p-CA to induce growth arrest,
detected by immunoblotting and fluorescence, correlated with
accumulation of elevated levels (1.2-fold) of the LC3-II protein
and acridine orange-stained autophagosomes, both autophagy
markers. The present study indicates p-CA was effective
in production of ROS-dependent mitochondrial
damage-induced cytotoxicity in N2a cells.
the antioxidant and neuroprotective effects of Hyptis
suaveolens methanol extract (HSME) using various in vitro
systems. The total phenol and flavonoids contents of the
HSME were quantified by colorimetric methods. The
HSME extract exhibited potent antioxidant activity as
determined by 2,20-azino-bis(3-ethylbenzothiazoline-6-
sulfonic acid) diammonium salt, 2,2-diphenyl-1-picrylhydrazyl,
and ferric reducing antioxidant power assays. The
neuroprotective activity of HSME was determined on
mouse N2A neuroblastoma cells using 3-(4,5-dimethylthiazol-
2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase,
intracellular ROS assays, and upregulation of
brain neuronal markers at genetic level. The N2A cells
were pretreated with different concentrations (0.5, 1, 1.5,
and 2 mg/ml) of the extract and then exposed to H2O2 to
induce oxidative stress and neurotoxicity. The survival of
the cells treated with different concentrations of HSME and
H2O2 increased as compared to cells exposed only to H2O2
(47.3 %) (p\0.05). The HSME also dose-dependently
reduced LDH leakage and intracellular ROS production
(p\0.05). Pretreatment with HSME promotes the upregulation
of tyrosine hydroxylase (2.41-fold, p\0.05),
and brain-derived neurotrophic factor genes (2.15-fold,
p\0.05) against H2O2-induced cytotoxicity in N2A cells.
Moreover, the HSME showed antioxidant activity and
decreased neurotoxicity. These observations suggest that
HSME have marked antioxidant and neuroprotective
activities.