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Potential Antioxidant Activity of New Tetracyclic and Pentacyclic Nonlinear Phenothiazine Derivatives.

Engwa GA, Ayuk EL, Igbojekwe BU, Unaegbu M - Biochem Res Int (2016)

Bottom Line: The synthesized phenothiazine derivatives exhibited reducing power potential to convert Fe(3+) to Fe(2+) and high ability to scavenge H2O2 free radical in vitro.The catalase activity significantly increased (p < 0.05) in groups 1 and 2 animals that received the phenothiazine derivatives compared to the controls (groups 3 and 4) suggesting the ability of the phenothiazine derivatives to scavenge H2O2 in vivo.The results suggest that phenothiazine derivatives, especially 6-chloro-11-azabenzo[a]phenothiazine-5-one, possess antioxidant activity though 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one was slightly toxic.

View Article: PubMed Central - PubMed

Affiliation: Biochemistry, Chemical Sciences Department, Godfrey Okoye University, PMB 01014, Thinkers Corner, Enugu, Nigeria.

ABSTRACT
The global increase in oxidative stress related diseases such as cancer, cardiovascular, and inflammatory diseases caused by overwhelming level of free radicals in the body has encouraged the search for new antioxidant agents. Based on the ability of newly synthesized phenothiazine derivatives (6-chloro-11-azabenzo[a]phenothiazine-5-one and 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one) to oxidize H2O2, a known free radical to sulfoxide, this study assessed the in vitro and in vivo antioxidant activity. The synthesized phenothiazine derivatives exhibited reducing power potential to convert Fe(3+) to Fe(2+) and high ability to scavenge H2O2 free radical in vitro. These activities were comparable to ascorbic acid, a standard antioxidant. The catalase activity significantly increased (p < 0.05) in groups 1 and 2 animals that received the phenothiazine derivatives compared to the controls (groups 3 and 4) suggesting the ability of the phenothiazine derivatives to scavenge H2O2 in vivo. The malondialdehyde level in groups 1 and 2 animals was lower than that in group 3 that received the reference compound (ascorbic acid) and group 4 that received the solvent suggesting the ability of the phenothiazine derivatives to prevent lipid membrane damage. AST and bilirubin levels were higher in group 2 animals which received 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one compared to group 3, the positive control. The results suggest that phenothiazine derivatives, especially 6-chloro-11-azabenzo[a]phenothiazine-5-one, possess antioxidant activity though 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one was slightly toxic. This activity may be due to the presence of electron donors such as sulfur as well as the richness of hydrogen in the additional benzene rings for substitution. Further study is needed to identify tolerable doses for possible therapeutic purposes.

No MeSH data available.


Related in: MedlinePlus

Catalase free radical scavenging potential in various animal groups. Group 1: 6-chloro-11-azabenzo[a]phenothiazine-5-one; group 2: 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one; group 3: ascorbic acid; group 4: solvent.
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fig4: Catalase free radical scavenging potential in various animal groups. Group 1: 6-chloro-11-azabenzo[a]phenothiazine-5-one; group 2: 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one; group 3: ascorbic acid; group 4: solvent.

Mentions: Catalase is an enzyme present in living organisms including man that decomposes hydrogen peroxide into water and molecular oxygen, thereby protecting the tissues from highly reactive hydroxyl radicals [47]. In this study, catalase was shown to have an increase of percentage of inhibition of hydrogen peroxide in group 1 animals treated with 6-chloro-11-azabenzo[a]phenothiazine-5-one, group 2 animals given 6-[4-Bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one, and group 3 given ascorbic acid (positive control) compared to group 4, the normal control, which was given organic solvents (Table 2 and Figure 4). The percentage of inhibition of hydrogen peroxide by catalase was significantly (p < 0.05) higher in group 1 animals given 6-chloro-11-azabenzo[a]phenothiazine-5-one than in those of group 2 given 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one and insignificantly (p > 0.05) higher than those of group 3 which received ascorbic acid, the reference compound. This result suggests that 6-chloro-11-azabenzo[a]phenothiazine-5-one has high abilities to promote catalase activities in the body.


Potential Antioxidant Activity of New Tetracyclic and Pentacyclic Nonlinear Phenothiazine Derivatives.

Engwa GA, Ayuk EL, Igbojekwe BU, Unaegbu M - Biochem Res Int (2016)

Catalase free radical scavenging potential in various animal groups. Group 1: 6-chloro-11-azabenzo[a]phenothiazine-5-one; group 2: 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one; group 3: ascorbic acid; group 4: solvent.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4834405&req=5

fig4: Catalase free radical scavenging potential in various animal groups. Group 1: 6-chloro-11-azabenzo[a]phenothiazine-5-one; group 2: 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one; group 3: ascorbic acid; group 4: solvent.
Mentions: Catalase is an enzyme present in living organisms including man that decomposes hydrogen peroxide into water and molecular oxygen, thereby protecting the tissues from highly reactive hydroxyl radicals [47]. In this study, catalase was shown to have an increase of percentage of inhibition of hydrogen peroxide in group 1 animals treated with 6-chloro-11-azabenzo[a]phenothiazine-5-one, group 2 animals given 6-[4-Bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one, and group 3 given ascorbic acid (positive control) compared to group 4, the normal control, which was given organic solvents (Table 2 and Figure 4). The percentage of inhibition of hydrogen peroxide by catalase was significantly (p < 0.05) higher in group 1 animals given 6-chloro-11-azabenzo[a]phenothiazine-5-one than in those of group 2 given 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one and insignificantly (p > 0.05) higher than those of group 3 which received ascorbic acid, the reference compound. This result suggests that 6-chloro-11-azabenzo[a]phenothiazine-5-one has high abilities to promote catalase activities in the body.

Bottom Line: The synthesized phenothiazine derivatives exhibited reducing power potential to convert Fe(3+) to Fe(2+) and high ability to scavenge H2O2 free radical in vitro.The catalase activity significantly increased (p < 0.05) in groups 1 and 2 animals that received the phenothiazine derivatives compared to the controls (groups 3 and 4) suggesting the ability of the phenothiazine derivatives to scavenge H2O2 in vivo.The results suggest that phenothiazine derivatives, especially 6-chloro-11-azabenzo[a]phenothiazine-5-one, possess antioxidant activity though 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one was slightly toxic.

View Article: PubMed Central - PubMed

Affiliation: Biochemistry, Chemical Sciences Department, Godfrey Okoye University, PMB 01014, Thinkers Corner, Enugu, Nigeria.

ABSTRACT
The global increase in oxidative stress related diseases such as cancer, cardiovascular, and inflammatory diseases caused by overwhelming level of free radicals in the body has encouraged the search for new antioxidant agents. Based on the ability of newly synthesized phenothiazine derivatives (6-chloro-11-azabenzo[a]phenothiazine-5-one and 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one) to oxidize H2O2, a known free radical to sulfoxide, this study assessed the in vitro and in vivo antioxidant activity. The synthesized phenothiazine derivatives exhibited reducing power potential to convert Fe(3+) to Fe(2+) and high ability to scavenge H2O2 free radical in vitro. These activities were comparable to ascorbic acid, a standard antioxidant. The catalase activity significantly increased (p < 0.05) in groups 1 and 2 animals that received the phenothiazine derivatives compared to the controls (groups 3 and 4) suggesting the ability of the phenothiazine derivatives to scavenge H2O2 in vivo. The malondialdehyde level in groups 1 and 2 animals was lower than that in group 3 that received the reference compound (ascorbic acid) and group 4 that received the solvent suggesting the ability of the phenothiazine derivatives to prevent lipid membrane damage. AST and bilirubin levels were higher in group 2 animals which received 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one compared to group 3, the positive control. The results suggest that phenothiazine derivatives, especially 6-chloro-11-azabenzo[a]phenothiazine-5-one, possess antioxidant activity though 6-[4-bromophenyl]-10-methyl-11-azabenzo[a]phenothiazine-5-one was slightly toxic. This activity may be due to the presence of electron donors such as sulfur as well as the richness of hydrogen in the additional benzene rings for substitution. Further study is needed to identify tolerable doses for possible therapeutic purposes.

No MeSH data available.


Related in: MedlinePlus