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Guava leaves polyphenolics-rich extract inhibits vital enzymes implicated in gout and hypertension in vitro.

Irondi EA, Agboola SO, Oboh G, Boligon AA, Athayde ML, Shode FO - J Intercult Ethnopharmacol (2016)

Bottom Line: Hence, this study characterized the polyphenolics composition of guava leaves extract and evaluated its inhibitory effect on XO and ACE in vitro.The extract effectively inhibited XO, ACE and Fe(2+)-induced lipid peroxidation in a dose-dependent manner; having half-maximal inhibitory concentrations (IC50) of 38.24 ± 2.32 μg/mL, 21.06 ± 2.04 μg/mL and 27.52 ± 1.72 μg/mL against XO, ACE and Fe(2+)-induced lipid peroxidation, respectively.The extract also strongly scavenged DPPH* and ABTS*(+).

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences and Biotechnology, Biochemistry Unit, Kwara State University, Malete, P.M.B., 1530, Ilorin, Nigeria.

ABSTRACT

Background/aim: Elevated uric acid level, an index of gout resulting from the over-activity of xanthine oxidase (XO), increases the risk of developing hypertension. However, research has shown that plant-derived inhibitors of XO and angiotensin 1-converting enzyme (ACE), two enzymes implicated in gout and hypertension, respectively, can prevent or ameliorate both diseases, without noticeable side effects. Hence, this study characterized the polyphenolics composition of guava leaves extract and evaluated its inhibitory effect on XO and ACE in vitro.

Materials and methods: The polyphenolics (flavonoids and phenolic acids) were characterized using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The XO, ACE, and Fe(2+)-induced lipid peroxidation inhibitory activities, and free radicals (2,2-diphenylpicrylhydrazyl [DPPH]* and 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic [ABTS]*(+)) scavenging activities of the extract were determined using spectrophotometric methods.

Results: Flavonoids were present in the extract in the order of quercetin > kaempferol > catechin > quercitrin > rutin > luteolin > epicatechin; while phenolic acids were in the order of caffeic acid > chlorogenic acid > gallic acids. The extract effectively inhibited XO, ACE and Fe(2+)-induced lipid peroxidation in a dose-dependent manner; having half-maximal inhibitory concentrations (IC50) of 38.24 ± 2.32 μg/mL, 21.06 ± 2.04 μg/mL and 27.52 ± 1.72 μg/mL against XO, ACE and Fe(2+)-induced lipid peroxidation, respectively. The extract also strongly scavenged DPPH* and ABTS*(+).

Conclusion: Guava leaves extract could serve as functional food for managing gout and hypertension and attenuating the oxidative stress associated with both diseases.

No MeSH data available.


Related in: MedlinePlus

% inhibition-extract concentration curves showing the dose-dependent inhibition of xanthine oxidase (XO), angiotensin 1-converting enzyme (ACE) and Fe2+-induced lipid peroxidation (LP) by guava leaves extract
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Figure 2: % inhibition-extract concentration curves showing the dose-dependent inhibition of xanthine oxidase (XO), angiotensin 1-converting enzyme (ACE) and Fe2+-induced lipid peroxidation (LP) by guava leaves extract

Mentions: The inhibitory effects of the extract on the activities of XO and ACE, and Fe2+-induced lipid peroxidation, expressed as IC50, are presented in Table 2. The extract inhibited XO, having IC50 of 38.24 ± 2.32 μg/mL, in comparison with the IC50 of 5.78 ± 0.25 μg/mL, observed for the standard reference XO inhibitor (allopurinol). The extract also inhibited ACE, with IC50 of 21.06 ± 2.04 μg/mL in relation to the IC50 of 4.96 ± 0.18 μg/mL, recorded for the captopril that was used as the standard reference ACE inhibitor. The result showed that the extract had an IC50 of 27.52 ± 1.72 μg/mL against Fe2+-induced lipid peroxidation. The patterns of the inhibitory effects of the extract on XO, ACE and Fe2+-induced lipid peroxidation were dose-dependent as depicted in Figure 2.


Guava leaves polyphenolics-rich extract inhibits vital enzymes implicated in gout and hypertension in vitro.

Irondi EA, Agboola SO, Oboh G, Boligon AA, Athayde ML, Shode FO - J Intercult Ethnopharmacol (2016)

% inhibition-extract concentration curves showing the dose-dependent inhibition of xanthine oxidase (XO), angiotensin 1-converting enzyme (ACE) and Fe2+-induced lipid peroxidation (LP) by guava leaves extract
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835986&req=5

Figure 2: % inhibition-extract concentration curves showing the dose-dependent inhibition of xanthine oxidase (XO), angiotensin 1-converting enzyme (ACE) and Fe2+-induced lipid peroxidation (LP) by guava leaves extract
Mentions: The inhibitory effects of the extract on the activities of XO and ACE, and Fe2+-induced lipid peroxidation, expressed as IC50, are presented in Table 2. The extract inhibited XO, having IC50 of 38.24 ± 2.32 μg/mL, in comparison with the IC50 of 5.78 ± 0.25 μg/mL, observed for the standard reference XO inhibitor (allopurinol). The extract also inhibited ACE, with IC50 of 21.06 ± 2.04 μg/mL in relation to the IC50 of 4.96 ± 0.18 μg/mL, recorded for the captopril that was used as the standard reference ACE inhibitor. The result showed that the extract had an IC50 of 27.52 ± 1.72 μg/mL against Fe2+-induced lipid peroxidation. The patterns of the inhibitory effects of the extract on XO, ACE and Fe2+-induced lipid peroxidation were dose-dependent as depicted in Figure 2.

Bottom Line: Hence, this study characterized the polyphenolics composition of guava leaves extract and evaluated its inhibitory effect on XO and ACE in vitro.The extract effectively inhibited XO, ACE and Fe(2+)-induced lipid peroxidation in a dose-dependent manner; having half-maximal inhibitory concentrations (IC50) of 38.24 ± 2.32 μg/mL, 21.06 ± 2.04 μg/mL and 27.52 ± 1.72 μg/mL against XO, ACE and Fe(2+)-induced lipid peroxidation, respectively.The extract also strongly scavenged DPPH* and ABTS*(+).

View Article: PubMed Central - PubMed

Affiliation: Department of Biosciences and Biotechnology, Biochemistry Unit, Kwara State University, Malete, P.M.B., 1530, Ilorin, Nigeria.

ABSTRACT

Background/aim: Elevated uric acid level, an index of gout resulting from the over-activity of xanthine oxidase (XO), increases the risk of developing hypertension. However, research has shown that plant-derived inhibitors of XO and angiotensin 1-converting enzyme (ACE), two enzymes implicated in gout and hypertension, respectively, can prevent or ameliorate both diseases, without noticeable side effects. Hence, this study characterized the polyphenolics composition of guava leaves extract and evaluated its inhibitory effect on XO and ACE in vitro.

Materials and methods: The polyphenolics (flavonoids and phenolic acids) were characterized using high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD). The XO, ACE, and Fe(2+)-induced lipid peroxidation inhibitory activities, and free radicals (2,2-diphenylpicrylhydrazyl [DPPH]* and 2,2´-azino-bis-3-ethylbenzthiazoline-6-sulphonic [ABTS]*(+)) scavenging activities of the extract were determined using spectrophotometric methods.

Results: Flavonoids were present in the extract in the order of quercetin > kaempferol > catechin > quercitrin > rutin > luteolin > epicatechin; while phenolic acids were in the order of caffeic acid > chlorogenic acid > gallic acids. The extract effectively inhibited XO, ACE and Fe(2+)-induced lipid peroxidation in a dose-dependent manner; having half-maximal inhibitory concentrations (IC50) of 38.24 ± 2.32 μg/mL, 21.06 ± 2.04 μg/mL and 27.52 ± 1.72 μg/mL against XO, ACE and Fe(2+)-induced lipid peroxidation, respectively. The extract also strongly scavenged DPPH* and ABTS*(+).

Conclusion: Guava leaves extract could serve as functional food for managing gout and hypertension and attenuating the oxidative stress associated with both diseases.

No MeSH data available.


Related in: MedlinePlus