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Revista de Biología Tropical, ISSN electrónico: 2215-2075 Vol. 69(2): 472-481, April-June 2021 (Published Apr. 01, 2021)

In vitro inhibitory potential of avocado fruits, Persea americana (Lauraceae)

against oxidation, inflammation and key enzymes linked to skin diseases

Muhammed M. Hürkul

Sezen Yılmaz Sarıaltın

Ayşegül Köroğlu

Tülay Çoban

1. Department of Pharmaceutical Botany, Faculty of Pharmacy, Ankara University, 06560, Ankara, Turkey;

huerkulmm@gmail.com, aguvenc@ankara.edu.tr

2. Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Ankara University, 06560, Ankara, Turkey;

sezenyilmazsarialtin@hotmail.com (*Correspondence), coban@pharmacy.ankara.edu.tr

Received 21-IV-2020. Corrected 14-XII-2020. Accepted 17-II-2021.

ABSTRACT

Introduction: Avocado (Persea americana Mill.) is a member of Lauraceae with one-seeded berry fruit and

cultivated in all tropical, subtropical regions in the world and in the Southern coast region of Turkey. Oxidative

damage caused by UV can trigger inflammation, resulting in serious inflammatory skin diseases including

eczema, seborrheic dermatitis, hyperpigmentation and ageing. Enzyme inhibitors involved in melanogenesis,

such as tyrosinase, have been used recently for hyperpigmentation and skin diseases in cosmetic products.

Objective: This study aimed to evaluate the antioxidant, anti-inflammatory, anti-tyrosinase activities and total

polyphenolic contents of the different parts of P. americana fruit. Methods: The fruit was divided into exo-

carp, mesocarp, seed, and then methanol and n-hexane extracts were prepared. DPPH and ABTS free radical

scavenging capacities and inhibitory potentials on lipid peroxidation were determined to investigate the anti-

oxidant potentials of the extracts. Anti-inflammatory activities of the extracts were evaluated by measuring the

stabilization level of the human red blood cell membrane. The tyrosinase inhibitory activities of the samples

were determined using mushroom tyrosinase. Results: In general methanol extracts possessed remarkable

higher DPPH free radical scavenging activities than n-hexane extracts. The highest activity was determined in

methanol extracts of seed (4.17 ± 0.04 mg/mL) followed by exocarp (5.25 ± 0.05 mg/mL). Overall methanol

extracts possessed higher ABTS free radical scavenging activities than n-hexane extracts. The greatest ABTS

free radical scavenging activity was obtained in methanol extracts of seed (0.03 ± 0.01 mg/mL). In the anti-

lipid peroxidation assay, the greatest activity was noticed in methanol extracts of seed (7.71 ± 0.36 µg/mL)

followed by exocarp (12.12 ± 0.34 µg/mL), while all n-hexane extracts were inactive. Overall methanol extracts

exhibited higher anti-inflammatory and antioxidant properties than n-hexane extracts. However, the maximum

anti-tyrosinase activity was determined in n-hexane extracts of exocarp (0.40 ± 0.01 mg/mL) followed by seed

(0.46 ± 0.01 mg/mL). Conclusions: These extracts are promising candidates for use as natural products-based

antioxidant and anti-inflammatory properties in inflammation-related disease, and also anti-tyrosinase properties

in dermatological applications.

Key words: anti-inflammatory; antioxidant; anti-tyrosinase; avocado; Persea americana.

Hürkul, M.M., Sarıaltın, S.Y., Köroğlu, A., & Çoban, T. (2021).

In vitro inhibitory potential of avocado fruits, Persea

americana (Lauraceae) against oxidation, inflammation

and key enzymes linked to skin diseases. Revista de

Biología Tropical, 69(2), 472-481. DOI 10.15517/rbt.

v69i2.41494

DOI 10.15517/rbt.v69i2.41494

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Revista de Biología Tropical, ISSN electrónico: 2215-2075, Vol. 69(2): 472-481, April-June 2021 (Published Apr. 01, 2021)

Lauraceae is a tropical and subtropical

family that includes evergreen, leathery trees,

and shrubs. The family has 50 genera and about

3 000 species (Evans, 2002). Persea ameri-

cana Mill. (Lauraceae) cultivated in tropical,

subtropical regions of the world and in the

Southern coastal regions in Turkey (Kendir &

Köroğlu, 2018). P. americana fruits contain

lipids (13.5-24 %), carbonhydrate (0.8-4.8 %),

protein (1-3 %), additionally, phytosterols,

terpenoids (monoterpenes, sesquiterpenes, tri-

terpenes), flavonoids, carotenoids, and alka-

loids (Araújo, Rodríguez-Jasso, Ruiz, Pintado

& Aguilar, 2018; Dabas, Shegog, Ziegler, &

Lambert, 2013). Lipids are of great impor-

tance in the chemical content of avocado.

Fruits are known to be rich in polar lipids,

and avocado oil has been reported to be rich

in monounsaturated fatty acids (71 %), poly-

unsaturated (13 %) and saturated fatty acids

(Araújo et al., 2018). By virtue of this rich

content, it can help to regulate lipid profiles

and cardiovascular risks and also used in der-

matological applications (Dreher & Davenport,

2013). Bioactivities of P. americana has been

reported such as antidiabetic, antihypertensive,

hypocholesterolemic, antifungal, antiprotozoal,

antibacterial, antioxidant and larvicidal (Anta-

sionas, Riyanto, & Rohman, 2017; Leite et al.,

2009; Lu, Chang, Peng, Lin, & Chen, 2012;

Monika & Geetha, 2015; Vinha, Moreira, &

Barreira, 2013). Exocarp and the avocado

seed contain great concentrations of bioac-

tive phytochemicals including polyphenols,

phenolic acids, procyanidins, flavonols, and

fatty acids (Rodríguez-Carpena et al., 2011).

The seed of P. americana exhibited high anti-

oxidant antimicrobial, antibacterial, insecti-

cidal and fungicidal activities (Cardoso et al.,

2017; Rodríguez-Carpena et al., 2011). Dabas,

Shegog, Ziegler, & Lambert (2013) reported

that seed of P. americana can help to improve

the conditions in hypercholesterolemia, hyper-

tension, diabetes and inflammation related dis-

eased. Methanol extracts were subjected to

evaluate the presence of flavonoids, alkaloids,

anthocyanins, condensed tannins and triterpe-

noids while hexane extracts were triterpenes

and sterols (Leite et al., 2009).

Inflammation is a complex response of the

body against several reactions including injury,

infection, irritation, allergy and also pathogens.

Free radicals from endogenous and exogenous

sources may cause inflammation by activat-

ing various genes involved in the inflamma-

tory pathways. They stimulate oxidative stress

inducing degradation of essential cellular ele-

ments altering lipids, proteins, and DNA struc-

ture resulting in inflammation-related diseases

(Munn, 2017; Sarıaltın & Çoban, 2018). Steroi-

dal and non-steroidal anti-inflammatory drugs

are used to treat these inflammation-related

diseases including arthritis, gout, psoriasis,

asthma, vasculitis, and even cancer. However,

there are some common side effects related to

these drugs, especially on the gastrointestinal

system such as bleeding, ulcers, and also in the

cardiovascular system such as stroke and heart

attack (Günaydın & Bilge, 2018). Therefore,

recent studies have focused on alternative,

plant-derived anti-inflammatory agents with

lower side effects (Okur et al., 2018; Adedapo,

Adewuyi, & Sofidiya, 2013; Badilla, Mora, &

Poveda, 1999).

Tyrosinase is a multifunctional copper-con-

taining monooxygenase enzyme that catalyzes

the production of melanin and other pigments,

using molecular oxygen. This enzyme is found

in human, animal, plant, bacteria, and fungi

tissues. Biosynthesis and activation of this

enzyme induce pigmentation in two cell types;

one are the melanocytes present in skin, hair,

eye and the others are epithelial pigment cells

(Ramsden & Riley, 2014). Activation of tyrosi-

nase may cause hyperpigmentation reactions

in human and animal skin via oxidation of

melanocytes and browning reactions in fruits

and vegetables via oxidation of phenolic com-

pounds (Lobo, Patil, Phatak, & Chandra, 2010;

Olivares, & Solano, 2009). Increased produc-

tion of free radicals and other reactive species

can initiate and progress these reactions and

disrupt the homeostasis. Tyrosinase inhibitors

have been used in cosmetics like sunscreen,

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anti-aging products, skin whitening agents,

and food industry as antibrowning agents.

Hence, several studies have recently been

conducted to develop synthetic and naturally

occurring tyrosinase inhibitors (Zolghadri et

al., 2019). The objective of this study was to

investigate the effectiveness of n-hexane and

methanol extracts of exocarp, mesocarp, and

seed from P. americana fruits as antioxidant,

anti-inflammatory and anti-tyrosinase as well

as total phenolic content. This is the first report

demonstrating antioxidant, anti-inflammatory,

and anti-tyrosinase potentials of different parts

of P.americana fruit as well as total polyphenol

content together. The graphical abstract of the

present study is shown in Fig. 1.

MATERIALS AND METHODS

Plant material: In this study, the “Bacon

variety” of avocado was studied. Plant mate-

rials were collected from Hatay (Turkey)

province. A voucher specimen was recorded

with code AEF 26915 and deposited in the

Ankara University Faculty of Pharmacy Her-

barium (AEF).

Extraction procedure: Four ripe avo-

cado fruits were divided into three sections,

exocarp (53 g), mesocarp (121 g) and seed

(74 g). These separated parts of the fruits were

mashed and dried in the oven at 60° C for 2

days. The dried parts were extracted by shak-

ing maceration with n-hexane (exocarp 400,

mesocarp 600, seed 400 mL) for 8 h at 60 °C

twice. The extracts were filtered and concen-

trated under reduced pressure at 40 °C. After

this process, each remaining plant parts were

macerated with methanol (exocarp 400, meso-

carp 600, seed 400 mL) for 8 h at 60 °C twice.

The extracts were filtered and concentrated

under reduced pressure at 40 °C (Güvenç et al.,

2012). Hence 6 different extracts (3 n-hexane

and 3 methanol) were obtained.

Determination of total polyphenols: The

total polyphenol content of extracts was deter-

mined by Folin-Ciocalteu method, referring

to the calibration curve of gallic acid, phenol

Fig. 1. The graphical abstract of the present study.

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compound used as a standard (Güvenç et al.,

2012). The results were expressed as mean mg

gallic acid equivalent (GAE)/g dry extract.

DPPH

•

free radical scavenging activ-

ity: Free radical scavenging activities of the

extracts were evaluated using the two different

DPPH assay: qualitative and quantitative meth-

ods (Güvenç et al., 2012). Propyl gallate (PG)

was assessed as a reference compound in both

methods. The scavenging activity on the DPPH

radical was expressed as inhibition percentage

and the half-maximal inhibitory concentrations

(IC

) of the samples were calculated by linear

regression analysis.

ABTS

•+

free radical scavenging activity:

The antioxidant activities of the extracts were

measured by ABTS

•+

radical cation decoloriza-

tion assay (Yalçın, Yılmaz, & Polat, 2020).

Trolox was used as a standard compound. The

scavenging activity on the ABTS radical was

expressed as inhibition percentage and IC

values of the samples were calculated.

Anti-lipid peroxidation activity: Thio-

barbituric acid (TBA) test was used to assess the

efficacy of the extracts in protecting liposomes

from lipid peroxidation (Güvenç et al., 2012).

PG was assessed as a reference compound. IC

values of the samples were calculated.

Anti-tyrosinase activity: Tyrosinase

inhibitory activity was performed using the

methods of Khatib et al. (2005) and Souza et al.

(2012) with minor modifications. Ascorbic acid

(AA) was used as a reference compound. IC

values of the samples were calculated.

Anti-inflammatory activity: Human

red blood cell (HRBC) membrane stabilizing

activities of the samples against heat-induced

hemolysis were assessed as an indicator of

anti-inflammatory activity (Yalçın, Yılmaz &

Polat, 2020). The study protocol for the anti-

inflammatory activity was approved by the

ethics committees of the Faculty of Med-

icine of Ankara University, Ankara-Turkey

(26.10.2015/16-695-15). Acetylsalicylic acid

(ASA) was used as a reference compound. IC

values of the samples were calculated.

Statistical analysis: All experiments were

performed at least in triplicate and the results

were expressed as mean IC

± standard devia-

tion (SD). Statistical analyses were carried

out with SPSS V23.0. Shapiro-Wilk test was

used to test the normality of the data. One-way

analysis of variance (ANOVA) followed by the

Fisher’s least significant difference (LSD) test

was used for multiple group comparisons. Sta-

tistically significant difference was considered

at the level of P < 0.05.

RESULTS

Antioxidant, anti-inflammatory, and anti-

tyrosinase activities and total phenolic content

of P. americana (avocado) fruit parts were

evaluated. n-hexane and methanol extracts

were obtained from exocarp, mesocarp, and

seed. All data is expressed in Table 1. All

biological activity results of the extracts and

reference compounds were observed statisti-

cally significant compared as solvent control

(p < 0.05).

Folin-Ciocalteu’s method was used to

determine the total phenolic compounds in

the extracts and the results expressed as GAE

(Table 1). According to the results obtained,

methanol extracts had more phenolic contents

than the n-hexane extracts. The greatest total

phenolic content was fixed in the methanol

extracts of the seed (168.33 ± 8.89 mg GAE/g

extract) following by exocarp (60.56 ± 5.81 mg

GAE/g extract).

The radical-scavenging activities of the

extracts were estimated by the DPPH on the

rapid TLC screening method (qualitative) and

by comparing the IC

values of formation of

DPPH radicals by the extracts and PG. In the

qualitative DPPH test, yellow zones were very

prominent for methanol extracts of exocarp

and seed whereas, n-hexane extract of exocarp

gave only a faint yellow zone. Besides, both

n-hexane extracts of mesocarp and seed parts

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and also methanol extract of meso-

carp showed no activity (Fig. 2).

In general methanol extracts

showed higher DPPH free radical

scavenging activities than n-hexane

extracts. In the quantitative DPPH

method, the major activity was

determinated in methanol extracts

of seed followed by exocarp parts

(Table 1). The ability to scavenge

DPPH free radical of fruit parts

was in the order of seed > exocarp

> mesocarp for methanol extracts

and exocarp > mesocarp > seed for

n-hexane extracts.

Overall methanol extracts pos-

sessed better ABTS free radical

scavenging activities than n-hexane

extracts. Extracts with the great-

est ABTS free radical scavenging

activity were obtained in methanol

extracts of seed with IC

value of

0.03±0.01 mg/mL which was com-

parable to reference compound tro-

lox with 0.02±0.01 mg/mL. This

was followed by methanol extracts

of exocarp and mesocarp with IC

values of 0.06±0.02 and 0.65±0.08

mg/mL, respectively. The maximum

activity among n-hexane extracts

was found in the seed part followed

by exocarp and mesocarp similar

order to methanol extracts.

The antioxidant activities of the

avocado fruit parts on liposomes

obtained from the anti-lipid perox-

idation assay are given in Table

1. Generally, methanol extracts

showed higher activity than n-hex-

ane extracts. In the TBA method, the

highest activity was observed with

seed and exocarp methanol extract,

also n-hexane extracts of three

parts of avocado were determined

as inactive.

The results of anti-tyrosinase

activity showed that hexane extracts

displayed higher inhibitory potential

TABLE 1

Biological activities and total phenolic contents of the extracts of P. americana fruit parts and reference compounds

mg GAE/g dry extract

Antioxidant activity Anti-tyrosinase activity

Anti-inflammatory

activity

(mg/mL) IC

(µg/mL) IC

(mg/mL) IC

(mg/mL)

Fruit parts

Total phenolic content

DPPH free radical

scavenging assay

ABTS free radical

scavenging assay

Anti-lipid peroxidation

assay

Anti-tyrosinase assay

HRBC membrane

stabilizing assay

Hexane Methanol Hexane Methanol Hexane Methanol Hexane Methanol Hexane Methanol Hexane Methanol

Exocarp 7.50±4.75 60.56±5.81 10.31±0.10 5.25±0.05 3.98±0.42 0.06±0.02 Inactive 12.12±0.34 0.40±0.01 0.89±0.06 9.96±1.03 2.01±0.06

Mesocarp 6.94±3.99 21.39±1.40 18.27±0.18 11.34±0.11 19.88±0.27 0.65±0.08 Inactive 627.86±0.50 1.49±0.44 1.02±0.04 5.89±0.89 2.22±0.15

Seed 4.44±2.80 168.33±8.89 19.80±0.19 4.17±0.04 0.75±0.02 0.03±0.01 Inactive 7.71±0.36 0.46±0.01 1.82±0.70 7.73±0.09 2.03±0.06

Reference Compounds

PG - 1.73±0.02 - 0.11±0.03 - -

Trolox - - 0.02±0.01 - - -

AA - - - - 0.02±0.0003 -

ASA - - - - - 0.27±0.02

Each result expressed as mean±SD.

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compared to the methanol extracts. The highest

anti-tyrosinase activity was found in hexane

extracts of exocarp followed by seed (IC

= 0.40±0.01 and 0.46±0.01 mg/mL, respec-

tively). Methanol extracts of exocarp showed

the most potent anti-tyrosinase activity among

methanol extracts similar to the results of

n-hexane extracts. Chai et al. (2015) reported

that proanthocyanidins, isolated and purified

from avocado, were irreversibly and competi-

tively inhibited the tyrosinase.

Methanol extracts has been generally

found to be more efficient in stabilization of

HRBC membrane than n-hexane extracts as

shown in Table 1. The highest HRBC mem-

brane stabilization potential was determined in

methanol extracts of exocarp with IC

value

of 2.01±0.06 mg/mL followed by methanol

extracts of seed with 2.03±0.06 mg/mL. The

membrane stabilizing capacities of the extracts

was in the following order: methanol extracts

of seed > exocarp > mesocarp and then n-hex-

ane extracts of mesocarp > seed > exocarp.

All biological activity results of the

extracts and reference compounds were found

statistically significant compared to control

(P<0.05).

DISCUSSION

The fruits of P. americana consist of high

concentrations of vitamins, minerals, dietary

fibers, saturated, and unsaturated fatty acids

(Dreher & Davenport, 2013). Because con-

sumption of P. americana is considered to be

beneficial for human health, especially for

cardiovascular system diseases and dermato-

logical applications. In the food industry pulp

of the fruit is consumed, while exocarp and

seed are discarded. In our study, overall metha-

nol extracts exhibited higher anti-inflamma-

tory and antioxidant properties than n-hexane

extracts. The total phenolic content of methanol

extracts was also greater and it is thought that

the phenolic compounds might be responsible

for these activities. The highest DPPH and

ABTS free radical scavenging and anti-lipid

peroxidase activity were observed in methanol

extracts of seed, followed by exocarp. The

maximum total phenolic content among all

extracts was also found in methanol extracts

of seed followed by exocarp. The inhibition of

lipid peroxidation may be owing to the elec-

tron transfer and hydrogen donating abilities

of phenolic compounds and subsequent ABTS

and DPPH free radical stabilization. Support-

ing this data methanol extracts of exocarp and

seed exhibited the greatest HRBC membrane

stabilization activity. Bioactive phytochemical

compounds of exocarp and seed obtained from

P. americana by methanolic extraction could

be responsible for the higher anti-inflammatory

activity registered in the HRBC membrane sta-

bilization assay and also antioxidant activity in

Fig. 2. Antioxidant activity by qualitative DPPH of the extract.

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ABTS and DPPH free radical scavenging and

anti-lipid peroxidation assays. The results of a

study conducted with fresh avocado fruit are

consistent with our results. According to the

previous study, the seed (43 %) and exocarp

(35 %) were more active than the mesocarp

(23 %) (Vinha, Moreira, & Barreira, 2013).

According to another study, the IC

value of

avocado exocarp methanol extract was found

for DPPH and ABTS tests 9.40±0.05 mg/mL

and 1.12±0.01 mg/mL, respectively (Antasio-

nas, Riyanto, & Rohman, 2017). According

to the results of our study, the IC

value of

exocarp methanol extract was found 5.25±0.05

mg/mL for DPPH and 0.06±0.02 mg/mL for

ABTS free radical scavenging test. Vinha et

al. (2013) used fresh avocado fruit parts and

the total phenolic contents were determined

as 679.0±117.0 mg/100 g, 410.2±69.0 mg/100

g, 704.0 ± 130.0 mg/100g for exocarp, meso-

carp and seed, respectively. The reason for the

higher total phenolic content in our current

study may be due to our dry extracts, while

the others used fresh fruits. It has been previ-

ously reported that avocado seeds and peels

are rich in polyphenolic compounds (Araújo

et al., 2018). Higher polyphenolic content

(307.09±14.16 and 254.40±16.36 mg GAE/g

extract) and high antioxidant capacity (DPPH:

266.56±2.76 and 221.69±20.12 mg ET/g

extract; ABTS: 607.28±4.71 and 516.34±11.81

mg ET/g extract; ORAC: 475.55±47.82 and

495.25±14.52 mg ET/g extract) have been

reported from avocado seeds by microwave

assisted extraction method using acetone 70

% and ethanol solvents, respectively. This

method made it possible to extract compounds

with high antioxidant capacity using safe sol-

vents such as ethanol in a short time (Araújo

et al., 2020). The total phenolic content and

ABTS radical scavenging capacity of metha-

nol and ethanol-water (50:50, v/v) extract

obtained from avocado seeds were reported

as 25.35±0.77-30.98±0.68 µg GAE/g dw, and

123.74±2.46, 263.58±17.85 µmol TE/g dw,

respectively. Additionally, avocado seed oil

has been reported to inhibit the oxidation of

sunflower oil, which is poor in polyphenolic

substances, by 80 % (Segovia, Hidalgo, Vil-

lasante, Ramis, & Almajano, 2018). Support-

ing our data Kristanti, Simanjuntak, Dewi,

Tianri, & Hendra (2017) reported that metha-

nol extracts of P. americana seed exhibited

significant inhibition at the dose of 3.33 g/kg

body weight in carrageenan induced mice paw

oedema test which is used as to determine anti-

inflammatory potential. Similarly, the aqueous

extract of P. americana leaves possessed sig-

nificant inhibition of carrageenan-induced paw

oedema in a dose dependent manner in rats and

77.1 % inhibition was observed at 800 mg/kg

(Adeyemi, Okpo, & Ogunti, 2002). Ethanol/

water (80:20, v/v) extracts of P. americana

fruit peel extract inhibited the release of tumor

necrosis factor-alpha, which is a well known

pro-inflammatory cytokine, at 495.3 pg/mL as

well as nitric oxide at 8.5 μM in activated RAW

264.7 macrophages (Tremocoldi et al., 2018).

On the contrary, n-hexane extracts exhibited

greater tyrosinase inhibitory activities than

methanol extracts, which could be due to the

nonpolar compounds brought out easily by

n-hexane. The maximum anti-tyrosinase activ-

ity was determined in n-hexane extracts of exo-

carp followed by seed. Tyrosinase is one of the

most essential and critical enzymes involved in

enzymatic browning and melanin synthesis in

mammals (Zolghadri et al., 2019). Therefore,

n-hexane extracts of exocarp and seed of P.

americana could be used in dermatological

applications as potent tyrosinase inhibitors.

The results of our study indicate that exo-

carp and seed which are residues and waste of

food-processing industries can contribute to the

treatment of inflammation-related diseases and

skin disorders as an economic option due to

their rich phenolic content. These extracts are

promising candidates for use as natural prod-

ucts-based antioxidant and anti-inflammatory

properties in inflammation-related disease, and

also antityrosinase properties in dermatological

applications. Moreover, our results could be

the basis to search for new nutraceutical and

pharmacological agents from P. americana.

Further studies are needed to identify, then

isolate and, purificate the active constituents

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by bioactivity-guided isolation which are

responsible for these activities, and also obtain

novel and specialized compounds in food and

pharmaceutical formulations.

Ethical statement: authors declare that

they all agree with this publication and made

significant contributions; that there is no con-

flict of interest of any kind; and that we

followed all pertinent ethical and legal proce-

dures and requirements. All financial sources

are fully and clearly stated in the acknowled-

gements section. A signed document has been

filed in the journal archives.

RESUMEN

Potencial inhibidor in vitro de frutos de aguacate,

Persea americana (Lauraceae) contra la oxidación,

inflamación y enzimas clave vinculadas a

enfermedades de la piel

Introducción: El aguacate (Persea americana Mill.)

es un miembro de Lauraceae, es una baya de una semilla

que se cultiva en todas las regiones tropicales y subtro-

picales del mundo y la región costera sur de Turquía. El

daño oxidativo causado por los rayos ultravioleta puede

desencadenar inflamación, lo que posteriormente da como

resultado enfermedades inflamatorias graves de la piel

como eccema, dermatitis seborreica, hiperpigmentación

y envejecimiento. Los inhibidores de enzimas implicados

en la melanogénesis, como la tirosinasa, se han utilizado

recientemente para la hiperpigmentación y enfermedades

de la piel en productos cosméticos. Objetivo: Evaluar las

actividades antioxidantes, antiinflamatorias, antitirosinasas

y los contenidos polifenólicos totales de las partes del

fruto de P. americana. Métodos: El fruto se dividió en tres

partes: exocarpio, mesocarpio y semilla, y se prepararon

extractos de metanol y n-hexano. Se determinaron las

capacidades de eliminación de radicales libres de DPPH y

ABTS y los potenciales inhibidores sobre la peroxidación

de lípidos para investigar los potenciales antioxidantes

de los extractos. Las actividades antiinflamatorias de los

extractos se evaluaron midiendo el nivel de estabiliza-

ción de la membrana de los glóbulos rojos humanos. Las

actividades inhibidoras de tirosinasa de las muestras se

determinaron utilizando tirosinasa de hongos. Resultados:

En general, los extractos de metanol poseían actividades

de eliminación de radicales libres de DPPH notablemente

más altas que los extractos de n-hexano. La actividad

más alta se presentó en extractos metanólicos de semilla

(4.17±0.04 mg/mL) seguido del exocarpio (5.25±0.05 mg/

mL). En general, los extractos de metanol poseían una

mayor actividad de eliminación de radicales libres ABTS

que los extractos de n-hexano. La mayor actividad capta-

dora de radicales libres de ABTS se obtuvo en extractos

metanólicos de semilla (0.03±0.01 mg/mL). En el ensayo

de anti-peroxidación lipídica, la mayor actividad se obser-

vó en los extractos metanólicos de semillas (7.71±0.36 µg/

mL) seguidos del exocarpio (12.12±0.34 µg/mL), mientras

que todos los extractos de n-hexano estaban inactivos. En

general, los extractos de metanol exhibieron mayores pro-

piedades anti-inflamatorias y antioxidantes que los extrac-

tos de n-hexano. Sin embargo, la actividad anti-tirosinasa

máxima se determinó en extractos de exocarpio de n-hexa-

no (0.40±0.01 mg/mL) seguido de semillas (0.46±0.01 mg/

mL). Conclusiones: Estos extractos son candidatos prome-

tedores como productos naturales debido a sus propiedades

antioxidantes y antiinflamatorias para tratar enfermedades

relacionadas con la inflamación, y también propiedades

antitirosinasas en aplicaciones dermatológicas.

Palabras clave: antiinflamatorio; antioxidante; anti-tirosi-

nasa; aguacate; Persea americana.

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