Nutritional Composition and Bioactive Compounds of Native Brazilian Fruits of the Arecaceae Family and Its Potential Applications for Health Promotion

The fruits from the Arecaceae family, although being rich in bioactive compounds with potential benefits to health, have been underexplored. Studies on their composition, bioactive compounds, and effects of their consumption on health are also scarce. This review presents the composition of macro- and micronutrients, and bioactive compounds of fruits of the Arecaceae family such as bacaba, patawa, juçara, açaí, buriti, buritirana, and butiá. The potential use and reported effects of its consumption on health are also presented. The knowledge of these underutilized fruits is important to encourage production, commercialization, processing, and consumption. It can also stimulate their full use and improve the economy and social condition of the population where these fruits are found. Furthermore, it may help in future research on the composition, health effects, and new product development. Arecaceae fruits presented in this review are currently used as raw materials for producing beverages, candies, jams, popsicles, ice creams, energy drinks, and edible oils. The reported studies show that they are rich in phenolic compounds, carotenoids, anthocyanins, tocopherols, minerals, vitamins, amino acids, and fatty acids. Moreover, the consumption of these compounds has been associated with anti-inflammatory, antiproliferative, antiobesity, and cardioprotective effects. These fruits have potential to be used in food, pharmaceutical, and cosmetic industries. Despite their potential, some of them, such as buritirana and butiá, have been little explored and limited research has been conducted on their composition, biological effects, and applications. Therefore, more detailed investigations on the composition and mechanism of action based on in vitro and/or in vivo studies are needed for fruits from the Arecaceae family.


Introduction
Brazilian biodiversity is known for sheltering 15% of the total number of live species in the world [1]. Although many native nuts and fruits have potential for industrial exploitation and can be an income source for small producers, most of them are still unknown and underexplored [2]. In Brazil it is possible to find 113 genera and 704 species of the Arecaceae family, which comprises approximately 704 genera and 3819 species. Geonoma, Syagrus, Bactris, Atallea, Allagoptera, Astrocaryum, and Euterpe are the genera with the highest number of occurrences worldwide [3]. Recently, the lipid composition [4], nutraceutical potential [5], and the chemical properties [6] of different species of fruits from the Arecaceae family have been reported. Bacaba (Oenocarpus bacaba), patawa (Oenocarpus bataua), juçara (Euterpe edulis), Brazilian economy in 2020 [11,50]. The processing of açai needs to be performed up to 12 hours after the harvesting, since the fruit degrades rapidly under the high temperatures observed in the north and northeast of Brazil [33]. The açaí is used as an ingredient in yogurts, candies, juices, nectars, and jam.

Buriti (Mauritia flexuosa L.f.)
Buriti is a palm tree found mainly in the biomes Amazon and Cerrado and it is also known as miriti, buriti coconut, buriti palm, and swamp palm. It grows in swamps close to permanent watercourses and on top of mountains, which is an advantage since these areas are not suitable for other activities [51]. The buriti palm tree usually reaches more than 15 m and specimens have been reported reaching more than 50 meters. The leaves have a fan-like shape ( Figure 2F) [51,52].
The fructification of the buriti happens between December and June, and each plant can produce between 150 and 200 kg of fruit per harvest. The fruits have an average weight of 50 g, longitudinal diameter of 5.25 cm, and a cross-sectional diameter of 3.91 cm ( Figure 2E) [53,54]. The shape is elliptical oval, surrounded by a pericarp (shell) composed of triangular scales of dark and hard red color. The mesocarp (pulp) is thin and soft, with a bittersweet flavor, striking and peculiar aroma, and dark red to yellow color. The fibers are used to make ropes and hammocks and leaf petioles to make bottle stoppers, toys, rustic beds, and rafts [55,56]. The pulp of buriti is used by the local population for preparing juice, marmalades, jams, ice cream, wine, and fermented beverages. The foodstuffs and beverages made with the fruit are also sold in local markets, generating income for the population and ensuring the maintenance of the local culture [57]. In addition, its oil and pulp are commonly used to prevent and treat some pathologies due to their potential antimutagenic, antibacterial, and healing properties [10,58].

Buritirana (Mauritiella armata Mart.)
Buritirana is also known as buriti mirim, buriti bravo, caranã in Brazil, and aguajillo in Colombia and Venezuela. The fruits are globose to oblong-ellipsoid ( Figure 2F). The pulp is fleshy and fibrous with a slightly reddish color and a strong and peculiar aroma. The endocarp is very thin and surrounds a hard seed. The shell, which is similar to the buriti shell, presents overlapping scales and a reddish-brown color. Its consumption by local populations is mainly in natura and it is also used to make drinks, wines, and sweets [6,59,60]. Figure 2G shows that the buriti and buritirana palm have similar fruits and leaves. The difference between these species is the stem. The buriti has a single stem with a diameter of 45 cm. On the other hand, the buritirana presents a stem divided in several segments with a diameter of 20 cm. The buritirana has globose to oblong fruits, fleshy and fibrous pulp, and a very thin endocarp surrounding a hard seed. It is consumed by local populations in natura or used in beverages, sweets, and wines [59][60][61].

Butiá (Butia odorata (Barb. Rodr.) Noblick)
The Butia odorata is a palm tree which is native to southern Brazil and east of Uruguay. It usually grows in open areas such as fields, savannas, dunes, and sandbanks in the Pampa biome [62], and is usually found in flat and flooded terrain, flowering between September and January. The peak of fruiting occurs between December and April [63]. Currently, the species in Brazil and Uruguay are considered of great vulnerability since the adult plants are centenary and suffer with the increase in the area for livestock and intensive agriculture. Human action in the native areas causes a great impact on the regeneration cycle of the trees [64][65][66].
The butiá palm tree has a single, straight, and inclined stem 3-6 m high, without visible palm hearts at the top. Its leaves  are pinnate, grey-green, and serrated, and the fruits are pale yellow to reddish-orange, with an average diameter of 1.7 to 4.2 cm [67]. The mesocarp is fleshy, with an endocarp containing one to three locules with three pores ( Figure 2H) [31,68]. The maturation of the fruits occurs mainly in summer between February and April, with maximum production in February [69]. Butiá has an intense aroma and flavor and high acidity. It is consumed fresh or used in juices, alcoholic beverages, and frozen products [70,71]. The pulp and leaves are also used to treat skin diseases and infections [55]. The commercialization of butiá can bring economic and social benefits without environmental degradation. Therefore, it is interesting to stimulate its research and sustainable production. Table 1 shows the macro-and micronutrient composition for fruits of the Arecaceae family. The moisture (from 30.36 to 88.90 g 100 g −1 ), lipids (2.18 to 21.02 g 100 g −1 ), and energy values (64.68 to 368.78 kcal 100 g −1 ) show great variation. The pulps of bacaba and buritirana have the highest content of lipids and energy value (21.02 and 21.01 g 100 g −1 ; 377.54 and 368.78 kcal 100 g −1 , respectively). On the other hand, the butiá pulp shows the lowest values for these parameters (2.18 g 100 g −1 and 70.46 kcal 100 g −1 , respectively). The buritirana and açaí pulp show the highest protein content (5.96 and 5.30 g 100 g −1 , respectively). Açaí, patawa, and bacaba present the highest content for carbohydrates (47.83, 46.10, and 42.80 g 100 g −1 , respectively), and the lowest value is observed for juçara palm (5.46 g 100 g −1 ). The highest fiber content was reported for buritirana (65.46 g 100 g 1 ), followed by patawa pulp (29.70 g 100 g −1 ). These fruits are richer in fibers when compared to commercial and popular fruits such as banana (10.50 g 100 g −1 ), mango (6.71 g 100 g −1 ), watermelon (8.73 g 100 g −1 ), and tamarind (13.93 g 100 g −1 ) [72]. The ingestion of 100 g of buritirana pulp can supply the recommended dietary intake (RDI) of fiber for healthy adults, which is 25-35 g on a 2000 kcal diet [73]. The patawa pulp, which represents 40% of the fruit weight, is rich in proteins (4.90%), oil (14.40%), and carbohydrates (46.10%) [74]. Butiá and buriti showed lower levels of fiber (1.31 and 6.02 g 100 g −1 , respectively). A diet rich in fiber has been related with health benefits such as blood pressure reduction, improvement in serum lipid profile, and glycemic control [73,75].

Macro and Micronutrients
The consumption of minerals is necessary for the proper functioning of the organism, and they are related to energy at the cellular level and macronutrient metabolism [76]. Moreover, the minerals are part of molecules such as vitamins, amino acids, hormones, and blood cells. Ca, Mg, and K are needed in higher amounts and Zn, Cu, I, Mn, and Se in lower levels [77]. The main mineral found in açaí, buritirana, and butiá was potassium (K) (930.00, 672.25, and 462.40 mg 100 g −1 , respectively). The RDI of K, which contributes to the reduction in blood pressure and the risk of cardiovascular diseases, is 3510 mg per day for healthy adults [78]. The consumption of 100 g of açaí, buritirana, and butiá fruit pulp represent 26.48%, 19.15%, and 13.23%, respectively, of the RDI of K, which is 3510 mg per day for a healthy adult. A deficiency of K in the diet can result in fatigue, leg cramps, muscle weakness, slow reflexes, acne, dry skin, and irregular heartbeat, among other symptoms [79,80]. Juçara, açaí, buritirana, and buriti are rich in Ca (up to 462 mg 100 g −1 ) and Mg (up to 317 mg 100 g −1 ). Considering the RDI for a healthy adult for Ca (1300 mg per day) and Mg (400 mg per day), the intake of 100 g of açaí represents 36 and 76% of the RDI for Ca and Mg, respectively. Magnesium and calcium form stable complexes with phospholipids that are part of cell membranes. The action of these minerals, which can act synergistically, depends on its the concentration in the cells [94]. Other minerals present in the fruits of the Arecaceae family in intermediate concentrations are Na (1.90-71.21 mg 100 g −1 ), Mn (0.61-45 mg 100 g −1 ), I (0.28-46.60 mg 100 g −1 ), and P (6.90-186 mg 100 g −1 ). Moreover, the highest concentrations of these minerals were found in the same fruits with higher potassium levels. Schulz et al. [40] observed the same behavior in dark-colored fruits found in Brazil, such as Myrcianthes pungens, Myrciaria cauliflora, and E. edulis. The consumption of 100 g of juçara and açaí provides more than 100% of the RDI for Mn (2.3 mg day −1 ) and iron (8 mg day −1 ). Furthermore, 100 g of buritirana can afford more than 100% of Mn, and 36% of I.
The buriti pulp showed a high level of Se (0.05 mg 100 g −1 ) and Cr (0.12 mg 100 g −1 ). The RDI for these minerals is 0.055 mg per day for Se and 0.03 mg per day for Cr. Chromium is linked to gene expression, energy production, synthesis of lipoproteins or lipids, and regulation of glucose metabolism [95]. The deficiency of Cr in the human organism can cause glucose intolerance, weight loss, peripheral neuropathy, and increase for the risk of cardiovascular disease [96]. The selenium is related to the function of the thyroid and immune system. It is associated with a reduction in the risks of several types of cancer [97], and its deficiency can contribute to cardiovascular disease, hypothyroidism, and deficiencies of the immune system [95]. Table 2 shows the lipid profile of the fruits from the Arecaceae family. The main fatty acids reported in these fruits were oleic (C18:1) > palmitic (C16:0) > linoleic (C18:2) > stearic (C18:0) > linolenic (C18:3). A content of 75.7, 72.7, and 52.1% of oleic acid was reported for the pulp of buriti [74], patawa [98], and açaí [99], respectively. The consumption of oils with a high content of oleic acid has been associated with the reduction of cholesterol. This fatty acid also presents higher oxidative stability when compared to polyunsaturated fatty acids (PUFAs) [98].

Lipid Profile
The linoleic acid, an essential PUFA, was found in açaí (48.05%), butiá (32.80%), and juçara (26.10%). The majority of the fruits present a balanced fatty acid composition, with high content in monounsaturated fatty acids (MUFAs) and saturated fatty acids (SFAs). In addition, the high levels of unsaturated fatty acids in its pulp make this raw material susceptible to oxidation reactions which may cause physical and sensory changes [100]. The patawa presented the lowest concentration of PUFA (2.72%). It has been reported that the fruit patawa has potential for the production of edible oil suitable as an ingredient in cosmetics, soaps, and foods such as popsicles, ice cream, and concentrated juices [74,98]. Its oil still has antimicrobial activity and high oxidative stability compared to other commercial oils [4,7]. Despite its interesting nutritional composition, patawa is still relatively unknown in Brazil, and it is used only by the local population in the regions where it is grown [101]. On the other hand, buriti oil has a lipid content of 22%, composed mainly of oleic acid (72.23%) and palmitic acid (21.18%). The nutritional composition of the fruits depends on the place of cultivation, soil, and genotype. The buriti oil is rich in unsaturated fatty acids and carotenoids. Oliveira et al. [102] reported an antioxidant and antidiabetic effect at low concentrations of buriti oil (10 and 15 mg mL −1 ).
The oils obtained from bacaba and patawa pulp have high concentrations of SFAs (38.98 and 36.65%, respectively), mainly lauric and stearic acids. These oils can be used in the oleochemical industry and for the development of new lipid-based formulations with diverse industrial applications [103,104]. Caproic (C6:0), caprylic (C8:0), and capric (C10:0) acids are also found only in patawa oil in concentrations of 0.40, 7.80, and 8.00%, respectively. The highest concentration of tocopherols was observed for buriti (1688.58 mg kg −1 ), followed by juçara, açaí, and patawa (1193.00, 645.00, and 341.00 mg kg 1 , respectively). The α-tocopherol was the only tocopherol identified in açaí oil, which presented the highest concentration reported for this isomer (645.00 mg kg −1 ) [110]. This concentration is higher than those reported for extra virgin olive oil (163.00 mg kg −1 ) and other refined oils such as soybean (352.00 mg kg −1 ), sunflower (575.00 mg kg 1 ), and corn (207.00 mg kg −1 ) [116,117]. The main tocopherols identified in the butiá and buritirana were α-tocopherol, β-tocopherol, and γ-tocopherol. The α-tocopherol is the isomer with vitamin E activity, and it has been reported that it is associated with the prevention of atherosclerosis and atherosclerosis and steatosis [118].
The patawa oil showed the highest content of phytosterols, followed by bacaba and buriti (1169.10, 106,00, and 100 mg kg −1 , respectively). The main phytosterol present was β-sitosterol. Data on the profile of the phytosterols for juçara, açaí, buritirana, and butiá were not found in the literature. It has been reported that the phytosterols can reduce the serum levels of fat-soluble vitamin E (α-tocopherols) and β-carotene, which has pro-vitamin A activity [119]. The highest concentrations of β-sitosterol were found in bacaba, patawa, and buriti (76.40, 479.20, and 76.6, respectively. It has been reported that the consumption of these fruits decreases blood cholesterol levels in hyper-and normocholesterolemic individuals [120]. Dumolt and Rideout [121] and Jones et al. [122] reported that phytosterols are considered GRAS (generally recognized as safe) and have not been correlated with any mutagenic activity or toxicity in experimental studies. Table 3 shows that patawa can be considered a source of essential amino acid (502.00 mg g −1 protein), when compared to açaí and buriti. The most prevalent amino acids in patawa were leucine, threonine, isoleucine, lysine, and valine. These branchedchain amino acids are related to the protein synthesis, as they stabilize the protein structure through hydrophobic interactions [123]. Data on the amino acid composition of bacaba, juçara, butiá, and buritirana have not been found in the literature.

Amino Acids
Buriti is rich in threonine, leucine, and tryptophan (85.50, 23.80, and 23.80 mg g −1 protein, respectively). Tryptophan, a precursor of serotonin which is involved in the modulation and regulation of anxiety and mood, is not usually found in foods [124]. Tryptophan is also a precursor of compounds associated with sleep regulation and stress reduction, such as nicotinamide (vitamin B6), tryptamine, melatonin, kynurenine, xanthurenic, and quinolinic acids [125].  Figure 3 shows the bioactive compounds reported in bacaba, patawa juçara, açaí, buriti, buritirana, and butiá. Phenolic acids, flavonoids, anthocyanins, and vitamins were the main compounds found in these fruits. Gallic acid, cyn 3-O-rutinoside, rutin, and (+)catechin in bacaba, and cyn 3-O-rutinoside and (−)-epicatechin in patawa were the main compounds assessed. Açaí and juçara have been reported as superfruits, and compounds such as apigenin, cyn 3-O-rutinoside, rutin, myricetin, quercetin, kaempferol, and vanillic acid have been reported in their composition. On the other hand, protocatechuic acid, rutin, chlorogenic acid, (−)-epicatechin, and luteolin are the main compounds found in buriti. For butiá, the main compounds are chlorogenic acid, quercetin, and myricetin. The presence of these compounds in the fruits from the Arecaceae family are presented and discussed in the next sections.  Table 4 shows the phenolic composition of the fruits of the Arecaceae family. The concentration of the total phenolic compounds (TPC) is directly proportional to the antioxidant activity (AA) in these fruits. The highest content of phenolic compounds was observed for juçara, açaí, bacaba, and butiá (5672.0, 3437.4, 1759.27, and 1250.30 mg GAE 100 g −1 , respectively). Santos et al. (2015) reported for buriti pulp from the Amazon 118 ± 2 mg GAE 100 g −1 of TPC. On the other hand, Candido et al. (2015) reported that buriti pulp from Cerrado biome had higher values of phenolic compounds when compared to the fruit of the Amazon biome. Royo et al. [130] reported that buritirana has a flavonoid content of 7.92, 5.93, and 0.93 mg g −1 in the leaves, roots, and petioles, respectively. It has been also reported that the fruit is rich in carotenoids such as trans-β-carotene (373.00 µg 100 g −1 ), alltrans-α-carotene (230.00 µg 100 g −1 ), trans-lutein (198.00 µg 100 g −1 ) and 9-cis-β-carotene (11.00 µg 100 g −1 ) [60]. Table 4. Bioactive compounds and antioxidant activity of extracts from fruits of the Arecaceae family.
Lutein, a dehydroxylated carotenoid belonging to the class of yellow-colored xanthophylls, is predominant in açaí (483 µg g −1 ) and buriti (226 µg g −1 ). The values of lutein in these fruits are higher than in vegetables considered rich in lutein, such as caruru (119 µg g −1 ), mentruz (111 µg g −1 ), and taioba (104 µg g −1 ). Moreover, the concentration of lutein in açaí is higher than the concentration reported in nasturtium (450 µg g −1 ), an edible flower that was considered the richest source of lutein reported in the literature [166]. Açaí has been reported as a super fruit [167], with carcinogenic [157] and neuroprotective [43] effects associated with its high content of lutein.
Nonato et al. [18] reported in vitro AA for buriti extracts using the ability to scavenge 2,2 -azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals and ferric reducing antioxidant power (FRAP). The 80.90% of chelating activity by FRAP observed for buriti was independent of the concentration (14-700 µg mL −1 ) for extracts recovered using ethyl acetate as solvent. The AA for the extracts of buriti was higher when compared to the results reported for extracts of açaí and juçara for DPPH, FRAP, and ORAC (Table 4). Buriti showed a potential to reduce the DPPH radical that was 20 times higher when compared to butiá and approximately 4 times higher when compared to açaí.
The AA using the ABTS assay was higher for patawa and açaí (2471.50 and 1154.43 µmol TE g −1 , respectively). Considering the patawa, the authors indicated that patawa presented AA that was about 41 times higher using ABTS radical when compared to bacaba, juçara, and buriti. Considering that the ABTS radical is soluble in organic and aqueous solvents, this indicates that patawa has antioxidant components with different solubility. In addition, the absorption at a wavelength of 734 nm of the ABTS radical eliminates possible interference from color, resulting from unsatisfactory extraction processes [173]. Rezaire et al. [101] and Saravia et al. [82] reported a high content of phenolic compounds in the patawa pulp extracts with high antioxidant activity, and that patawa has higher antioxidant activity (TEAC and FRAP assays) compared to açaí. The authors indicated that patawa could be used as an ingredient in foodstuffs, cosmetics, and pharmaceutics. Medicinal properties have been reported for its pulp, leaves, and roots, such as treating hair loss, dandruff, bronchitis, tuberculosis, and malaria [174].
Buriti showed the highest antioxidant capacity in FRAP and ORAC assays (8890.00 µmol FeSO 4 g −1 and 2470.00 µmol TE g −1 , respectively), followed by patawa (1869.90 µmol FeSO 4 g −1 and 1626.70 µmol TE g −1 ) and juçara (1745.33 µmol FeSO 4 g −1 and 1266.36 µmol TE g −1 ). The differences observed between the AA assays are related to the differences within the assays, such as the radicals, pH, temperature, time, solvents, and method of extraction [40,175,176]. Buriti showed approximately 134 times more power to reduce the ferric ion by the FRAP and 13 times more power of reduction by the ORAC test when compared to bacaba. These higher FRAP and ORAC values observed for these fruits are probably correlated with the polyphenol contents.
Most of the in vivo studies that evaluated the AA were carried out with animals exposed to adverse conditions, such as high-fat diets, oxidative stress, and diabetes. Copetti et al. [14] evaluated the effect of acute consumption of juçara juice on the reduction of biomarkers of oxidative stress and fatigue in 15 healthy men using a HIIT protocol (high-intensity interval training). The results showed that the acute consumption of juçara juice immediately decreased the oxidative stress index (OSI) and fatigue. On the other hand, the consumption of juçara increased the levels of reduced glutathione (GSH) after 1 hour under HIIT. Moreover, the consumption of juçara juice significantly increased the content of uric acid and total phenols over time, indicating that it can induce antioxidant responses and reduce fatigue after training. It also suggests that more benefits to the human health can be achieved when practicing sports together with the consumption of juçara juice than practicing the sports only.
The AA for the pulp, shell, and seed of buriti was evaluated using thiobarbituric acid reactive substances (TBARS) and the oxidative hemolysis inhibition, DPPH, ABTS, and FRAP assays. The shell of buriti showed significantly higher AA when compared to the seed and pulp. Moreover, the bioaccessibility of phenolic compounds for pulp, shell, and seed after simulated in vitro digestion decreased from 553, 1288, and 597 mg L −1 to 102, 498, and 133 mg L −1 , respectively, which represent 18.70, 38.70, and 22.30% reduction on the content of bioactive compounds. The ability of the extracts of buriti to cause hemolysis in red blood cells was determined, and even at the highest concentration (8.0 mg mL −1 ), the induction of the lysis was not observed. The authors also report that the blood cells treated with the extracts (0.5, 1.0, 2.0, 4.0, and 8.0 mg mL −1 ) were protected when exposed to the peroxide radicals produced by the thermal decomposition of AAPH (2,2 -Azobis(2-amidinopropane) dihydrochloride)) [177]. Table 5 shows in vitro and in vivo studies on antioxidant activity, anti-inflammatory, chemopreventive, cardioprotective, and antimicrobial effects of the fruits belonging to the Arecaceae family.    Crude and refined oil Rats
Maternal consumption of buriti oil ↓ weight gain and reflex maturation, but ↑ somatic maturation in newborn rats.
↑ Increases the deposition of serum retinol and liver in the offspring.

Serum retinol and liver retinol
Medeiros et al. [191] ↓    ↑ Butiá odorata extract showed high antimicrobial activity against the studied Salmonella strains. ↑ The zones of inhibition varied between 8 and 14 mm.

5-(hydroxymethyl)-2furfural and piranone
Haubert et al. [188] Pulp extract In vivo and in vitro Deteriorating and pathogenic microorganisms Antimicrobial Lyophilized samples. The compounds of interest were extracted with acetone; 30 g/300 mL of solvent/2 h of stirring (190 rpm  ↑ The antioxidant analysis of the parts of M. flexuosa showed promising chemopreventive potential. ↑ More significant results were found for the bark.
I None of the extracts induced lysis of rat erythrocytes, being able to protect blood cells.
Phenol, flavonoid, condensed tannin Freire et al. [177]   ↓ AST. Maternal consumption of buriti oil ↓ weight gain and reflex maturation, but ↑ somatic maturation in newborn rats. ↑ Increases the deposition of serum retinol and liver in the offspring.
Maternal consumption of buriti oil ↓ weight gain and reflex maturation, but ↑ somatic maturation in newborn rats.
↑ Increases the deposition of serum retinol and liver in the offspring.

Antimicrobial Effects
The antimicrobial potential of extracts obtained from butiá has been reported [188][189][190]. Maia et al. [190] reported that the hexane extract of butiá (3 and 7 mg mL −1 ) presented activity against Gram-negative bacteria such as Salmonella Typhimurium, Escherichia coli O157: H7, and Pseudomonas aeruginosa), with zones of inhibition ranging from 59.50 to 86.00 mm using the agar diffusion method.
On the other hand, Listeria monocytogenes and Bacilus cereus were not inhibited at the highest concentrations tested (11 mg mL −1 ). Gram-positive bacteria are more sensitive to antimicrobial compounds from plant origin when compared to Gram-negative bacteria [192]. Such behavior may be correlated to the cellular membrane of Gram-negative bacteria, which is composed of lipopolysaccharides ensuring protection against various agents. It has been reported that (+)-catechin, (−)-epicatechin, quercetin, and phytosterols present synergistic action against the Gram-negative bacterium [188,189,193].
The extracts of butiá obtained with acetone showed activity against Escherichia coli inoculated in sliced cheese with a minimal inhibitory concentration (MIC) value of 15 mg mL −1 . The logarithmic decrease observed for the number of colony forming units (CFUs) of Escherichia coli in the samples treated with the extract after 72 h was eight times higher when compared to the control (2.8 log CFU cm −2 and 0.5 log CFU cm −2 , respectively). The authors associated the antimicrobial activity of the extract with the main compounds such as Z-10-pentadecenol (80.1%) and palmitic acid (19.4%), identified in the butiá extract [189].
Haubert et al. [188] reported that methanolic extracts of Butiá odorata showed antimicrobial and antibiofilm activity against 26 serovars of Salmonella spp. isolated from food and environment where food was prepared. The MIC of Butiá odorata extract ranged from 10 to 19 mg mL −1 . This inhibition may be correlated with the presence of bioactive compounds in the extract such as phenolics, phenols, and flavonoids. The main compounds identified in the extracts were the 5-(hydroxymethyl)-2-furfural (65.17%), followed by the pyranone, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (8.49%). Polovková and Šimko [194] reported that the formation of 5-(hydroxymethyl)-2-furfural is due to the Maillard reaction or the dehydration of reducing saccharides caused by exposure to high temperatures. In this study, in the process of elaboration and characterization of the extracts, the temperatures did not exceed 40 • C. The activity of piranones against Salmonella spp. and Gram-negative and Gram-positive bacteria has been reported [188].
The antimicrobial activity of nonencapsulated buriti oil against Klebsiella pneumonia, Pseudomonas aeruginosa, and Staphylococcus aureus has been reported ( Table 5). The nonencapsulated buriti oil increased the antimicrobial activity against Pseudomonas aeruginosa (59%), Klebsiella pneumonia (62%), and Staphylococcus aureus (43%) when compared to the control group without treatment. The inhibition of the bacterial growth was related to the particle size and the phytochemicals, such as quercetin, eugenol, and vanillic acid, present in the oil. Leão et al. [195] reported that nanoemulsions of interesterified and noninteresterified buriti oil were effective against Gram-negative bacteria.

Anti-Inflammatory and Hypocholesterolemic Effect
The inflammatory process is a complex immune response of the organism to heal infections or repair damaged tissue. However, inflammation can produce an uncontrolled response or can be related to the disruption of the homeostasis state of physiological processes. It can lead to chronic systemic damage and inflammatory diseases such as diabetes, asthma, Alzheimer's, atherosclerosis, cancer, neurodegenerative, and neurological diseases [196]. The free radicals produced by active inflammatory leukocytes in chronic and acute inflammation are highly deleterious [197]. High levels of proinflammatory molecules such as C-reactive protein, nitric oxide (NO), reactive oxygen species (ROS), cyclooxygenase-2 (COX-2), tumor necrosis-α (TNF-α), interleukins (IL-1β, IL-6, IL-8), and transforming growth factor-β are found in the inflammatory process [198][199][200].
Several plants have been used in folk medicine as an alternative to the treatment of chronic inflammation with fewer side effects and low toxicity. Nonsteroidal anti-inflammatories (NSAIDs), which are the traditional anti-inflammatory drugs used, can cause adverse effects such as a decrease in COX-prostaglandin production, gastrointestinal disorders, kidney problems, and severe peptic ulcer. A positive correlation has been reported between ingestion of foods rich in phenolic compounds and a negative modulation of the inflammatory response [198,199]. The mechanism for the anti-inflammatory activity has not been elucidated yet [201].
Silva et al. [181] studied the anti-inflammatory activity of lyophilized juçara pulp in obese Wistar rats in a proinflammatory state. The animals were fed for 16 weeks with hypercaloric and hyperlipidemic diets with 0.5% and 2% of lyophilized juçara pulp, and the tumor necrosis factor-alpha (TNF-α), interleukin 1β, concentrations of lipopolysaccharides (LPS), and toll-like receptor-4 (TLR-4), which is an encoded protein, were assessed. The results showed that the serum concentration of lipopolysaccharides (LPS) and tumor necrosis factor-alpha (TNF-α) in the colon of the animal consuming 0.5% and 2.0% of juçara pulp and the control group were statistically lower in the 0.5% group compared to the control group. On the other hand, the authors observed a significant decrease in the concentration of interleukin 1β in the groups fed with 0.5% and 2.0% compared to the control group. The TNF-α and the TNF-α/interleukin ratio was statistically lower in the group that consumed 0.5% of juçara lyophilized than the control group. The protein content of toll-like receptor-4 (TLR-4) was significantly lower in the rats' groups fed with the diet supplemented with juçara compared to the control group. It can explain the decrease in the concentrations of proinflammatory cytokines. Moreover, an increase in interleukin in adipose tissue in the rats fed with juçara was reported by Argentato et al. [202], Morais et al. [203], and Freitas et al. [180].
Xie et al. [184] evaluated the effect of velutin, a flavonoid isolated from açaí fruit pulp, on decreasing TNF-α and interleukin-6 (IL-6) induced by lipopolysaccharide in peripheral macrophages and peritoneal macrophages of mice. The inhibition of the expression of TNF-α and IL-6 mRNA and protein levels in two macrophages was higher for velutin when compared to luteolin and apigenin. These flavonoids have been reported as the most effective in inhibiting the production of inflammatory cytokines [204,205].
The anti-inflammatory and antilipidemic activity of extracts rich in polyphenols (2.5-10 µg GAE mL −1 ) obtained from açaí was investigated using 3T3-L1 adipocytes [183]. The extracts inhibited the expression of mRNA and PPAR-γ protein and regulatory genes associated with lipid metabolisms such as aP2, FAS, FATP1, and LPL. In addition, açaí polyphenols with and without TNFα decreased the expression of proinflammatory cytokines, thus reducing the production of reactive oxygen species (ROS). The results were independent of the dose (2.5, 5, and 10 µg GAE mL −1 ). The bacaba phenolic extract showed the same behavior, demonstrating that BPE attenuates adipogenesis through downregulation of PPARγ2 and C/EBPα during differentiation's early to middle stages. This, in turn, decreases the induction of metabolic genes associated with the adipocyte phenotype, such as FABP-4 and adiponectin [24].
The anti-inflammatory effects of defatted and lyophilized juçara pulp and its byproducts were evaluated in rats fed for four weeks with a high-fat diet [180]. The diet with supplementation of defatted and lyophilized juçara pulp was able to attenuate diet-induced nonalcoholic fatty liver disease (NAFLD). A decrease in inflammatory infiltrate, steatosis, and lipid peroxidation in the liver tissue was observed. These effects were correlated with the low lipid content and high content of polyphenolic compounds and anthocyanins in pulp of juçara.
Obesity is defined as a low-grade chronic inflammatory disease, and it can lead to several health problems, such as Type 2 diabetes, osteoarthritis, cancer, and cardiovascular disorders. Obesity is mainly caused by the positive energy balance resulting from a higher energy intake or a hypercaloric diet compared to the energy expenditure observed in a sedentary lifestyle [206][207][208]. The activation of inflammatory signaling pathways and atypical production of proinflammatory cytokines and fat storage cells (adipokines) are observed in chronic obesity [209,210]. It has been reported in the literature an antiobesity synergistic effect for phenolic compounds, flavonoids, carotenoids, and tocopherols [211,212]. The mechanism is related to the mediation of complex cell signaling pathways for lipolysis and β-oxidation of fatty acids, reducing the lipogenesis and adipogenesis [213].
Oyama et al. [214], Santamarina et al. [215], and Jamar et al. [216] reported a decrease in the inflammatory response in rats fed with a high-fat diet supplemented with juçara and its byproducts. Udani et al. [182] studied the influence of consuming 100 g of açaí pulp twice a day for one month in ten overweight adults. The results showed that the total cholesterol, LDL cholesterol, and the ratio of total cholesterol: HDL cholesterol, insulin, and plasma glucose decreased significantly compared to the control group. In addition, the consumption of açaí pulp for thirty days improved the postprandial rise in plasma glucose after the consumption of a standardized meal when compared to the placebo group.

Antitumoral/Antiproliferative Activity and Other Effects
The World Health Organization (WHO), in partnership with the International Agency for Research on Cancer (IARC), reported an increase in cancer from 18.1 million of cases in 2018 to 19 million in 2020, with 10 million deaths. It is expected that there will be 28.4 million new cases of cancer worldwide until the year 2040, which represents an increase of approximately 47% compared to 2020. In countries where the human development index (HDI) is considered low or medium, this expectation of cancer incidence for 2040 is estimated to increase by 96% when compared to 2020 [217].
Poor eating habit is considered the most important factor in the incidence of cancer and other noncommunicable diseases (NCDs) such as neurological, inflammatory, cardiovascular, and endocrine diseases [218]. Epidemiological studies show that a healthy lifestyle, which includes a balanced diet, can reduce the risk of several cancer types. A diet rich in fruits, vegetables, and grains, which are rich in phytochemicals, is widely recommended by several international bodies, such as the American Cancer Institute (AICR) and the World Cancer Research Foundation (WCRF) [219,220]. It has been reported that phenolic compounds promote the neoplastic effect and chemoprevention against cancer cells, reducing oxidative stress and modulating the signal transduction pathways involved in cell proliferation and survival.
Finco et al. [178] evaluated the in vitro antiproliferative potential of bacaba extracts and the apoptotic effect on the MCF-7 breast cancer cell line. Bacaba extract showed antiproliferative activity between 100-800 µg mL −1 . Furthermore, a cell shrinkage and reduction of the cell monolayer area was observed in the MCF-7 breast cancer cells with the treatment at a concentration of 400 µg mL −1 . The results indicated that the extracts obtained from bacaba induced apoptosis in MCF-7 cells. The authors suggested that bacaba extracts present chemopreventive potential and correlated such effects with dietary phenolics that are important preventive agents in cancer diseases.
Fuentes et al. [186] evaluated the effect of açaí oil nanoemulsion as a photosensitizer for photodynamic therapy (PPT) on the cell death of nonmetastatic melanoma in vitro and in vivo models. In vitro tests showed that the nanoemulsion induced the apoptosis of 85% of the melanoma cells and kept the normal cells viable. Moreover, the in vivo tests in mice showed that the photosensitizer formulated with açaí oil induced 82% reduction in the tumor of the animals submitted to the photodynamic therapy compared to the control group. The authors attributed the effect of anticancer to the polyphenols such as flavonoids, lignins, anthocyanins, and proanthocyanidins present in the açaí oil.
Boeing et al. [15] evaluated the antiproliferative effects of an ethanolic extract (80:20, v/v) obtained from the pulp and peel of butiá against cell lines strains of human intestinal cancer (Caco-2), cervical cancer lineage (HeLa), and human papillomavirus cells (SiHa and C33a). The ethanolic extract presented higher activity against the SiHa and C33a strains with a 50% inhibitory concentration (IC 50 ) of 528 and 411 µg mL −1 , respectively. On the other hand, the butiá extract did not reach half of the maximum inhibitory concentration (IC50) for the cell lines strains Caco-2 and HeLa. The treatment with the butiá extract did not affect the cell viability of murine fibroblasts and human keratinocytes. The chemo-preventive activity was different between the cancer cell line strains. The variation in the chemopreventive activity among the cancer cells tested indicated different mechanisms of action for the ethanolic extract of butiá pulp. The authors indicated that (+)-catechin (259.00 mg kg −1 ), (−)-epicatechin (211.00 mg kg −1 ), and rutin (161 mg kg −1 ), present in the extract, were the compounds with bioactivity. The cytoprotective, antioxidant, cardioprotective, neuroprotective anticarcinogenic, and chemopreventive activities for these compounds are widely reported in the literature [221][222][223].
Medeiros et al. [191] investigated the effect of the consumption of buriti oil on somatic reflex development and retinol levels in neonatal rats. Thirty-six newborn male Wistar rats born to mothers who consumed a 7% lipid diet during pregnancy and lactation were used. The authors concluded that consumption of buriti oil interferes with weight gain and reflex maturation, accelerating tail growth and somatic development and increasing the availability of serum and hepatic retinol in newborn rats.

Conclusions
Arecaceae palm tree fruits have high nutritional value and are rich in bioactive compounds such as phenolic acids (gallic, vanillic, p-coumaric, and chlorogenic), flavonoids ((+) catechin, (−)-epicatechin, rutin, kaempferol), phytosterols, tocopherols, and carotenoids. These compounds are responsible for the antioxidant activity and potential health benefits such as antimicrobial, chemopreventive, cardioprotective, anti-inflammatory, and antiobesity effects. The Arecaceae palm tree fruits have potential for use in food, pharmaceutical, biotechnology, and cosmetic industries. Despite their rich nutritional and bioactive compounds composition, butiá (Butia odorata) and buritirana (Mauritiella armata) need more attention, considering the limited studies that have been reported in the literature. This review demonstrates the importance of valorizing underexploited Brazilian native fruits whose products and coproducts are rich in phytochemicals with potential benefits for human health. It also highlights the need for further research on the composition, health effects, processing, and full use of these raw materials. Moreover, the mechanisms and the synergism between the bioactive compounds of these fruits, and their effects, especially in human models, need to be further studied. In addition, government public policies and partnerships with local producers may improve the socioeconomic situation of extractivist populations, and can also encourage the consumption and processing of these fruits, ensuring the preservation of natural resources. This review can contribute to the dissemination of such products whose consumption and applications may help to promote a healthy diet.

Conflicts of Interest:
The authors declare no conflict of interest.