Potential antioxidant and antibacterial bioactivity of leaf and stem bark extracts in wild cashew (Anacardium occidentale L.) populations from coastal Piauí, northeastern Brazil

Abstract

Wild cashew Anacardium occidentale L., used locally for food and medicinals, occurs in coastal restinga vegetation in northeastern Brazil. Leaf and bark hydroethanolic extracts from four populations in Piauí state were studied for secondary metabolites, estimation of total phenolics and flavonoids (UV‐Vis spectrophotometry), identification of the selected phenolic compound gallic acid (HPLC), antioxidant (DPPH) assays and estimates of antibacterial activity (agar diffusion, MIC, MBC). Results varied between populations and between leaf and bark. Alkaloids, flavonoids, organic acids, phenolics, reducing sugars, saponins and triterpenoids were observed. Total phenolics and flavonoids levels exceeded those of domesticated cashew (phenolics mg GAE g‐1: leaves 235.6–521.6, bark 430.5–546.3; flavonoids mg QE g‐1: leaves 22.1–30.8, bark 22.3–27.1). Presence of gallic acid was confirmed. Antioxidant IC50 values (DPPH inhibition) ranged from 45.81 to 88.53 µg/mL. Gram‐positive bacterial growth was inhibited (MIC 62.5–250 [‐500] µg/mL in Staphylococcus aureus [sensitive and MRSA strains], S. epidermidis, S. saprophyticus; MIC 500–2000 µg/mL in Streptococcus mutans). Bactericidal activity was observed in two populations (MBC 500–1000 µg/mL). The results corroborate studies of cerrado forms indicating that wild populations are richer in bioactive compounds than domesticated forms and highlight the need to conserve their habitats.

Potencial antioxidante, antimicrobiano, anti-inflamatória e antifúngica da Anacardium occidentale (Linn): Revisão de literatura

“…Enquanto ao período de publicação, ocorreu entre 2018 a 2022, predominando no ano de 2021 com 04 artigos [16][17][18][19], seguido pelo ano de 2020 com 02 artigos [20,21], 2019 com 02 artigos [22,23], 2018 com 02 artigos [24,25], por último o ano de 2022 apresentou 01 artigo [26].…”

“…Com relação a atividade antioxidante dos diferentes extratos de Anacardium occidentale L., foi visualizado em quatro artigos [18,21,23,26]. Sete artigos selecionados para compor a revisão integrativa relatam sobre a atividade antimicrobiana [16,19,20,22,[24][25][26], um artigo descreve sobre a atividade antifúngica [17] e apenas um artigo fala sobre atividade anti-inflamatória [21].…”