Antimicrobial Effects Of Three Species Of Mangifera Indica

1. 1. 1. PHYTOCHEMICAL COSTITUENTS OF Mangifera indica

      
       

 All parts of the mango plant contain secondary metabolites that possess several beneficial properties (Katike et al., 2019). Plants have limitless ability to synthesize aromatic secondary metabolites, most of which are phenols or their oxygen-substituted derivatives (Rajendra Prasad et al., 2013).

1. 1. 1. 1. Phenolic acids

Phenolic acids are plant secondary metabolites that form part of human diet and are of significant importance because of their biological abilities and health benefits (Brglez et al., 2016; Yahia et al., 2017). Mango pulp includes the two major categories of phenolic acids in plants, hydroxybenzoic and hydroxycinnamic acid derivatives. These phenolic acids may be present in free or conjugated forms with glucose or quinic acid (Mattila et al., 2002, Burton-Freeman et al., 2017). The hydroxybenzoic acids that have been detected in the mango pulp are gallic acid, vanillic, syringic, protocatechuic acid, p-hydroxybenzoic acids, while the hydroxycinnamic acid derivatives are p-coumaric, chlorogenic, ferulic, and caffeic acids (Eridiweera et al., 2017). The content and characteristics of phenolic acids depend on the cultivar, crop, and ripening stage (Corrales et al., 2014, Burton-Freeman et al., 2017).

Different phenolic acids were identified in the flesh and skin of nine mango varieties cultivated in China (Abassi et al., 2015). The highest phenolic acid in 100 g of fresh weight (FW) of pulp was ferulic acid (33.75 mg), followed by protocatechuic (0.77 mg), chlorogenic (0.96 – 6.20 mg), gallic (0.93 – 2.98 mg), vanillic (0.57 – 1.63 mg) and caffeic acids (0.25 –0.10 mg) (Abassi et al., 2015). Hu et al. (2018) recently identified tentatively 34 compounds as derivatives of phenolic acids including gallo-tannins and quercetin derivatives, reporting by first time the detection of rosmarinic acid in mango fruit in different stages of ripeness, both in the peel and in the pulp. All the determinations were done by ultra-performance liquid chromatography in combination with mass spectrometry (UPLC-ESI-QTOFMS).

Several authors, using different methods such as high-performance liquid chromatography/electrospray ionization mass spectrometry (Berardini et al., 2004) and HPLC-PDA-MS (Ramirez  et al., 2013) to detect and identify other derivatives of phenolic compounds. Berardini et al. (2004) have detected in the peel of mango Tommy Atkins 18 gallotannins (1.4 mg/g dm expressed as gallic acid) and five benzophenone derivatives identified tentatively as galloylated maclurin and iriflophenoneglucosides, 21 (15.5 mg/gdm) and 8 gallotannins (0.2 mg/g dm) found in the seed and pulp, respectively.

Among the Gallotanins some identified derivative compounds were assigned provisionally as iso-Penta-O-galloyl-glucose, iso-hexa-O-galloy-glucose, Penta-O-galloyl-glucose, tetra-O-galloylglucose, and hexa-O-galloy glucose (Berardini et al., 2004). Some identified derivatives of quercetin were consigned as quercetin-3-O-galactoside and quercetin-3-O-glucoside(Ramirez  et al., 2013), quercetin-3-O-xyloside, quercetin-3-O-arabinopyranoside andquercetin-3-O-arabinofuranoside (Schieber et al., 2003).Ramirez  et al. (2013) reported that the peel of Pica cultivar from Chile presented the highestcontent of total phenolic compounds (66.02 mg/100 g FW) analyzed by HPLC-PDA, and these authors detected 18 compounds present in Pica pulp and 13 in Pica peel more than whatwas detected in the peel and pulp of Tommy Atkins from Chile. The phenolic compoundsidentified in these fruits were three procyanidin dimers, seven phenolic acid derivatives, and four xanthones including homomangiferina, mangiferin, and mangiferingallate in both peel and pulp of Pica and Tommy Atkins cultivars, just dimethyl mangiferin was identified in Tommy pulp (Ramírez et al., 2014).

1. 1. 1. 1. Flavonoids and other polyphenolic compounds

Polyphenols are a class of phytochemicals abundant throughout the plant kingdom. These molecules are generally involved in protecting plants from the ultraviolet radiation, aggression by pathogens, and reactive oxygen species (ROS) (Manach et al., 2005; Mathembayath et al., 2016).

The most abundantly occurring polyphenols in plants are flavonoids, stilbenes, and lignans, of which flavonoids account for 60% of dietary polyphenols (Ramos, 2007, van Breda et al., 2008). Current interests are the antioxidant, anti-inflammatory, and anti-carcinogenic activities of polyphenolic phytochemicals. The relevant polyphenols in the mango fruit related with the antioxidant capacity and/or quantity are the class of flavonoids: catechins, quercetin, kaempferol, rhamnetin, anthocyanins, tannic acid and the class of xanthones: mangiferin (Manach et al., 2004; Masibo et al., 2008). In the pulp of mango, the major flavonols are glycosides of quercetin (glucose, galactose, rhamnose, xylose and arabinose), whereas kaempferol, isorhamnetin, fisetin and myricetin are present in minor levels (Ramirez et al., 2013, USDA, 2018).

The seed and peel of mango fruit are also considered promising sources of polyphenols, with a total phenolic content for these residues of 6-8 % of dry matter in Uba cultivar from Brazil which is 4.6 and 7.3 times higher, respectively compared to the content of the pulp, and a similar profile was reported for the flavonoids and xanthones of this variety (Ribeiro et al., 2008). The Xanthones are molecules formed by a C6-367 C3-C6 backbone structure with hydroxyl, methoxyl and isoprene units linked to the A and B rings, mostly occurs as ethers or glycosides (Negi et al., 2013). Six xanthone derivatives have been identified (mangiferin, dimethyl mangiferin, homomangiferin, mangiferin gallate, isomangiferin, and isomangiferingallate), among this group mangiferin (C 2-b-D-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone), a C glucosyl     xanthone, is broadly distributed in higher plants, with demonstrated pharmacological and antioxidant activity. Mangiferin can be obtained from the bark, fruits, roots, and leaves of Mangifera indica Linn (Mathembayath et al., 2016).

It has also described that mangiferin is able to activate anticancer, antimicrobial, antiatherosclerotic, antiallergenic, anti-inflammatory, analgesic, and immunomodulatory activities (Saleem-Dar  et al., 2016; Ediriweera et al., 2017; Imran  et al., 2017). The content of mangiferin and derivatives is higher in the peel from Pica and Tommy Atkinmango fruit (22.15 and 9.68 mg/FW respectively) compared to the pulp, 4.24 mg, and 3.25 mg/FW, respectively (Ramirez  et al., 2013). For the derivative compounds of mangiferin some characteristic peaks were identified as corresponding to compounds identified provisionally as maclurin-mono-O-galloyl-glucose, maclurin-di-O-galloyl-glucose, iriflophenone di-O-galloyl-glucose (Berardini et al., 2004), and mangiferingallate (Schieber et al., 2003).

1. 1. ANTIMICROBIAL ACTIVITY OF Mangifera indica

A lot has been written on the antimicrobial ability of Mangifera indica on various bacteria species. Aqueous and ethanolic leaf extracts of Mangifera indica has shown antimicrobial effects against these species of microbes namely: Stapylococcus aureus, Micrococcus virians, Micrococcus leteus, Escherichia coli, Klebsellia pneumoniae, Pseudomonas aeruginosa and a fungus, Candida albicans (Olasehinde et al., 2018).Stem and leaf extracts of Mangifera indica has shown to be very potent against methicillin resistant Staphylococcus aureus (Diso et al., 2017). The bioactive phytochemicals in the methanol extract of mango exhibited antimicrobial effects against bacterial pathogens including Escherichia coli, Staphylococcus aureus and Vibrio vulnificus (Bushra and Rizwan., 2019). Stem bark extracts of Mangifera indica has shown antimicrobial activity against Staphylococcus aureus (Mushore and Matuvhunye., 2013).

Further researches have also been carried out incorporating the antimicrobial activity of Mangifera indica to betterment of medical and technological sector. Leaf extracts of Mangifera indica has been developed and incorporated into carbopol hydrogel to enable its antibacterial efficacy against Staphylococcus aureus (Ruth et al., 2019). Extracts of Mangifera indica has activated the reduction of biofilms formation of Staphylococcus spp in stainless steel and teacup rubbers (Andressa et al., 2019). Methanolic and ethanolic leaf extracts of Mangifera indica has shown to be potent against the following miocroorganisms: Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus substillis, Salmonella typhi, Staphylococcus epidermidis, Streptococcus iniae, Aeromonas hydrophila and Aspergillus niger (Olusola et al., 2019).

Mangifera indicaleaf extract has been used to synthesize and stabilize copper quantum dots (Cu QDs). Cu QDs depict good antibacterial activity against Escherichia coli and Staphylococcus aureus at 24 h (Humaira et al., 2019). Antibacterial and antifingal activity were checked for the peel extracts of five Indian cultivars of Mangifera indica using varying extraction solvents (hexane, ethyl acetate and methanol), the results showed that all five cultivars have antimicrobial effects against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginsa, Saccharomyces cerevisiae, Aspergillus fumigatus, Enterococcus aerogenes, Klebsiella pneumoniae, Candida albicans (Katike et al., 2019).

Stigmasterol and β-sitosterol has been extracted from the root of Mangifera indica and they have shown potency against pathogens such as vancomycine resistant Enterococci, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Aspergillus fumigatus, Aspergillus niger. Coniophora putaena, Fibrophoria Vaillentii, Fusarium prolifuratum, Scelerotum rofsii, Rhizopus spp, Serpula lacrymans (Nna et al., 2019). Mangifera indica flower extract has been used to synthesize silver nanoparticles, conferring antibacterial activity on the silver particles which afterwards showed potency against Staphylococcus species, Klebsiella species, Pantoea agglomerans and Rahnella species (Ameen et al., 2019).