Species of mango:

Botanical description

MI is a large evergreen tree in the anacardiaceae family that grows to a height of 10-45 m, dome shaped with dense foliage, typically heavy branched from a stout trunk. The leaves are spirally arranged on branches, linear-oblong, lanceolate – elliptical, pointed at both ends, the leaf blades mostly about 25-cm long and 8-cm wide, sometimes much larger, reddish and thinly flaccid when first formed and release an aromatic odour when crushed. The inflorescence occurs in panicles consisting of about 3000 tiny whitish-red or yellowish – green flowers. The fruit is a well known large drupe, but shows a great variation in shape and size. It contains a thick yellow pulp, single seed and thick yellowish – red skin when ripe. The seed is solitary, ovoid or oblong, encased in a hard, compressed fibrous endocarp.

Habitat

It is native tropical Asia and has been cultivated in the Indian subcontinent for over 4000 years and is now found naturalized in most tropical countries.

Parts used: Roots, bark, leaves, fruits, seeds, flowers and kernels are used.

Pharmacology

Although a lot of pharmacological investigations have been carried out based on the ingredients present but a lot more can still be explored, exploited and utilized. A summary of the findings of these studies is presented below.

Anti-oxidant

Reactive oxygen species (ROS) possess a strong oxidizing effect and induce damage to biological molecules, including proteins, lipids and DNA, with concomitant changes in their structure and function.[17] The major nutritional antioxidants, vitamin E, vitamin C and β-carotene, may be beneficial to prevent several chronic disorders[18] considerable interest has arisen in the possible reinforcement of antioxidant defenses, both for chemoprevention and treatment purposes.[19] The extract showed a powerful scavenging activity of hydroxy radicals and acted as a chelator of iron. It also showed a significant inhibitory effect on the peroxidation of rat brain phospholipid and prevented DNA damage caused by bleomycin or copper-phenenthroline systems[20] The interaction of Vimang (MI extract) with Fe (III) was studied and the results justify the high efficiency of Vimang as an agent protecting from iron-induced oxidative damage.[21] The work has been carried out to investigate the pulp composition of four mango cultivars (Haden, Tommy Atkins and Ubá) at the ripening stage in relation to three components with antioxidant potential (total phenolics, carotenoids and ascorbic acid). These results corroborated previous information that mangoes are a good source of antioxidants in human diet.[22] In vitro antioxidant and free radical scavenging properties of a stem bark aqueous extract of mango tree (MI), whose formulations are used in Cuba as food supplements under the brand name of Vimang, Luminol-enhanced chemiluminescence was used to elucidate the effect of this extract on the generation of reactive oxygen species in PMA- or zymosan-stimulated human polymorphonuclear leukocytes and on superoxide radicals generated in the hypoxanthine–xanthine oxidase reaction. Part of this MI extract antioxidant activity could be ascribed to the presence of mangiferin as its main component.[23] The iron-complexing ability of Vimang as a primary mechanism for protection of rat liver mitochondria against Fe²⁺-citrate-induced lipoperoxidation was reported. The results are of pharmacological relevance since Vimang could be a potential candidate for antioxidant therapy in diseases related to abnormal intracellular iron distribution or iron overload.[24] The protective abilities of MI stem bark extract (Vimang) 50-250 mgkg(-1), mangiferin 50 mgkg(-1) and selected antioxidants (vitamin C 100 mgkg(-1), vitamin E 100 mgkg(-1)and beta -carotene 50 mgkg(-1)) against the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced oxidative damage in serum, liver, brain as well as in the hyper-production of reactive oxygen species (ROS) by peritoneal macrophages was compared.[25]

Anti-diabetic

A 50% ethanolic extract of the leaves of MI produced a significant hypoglycemic effect at a dose of 250 mg/kg, both in normal and streptozotocin-induced diabetic animals. The stimulation of β-cells to release insulin was thought to be part of the mechanism of action.[26] The effect of the aqueous extract of the leaves of MI on blood glucose level in normoglycaemic, glucose - induced hyperglycaemic and streptozotocin (STZ)-induced diabetic rats has been assessed. The results indicate that the aqueous extract of the leaves of MI possess hypoglycaemic activity. This action may be due to an intestinal reduction of the absorption of glucose.[27] The leaves of MI used for antidiabetic properties using normoglycaemic, glucose-induced hyperglycaemia and streptozotocin (STZ) induced diabetic mice. The aqueous extract of the leaves of MI possess hypoglycaemic activity.[28] The effect of mango (MI) ingestion on blood glucose levels of normal and diabetic rats has been studied. The results from this research suggest that mango flour can possibly help in the treatment of diabetes.[29] The stem-bark of aqueous extract of MI was used to examine the antiinflammatory, analgesic and antidiabetic properties. The different chemical constituents of the plant, especially the polyphenolics, flavonoids, triterpenoids, mangiferin, and other chemical compounds present in the plant may be involved in the observed antiinflammatory, analgesic, and hypoglycemic effects of the plant's extract. The results of this experimental animal study lend pharmacological credence to the suggested folkloric uses of the plant in the management and control of painful, arthritic and other inflammatory conditions, as well as in the management of adult-onset type 2 diabetes mellitus in some rural African communities.[30] Investigations were carried out to evaluate the effect of MI on glucose absorption using a rat intestinal preparation in situ. The ethanol extracts of stem-barks reduced glucose absorption gradually during the whole perfusion period in type 2 rats.[31] In glucose-loaded normal rats, mangiferin induces a significant improvement in oral glucose tolerance but without alteration of basal plasma glucose levels[32] these studies show that mangiferin (10 and 20 mg/kg, i.p.) exhibits potent antidiabetic, antihyperlipidemic, antiatherogenic and antioxidant properties without causing hypoglycaemia; mangiferin would then offer a greater therapeutic benefit for the management of diabetes mellitus and diabetic complications associated with abnormalities in lipid profiles. It has been reported that long standing hyperglycaemia with diabetes mellitus leads to the formation of advanced glycosylated end-products which are involved in the generation of ROS, leading to oxidative damage, particularly to heart and kidney.[33]

Antiviral activity

In vitro the effect of mangiferin was studied against Herpes simplex virus type 2; mangiferin does not directly inactivate HSV-2 but inhibits the late event in HSV-2 replication.[34] In vitro mangiferin was also able to inhibit HSV-1 virus replication within cells[35] and to antagonize the cytopathic effects of HIV.[36]

Anthelmintic and anti-allergenic activity

Anthelminthic and antiallergic activities of MI stem bark components Vimang and mangiferin was investigated in mice experimentally infected with nematodes, Trichinella spiralis.[37] The study was carried out to find out anti-allergic properties of vimang and mangiferin, a C-glucosylxanthone isolated from extract of MI. The results constitute the anti-allergic properties of Vimang on allergic models, as well as suggesting that this natural extract could be successfully used in the treatment of allergic disorders. Mangiferin, the major compound of Vimang, contributes to the anti-allergic effects of the extract.[38]

Antiparasitic activity

In a neonatal mouse model, mangiferin at 100 mg/kg has a similar inhibitory activity on Cryptosporidium parvum than the same dose (100 mg/kg) of an active drug, paromomycin.[39]

Antibone resorption

Four water extracts of Kampo formulae were screened for their inhibitory effect on bone resorption induced by parathyroid hormone in organ culture of neonatal mouse parietal bones. Mangiferin isolated and tested in vitro showed a significant inhibitory effect on this model.[40]

Anti-tumor-anti-HIV

The significant cytotoxic activities has been demonstrated by the stem bark extract of mango against the breast cancer cell lines MCF 7, MDA-MB-435 and MDA-N, as well as against a colon cancer cell line (SW-620) and a renal cancer cell line (786-0).[41] The ethanol/water (1:1) extract of dried aerial parts of mango administered intraperitoneally to mice at a dose of 250.0 mg/kg was inactive on Leuk-P388.[42] In vitro, mangiferin dose- and time-dependently inhibited the proliferation of K562 leukemia cells and induced apoptosis in K563 cells line, probably through down-regulation of bcr/abl gene expression.[43] These results suggest that mangiferin has a potential as a naturally-occurring chemopreventive agent.[44]

Antispasmodic and antipyretic activity

The stem bark extract of MI was evaluated for antiplasmodial activity against Plasmodium yoelii nigeriensis. The extract was also screened for antipyretic activity in mice. The extract exhibited a schizontocidal effect during early infection, and also demonstrated repository activity. A reduction in yeast-induced hyperpyrexia was also produced by the extract.[45] The in vitro antimalarial activity of chloroform: methanol (1:1) extract of MI was evaluated. The extract showed a good activity on P. falciparum in vitro with a growth inhibition of 50.4% at 20 μg/mL.[46]

Immunomodulatory

Immunomodulatory activity of alcoholic extract of stem bark of MI was investigated in mice. It is concluded that test extract is a promising drug with immunostimulant properties. Mangiferin mediates the down-regulation of NF-xB, suppresses NF-xB activation induced by inflammatory agents, including tumor nuclear factor (TNF), increases the intracellular glutathione (GSH) levels and potentiates chemotherapeutic agent-mediated cell death; this suggests a possible role in combination therapy for cancer.[47] It is likely that these effects are mediated through mangiferin ROS quenching and GSH rising; increased intracellular (GSH) levels are indeed known to inhibit the TNF-induced activation of NF-κB.[48]

Anti-diarrhoeal

The potential anti-diarrhoeal activity of methanolic (MMI) and aqueous (AMI) extracts of seeds of MI has been evaluated in experimental diarrhoea, induced by castor oil and magnesium sulphate in mice. The results illustrate that the extracts of MI have significant anti-diarrhoeal activity and part of the activity of MMI may be attributed to its effect on intestinal transit.[49]

Anti-inflammatory

An ethanolic (95%) extract of the seed kernel of MI exhibited significant anti-inflammatory activity in acute, subacute and chronic cases of inflammation. The MI leaf extract exhibited antibacterial activity against Bacillus subtilis, staphylococcus albus and Vibrio cholerae.[50] Analgesic and anti-inflammatory effects of MI extract (Vimang) has studied. The polyphenols found in the extract were found to account for the activity reported[51] In vivo and in vitro anti-inflammatory activity of MI extracts (VIMANG) was investigated. MI extract, administered topically (0.5-2 mg per ear), reduced ear edema induced by arachidonic acid (AA) and phorbol myristate acetate (PMA, ED50 = 1.1 mg per ear) in mice. The results represent an important contribution to the elucidation of the mechanism involved in the anti-inflammatory and anti-nociceptive effects reported by the standard MI extract VIMANG.[52]

Anti-bacterial and antifungal activity

In an in vitro agar diffusion technique, mangiferin showed activity against 7 bacterial species, Bacillus pumilus, B. cereus, Staphylococcus aureus, S. citreus, Escherichia coli, Salmonella agona, Klebsiella pneumoniae, 1 yeast (Saccharomyces cerevisiae) and 4 fungi (Thermoascus aurantiacus, Trichoderma reesei, Aspergillus flavus and A. fumigatus).[53]

Anti-microbial

The antimicrobial activities of methanolic extracts of P. guajava and MI have been investigated. The results show that P. guajava and MI extracts exhibited antimicrobial activities at a concentration of 20 mg/ml. Overall, P. guajava extract show more antimicrobial activity than MI extract against tested organisms.[54]

Hepatoprotective

Chemopreventive properties of lupeol and mango pulp extract (MPE) was evaluated against 7, 12-dimethylbenz (a) anthracene (DMBA) induced alteration in liver of Swiss albino mice. Lupeol/MPE was found to be effective in combating oxidative stress induced cellular injury of mouse liver by modulating cell-growth regulators.[55]

Gastroprotective

A novel gastroprotective agent, mangiferin, a naturally occurring glucosylxanthone from MI (Anacardiaceae), was evaluated in mice on gastric injury induced by ethanol and indomethacin. The effects of mangiferin on gastric mucosal damage were assessed by determination of changes in mean gastric lesion area or ulcer score in mice and on gastric secretory volume and total acidity in 4-h pylorus-ligated rats. These findings provide evidence that mangiferin affords gastroprotection against gastric injury induced by ethanol and indomethacin most possibly through the antisecretory and antioxidant mechanisms of action.[56]