Int.J.Curr.Microbiol.App.Sci (2020) 9(8): 2670-2696 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 8 (2020) Journal homepage: http://www.ijcmas.com Review Article https://doi.org/10.20546/ijcmas.2020.908.305 Best from Waste: Therapeutic Potential of Plant Waste (Seeds, Peels, Flowers) Savan Donga* and Sumitra Chanda Phytochemical, Pharmacological and Microbiological Laboratory, Department of Biosciences (UGC-CAS), Saurashtra University, Rajkot-360 005, Gujarat, India *Corresponding author ABSTRACT Bio waste which includes fruit and vegetable peels, seeds, pomace, rind are generated in K e yw or ds enormous amounts and discarded into the environment adding to pollution. Flowers which are generally used for decoration and religious purpose are also thrown into nature as Seeds , Peels, unwanted material. They create lot of waste and are also hazardous. However, these parts Flowers , Bioactive of the plant are seeds, endowed with phytoconstituents and sometimes more than those compounds, present in other parts. The best was to minimize this hazard is making use of them in food, Medicinal plants, pharmaceutical and allied industries after proper extraction of bioactive compounds from Plant waste, them. To enumerate this idea, in this review, we have enlisted seeds, peels and flowers of Nanoparticles, 60 different plants along with their biological activity and bioactive compounds present in Biological activity them. Some are used directly as crude extracts while some are used to synthesize nanoparticles which show promising biological activities. Thus, plant waste i.e. seeds, Article Info peels and flowers can be used profitably as a source of natural medicine or ingredients in Accepted: many industries. Some activities are reported but other activities can be tried out. Detailed 22 July 2020 structurally analysis also should be done which may give new lead molecules or new drugs Available Online: to be used as safe, natural and novel antimicrobics or antioxidants or anticancer or 10 August 2020 antiulcer agents. This review undeniably and definitely opens up the possibility for utilization of these plant waste products for therapeutic and industrial purpose. Introduction they are easily available and affordable by all the people. The diversity of medicinal plants Medicinal plants are important sources for is vast and there is cure for any and every discovering new drugs for many diseases and ailment in them. They may be directly used as disorders. From times immemorial, plants are drugs or they may act as lead molecules for being used to cure many ailments and recently the discovery of new drug candidates. Many the trend of use of this green medicine has of the drugs used for deadly diseases like increased. This is merely because medicinal cancer are of plant origin (Chanda and plants are free from many side effects that are Nagani, 2013). generally associated with synthetic drugs, 2670 Int.J.Curr.Microbiol.App.Sci (2020) 9(8): 2670-2696 Plants show various biological activities viz. the plant may show very good antioxidant antioxidant (Punica granatum - Kaneria et al., activity but stem or seed may not show 2012), hepatoprotective (Abelmoschus similar activity. The phytoconstituents may moschatus - Singh et al., 2012), anticancer act individually or synergistically. Plant and antimicrobial and synergistic secondary metabolites are bioactive antimicrobial (Pterocarpus santalinus - molecules that are not essential for plant Donga et al., 2017a, 2017b), antioxidant and survival, but have important role in plant anti-inflammatory (Moringa oleifera - Xu et growth, development, reproduction and al., 2019), anti-ulcer (Nigella sativa - Paseban protection from predators and environmental et al., 2020), antiurolithiatic (Mangifera stresses. indica - Iman et al., 2020) etc. The therapeutic property is not isolated to any Fruits and vegetables generate lot of biowaste specific part of the plant. All plant parts show in the form of peels and seeds which are medicinal properties for eg. fruit and thrown into the environment. They increase vegetable peels showed antimicrobial activity pollution and their discard is a major problem. (Rakholiya et al., 2014), Emblica officinalis Flowers are another part of the plant which fruit showed anti-inflammatory activity are generally used for decoration or religious (Golechha et al., 2014), Mangifera indica purpose. They are also discarded into the stem bark showed anti-viral activity (Abdel- environment increasing biowaste. However, Mageed et al., 2014), Nephelium lappaceum these parts can be used as a source of natural peels showed antidiabetic activity (Ma et al., antioxidant, antimicrobial or antiulcer or 2017), aerial parts of Polygonum antidiabetic agent. They are also rich in equisetiforme showed hepatoprotective various phytoconstituents like any other part property (El-Toumy et al., 2019), Pouteria of the plants. The therapeutic use of these caimito peel showed antimicrobial and parts will reduce environmental pollution and antidiarrheal activity (Abreu et al., 2019), this is the best use of the waste. The discarded Opuntia ficus indica seed oil showed peels, seeds or flowers can be used as gelling protection against gastric ulcer (Khemiri and and thickening agents in the refined foods; Bitri, 2019); Lawsonia inermis and Murraya Polysaccharides from them can be a source of koenigii seed extract also showed antiulcer gum and can be used as thickeners, gelling activity (Eggadi et al., 2019). Lavendula agents, texture modifiers and stabilizers; as a bipinnata leaves showed antioxidant activity source of bio-pigments like carotenoids and (Pande and Chanda, 2020) while Annona colourants, as emulsifiers, essential oils, squamosa leaf showed anticancer effect (Al- organic acids and minerals, as substrate for Nemari et al., 2020), Carica papaya flowers microbial fermentation for enzymes showed antioxidant and antibacterial activity production, for bio-ethanol/methanol (Dwivedi et al., 2020), Beta vulgaris root production, for production of biodegradable showed antimicrobial and anticancer activities plastics, as bio fuels and biofertilizers, bio- (El-Mesallamy et al., 2020), etc. pesticides, bio-preservatives, mushroom cultivation, etc (Wadhwa et al., 2015). Plant parts are enriched with phytoconstituents like alkaloids, flavonoids, There are many types of seeds. Some seeds phenols, tannins, saponins, glycosides, are used as spices (Cuminum cyminum, steroids, etc. But their concentration varies Trigonella foenum-graecum, Coriandrum from part to part and hence the therapeutic sativum, Nigella sativa, Foeniculum vulgare), efficacy of plant part also varies. The leaf of some seeds are eaten along with fruits and 2671 Int.J.Curr.Microbiol.App.Sci (2020) 9(8): 2670-2696 vegetables (Solanum lycopersicum, Pisum activity. Myrciaria dubia (Camu-camu) seed sativum, Cicer arietinum, Psidium guajava, coat showed antioxidant and antihypertensive Actinidia deliciosa) while some are thrown activity (Fidelisa et al., 2018). They were rich into the environment (Carica papaya, in phenolic acids and flavonoids. The aqueous Cucumis melo, Manilkara zapota, Citrus extract showed higher antioxidant activity; it limon, Momordica dioica). However, seeds contained total phenolics, non-tannin possess various phytoconstituents and can be phenolics, (−)-epicatechin, chlorogenic acid, therapeutically used. The seeds may have 2,4-dihydroxybenzoic acid, 2,5- extractible high value-added components. dihydroxybenzoic acid and gallic acid. On the Seeds showed various biological activities other hand the propanone extract showed like antioxidant, anti-inflammatory, higher antihypertensive activity and Cu2+ antimicrobial, antidiabetic, antidiarrheal, chelating ability; it had higher levels of wound healing, etc (Table 1). All these quercetin, quercetin-3-rutinoside (rutin), t- properties are because of the resveratrol, ellagic, caffeic, rosmarinic, phytoconstituents present in them in different ferulic, and p-coumaric acids. The ethanolic concentrations which act individually or extract possessed only condensed tannins, synergistically. Mesua ferrea seed extract syringic acid, and (−)-epicatechin. The showed antimicrobial activity (Chanda et al., extracting solvent plays an important role in 2013). Mangifera indica seed kernel showed extracting the phytoconstituents or bioactive inhibition of Pseudomonas spp (Rakholiya et compounds from this biowaste and in al., 2015). Oil extracted from seeds of Citrus exhibiting a particular activity. Parkia sinensis (orange) showed antioxidant activity; speciosa seeds possessed phenols, flavonoids, they contained phenols, carotenoids, terpenoids and alkaloids and showed phytosterols and α-tocopherols (Jorge et al., antimicrobial and antioxidant activities 2016). Parikh and Patel (2017) reported (Ghasemzadeh et al., 2018). There was a antioxidant activity by Manilkara hexandra significant correlation between biological fruit and seeds; the fruits contained phenolics activity and flavonoid content followed by like gallic acid, quercetin and kaempferol, phenolic content. Durio zibethinus (durian) while seeds contained quercetin, gallic acid seeds showed antimicrobial, cytotoxic and and vanillic acid. 11 varieties of Phoenix photocatalytic activity (Sumitha et al., 2018). dactylifera (date palm) seeds were evaluated for phenol, flavonoid and anthocyanin content The pulp, peel and seed of four avocado and antibacterial and antioxidant properties by