Phytochemistry, pharmacological activities, nanoparticle fabrication, commercial products and waste utilization of Carica papaya L.: A comprehensive review

Fruits and vegetables are an important part of a healthy diet. In this regard, Carica papaya (papaya) is one of them, a native to Mexico and northern South America, now naturalized in many parts of the world including tropical and subtropical regions. The papaya fruit pulp is rich in minerals and many vitamins, while seed contains glucosinolates, tocopherols, carotenoids, and benzyl isothiocyanate. Papaya is known for numerous activities such as antioxidant, antibacterial, anticancer activity, anti-fertility agent, anti-inflammatory, antiulcer, antidiabetic, hepatoprotective, and many more due to the presence of phenolics, flavonoids, and alkaloids as the key phytochemicals. Many commercial products obtained from different plant parts are available in the market and are being utilized for various purposes. More specifically, papaya fruit is used to produce a large number of processed foods such as jam, jelly, pickle, candied fruit, puree, concentrate, and canned slices/ chunks. Fruit peels find its application in cosmetics, in wastewater treatment, as animal feed, and as a binder in ceramics. Papaya leaf, bark, root, and seeds have also shown the insecticidal and repellent activities. More interestingly, in the recent past, papaya and different parts are used for nanoparticle synthesis which has shown numerous applications. This review mainly focuses on the various phytochemicals present in different parts of plant C. papaya, their pharmacological activities, and several other applications. For writing this review paper, a literature survey was carried out via classic books of medicinal and fruit plants. Online scientific databases, for instance, PubMed, Scopus, Sci Finder, Science Direct, the Web of Science, Wiley Online, Google Scholar, ResearchGate, and other search engines were explored up to October 2020 to detect valid reports, studies, and investigations. All literature on the proposed topics were analyzed and summarized in this review paper.