Adeeyo et al. Clinical Phytoscience (2021) 7:31 https://doi.org/10.1186/s40816-021-00258-4 REVIEW Open Access Plant active products and emerging interventions in water potabilisation: disinfection and multi-drug resistant pathogen treatment Adeyemi O. Adeeyo1* , Joshua N. Edokpayi2, Mercy A. Alabi3, Titus A. M. Msagati4 and John O. Odiyo2,5 Abstract Background: This review aims at establishing the emerging applications of phytobiotics in water treatment and disinfection. Results: Statistical analysis of data obtained revealed that the use of plant product in water treatment needs more research attention. A major observation is that plants possess multifaceted components and can be sustainably developed into products for water treatment. The seed (24.53%), flower (20.75), leaf (16.98%) and fruit (11.32%) biomasses are preferred against bulb (3.77%), resin (1.89%), bark (1.89%) and tuber (1.89%). The observation suggests that novel applications of plant in water treatment need further exploration since vast and broader antimicrobial activities (63.63%) is reported than water treatment application (36.37%). Conclusions: This review has revealed the existing knowledge gaps in exploration of plant resources for water treatment and product development. Chemical complexity of some plant extracts, lack of standardisation, slow working rate, poor water solubility, extraction and purification complexities are limitations that need to be overcome for industrial adoption of phytochemicals in water treatment. The field of phytobiotics should engage modern methodologies such as proteomics, genomics, and metabolomics to minimise challenges confronting phytobiotic standardisation. The knowledge disseminated awaits novel application for plant product development in water treatment. Keywords: Microbial resistance, Phytochemicals, Water treatment, Standardisation Introduction have been reported for their antioxidant activity exerted Although plant products are available [1–3]and exhibit by scavenging the ‘free-oxygen radicals’ thereby giving different mechanisms of action from conventional anti- rise to a fairly ‘stable radical. Cinnamaldehyde and other microbials [4, 5], there are critical gaps in the explor- polyphenols have been known for their anti-diabetic ac- ation of plant resources [6] for development of useful tivity by enhancing the amount of insulin-like TTP products [7]. The variation and complexity in chemical (Thrombotic Thrombocytopenic Purpura), IR (Insulin compositions of plants potentiate their activity [5]. Dif- Resistance), and GLUT4 (Glucose Transporter-4) in 3 ferent phytochemicals present in plants such as phenols, T3-L1 Adipocytes. Phenolic acids are known for their quinones, flavonols, tannins, coumarins and alkaloids are antimicrobial activity by reduction of adherence of or- responsible for plant activities. Flavonols and phenolics ganisms to cells and essential oils for their anti- inflammatory effect by suppressing nitric oxide produc- * Correspondence: [email protected] tion [8, 9]. 1 Department of Ecology and Resource Management, University of Venda, Current interventions of plants dealing with microbial Private Bag X5050, Thohoyandou 0950, South Africa Full list of author information is available at the end of the article resistance, immunomodulation, as antitumour agents, © The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Adeeyo et al. Clinical Phytoscience (2021) 7:31 Page 2 of 16 maintenance of illnesses affecting immune systems and various fields. The search was restricted to articles writ- in microbial virulence attenuation have been described ten in English language and covered the period between in various researches [10–13]. In the early days of use, 1993 and 2020. A review of studies reporting the use of plants were used in their crude state [14] and contribute plants as alternative against resistant microorganism es- greatly to the health care system of local communities pecially in water treatment was attempted. Studies [15]. Ethnomedicinally, plants have found application in reporting the mechanisms of action of phytobiotics, the treatment of several diseases and ailments. Examples methods employed in standardisation of herbal drug and are Astragalus membranaceus, roots of Trichosanthes current existing challenges in this field were examined. kirilowii, roots and rhizomes of Panax quinoquefolusin Raw information obtained were computed in MS-excel and pulps of Cornus officinalis reported for treatment of 2016 to convert data into processed statistics for the in- diabetes mellitus. terpretation of the data. Tables, figures charts and sim- Terminalia chebulaand Adenocarpus mannii are known ple percentages were used to present and interpret the for their immunomodulation properties [16, 17], Thea results of data. assamica in the treatment of impetigo [18], Ocimum gra- tissimum in the treatment of acne [19], Drechslera rostata Results and discussion and Polygala molluginifolia for their antitumor activities Classification of synthetic and plant-based antimicrobials [20, 21]. Medicinal plants including Ageratum conyzoides, The treatment of microbial infections and contamination Celosia trigyna, Centella asiatica, Brassica nigra, Racun- has mainly involved the use of antimicrobial agents like culus oreophytus, Azadiracha indica, Ficus exasperate, antiseptics, sanitizers, disinfectants, as well as antibiotics Senna hirsuta, Morus alba, Artocarpus heterophyllus have [32]. Antibiotic could specifically denote a substance all been reported for their ethnomedicinal use in various with the capacity to inhibit, that is, cause static or cidal ethnic groups [22–24]. effect to microbes at low concentrations [33]. Pharma- Microbial resistance has increased with drug discovery ceutical agents such as antibacterial, antifungal, antiviral, resulting in serious health concerns globally [25, 26] and and antiparasitic drugs are broadly referred to as antibi- indiscriminate use of antimicrobial remains the main otics [34]. Among the several classification schemes for cause [27]. Therefore, the emergence of multidrug resist- antibiotics, those based on the molecular structures, ant microbes in water and undesirable effects of conven- spectrum of activity and modes of action [35] are more tional antimicrobials call for alternative means of water preferred as indicated in Table 1. Antibiotics can also be treatment of plant origin [28]. Various microbial con- classified as injectable, oral or topical based on route of tamination of human origin in water may be controlled administration. Antibiotics with similar structure will by extracts of plants [29]. In Kirui et al. [30]. Aqueous usually exhibit similar trends of actions and effects. extract of Acacia nilotica, Acacia seyal, Acacia tortilis, The antimicrobial activity of plants has been credited Acacia etbaica, Albizia anthelmintica, Euclea divinorum to the existence of phytochemicals in specific parts of and Plumbago zeylanica were investigated for their plants [38] where they contribute to enhanced plant’s water treatment capacity and report indicates a notable survival by warding off pathogenic microorganisms [39, effect. Extracts of Moringa oleifera, Jatropha curcas and 40]. Some major groups of antimicrobials derived from Guar gum have also been investigated for their water plants include saponins, polyphenols, alkaloids, lectins, treatment potential and reduction in turbidity of the tannins, flavonoids, and terpenoids [41]. Synthetic path- treated water was observed [31]. These observations ways of some phytochemicals and related enzymes are show the potential of plant product for water treatment. indicated in Fig. 1. This attempts made to finding alternative way to combat resistant microorganisms and water disinfection is noble. It is of low cost and mostly available for safe water espe- Basic phenolic acids and phenols cially, in Africa. This review discusses the prospects of These are made of mono-substituted ring of phenol [43]. plant and plant products in less reported areas of water It is thought that the site(s) as well as numbers of hydroxyl and antimicrobial resistance interventions. components in this group influence the level of toxicity against microorganisms as it is evident that higher hydrox- Methodology ylation correlates with improved toxicity [44]. When phe- A desktop structured study of scholarly published arti- nolics possess a lower level of oxidation and a C3 side cles was employed in the study of over 200 relevant liter- chain, it is referred to as an essential oil [45]. This group atures. The searched databases included Science Direct, includes cinnamic acids, caffeic acids, and pyrogallol with Google Scholar and Web of Science. The