5. Health benefit of water lilies and lotus
The medicinal value of water lilies and lotus as confirmed in vivo and in vitro studies of were reported to be attributed to the presence of several phytochemicals like phenolic acids and flavonoids (Limwachiranon et al., 2018; Wang et al., 2021). Comprehensive review on seven different nymphaea species was reported to possess cardiovascular protective, hepatoprotective, antioxidant, nephroprotective, and anti-inflamatory activities (Prodhan & Mridu, 2023). The phytochemicals responsible for wide ranges of pharmacological activities are phenolic, flavonoids, alkaloids and other miscellaneous compounds (Kamdem et al., 2022). Anatomical parts, solvent used to extract phytochemicals and their health benefits of water lilies and lotus are presented in Table 5. In India, N.nouchali was reported to have health and nutritional benefits to marginalized communities (Jarapala et al., 2021). Nymphaea (water lily) has long history in traditional medicine as Ayurvedic herb. The water lily, also known as N.lotus, is a well-known traditional medicinal plant in China, India, Thailand, Indonesia, Vietnam, Sri Lanka, Nepal, Egypt, and many other African nations. The rhizome and roots of water lilies and lotus cure many disease and ailments. Similarly Nelumbo nucifera was reported to be used for traditional medicines to treat anti-diabetic, anti-inflammatory, anti-obesity, anti-angiogenic and anti-cancer activities (Tungmunnithum et al., 2018). N.pubescens is used as food and medicine by the local community of lebak area, Indonesia (Yuliarti et al., 2022). Nymphaea (water lily) has long history in traditional medicine as Ayurvedic herb. The phytoconstituents in water lily has the functions of hepato-protective, pain killer (analgesic), ant-inflammatory, anaphrodisiac, uterotonic, anti-diarrheal, antibacterial, and antitumor (Arooj et al., 2021). Alkaloids extracted from N.nucifera was reported to possess anti-depressant, anxiolytic, sedative-hypnotic, analgesia-potentiating action, antipsychotic, anticonvulsant and memory enhancer (Mitra et al., 2022) (). N.stellata and N.nouchali are an important water lilies that are widely used in Ayurveda and Siddha medicines for the treatment of abortion, liver disorders, blood dysentery, jaundice, dyspepsia, cystists, cytoxic, nephritis, blood purifier, insomnia, hemorrhoids, leucorrhoea, diabetes, inflammation, urinary disorders, blenorrhagia, menorrhagia, anti-cancer, immunomodulatory, menstruation disorders, and an aphrodisiac (Raja et al., 2010). Flowers of edible plants have health promoting compound (Rivas-García et al., 2021). Additionally, the aqueous extract of flower of N.lotus has androgenic and reproductive properties (Mireille et al., 2017).
Table 5. Health benefits of water lilies and lotus parts.
| Water lilies/ lotus parts | Doses | Duration | Health benefits | Refs. |
|---|---|---|---|---|
| Petals of N.pubescens | 200–1000 µg/kg | 24 h | Extract of N.pubescens suppress melanoma cells progression by reducing oxidative stress in B16 melanoma cells. This extract can be used for pharmaceutical products for the treatment of melanoma | Aimvijarn et al. (2018) |
| Aqueous extract of N.lotus flowers | 75 mg/kg | 55 days | Increased index of libido (83.33%), sperm count, sperm viability, sperm motility, weight of testis and penis in albino male rats | Mireille et al. (2017) |
| Methanolic extracts of N.pubescens | 0.5, 250, 500 mg/kg | 28 days | Induced insulin production from pancreatic cells, decreased glycosylated hemoglobin, lipid profile and quenched lipid peroxidation in diabetes induced albino rats by alloxan monohydrate | Angadi et al. (2013) |
| Roots of N.tetragona | 10 g/100 mL solvents | 18–24 h | N.tetragona extract has good anti S.typhimurium activity (MIC 781 µg/mL) and quorum sensing inhibitor | Hossain et al. (2014) |
| Aqueous extract of N.lotus leaves | 250,500,1000 mg/kg | 24 h | Aqueous extract of N.lotus contains therapeutic potential against gastric ulcers in ethanol induced gastric lesions in rats | John-Africa et al. (2012) |
| Aqueous and ethanol extracts of N.lotus | 20–200 mg/kg | 1 h | Inhibit GABA ergic/ antioxidant signaling and glutamatergic neurotransmission in epilepsy induced mice using kainic acid | Ishola et al. (2022) |
| Aqueous leaves extract of N.lotus | 50–250 mg/kg | 7 days | Writhing, formalin tests, tail clip and hot plate test revealed peripheral and central anti-nociceptive activities through the interactions of opioid and alpha 2 adrenergic systems | Agbaje et al. (2020) |
| Leaves of N.lotus | 20–40 g/kg | 30 days | Treatment and management of anxiolytic/anxiety in mice | Aduema et al. (2018) |
5.1. Uterotonic
Study in female rats was indicated that, the ethanol extract of N.alba produced a dose related increase in the force of uterine contraction similar to oxytocin (Bose, Sahoo, Rout, & Si, 2014)
5.2. An aphrodisiac
Study conducted in 40 male rats was indicated that, N.lotus (75 mg/kg) was suppressed the effects of erectile dysfunction induced by nitric oxide (Kameni et al., 2019). It was also indicated that N.lotus has double medicinal use, against erectile dysfunction and anxiety. Some species of water lilies (N.alba) contains nupharine and nymphaeine that has sedative and an aphrodisiac property.
5.3. Analgesic
Ethanolic extracts of N.lotus decrease pain sensation in mice (Aduema, Amah, Akunneh-Wariso, & Vidona, 2019). In another study, the crude leaf extracts of N.lotus was reported to possess anti-anxiety and antidepressant activities (Fajemiroye et al., 2018). The phytochemicals responsible for sedative and CNS depressant with mild anxiogenic effect from N.lotus were alkaloids, saponins, tannins, cardiac glycosides, flavonoids, and terpenoids (Folashade et al., 2021).
5.4. Anti-inflammatory
The methanolic extracts of bioactive constituent from N.lotus were reported to manage pain and inflammatory diseases (Rege et al., 2021). The high-resolution mass spectroscopic technique profiled secondary metabolites from N.nouchali that prevent oxidative stress stimulated diseases and disorders (Alam et al., 2021). Ethyl acetate fraction from N. hybrid was known to treat lipopolysaccharide inflammatory induced inflammation by blocking the activation of NF-κB and MAPKs pathways in RAW264 7 cells (Zhang et al., 2021).
5.5. Anti-microbial
The rhizomes and seeds of N.lotus reported to possess phytochemicals such as phenolic, flavanols, tannins, saponins, steroids, and proanthocyanidins that aid as effective antimicrobial (Adenola et al., 2021). The functional groups of phytochemicals in N.lotus extracted using water, ethanol and N-hexane were identified using Fourier transform infrared spectroscopy. These compounds are antimicrobial in nature, medicinal to human and animal diseases that are caused by multidrug resistant enteric bacteria (Jesse, 2020). Additionally, it was reported that N.lotus anthraquinones, alkaloids, terpenes, deoxy-sugar, and glycosides for controlling bacteria and fungi like Enterobacter spp., C.albicans and A.flavus responsible for middle ear infection. Moreover, Salisu and Nura (2022) reported the stem extract of N.lotus contains phytochemicals responsible for inhibiting the growth of Salmonella typhi and Enterococcus faecalis. The inhibition zone created by seed extracts for C.albicans, E.coli, S.aureus, and P.aeroginos were 19.3, 19.0, 15.7, and 19.7 mm, respectively (Anywar et al., 2014). Extracts from different parts of N.lotus were used to treat different bacteria and fungi. Ethanolic root extracts of N.lotus were reported to possess antimicrobials against multidrug resistance enteric bacteria (Adenola & Adeleke, 2021). Similar solvent (ethanol) was used by (Dissanayake & Bandaranayake, 2020) to extract bactericidal from N.nouchali. It was observed that 20 mg/mL and 100 mg/mL concentrations were bactericidal against E.coli and S.aureus respectively (Dissanayake & Bandaranayake, 2020). Gold nanoparticles (AuNPs) prepared using root extract of N.alba at Au/root extract (0.24), pH (7.8) and sonication time (40 min) were reported to possess high antimicrobial activities against S.aureus and E.coli with minimum inhibitory concentration value of 100 µg Au/mL and 200 µg Au/mL, respectively (Cudalbeanu et al., 2021).
5.6. Hepato-protective
Medicinal plants that possess phenolic acids, flavonoids, alkaloids, triterpenoids, diterpenoids, monoterpenoids, chromenes, capsaicinoids, curcuminoids, and anthraquinones are major phytochemicals that are heptoprotective (Das et al., 2022). Ethanolic extracts of N.alba revealed the presence of phytoconstituents like phenolic, alkaloids, glycosides, steroids, flavonoids and tannin. Isostrictinin isolated from N.candida was reported to be hepatoprotective (hepatic fibrosis) in mice induced by 10% CCl4 (Dong et al., 2022). The leaf extract of N.nucifera was reported to be hepatoprotective at doses of 300 and 500 mg/kg against CCl4 induced liver toxicity in rats (Huang et al., 2010). Ethanolic extract of N.alba (400 mg/kg) significantly reduce liver functions tests like serum glutamic-oxaloacetic transaminase, serum gluamic pyruvic transaminase, alkaline phosphatase, bilirubin and cholesterol level as compared to the control group (Paharia & Pandurangan, 2013). Rats feed at a dose of 250 mg/kg of N.lotus leaf extract twice for two weeks was reported to antagonize the liver damage induced by CCl4 and aspirin (Usman et al., 2018).
5.7. Antihyperglycaemic and antihyperlipidaemic
Water lilies and lotus contain alkaloids important for bioactivities (Ren et al., 2019). Among the alkaloid, nymphayol (25, 26-dinorcholest-5-en-3b-ol) is the bioactive content in flower and leaf of N.stellata responsible to increase insulin levels in diabetic rat. The oral administration of nymphayol was reported to reduce blood glucose levels and stimulated pancreatic beta cells regeneration (Khyade, 2018). The ethyl acetate extract of lotus leaf (N.nucifera Gaertn.) had flavonoids that aid in reduction of blood glucose and hypoglycemic effect on streptozotocin induced diabetic mice (Rumanti et al., 2017). Rhizome of N.nouchali may become an important dietary supplement to reduce postprandial hyperglycemia and hyperlipidaemia, oxidative stress and can be considered as herbal therapeutics for the management of type 2 diabetes mellitus and obesity (Anand et al., 2021). These antihyperglycemic compounds can display strong inhibitory properties against intestinal α-glucosidase and pancreatic lipase and increase cellular glucose uptake activities. The inclusion of boiled rhizome of water lily into diabetics’ food were indicated to have several health benefits in managing hyperglycemia and resultant oxidative stress (Anand et al., 2021). Flowers of N.pubescens and N.nucifera were reported to possess antidiabetic activities (α-glucosidase inhibition) (Pokhrel et al., 2022). Similarly, the whole flower of N.lotus was reported to better food supplements and beneficial to diabetic patients (Chaiyawathanananthn et al., 2022). Nymphayol extracted from N.stellata is phytochemicals which has anti-diabetic properties was reported to improve damaged endocrine tissue and stimulates secretion of insulin in the β-cells (Raja et al., 2010). Phytochemical screening of lotus leaf extracts using ethyl acetate indicated the presence of flavonoids (150 mg/kg) that are responsible for the reduction of blood glucose on diabetic induced mice (Rumanti et al., 2017). The antidiabetic potential of N.nucifera and N.pubescens was compared. It was reported that N.nucifera, N. pubescens, and acarbose possessed IC50 value of α-glucosidase inhibition activity of 66.32 µg/mL, 5.29 µg/mL, and 5.65 µg/mL, respectively (Pokhrel et al., 2022). Nymphaea species are effective aquatic plants to inhibit glycation end products and type II diabetes mellitus (Ishrat et al., 2021). Specifically, N.stellata was reported to possess anti α-glucosidase and α-amylase activities (Chaiyawathanananthn et al., 2022). Moreover, seven different water lilies species were reported to possess antihyperlipidemic, antihyperglycemic, glucose uptake and metabolizing protein expressing, pancreatic β cell-regenerating, insulin secretion, sensitivity promoting, and intestinal glucose metabolizing enzyme inhibiting (Prodhan & Mridu, 2023).
5.8. Anti-convulsant
Aqueous and ethanol extracts of N.lotus was reported to ameliorate neurotoxin induced seizures by enhancing the inhibition of Gamma aminobutryric acid neurotransmitter. The extracts also prevented kainic acid induced anxiety, depression and amnesia in mice (Ishola et al., 2022). Similarly, alcohol extract of N.indica possesses phytochemicals for treatment of epilepsy (Madhavan et al., 2009).
5.9. Anti-diarrheal
Traditionally the rhizome of N.lotus is used to cure diarrhea. Methanolic extracts of the rhizome of N.lotus was reported to have anti-diarrhoeal properties (Bello et al., 2016).
5.10. Anticancer
The in vitro studies on breast cancers, ovarian and prostate cancer cells indicated that, extracts of water lilies and lotus possess phytochemicals that can play significant role in cancer prevention. The ethanolic extract of N.nouchali was reported to shown superoxide scavenging, DPPH, lipid peroxidation and exhibit significant IC50 values against MCF-7 cells (Ramesh et al., 2022). The ethanolic flower extracts of N.pubescens was reported to be cytotoxic against human breast carcinoma MCF and cervical carcinoma Hela cell lines with IC50 value of 91.57 µg/mL and 99.6 µg/mL respectively (Selvakumari, Shantha, Purushoth, & Sreenathkumar, 2012). Whereas, the methanolic root and leaf extract of N.alba is promising against MCF-7 breast cancer, A2780/A2780cisR ovarian, and LNCaP prostate cells (Cudalbeanu et al., 2019). The same author was confirmed that, gold nanoparticles prepared using ultrasonic irradiation at Au/root extract ratio of 0.24, pH 7.8 and 40 min from root extracts of N. alba inhibit A2780 ovarian cancer cells by 50% at 51.9 µg Au/mL and 33.5 µg Au/mL concentrations (Cudalbeanu et al., 2021). Nymphayol (17-(hexan-2-yl)−10, 13-dimethylhexadecahydro1H-cyclopenta[a]phenanthren-3-ol) isolated from N.stellata was confirmed to inhibit MCF-7 breast cancer cells viability up to 78%, and the IC50 value was observed as 2.8 µM in 24 h and 1.4 µM in 48 h (Al-Harbi et al., 2020).
6. Miscellaneous uses of water lilies and lotus
The major component of water lilies and lotus is starch (50%) that can be exploited as potential for food and non-food applications. Starch could be good biodegradable polymers for fabricating food packaging materials (Priyadarshini et al., 2022). Studies undertaken to prepare edible films from lotus seed starch, nisin and glycerol as plasticizer indicated that, it reduced the rate of browning, softening, and microbial growth of the pineapple fruit (Zhu, 2017). Water lilies and lotus can be low cost, eco-friendly and helpful for environmental management. The leaf of water lily (N.lotus) was reported to remove toxic dyes like malachite green from aqueous solution. Biochar (activated carbons) prepared from stem of N.lotus was reported to be better adsorbent of green dye from waste water (Jabar & Odusote, 2021). The phytochemicals found in water lilies and lotus, particularly flavonoids from N.lotus has potential for the development of cosmetics (Tungmunnithum et al., 2021). Flower of N.pubescens was reported to have great potential to prepare herb-based deodorant to inhibit the growth of S.aureus (Wanigasekara et al., 2022). The flowers of N.pubescens and N.nucifera were reported to be used during prayers in temples offerings in many countries. Moreover, the juice extract of N.nouchali blended with milk can potentially treat jaundice, anti-aging and helps to loss body weight in chehchu tribes of India (Jarapala et al., 2021). The ethanol extracts of petal and stamen of N.rubra was reported to possess skin lightening and anti-aging properties as it was confirmed on 30 volunteers painted twice for 60 days (Kamma et al., 2019). The leaf extracts of water lilies helps to control some vectors help the fight against malaria control. The N-hexane extracts of N.louts manage larvae of anopheles mosquito (Yakubu et al., 2017). Metabolimic analysis of middle cerebral artery occlusion rat serum using ultra performance liquid chromatography to quadrupole time-of-flight mass spectrometry was elucidated the presence of nucifera that helps to improve neurological deficit scores, ameliorate cerebral edema, infraction, and anti-ischematic stroke properties (Wu et al., 2020). The leave extract of N.lotus help to manage some physiological activities of rat. It was reported that leaf extract of N.lotus reduce anxiety and fear in mice (Aduema et al., 2018). The optimum moisture content to dehull seed of N.pubescens is 10% (Fatimah et al., 2022). Supplementation of lily bulbs or lotus seed powder into goat milk was reported to improve water holding capacity, reduce fermentation time, and inhibit post-acidification during storage of goat yogurt (Zhao et al., 2022). Additionally, the flower of N.alba (400 mg/kg) extracted using ethanol was reported to be anti-ulcer, reduce gastric volume, free acidity and ulcer index (Paharia & Pandurangan, 2020). Methanolic extracts of N.tetragona was reported to inhibit quorum sensing-mediated virulence factors of bacteria (Hossain et al., 2015).
7. Conclusions and future perspectives
With the ever-increasing population growth and rapid dwindling of natural resources, it has become important to diversify the present time agricultural products with the cultivation of some wild varieties of edible tubers, rhizomes and corms in order to meet various human nutrient needs. Water liles and lotus have known to contain good source of protein, dietary fiber, carbohydrate, amino acids, fatty acids, vitamins, minerals and phytochemicals that have health importance. More than 150 compounds have been identified from rhizome, seed, leaf, stem, flower and seed of water lilies and lotus. The in vitro and in vivo studies indicate water lilies and lotus are promising medicinal plants. It can be suggested that these edible aquatic plants could be commercially cultivated, harvested and processed to feed the increasing human population. It is recommended that, physicochemical, thermal, rheological and pasting properties of starch isolated from rhizomes, the nutritional value, and metabolites of seeds of water lilies and lotus need to be characterized. Moreover, studies involving in vivo and in vitro should be done to address safety, toxicity and cytotoxicity of water lilies and lotus extracts are recommended for application in food and pharmaceutical insustry.
Ethical statement
No human and animal study was conducted.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Data availability
-
No data was used for the research described in the article.