Mucunais a valuable genus of Leguminosae family; it has tremendous value in food and medicine. The genus Mucunaoriginated in Eastern India and China and then was transferred throughout tropical and subtropical regions of the world creating new populations . Traditionally, Mucunais known by different names including beans, buffalo beans, dopa bean, cowitch, kappikachhu and atmagupta. Out of 100 Mucunaspecies found worldwide, 8 species and 3 varieties of Mucunaare predominantly found in different localities of India [1, 2, 3, 4]. The Mucunaplant is an annual perennial climbing shrub with long vines having a length of 15–25 m with trifoliate leaves and yielding long inflorescences with purple or pale yellow flowers. They produce green or brown pods covered with rigid hair, which causes intense itching . Pods contain four to six ellipsoidal-shaped seeds that are rich dark brown or blotched  varying from species to species. Mucunaseeds are a rich source of nutritional, antinutritional and phytochemical compounds containing l-dopa as a prime constituent . The content of l-dopa varies between from species to species and locality to locality. Among them, M. pruriensis the most exploited species as a remedy against Parkinson’s disease . Due to huge international and national trade price and scarcity of M. pruriens, other Mucunaspecies are reported to be adulterants for M. pruriens.
Ancient reports of Ayurveda suggest that Mucunaseed powder contributes in reducing the risks of certain cardiovascular diseases and neurodegenerative disease and also as a remedy for snake bite. The seeds of Mucunahave gained increasing attention among food scientists, nutrition specialists and pharmaceutical expertise due to their rich source of antioxidant, phenolic, flavonoids, l-dopa, proteins, starch, micronutrients, dietary fiber and bioactive compounds that play a pronounced role in the traditional as well as modern medicine all over the world [9, 10]. The existing scenario shows ten reported Mucunaspecies that were studied recently by Pulikkalpura et al., from the Indian subcontinent , whereas Patil et al., also collected fourteen different species of Mucunafrom various localities and further studied for their l-dopa content (anti-Parkinson’s activity) [6, 12].
Mucunagrows best under moist, warm conditions and in areas with plenteous rainfall. It can propagate in any type of soil but sandy lome soil is mostly favorable with pH of 5.5–7.5. Several researchers have investigated different species having typical characteristics like size and shape of bracts, leaflets and pods, color, thickness, density as well as number of seeds in pod and flower, respectively . The evaluation of genetic-level studies of Mucunaspecies from India was also carried out using inter-simple sequence repeat markers and randomly amplified polymorphic DNA . The seeds show tolerance against different abiotic stress including low soil fertility and acidic pH and also grow in wet soils (Duke, 1981). Similar to different species, Mucunaalso has 2n = 2x = 22 number of chromosomes with genome size ranging between 1281 and 1361 Mbp/C . Due to wild fluctuating climatic and geographical distribution, these species show gigantic diversity in phenotype in the Indian subcontinent. Corresponding to the family Leguminosae, it also has the ability of atmospheric nitrogen fixation. It is also grown for the potential utility in animal feed and human food due to its rich source of nutritional content [15, 16]. Thus, it was consumed universally for the treatment of Parkinson’s disease. Traditionally, in Ayurvedic science, Mucuna(velvet bean) plant is widely used to treat numerous diseases including parkinsonism [17, 18, 19, 20, 21] due to its l-dopa content as one of the principal constituents . All parts of Mucunahave a great medicinal value in the ancient traditional medicinal system, and hence, it has a prodigious demand in the international and the Indian market [7, 22].
Mucunais a superb source of protein and bioactive compounds that have increased consumption per capita after being considered as a functional food by the US . The previous literature survey shows that the declining occurrence of numerous long-lasting disorders, namely neurological disorder, cardiovascular diseases, diabetes, obesity and cancer, has a positive correlation with the consumption of legume seeds . Considering all the evident health profits, studying its bioactive compounds is of great importance. Among all the under-utilized Mucunaspecies, normally available and commonly used Mucuna pruriensseeds were studied enormously and have been reported in numerous of articles published till date. To avoid the burden on commonly available and used Mucuna Purience,various researchers are studying bioactive components and the use of other Mucunaspecies like M. imbracata, M. bracteata, M. monosperma, M. macrocarpa, M. sanjappae,M. atropurpurea, M. nigricans, M. gigantea, M. pruriens var hirsuta, M. laticifera, M. yadaviana, etc. in the treatment of various diseases [5, 6, 7, 9, 11, 12, 13, 14, 17, 20, 22, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34]. Phytochemistry, toxilogicalogycal and food potential on the Mucunaspecies under study in the world were described by Lorenzetti et al. .
2. Bioactive compounds from various parts of Mucunaspecies
2.1 Bioactive compounds from seeds of Mucuna
Seeds of Mucunaare commonly used part of the plant, which are a rich source of nutritional and anti-nutritional compounds like l-dopa (anti-Parkinson’s activity), antioxidants, phenolic, flavonoids, tannin, carbohydrates, starch, protein, micronutrients Sopanines and many more [9, 12, 26]. Antioxidant activities in this plant are mainly due to phenolic and various bioactive compounds present in the seed material [36, 37]. There are various extraction techniques, different solvents and processing methods that were used to extract the biologically active compounds from the seed of Mucuna[26, 31]. The prior study reports that M. macrocarpa, M. sanjappaeand M. atropurpureadisclosed a higher level of l-dopa content, which also concludes that l-dopa content has a positive correlation to the protein content of seeds . These high-yielding varieties of Mucunacan be commercially cultivated, which can thus serve to be a good option to lower the burden exerted on commonly used M. pruriencevariety . LCMS analysis of four different species demonstrates the presence of diverse group of phenolics, alkaloids, flavonoids, different derivatives of gallic acid, l-dopa, catechin, alkaloids, quercetin, tannic acid, glycosides, saponins, tubastatin and a variety of amino acids in the seed extract . Apart from that, it is also concluded that few anticancer compounds like Spergualin,sanggenon G, isopentenyl adenosine and spisulosine are also present in the seed extract [28, 38].
2.2 Bioactive compounds from leaves and roots of Mucuna
The root extract of Mucunahas various activities like stimulant, thermogenic, purgative, emollient, diuretic anthelmintic, emmenagogue and tonic; hence, they are used in the vitiated circumstances in Veda and Ayurveda . l-Dopa content of leaves and roots is as much as 1% and 4–7% in Mucunaplant . Mucunaplants release secondary chemical compounds called allelochemical in the form of l-3,4-dihydroxyphenylalanine (l-dopa) in the surrounding environment which show an impact on growth of nearby plants, either negatively or positively. These substances are produced through its roots, seeds or leaves . These secondary chemical agents play a role in damaging root growth, terminating seedling growth, inhibiting plantlet growth or suppressing seed germination of other plants . Plant-box bioassay explains that the secondary chemical compound produced from the root of Mucunais l-dopa , which affects the cell and root of various plant seedlings . Leaf extracts are used to treat various complications like Anticataleptic, antiepileptic, aphrodisiac, antimicrobial, tonic and ulcers are some applications in which Mucunaleaves were reported being used previously [8, 20, 43, 44].
2.3 Bioactive compounds from callus of Mucuna
Production of callus from Mucunaplant material is a new era in the advancement of biochemical engineering and industrial biotechnology, which has the potential to produce different biologically active agents from the explant [45, 46]. Their application in cost-effective industrially important product formation is helpful for humankind, which upshots effective drug formulations and upsurges the nutritional level of food [47, 48]. l-Dopa is a major component in different parts of Mucunaspecies . This also helps in storing germplasm of endangered species, which in turn leads to regenerate new plantlets at any time. Production of callus from Mucunaspecies was done previously by the researcher at the lab scale . An earlier study by Chattopadhyay et al. depicted the formation of callus culture of commonly used Mucuna pruriens. Media containing various concentrations of media components affects biologically active chemicals and growth of the callus [51, 52]. The use of different elicitors and precursors are studied by Nandeo and Patel et al. [53, 54]. Implementation of precursor in the media of callus enhances the phenolic content as reported in prior studies. The percentage of phenolic is greater in callus culture than in seeds, which is very helpful for industrial production [55, 56].
2.4 Bioactive compounds from cell suspension of Mucuna
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are stress-producing free radicals, but at usual level perform an important part in the physiology of the body  to accommodate the massive demands for l-dopa and other secondary metabolites. In vitroproduction of biologically active compounds from suspension culture is predominantly studied before in Mucunaplant by Chattopadhyay et al. . The use of mevalonic acid and its precursor gibberellic acid affect the growth. l-Dopa in callus exhibits a declining trend in fresh weight with a rise in concentration of l-dopa as shown by Desai et al. . The comparative study of production of l-dopa from cell suspension culture and effect of elicitor on two different species like Mucuna pruriensL. and Mucuna pruritaH were also done previously . Large-scale production of phytochemicals and l-dopa was done from Mucuna pruriensL. Commercial production of the drugs (l-dopa), phenolic flavonoids and antioxidants using cell suspension cultures is in extensive practice nowadays.
3. Use of different bioactive compounds from Mucunain various application
3.1 Antioxidant activity of Mucunaspecies
Numerous studies on antioxidant activity and phytoconstituents content of Mucunaseeds, leaves and roots were performed previously [4, 7, 19, 30, 31, 59, 60, 61, 62]. Optimization of different solvents for the extraction of antioxidants was done by Aware and Patil et al. [9, 10, 26]. They concluded that depending on solubility of antioxidant compounds present in different species of Mucuna, concentration of antioxidants differs. Most commonly, ethanolic extract of Mucunashows good antioxidant activity due to high phenolic content . Some reports also conclude that water is a universal solvent, which shows significant quantity of phenolic, flavonoids and strong antioxidants that can scavenge free radicals using different assays. Diseases like neurodegenerative diseases, cardiovascular diseases, aging, cancer, rheumatoid arthritis and inflammation are caused by oxidative stresses, which are protected by ROS and RNS . LCMS report of four different species of Mucunadetermines the presence of various components like phenolic, flavonoids and bioactive compounds, which are responsible for production of reactive species .
3.2 Antimicrobial activity of Mucunaspecies
There are several compounds in Mucunathat contribute for the antimicrobial activity as reported in a previous study [38, 43]. These compounds are responsible for the treatment of various infectious diseases and ulcers . The study on various plant pathogens suggests that methanolic extract of Mucuna pruriensseeds showed highest antimicrobial activity  from all used solvents. A similar type of study was done by Pujari et al., who concluded that methanol extract of seeds of Mucuna prurienswas found to impart the best inhibiting activity among all scrutinized pathogens as compared to ethanol and acetone solvents. But alcoholic extract of Mucuna pruriens(L.) leaves has significant antioxidant and antibacterial activity, which has strongly recommended the use of Mucunaleaves and seed extract in traditional as well as modern medicine .
3.3 Protective effect against snake venom
Snakebite kills countless people annually since ancient days . Various reports show the cross-reactivity between the enzyme of snake venom and protein from Mucuna, which determines the activity of Mucunaagainst snake venom [32, 67, 68, 69]. Betancur et al.in their review on therapeutics of antisnake venom explain the effectiveness of herbal plants, which act as coadjuvants and thus help to nullify the venom toxic action . In recent literature, Kasturiratne et al.studied the global scenario of snakebite and deaths. They also elucidate that various traditional medicines were sometimes preferred with western drugs . The protective effect of Mucunain a study on mice or rat models proves that it has a good activity for curing snake bite, than few reported antivenom [71, 72].
3.4 Anti-Parkinson’s activity of Mucunaspecies
Parkinson’s disease (PD) was initially discovered by Dr. James Parkinson in 1817. It is a chronic neurological disorder triggered by a progressive loss of dopaminergic neurons present in the nigrostriatal part of the brain and found to be common in the US . The major signs of the disease are complications in body movements, speaking, walking and many more complications arise as the disease progresses. Anti-Parkinson’s potential of Mucunais well known from ancient times due to its l-dopa content [7, 74]. l-Dopa is a precursor of dopamine used in the treatment of neurodegenerative disorders. Various scientists studied the potential of Mucunato produce l-dopa as a source of anti-Parkinson’s drug [8, 19, 75]. l-Dopa with other phytochemical compounds has a cumulative effect on the management of Parkinson’s disease. Patil et al.describe that there is a correlation among the l-dopa, protein and carbohydrate content . Mucunais a rich source of antioxidant compounds, which performs a very important role in the physiology of the body mainly functioning in the inhibition of damage occurred because of free radicals . There are hundreds of compounds that function as antioxidants in the plant system mainly vitamins, polyphenols, enzymes, flavonoids and metals like zinc, selenium, etc. . The efficiency of the use of l-dopa and another dopaminergic agent in the treatment of Parkinson’s disease is reviewed previously by Koller and Rueda . The use of plants for the treatment is more beneficial than chemically manufactured medicines due to their infinitesimal occurrence of secondary complications by routine use and economical feasibility.
3.5 Use of Mucunaspecies in soil fertility
Cover crops have a role in the nitrogen-fixing bacteria and improvement of soil fertility by restoration of soil nutrients. Enormous use of chemical fertilizer and water in soil makes soil infertile, to overcome this problem, farmers are implementing traditional methods to enhance soil fertility. Mucuna is one of the best examples of a cover crop that has a rich source of biological natural products, which will increase the enhance soil fertility and fix atmospheric nitrogen .