Role of Medhya Rasayanas (Nootropic Drugs) in Developmental Disabilities of Children

Developmental disabilities are combination of many conditions such as physical impairment, learning impairment, language impairment and behavior impairment etc. Developmental disabilities arise through the developmental period i.e. infancy (birth to 1years old), early childhood (3 to 6 years old), middle childhood (6 to 12 years old), and adolescence (12 to 18 years old) may influence on day-to-day function and usually last throughout a person’s lifetime [1]. A suitable definition has been given by the Federal government of the United States of America (federal development disability act USA title V of the rehabilitation act 1978) as follows: “developmental disability is chronic disability that has mental, physical or both impairment and can be manifested up to 18 years of age. [2].

Medha means intelligence or power of retention and Rasayana means rejuvenation therapy. By Rasayana one gets the excellence of Rasa and apart from the excellence of Rasa, the individual is endowed with Psychic excellence like sharp memory etc. In Charak Samhita mainly four “Medhya Rasayanas” are described which help in enhances memory, cognition, intelligence and nerve functions. They are Mandukaparni (Centella asiatica) swarasa, Yastimadhu (Glycirrhiza glabra) churna, Guduchi (Tinospora cordifolia)swarasa and Shankhapushpi (Convolvulus pleuricaulis) kalka[3]. The word nootropic was derived from the Greek words nous, or ‘mind’ and trepein meaning 'to bend/turn'. Nootropic drugs are referred as memory enhancer, cognition, intelligence and nerve tonic. Nootropic drugs improve the oxygen supply of brain by stimulating nerve growth. Recent article elaborate a new potential of Medhya Rasayanas (herbal nootropic drugs) for treatment of developmental disabilities of children.

Developmental Disabilities of Children

Developmental disabilities have broad definition, it include a complex group of disorders that cause physical, intellectual and speech disabilities. Incidence of developmental disabilities in children Cerebral palsy (CP) is a form of chronic motor disability which is non-progressive, non-fatal, yet non-curable and results from damage to the growing brain before birth, during birth or after birth. It is one of the three most common lifelong developmental disabilities; the other two are autism and mental retardation which affected individuals and their families [4]. The incidence of CP is approximately 2.5 cases/1000 live births worldwide [5]. But in India it is 3.8% of population [6] which includes approximately 25 Lakhs Cerebral Palsy children as per the last statistical information.[7]Nearly 15-20% of total physically handicapped children are suffering from CP[8].Cerebral palsy results from insult of developing brain in antenatal, natal and postnatal life [9]. The incidence of cerebral palsy is higher in premature babies than mature babies and 15-20% of total physically handicapped are due to cerebral palsy in India [10]. Main clinical presentation of cerebral palsy is spasticity, hypotonia, delayed milestone, learning disabilities, feeding difficulties, involuntary movements like seizures etc., speech disability, hearing impairment, gait abnormality and mental retardation.In1000 cases of Cerebral Palsy from India, it was found that spastic quadriplegia constituted 61% of cases followed by diplegia 22%.[11].For management of cerebral palsy, multidisciplinary approach is necessary and use of Medhya rasayanas (nootropics herbal drugs) can give significant result to control spasticity, hypotonia, delayed milestone and speech disability.

Mental Retardation

Mental retardation is defined as significantly sub average general intelligence, with onset during early developmental period and concurrent deficits in adaptive functioning [12].Mental retardation (MR) is second most commonly detected neuropsychiatric disorders among children and adolescents. Its occurrence among young individuals is about 1 to 2 % [13]. Mental Retardation is more common in males and common presentation is speech delay, behavioral disorders, or low school performance [14].Intelligence quotient (IQ) tests are more valid and reliable in children older than five years age [15] and many authors prefer to use other names for MR, such as developmental delay [16], learning disabilities [17], developmental disorder [18] or developmental deficiency. Widely accepted medical classification (ICD-10) and DSM IV of the American psychiatric association (1994) recognize 4 categories of intellectual disability based on IQ level shown in table no-2.

In Ayurveda, Medhya is described much vastly and it means power of Grasping, retention discrimination and recollection of knowledge and Rasayana means rejuvenation. In Ayurvedic system many medicinal plants are classed as brain tonics or rejuvenators. Developmental disabilities are a severe chronic disability of mental or physical impairment or a combination of both. Broad definition of developmental disabilities included; mental retardation, cerebral palsy, communication disorders, learning disability, attention deficit hyperactive disorder and childhood autism. Main goal in treatment of developmental disabilities is to repair physical and mental impairment by boost brain function and make brain healthier. Medhya Rasayanas (Herbal nootropic drugs) are group of medicinal plants described by Acharya Charaka for improve memory and intellect by Prabhava (specific action). Acharya Charaka described four Medhya rasayanas e.g., Mandukparni swarasa, Yashtimadhu churna, Guduchi swarasa, and Shankhapushpi kalka for improve the intelligence [30]. These drugs can be used singly or in combinations [31]. Developmental disorders of children are generally associated with loss of memory, cognitive deficits, impaired mental function etc. Medhya Rasayanas are established in boost the brain function and make the brain healthier also. They act as a vasodilator against the veins and small arteries in the brain [32]. Medhya drugs activate brain function by improve the function of Agni and get better circulation of Rasa by cleaning the micro channel [33]. Main function of Medhya rasayanas is to improve power of grasping, power of Retention, power of discrimination and power of recollection.

Mode of Action

Medhya Rasayanas drugs are known to have specific effect on mental performance by producing nueuro-nutrient effect and improve cerebral metabolism [35]. These drugs support the Intellect (Dhi) Retention power (Dhriti) and memory (Smriti).The pharmacodynamic action of Medhya Rasayana having Shita Virya and Madhura Vipaka promotes Kapha and enhances “Dharana Karma” (retention of cognition) e.g., Yastimadhu, Mandukaparni, Bramhi and Sankhpushpi. Medhya Rasayana having Ushna Virya and Tikta Rasa promotes Pitta and enhances Grahana karma (grasping power and Memory) e.g., Guduchi and Vacha.

Mandukaparni (Centella Asiatica Linn)

Mandukaparni plays an important role in improving cognition and memory. It has anti-oxidant and anti-apoptotic property. Juice of whole plant juice is used as cognitive enhancer (Medhya) property [36]. Major constituents of Mandukaparni are saponinsuch as medacoside, asiaticoside, medacassoside, Asiatic acid and triterpenic acid [37]. Asiatic acid in Mandukaparni, have neuro-protective effects both in vitro and in vivo [38]. This was revealed to assuage glutamate-induced cognitive deficits of mice [39]. Mandukaparni act on behavior in addition being brain growth promoter [30] improve learning and memory [41] and anti convulsion activity [42]. C. asiatica, owing to an increase in the concentration of GABA (γ-aminobutyric acid) in the brain [43]

Yastimadhu (Glycyrrhiza Glabra Linn)

Fine powder of Yastimadhu dried root is use for Medhya property. Its effect is more supportive when use with milk. Active ingredients of Yastimadhu are glycyrrhizine, flavonones, phenolic compounds, isoflavones and glycyrrhetenic acid etc. [44, 45]. Yastimadhu Churna is effective for spatial learning and cerebral ischemia [46, 47]. It has free radical scavenger activity, Memory-strengthening activity and antioxidant activity [48]. The dried roots of Yastimadhu area competent brain tonic; it increases the circulation of CNS system and help to balance the blood sugar level [49]. Yastimadhu significantly improve in learning and memory on scopolamine induced dementia and have significant action on memory enhancing activity in dementia [50].

Guduchi (Tinospora Cordifolia Wild)

Main constituents of Guduchi are alkaloids, steroids, glycosides, diterpenoid lactones, phenolics and polysaccharides [51]. Guduchi swarasa is rich source of trace elements such as Zinc and Copper which act as antioxidants and protects cells from the harmful property of oxygen radicals generated at some stage of immune activation [52]. It has neuro-protective activity, learning and memory enhancing activity [53] antioxidant activity [54, 55] and anti-stress activity [56]. Guduchi helps in cognitive enrichment by increase production of acetylcholine, which enhances choline [57]. Another important action of Guduchi is immune-modulator [58]. Guduchi Swarasa may also play an efficient role alongside ischemic brain damage in rat [59].

Shankhapushpi (Convolvulus Pleuricaulis Chois)

Kalka of Shankhapushpi is used as Medhya rasayans (intellect promoter) and its important ingredients are microphyllic acid, kaempferol-kaempferol-3-glucoside, 3, 4 dihydroxycinnamic acid and sitosterols. It has neuroprotectve activity, intellect promoting activity, free radical scavenging activity and antioxidant activity. [60]. CCRAS develop Ayushman-8 which is effective in Manasika-mandata (mental retardation) and its main ingredients are Shankhpushpi, Brahmi and Vacha [61]. Shankhapushpi is also effective in anxiety, neurosis, insomnia, cerebral abnormalities and serve as wonderful nervine tonic [62]. Shankhapushpi enhances memory function due to its Antioxidant and Acetyl cholinesterase Inhibitory Properties [63].

Conclusion

Herbal nootropic drugs (Medhya rasayans) improve memory, sharpen concentration, and improve grasping, without the side effects, tolerance, or withdrawal. Medhya rasayans help in increasing circulation to the brain, varying the concentration of neurotransmitters, falling brain inflammation, activating the formation of new brain cells and defending the brain from free-radical damage. Medhya rasayans act at different levels such as at level of Rasa, act by stimulating and improving the function of Agni and improve circulation of Rasa by opening and cleaning the micro channel for improve mental performance. Hence, this is need of present era to explore medicinal plants globally for improving cognitive function and mental performance owing to their minimum adverse effects.