Cognitive dysfunction is a major health problem in the 21st century, and many neuropsychiatric disorders and neurodegenerative disorders, such as schizophrenia, depression, Alzheimer's Disease dementia, cerebrovascular impairment, seizure disorders, head injury and Parkinsonism, can be severly functionally debilitating in nature. In course of time, a number of neurotransmitters and signaling molecules have been identified which have been considered as therapeutic targets. Conventional as well newer molecules have been tried against these targets. Phytochemicals from medicinal plants play a vital role in maintaining the brain's chemical balance by influencing the function of receptors for the major inhibitory neurotransmitters. In traditional practice of medicine, several plants have been reported to treat cognitive disorders. In this review paper, we attempt to throw some light on the use of medicinal herbs to treat cognitive disorders. In this review, we briefly deal with some medicinal herbs focusing on their neuroprotective active phytochemical substances like fatty acids, phenols, alkaloids, flavonoids, saponins, terpenes etc. The resistance of neurons to various stressors by activating specific signal transduction pathways and transcription factors are also discussed. It was observed in the review that a number of herbal medicines used in Ayurvedic practices as well Chinese medicines contain multiple compounds and phytochemicals that may have a neuroprotective effect which may prove beneficial in different neuropsychiatric and neurodegenerative disorders. Though the presence of receptors or transporters for polyphenols or other phytochemicals of the herbal preparations, in brain tissues remains to be ascertained, compounds with multiple targets appear as a potential and promising class of therapeutics for the treatment of diseases with a multifactorial etiology.

Natural sources have been important for the development of new active molecules for many years. Various small molecules with unique chemical skeleton and potent bioactivities were discovered through various sources like plants, marine products, and microorganisms, etc., which are considered as very important part of the nature. A number of potent antifungals have been originated from various natural sources. This account describes structure and activities of selected agents isolated from various natural sources.

Plants of genus Leucas (Lamiaceae) are widely distributed throughout Asia, Africa, and India. The plant is used in traditional medicine to cure many diseases such as cough, cold, diarrhea, and inflammatory skin disorder. A variety of phytoconstituents have been isolated from the Leucas species, which include lignans, flavonoids, coumarins, steroids, terpenes, fatty acids, and aliphatic long-chain compounds. Anti-inflammatory, analgesic, anti-diarrheal, antimicrobial, antioxidant, and insecticidal activities have been reported in the extracts of these plants and their phytoconstituents. An overview of the ethnobotanical, phytochemical, and pharmacological investigations on the Leucas species is presented in this review.

From the centuries, herbal medicines are used to treat various diseases and now they had become an item of global importance, with both medicinal and economic implications. The demand of herbal medicine is being increasing day by day due to their safety and efficacy. Now herbals had taken over the allopathic system due to their less side effect and efficient working mechanism. Herbals are playing and pivotal role in increasing the economy of the country and had taken the nation on to the new path to achieve the goal of development. Lygodium flexuosum (Linn) Sw. is a fern found nearly throughout India up to an elevation of 1500 meter. It belongs to the family Lygodiaceae and widely used in treating various ailments like jaundice, dysmenorrhea, wound healing and eczema. It is the rich source of alkaloids, flavonoids, saponins and cumarin. The main constitute of the plant is lygodinolide which is mainly used in wound healing. In the present review an attempt had been made to explore different aspects of L. flexuosum.

Mimosa pudica L. (Mimosaceae) also referred to as touch me not, live and die, shame plant and humble plant is a prostrate or semi-erect subshrub of tropical America and Australia, also found in India heavily armed with recurved thorns and having sensitive soft grey green leaflets that fold and droop at night or when touched and cooled. These unique bending movements have earned it a status of 'curiosity plant'. It appears to be a promising herbal candidate to undergo further exploration as evident from its pharmacological profile. It majorly possesses antibacterial, antivenom, antifertility, anticonvulsant, antidepressant, aphrodisiac, and various other pharmacological activities. The herb has been used traditionally for ages, in the treatment of urogenital disorders, piles, dysentery, sinus, and also applied on wounds. This work is an attempt to explore and compile the different pharmacognostic aspects of the action plant M. pudica reported till date.

Extensive studies have been carried out in the last decade to assess the pharmaceutical potential and screen the phytochemical constituents of Cinnamomum burmannii. Databases such as PubMed (MEDLINE), Science Direct (Embase, Biobase, biosis), Scopus, Scifinder, Google Scholar, Google Patent, Cochrane database, and web of science were searched using a defined search strategy. This plant is a member of the genus Cinnamomum and is traditionally used as a spice. Cinnamomum burmannii have been demonstrated to exhibit analgesic, antibacterial, anti-diabetic, anti-fungal, antioxidant, antirheumatic, anti-thrombotic, and anti-tumor activities. The chemical constituents are mostly cinnamyl alcohol, coumarin, cinnamic acid, cinnamaldehyde, anthocynin, and essential oils together with constituents of sugar, protein, crude fats, pectin, and others. This review presents an overview of the current status and knowledge on the traditional usage, the pharmaceutical, biological activities, and phytochemical constituents reported for C. burmannii.

World Health Organization (WHO) has recommended that traditional health and folk medicine systems are proved to be more effective in health problems worldwide. Trianthema portulacastrum Linn. is a herb used in Ayurvedic medicine. The principal constituent of T. portulacastrum Linn. is ecdysterone and the other constituents are trianthenol, 3-acetylaleuritolic acid, 5,2'-dihydroxy-7-methoxy-6,8-dimethylflavone, leptorumol, 3,4-dimethoxy cinnamic acid, 5-hydroxy-2-methoxybenzaldehyde, p-methoxybenzoic acid, and beta cyanin. Different parts of Trianthema portulacastrum Linn. are traditionally used as analgesic, stomachic, laxative, treatment of blood disease, anemia, inflammation, and night blindness. Laboratory investigations on extracts of the plant have demonstrated significant pharmacological activities, such as antioxidant, diuretic, analgesic, hepatoprotective, and anticarcinogenic. This article compiles all updated information related to T. portulacastrum Linn. Scientifically proved activities are co-related with traditional concepts. Scientific evidence exists with respect to their major and minor constituents. The novelty and applicability of T. portulacastrum are hidden. Such things should be overcome through modern scientific concepts.

Ferula asafoetida is herbaceous plant of the umbelliferae family. It is oleo gum resin obtained from the rhizome and root of plant. This spice is used as a digestive aid, in food as a condiment and in pickles. It is used in modern herbalism in the treatment of hysteria, some nervous conditions, bronchitis, asthma and whooping cough. It was at one time employed in the treatment of infantile pneumonia and flatulent colic. The gum resin is antispasmodic, carminative, expectorant, laxative, and sedative. The volatile oil in the gum is eliminated through the lungs, making this an excellent treatment for asthma. The odor of asafoetida is imparted to the breath, secretions, flatus, and gastric eructations. Its properties are antispasmodic, expectorant, stimulant, emmenagogue and vermifuge. Asafoetida has also been used as a sedative. It also thins the blood and lowers blood pressure. It is widely used in India in food and as a medicine in Indian systems of medicine like ayurveda. Asafoetida has been held in great esteem among indigenous medicines, particularly in Unani system from the earliest times.

Cognitive deficits that present with many of neuropsychiatric conditions and/or alone as developmental deficit demand use of nootropics to boost cognitive abilities. Recently there is a tremendous urge to explore medicinal plants globally for improving cognitive function owing to their less adverse effects. Ayurveda provides a list of herbs known for nootropic activity as well as their multi-dimensional utility in various conditions. Present paper is a review to update knowledge on pharmacological properties, major chemical constituents, therapeutic actions, preclinical studies, safety and possible mode of action of the selected herbs from ayurvedic pharmacopoeia. Concurrently, it opens up for further research and standardization on nootropic herbs

Traditional medicines that formed the basis of health care throughout the world since the earliest days of mankind are still widely used and have considerable importance in international trade. Recognition of their clinical, pharmaceutical, and economic value is still growing, although this varies widely between countries and therefore regulation of exploitation and exportation is essential, together with international cooperation and coordination for their conservation so as to ensure their availability for the future. World Health Organization and European Union issued the guidelines defined the basic criteria for the evaluation of quality, safety, and efficacy of herbal medicines with the goal of assisting national regulatory authorities, scientific organizations, and manufacturers in assessing documentation, submissions, and dossiers in respect of such products. Legislative controls in respect of medicinal plants have not evolved around a structured control model. There are different ways in which countries define medicinal plants or herbs or products derived from them. The present review highlights the status of different countries adopted various approaches to licensing, dispensing, manufacturing, and trading to ensure their safety, quality, and efficacy.