Medicinal plants are value added for the content and chemical composition of their active components. Therefore, the demand on plant based therapeutics has increased many fold in both developing and developed countries due to the growing recognition that they are natural products, being non-narcotic, having no side-effects, easily available at affordable prices. In a wider context, there is a growing demand for plant-based medicines, health products, pharmaceuticals, food supplements, cosmetics etc. International market of medicinal plants is over US $ 60 billion per year, which is growing at the rate of 7% and expected to be US $ 5 trillion by 2050. Herbal remedies would become increasingly important especially in developing countries. Progress in medicinal plants research has undergone a phenomenal growth during last two decades. The input of biochemistry to pharmacology has grown. Molecular pharmacology puts more emphasis on the mode of action of drugs. Worldwide trend towards the utilization of natural plant remedies has created an enormous need for information about the properties and uses of the medicinal plants. Based on this rationale, the present series Recent Progress in Medicinal Plants brought out eight volumes, in the first phase, providing edited information from over 225 original and review papers by eminent scientists and researchers from India and abroad on a wide range of topics in the areas of Ethno medicine, Pharmacognosy, Photochemistry, Pharmacology, Aesthetics, Biotechnology, Genetic Engineering, Crop Improvement, Production Technology, Trade and Commerce, Diseases and their Management etc. In continuation to these foregone efforts, further eight volumes (9-16) viz., Plant Bioactive in Traditional Medicine; Phototherapeutics; Drug Development from New Molecules; Globalization of Herbal Health; Search for Natural Drugs; Biopharmaceuticals; Natural Products; Phytomedicines, providing recent research data in the areas of medicinal plants investigations, aimed at discovering new drugs of plants origin, were presented. Continuing with the ongoing efforts and over-whelming response, the Series editors have been hard pressed to bring out further nine volumes (Vols: 17-25) of the series on herbal drugs containing recent researches on bioreactive components based on their photochemistry and psychopharmacology in order to discover potential drugs coupled with their therapeutic values. In this direction, nine volumes (17-25) on Photochemistry and Pharmacology III, Natural Products II, Psychopharmacology and Therapeutic Values I, II, III, IV & V, Standardization of Herbal / Ayurvedic Formulations and Chemistry and Medicinal Value were published. Thus the publication of 25 volumes of "Recent Progress in Medicinal Plan ts" (2002-2009) provides a comprehensive account of nearly 1800 important medicinal plants for producing drugs, cosmetics, perfumery etc. Hence, it was felt that there is an urgent need to document these 25 volumes in a more condensed form for scientist's desk reference in day to day research activity. Considering the importance of such a resource book, it was planned to bring out Vol. 26 containing the abstracts of papers published in 25 volume-set of Recent Progress in Medicinal Plants. The Vol. 26- "Cumulative Index to Abstracts, Vols. 1-25"- provides information on some 1282 abstracts of original and review papers published in the aforesaid volumes. Considering the fact that many traditional remedies are back to therapeutic use, including plants as such, or extracts prepared in accordance with the pharmacopoeia of the country where they are used. These medicinal plants are increasingly used as (i) source of direct therapeutic agents; (ii) as a raw material base for the elaboration of more complex semi-synthetic chemical compounds; (iii) as models for new synthetic compounds; and, (iv) as taxonomic markers for the discovery of new compounds. In addition to these applications in developed countries, naturally, the medicinal plants will continue to be used increasingly in developing countries, where they are a traditional source of medicine for generations. This has created renewed interest of scientists in medicinal plants and research is at phenomenal rate. We have received excellent studies for publication. It was, therefore, felt desirable to bring out further Volumes of the series, covering recent global updates in medicinal plants researches. This includes 3 specialized Vols (Vol. 36-38) on Essential Oils. Learning, recently, the intense research activities in biotechnology, pharmacology and biochemical actions and the rapid increase of knowledge in the field of traditional medicine, it appeared desirable to bring further specialized volumes on Biotechnology and Genetic Engineering II (Vol. 39), Flavonoids and Antioxidants (Vol. 40), Analytical and Processing Techniques (Vol. 41), Nutraceutical and Functional Foods (Vol. 42) and Phototherapeutics II & III (Vols. 43 & 44).The Chief Editor Dr. J N Govil was hard pressed by Academicians, Researchers, Industries & Relevant Govt. Agencies to further bring disease-oriented volumes in the Series. Considering the great demand, the editors have brought out four volumes on Metabolic Disorders. Two volumes on Diabetes I & II (Vols 45 & 46), while one volume each on Hyperlipidemia (Vol. 47) and Hypertension (Vol. 48) publication of these volumes incorporating the articles contributed by eminent scholars over the globe in the field of Medicinal Plants will definitely be useful by way of providing latest upcoming advances and developments in the field of Herbal Drugs. It is hoped these volumes will open new vistas of knowledge and the information presented will lead to further research in the discovery of new drugs of natural origin and serve as good source of material for future work.