Natural Products in Clinical Trials: Volume 1

Atta-ur-Rahman, Shazia Anjum, Hesham R. El-Seedi

• Publisher: Bentham Science Publishers
• Year: 2018
• ISBN:
  9781681082134
• Topic: Medicina
• Subtopic: Farmacologia

Natural products continue to play a key role in drug development. A recent analysis of the drug market in the developed world revealed that 40% of total clinically approved drugs were either unmodified natural products or their semi-synthetic derivatives.

Anti-HIV Drug Discovery Struggle: From Natural Products to Drug Prototypes

Mehtab Parveen^*, Ali Mohammed Malla, Faheem Ahmad, Shaista Azaz

Division of Natural Products, Department of Chemistry, Aligarh Muslim University, Aligarh, U.P, India

Abstract

From the prehistoric time man has always struggle to fight and control diseases and motivated to nature for inspiration and guidance. During thousands of years of early human existence, number of natural materials by instinct or intuition has been used as folk medicines for human ailments. This brought to the forefront a large number of herbs used in Indian indigenous system for their approved efficiency and administration in modern medicines. Acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) is an immuno-suppressive disease that results in life-threatening opportunistic infections and malignancies. Now, there is an urgent need for novel anti-HIV/AIDS drugs for global concern. In addition to obvious economical and commercial obstacles, HIV/AIDS patients are faced with varied difficulties associated with the currently approved anti-HIV drugs. The therapeutic usefulness of the various reverse transcriptase and protease inhibitors available in the market have been limited due to its adverse effect, emerging drug resistance and low activity. This encourages many scientists to look for new anti-retrovirals with better efficacy, safety and affordability. Several natural products isolated from plants have been shown to possess promising activities that could assist in the prevention and/or amelioration of the disease. Biodiversity of the plant kingdom has always been a source of new drug candidates for various diseases. The appearance of drug resistant virus urged the scientists to explore new anti-HIV agents and targets. In this regard, natural products embody a treasure-trove of anti-HIV drugs waiting to be explored by all the modern techniques. Numerous natural product based anti-HIV drugs such as Robustaflavone, Chamaeflavone A, Longipedunins A, Binankadsurin A, Schisanlactone A, Anibamine, Altertoxine, Betulinic acid, Baicalin, Hinokiflavone, etc., have been reported in the literature which possess promising anti-HIV activity. This chapter embodies the recent progress that has been accomplished in the discovery of promising anti-HIV agents from natural sources.

Keywords: Anti-HIV/AIDS, CD4 cells, Drugs, HIV-1, HIV-2, Medicinal plants, Natural products, Protease inhibitors, RTase inhibitors, Treasure-trove.

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^* Address correspondence to Mehtab Parveen: Division of Natural Products, Department of Chemistry, Aligarh Muslim University, Aligarh, U.P, India; Tel: [phone]; Fax: [phone]; E-mail: [email protected]

INTRODUCTION

The association between plants and man is an age-old process starting from human civilization. There has always been a battle between nature and human knowledge. The plants endure nature and nature sustains them. The interdependence of man and nature increases day by day. Since their evolution, plants became primarily useful for mankind. Realization of the importance of plants in the well-being of humanity prompted their systematic study from different angles. Thus, many plant species [1, 2] have been subjected to detailed scientific analysis over the years. Yet not more than 10% of all the plants could be analyzed and a vast majority still remains uninvestigated. More recently, World Health Organization (WHO) has shown in their study that about 80% of the world’s population still relies on traditional medicine [3]. The study continues in various fields and provides challenges to several groups of plant scientists. India, like all other countries, has made significant progress by a systematic scientific study of these plant drugs from the pharmacological, chemical and clinical points of view during the past 65 years. This brought to the forefront a large number of herbs used in Indian indigenous system for their approved efficiency and administration in modern medicines. If the modern methods of investigation of medicinal plants in India with the newly developed scientific approach are applied, this type of research will provide new route for the discovery of effective plant drugs. Chemists therefore got interested and started analyzing plant materials chemically, which led to a branch of chemistry known as Phytochemistry [4^-9] dealing with extraction, isolation, purification and identification of compounds from plants sources. Furthermore, chemists were also involved in the modification of these products and their synthesis both for their characterization as well as synthesizing these in bulk for human use. In the last few decades, medicinal plants and their phytochemical studies have become subject of much interest because most of the compounds isolated were found to be disease curing and life saving.

Tracing the history of medicinal uses of plants we can go back to the prehistoric periods. The remarkable properties and therapeutic uses of about 700 plant drugs have been recorded by ancient Indian scholars, Sushruta, Charaka and Vagbhata before 1000 B.C [10^-13].

The ancient documentation like Rig Veda (4500-1600 BC) and Atharva Veda mention the use of several plants as medicine, followed by Chinese use of these medicinal plants represented in a large compilation called “Pen Ts'ao” (Great Herbal) unfolding thousands of preparations from plants as medicines [14, 15].

The therapeutic use of plants continued to grow with progress of civilization and technological developments and has resulted in the isolation of a large number of therapeutic active ingredients from plant sources. The discovery of the β-lactam antibiotics such as penicillin G from Pencillium notatum (filamentous fungus) by Fleming in 1929 marked the first real breakthrough in the field of anti-infectives and had a great impact on the explo...