Medicinal chemistry deals with the discovery, design and development of drug substances along with the pharmacological
and analytical characterization. Medicinal chemists are indispensable in the preclinical stages of drug development, and again
as pharmaceutical chemists in drug quality control.
Green chemistry is considered as frontiers of interdisciplinary science and is used to design chemical products and
procedures that reduce the generation of hazardous chemical substances. Green chemistry has come a long way since its birth in
1991, growing from a small grassroot idea into a new approach to scientifically based environmental protection. It is also
known as sustainable chemistry. Green chemistry applies the life cycle of a chemical product, including its manufacture, use,
design, and ultimately disposal. Green chemistry is very helpful in the prevention of pollution at the molecular level and
provides innovative scientific solutions. It is able to reduce the negative impacts of chemical products on human health. The
main aspects of Green chemistry are; prevent waste, design less hazardous chemical synthesis, design safer chemicals and
products.
Green chemistry also plays an important role in the agriculture sector and has a very wide application in pharmaceutical
industry in developing innovatory drug delivery methods which are less toxic and more effective with minimum side effects
and could help millions of patients. At the beginning of this special issue, we called to Medicinal and Green Chemistry
researchers to contribute their review articles to shed light on the above topic by touching following two subtopics:
1. Medicinal drugs for management of neurodegenerative disease, cancer, immune dysfunction and diabetes.
2. Green chemistry approaches for the management of neurodegenerative disease, cancer, immune dysfunction and diabetes.
Karim et al. [1] have shed light on an increasing role of polyphenols as novel therapeutics for Alzheimer’s disorder (AD) as
it is the most prevalent neurodegenerative disorder with approximately 29 million aging people suffering from this disease
worldwide. This number is projected to triple by 2050. Alzheimer's is a complex and multifactorial neurodegenerative
condition, characterized by complex pathology including oxidative stress, the formation of aggregates of amyloid and tau,
enhanced immune responses, metal deposition and disturbances in cholinesterase enzymes. There is no effective
pharmacological treatment for combating the disease to date. The ineffectiveness of current pharmacological interventions in
AD has led scientists to search for more safe and effective alternative therapeutic agents. Thus, natural products have become
an important avenue for drug discovery in AD research. In this connection, polyphenols are natural products that have been
shown to be effective in the modulation of the type of neurodegenerative changes seen in AD, suggesting a possible therapeutic
role. In their review, they focus on the chemistry of polyphenols, clinical studies for evaluating polyphenols as effective
alternatives in AD treatment, cellular and molecular aspects of polyphenols in improving cognitive deficits and the current
challenges and futuristic approaches to use polyphenols as safe and effective therapeutic agents in AD treatment [1].
Khan et al. [2] focused on herbal medicine for glioblastoma with respect to current and future prospects. Actually,
glioblastoma is one of the most aggressive and devastating tumours of the central nervous system with short survival time.
Glioblastoma usually shows fast cell proliferation and invasion to normal brain tissue causing poor prognosis. The present
standard of care in patients with glioblastoma includes surgery followed by radiotherapy and temozolomide based
chemotherapy. Unfortunately, these approaches are not sufficient to lead a favourable prognosis and survival rates. As the
current approaches do not provide a long-term benefit in those patients, new alternative treatments, including natural
compounds, have drawn attention. Due to their natural origin, they are associated with minimum cellular toxicity towards
normal cells and it has become one of the most attractive approaches to treat tumours by natural compounds or phytochemicals.
In their review, the role of natural compounds or phytochemicals in the treatment of glioblastoma described in the light of
efficacy on various aspects of glioblastoma pathophysiology such as cell proliferation, apoptosis, cell cycle regulation, cellular
signaling pathways, chemo-resistance and their role in combinatorial therapeutic approaches. Preclinical data available in the
literature suggest that phytochemicals hold immense potential to be translated into treatment modalities. However, further
clinical studies with conclusive results are required to implement phytochemicals in treatment modalities [2].
Mohammed has mentioned recent updates on the valuable impacts of halophytic genus Suaeda in respect to its nutritional,
chemical, and biological values [3]. Suaeda is a halophytic genus belonging to the Amaranthaceae family and is able to survive
in the high salted marsh areas of the world. Suaeda plants have the ability to biosynthesize natural substances with powerful
antioxidant activity and are considered as a renewable source of energy, food and edible oil for a larger number of populations
living in the harsh environment with high salinity and drought conditions. These plants also meet folk and alternative medicine
needs. Mohammed encompassed in his review available scientific literature related to folk medicinal uses of Suaeda plants, their nutritional values and chemical constituents. In addition, the biological trials applied for the Suaeda plants are also
incorporated within this review. The review covers research from major science literature search engines and other sites
representing scientific literature, i.e., Scifinder, Google Scholar, PubMed, ScienceDirect, Scopus and Google. The searches
were programmed on the advance options available in the search engines and are latest up to November 2019. The searches
were exhaustive and rechecked for accuracy. The study summarizes the uses of Suaeda plants as a remedy for various ailments
due to their contents from the polyphenols and flavonoids. The comparatively large amounts of fixed oils, minerals, and
vitamins in Suaeda plants have also made them a potential renewable source for foods [3].
Fayaz et al. [4] wrote on the outcome of chemicals on amyotrophic lateral sclerosis: Is green chemistry the answer?
Medicinal Chemistry has played a critical role in evolving new products, resources and processes which inexorably correspond
to our high standards of living. Unfortunately, this has also caused deterioration of human health and threats to the global
environment, even deaths when highly exposed to certain chemicals, whether due to improper use, mishandling or disposal.
There are chemicals, which apart from being carcinogens, endocrine disruptors or neurotoxins, are also responsible for climate
change and ozone depletion. Certain chemicals are known to cause neurotoxicity and are having tendencies to damage the
central as well as peripheral nervous system or brain by damaging neurons or cells which are responsible for transmitting and
processing of signals. This has raised serious concerns for the use and handling of such chemicals and has given the growth in a
relatively new emerging field known as Green Chemistry that strives to achieve sustainability at the molecular level and has an
ability to harness chemicals to meet environmental and economic goals. It has been reported in the literature that apart from
family history in the aetiology of Amyotrophic lateral sclerosis (ALS), also termed as “Lou Gehrig’s disease”, a neurological
disorder, environmental factors, heavy metals, particularly selenium, lead, mercury, cadmium, formaldehyde, pesticides and
certain herbicides also play a role in ALS. ALS a progressive neurodegenerative disease affects motor cortex, brain stem and
spinal cord, causing muscular weakness, spasticity, and hyperreflexia. In this review, Fayaz et al. discussed and summarized
the evidence supporting the undesirable role of chemical substance/herbicides/pesticides in ALS aetiology and its mitigation by
adopting green chemistry [4].
Sobhani et al. [5] described the therapeutic effects of Ziziphus jujuba Mill fruit in traditional and modern medicine. Ziziphus
jujuba Mill belonging to the Rhamnaceae family and it has been consumed since ancient times as a medicine and food. In the
different traditional medical schools, Z. jujuba has been used to treat various diseases such as respiratory system diseases
(asthma, cough, and laryngitis), gastrointestinal problems (constipation, colitis and liver diseases), as well as, cardiovascular
and genitourinary system diseases. From the perspective of Islamic traditional medicine, Z. jujuba fruit is an emollient, laxative,
and maturative. It can purify the blood and improve blood circulation, relieve internal heat and reduce inflammation. Some
therapeutic uses of Z. jujuba such as antibacterial, antioxidant, sedative, hepato-protective, anti-hyperglycemic, and antihyperlipidemic
activities have been shown in modern pharmacological studies. Sobhani et al. reported traditional and
ethnomedicinal uses, botany, phytochemistry and pharmacological activities of Z. jujuba in their review article [5].
This special issue was written to enable an in-depth understanding of the special issue topic. As a result, a new approach can
be developed towards drug development and clinical aspects for enhanced progress in management strategies of different
disorders. We wish to end this editorial by thanking Prof. Dimitra Hadjipavlou-Litina, the Editor-in-Chief, as well as Akhtar
Waheed (Sr. Manager) along with all the contributing authors who have enthusiastically responded to our request in
contributing in this special issue of Medicinal Chemistry. I additionally extend my thanks to all peer reviewers for their time
and expertise in reviewing individual contribution. Due to team efforts of such a great scientific team-gifted with extensive
experience in the arena of Medicinal and Green Chemistry, this special issue provides a scholarly and important resource of
reference for the benefit of medical-researchers and those suffering from various diseases.