Herbal Drugs as Immune Booster Against Viral Infections

Abstract:

The immune system involves both active and passive immunization. The antibodies are developed against the antigens during active immunization and are permanently stored. But, in the case of passive immunization, the antibodies are exposed to the same antigens in every person who is already infected. In order to enhance the immune systems i.e. innate and adaptive immune responses, herbal plants are used as an immune booster. Some of the herbal plants have been proven clinically to enhance immunity that includes Morniga oleifera (Drumstick), Azadirachta indica (Neem), Ocimum sanctum (Tulsi), Withania somnifera (Aswagandha), Zingiber officinale (Ginger), Allium sativum (Garlic), Curcuma longa (Turmeric), Emblica officinalis (Amla) etc. Compared to synthetic drugs, herbal drugs have fewer side effects and stimulate the immune system to defend against various foreign pathogens. Even though herbal medicines are usually considered as safe and effective therapy, it is clinically proven that if a drug is effective, it would have some side effects. But, sometimes, the antioxidant property of herbal medicines is helpful in reducing the toxicities produced by any toxic substances or any drugs. This review aims to encourage the study of various herbal constituents and their role in the treatment of different types of viral infections.

Green and Sustainable Technology: Efficient Strategy for the Synthesis of Biologically Active Pyrimidine Derivatives

:

Green chemistry is also referred to as sustainable technology, which involves the design, synthesis, processing and the use of chemical substances by reducing or eliminating the chemical hazards. This strategy focuses on atom economy, use of safer solvents or chemicals, use of raw materials from renewable resources, consumption of energy and decomposition of the chemical substances to non-toxic material which are eco-friendly. So, this technology is utilized for the sustainable development of novel heterocyclic scaffold like pyrimidine derivatives. Pyrimidine is a six membered heterocyclic aromatic compound with two nitrogen atoms at positions 1 and 3 in the ring system. Among the other heterocyclic compounds, pyrimidine derivatives play a major role due to their diverse promising biological activities, such as antimicrobial, antifungal, anti-viral, anti- tubercular, anti-diabetic, anti-hypertensive, anticancer, anthelmintic, antioxidant, anti-epileptic, antipsychotic, anti-anxiety, antimalarial, antihistaminic, anti-parkinsonian, analgesic and anti-inflammatory etc. The various green methods used for the synthesis of pyrimidine derivatives include microwave assisted synthesis, ultrasound induced synthesis, ball milling technique, grinding technique and photo-catalysis. These processes enhance the rate of the reaction that leads to high selectivity with improved product yields as compared to the conventional synthetic methods. This review is focused on the green synthesis of biologically active pyrimidine derivatives.

Biomarkers, tools, and test kits for COVID-19

Currently, the COVID-19 pandemic appears to be the biggest challenge to man, claiming over 600,000 lives within 7 months. Various diagnostic kits for COVID-19 have emerged which is important in keeping track of the escalation of the disease. The World Health Organization has implored health agencies time and again to make the test for the novel coronavirus a top priority in their response to the pandemic. Another most challenging task of COVID-19 is to identify asymptomatic cases which silently spread virus to close contacts and become the super spreader. Hence rapid diagnosing, identifying the positive cases, and quarantining are the only ways to prevent the pandemic outbreak. This chapter highlights the different possible diagnostic tests for COVID-19 with their errors in prediction and future directions.

QbD enabled optimization of solvent shifting method for fabrication of PLGA-based nanoparticles for promising delivery of Capecitabine for antitumor activity

The key objective of the current research was to fabricate and optimize Capecitabine (Cap)-loaded [poly(lactic-co-glycolic acid)] PLGA-based nanoparticles (NPs) by enabling quality by design (QbD) approach for enhancing antitumor activity by promising delivery of the drug at the colonic site. The current research was based on fabricating PLGA-based nanoparticles along with Eudragit S100 as enteric polymer employing solvent shifting method followed by optimization using QbD approach. This approach was found to be useful for understanding the multiple factors and their interaction influencing the product by utilizing Design of Experiment (DOE). Box-Behnken design (BBD) was adopted to achieve the required critical quality attributes (CQAs), i.e., minimizing particle size, maximizing entrapment efficiency, and minimizing PDI value. The optimized nanoparticles were lyophilized and characterized by FT-IR, DSC, TEM, DLS, MTT assay using HT-29 cell lines, and in vivo pharmacokinetic studies. The optimized PLGA-based nanoparticles were found to possess average particle size, PDI, zeta potential, and entrapment efficiency of 195 nm, 0.214, -6.65 mV, and 65%, respectively. TEM analysis revealed the spherical nature of nanoparticles. The FT-IR and DSC studies revealed no interaction. The bioavailability of Cap-loaded nanoparticles was found to be two fold increased than the pure drug, and also, it exhibited significantly more cytotoxic to tumor cells as compared to pure drug as confirmed by MTT assay. The optimized PLGA-based nanoparticles found to possess enhanced bioavailability and significantly more cytotoxic potential as compared to pure drug.

Drug Repurposing Strategy (DRS): Emerging Approach to Identify Potential Therapeutics for Treatment of Novel Coronavirus Infection

Drug repurposing is also termed as drug repositioning or therapeutic switching. This method is applied to identify the novel therapeutic agents from the existing FDA approved clinically used drug molecules. It is considered as an efficient approach to develop drug candidates with new pharmacological activities or therapeutic properties. As the drug discovery is a costly, time-consuming, laborious, and highly risk process, the novel approach of drug repositioning is employed to increases the success rate of drug development. This strategy is more advantageous over traditional drug discovery process in terms of reducing duration of drug development, low-cost, highly efficient and minimum risk of failure. In addition to this, World health organization declared Coronavirus disease (COVID-19) as pandemic globally on February 11, 2020. Currently, there is an urgent need to develop suitable therapeutic agents for the prevention of the outbreak of COVID-19. So, various investigations were carried out to design novel drug molecules by utilizing different approaches of drug repurposing to identify drug substances for treatment of COVID-19, which can act as significant inhibitors against viral proteins. It has been reported that COVID-19 can infect human respiratory system by entering into the alveoli of lung via respiratory tract. So, the infection occurs due to specific interaction or binding of spike protein with angiotensin converting enzyme-2 (ACE-2) receptor. Hence, drug repurposing strategy is utilized to identify suitable drugs by virtual screening of drug libraries. This approach helps to determine the binding interaction of drug candidates with target protein of coronavirus by using computational tools such as molecular similarity and homology modeling etc. For predicting the drug-receptor interactions and binding affinity, molecular docking study and binding free energy calculations are also performed. The methodologies involved in drug repurposing can be categorized into three groups such as drug-oriented, target-oriented and disease or therapy-oriented depending on the information available related to quality and quantity of the physico-chemical, biological, pharmacological, toxicological and pharmacokinetic property of drug molecules. This review focuses on drug repurposing strategy applied for existing drugs including Remdesivir, Favipiravir, Ribavirin, Baraticinib, Tocilizumab, Chloroquine, Hydroxychloroquine, Prulifloxacin, Carfilzomib, Bictegravir, Nelfinavir, Tegobuvir and Glucocorticoids etc to determine their effectiveness toward the treatment of COVID-19.

Osmotic drug delivery systems: basics and design approaches

Osmotic drug delivery system utilizes the principles of osmotic pressure for the controlled delivery of active pharmaceutical ingredient at a predetermined zero order rate. An appropriately designed osmotic drug delivery is not influenced by different physiologic factors but affected by pharmaceutical factors, which play a pivotal role in modulating the release of drug. The present review critically discussed about the factors affecting drug release from the delivery system such as solubility, osmotic pressure, size of delivery orifice and membrane characteristics. The major arena of this review is to highlight about the different types of osmotic drug delivery systems such as implantable, single chamber, multi chamber osmotic pumps and several specialized type of osmotic pumps. Apart from that this system is a versatile technology useful for delivery of drugs with varying solubility. The additional properties of this delivery system can also exhibit pulsatile release, burst release and colon targeting of drug. Because of its versatility, this above system seems to have promising approach which can result in improved safety profile, stable drug concentrations, uniform drug effects and dosing frequency. Current review also briefly discussed about the patents related to delivery of drugs by the principle osmotic pressure.

Improvement in Dissolution Rate of Cefuroxime Axetil by using Poloxamer 188 and Neusilin US2

A combination of fusion and surface adsorption techniques was used to enhance the dissolution rate of cefuroxime axetil. Solid dispersions of cefuroxime axetil were prepared by two methods, namely fusion method using poloxamer 188 alone and combination of poloxamer 188 and Neusilin US2 by fusion and surface adsorption method. Solid dispersions were evaluated for solubility, phase solubility, flowability, compressibility, Kawakita analysis, Fourier transform-infrared spectra, differential scanning calorimetry, powder X-ray diffraction study, in vitro drug release, and stability study. Solubility studies showed 12- and 14-fold increase in solubility for solid dispersions by fusion method, and fusion and surface adsorption method, respectively. Phase solubility studies showed negative ΔG⁰_tr values for poloxamer 188 at various concentrations (0, 0.25, 0.5, 0.75 and 1%) indicating spontaneous nature of solubilisation. Fourier transform-infrared spectra and differential scanning calorimetry spectra showed that drug and excipients are compatible with each other. Powder X-ray diffraction study studies indicated that presence of Neusilin US2 is less likely to promote the reversion of the amorphous cefuroxime axetil to crystalline state. in vitro dissolution studies, T50% and mean dissolution time have shown better dissolution rate for solid dispersions by fusion and surface adsorption method. Cefuroxime axetil release at 15 min (Q15) and DE15 exhibited 23- and 20-fold improvement in dissolution rate. The optimized solid dispersion formulation was stable for 6 months of stability study as per ICH guidelines. The stability was ascertained from drug content, in vitro dissolution, Fourier transform-infrared spectra and differential scanning calorimetry study. Hence, this combined approach of fusion and surface adsorption can be used successfully to improve the dissolution rate of poorly soluble biopharmaceutical classification system class II drug cefuroxime axetil.

Stabilization and delivery approaches for protein and peptide pharmaceuticals: an extensive review of patents

Proteins and peptides are the building blocks of human body and act as the arsenal to combat against the invading pathogenic organisms for treatment and management of diseases. Majority of such biomacromolecules are synthesized by the human body itself. However, entry of disease causing pathogens causes misleading in the synthesis of desired proteins for antibody formation. In such alarming situations, the delivery of requisite protein and peptide from external source helps in augmenting the body's immunity. The major drawbacks underlying poor biopharmaceutical performance of high molecular weight protein and peptide drugs are due to poor oral absorption, formulation stability, degradation in the gastric milieu, susceptible to presystemic metabolism. Numerous literature recounts the application of myriad drug delivery strategies for the effective delivery of protein and peptides viz. parentral, oral, transdermal, nasal, pulmonary, rectal, buccal and ocular drug delivery systems. There are many reviews on various delivery strategies for protein and peptide pharmaceuticals, but the present review article provides a bird's eye view on various novel drug delivery systems used for enhanced delivery of protein and peptide pharmaceuticals in the light of patent literature. Apart from this, the present manuscript endeavor provides idea on possible causes and major degradation pathways responsible for poor stability of protein and peptide drugs along with recent market instances on them utilizing novel drug delivery systems.

Design and characterization of sustained release mucoadhesive microspheres of tolterodine tartrate

The work was aim to design and characterize the sustained release mucoadhesive microspheres of Tolterodine tartrate prepared by non-aqueous solvent evaporation technique using ethyl cellulose based selected mucoadhesive polymers. Selected microspheres formulations of were found to be discrete, spherical and free flowing from the preliminary formulations. The microspheres exhibit good mucoadhesive property in in-vitro wash off test and showed high drug entrapment efficiency. Tolterodine tartrate release from these microspheres was slowed, extended and depended on the concentration of ethyl cellulose and type of mucoadhesive polymer used. In vitro drug release studies suggested that formulation F6c showed consistent drug release for up to 24 h time period. Among all the formulations, F6c containing ethyl cellulose with chitosan showed the reproducible results with best mucoadhesive profile and good surface morphology. The correlation value (r(2)) indicated that the drug release followed Higuchi model. Analysis of variance (ANOVA) showed significant difference in the release of drug from all formulations at P < 0.05 level. Accelerated stability study of optimized formulation (F6c) up to 3 month showed there was no change in drug content and release characteristics during storage.

Spironolactone; the ultimate blocker of RAAS cascade in hypertensive patients with special reference to its cardiovascular benefits: Revisiting the forgotten ways

Hypertension is a major risk factor for various macro and microvascular complications in a patient with diabetes. Control of hypertension is of paramount importance in the care of a diabetes subject. The goals for blood pressure in diabetes subjects are below 130/ 80 mmHg and below 125/75 mmHg if accompanying renal impairment is there. Spironolactone is a medication that has been used to treat high blood pressure since the 1960s. While there is some belief spironolactone reduces blood pressure, there are concerns due to the potential for this drug to cause adverse effects. Previous Meta analysis has shown that spironolactone reduces systolic/diastolic blood pressure by approximately 20/7 mmHg compared to placebo. Spironolactone has also been shown to decrease morbidity and mortality in patients with heart failure. We have tried to emphasize upon the usage of this old but important drug in management of resistant hypertension with reference to its mode of action, benefits and recent studies pertinent to cardiovascular benefits of spironolactone. Data Source:We searched PUBMED and MEDLINE database for relevant articles including key words. References of each article were further reviewed for final synthesis of the manuscript. DOI: http://dx.doi.org/10.3329/bjms.v11i2.8664 Bangladesh Journal of Medical Science Vol. 11 No. 02 April 2012: 80-86

Pheochromocytoma with renal artery stenosis: A case-based review of literature

Pheochromocytomas have been described to be associated with rare vascular abnormalities, most common of them being renal artery stenosis. A 45-year-old woman was admitted to our hospital with complaints of headache, sweating, anxiety, dizziness, nausea, vomiting and severe hypertension. Hypertension was confirmed to result from both excess catecholamine production and hyperreninemia of left kidney. The technical images (abdominal CT and renal arteriography) revealed the presence of a left adrenal pheochromocytoma and stenosis of the renal artery. Surgical removal of pheochromocytoma and correction of renal artery stenosis restored the postoperative plasma catecholamine, renin and blood pressure to normal. To our belief, this is the first such case report from India citing this rare association. We conclude that when the two diseases occur simultaneously, both must be diagnosed accurately and treated in a different manner. We also hereby review the existing literature.