Biotechnological Innovations from Ocean: Transpiring Role of Marine Drugs in Management of Chronic Disorders

Marine drugs are abundant in number, comprise of a diverse range of structures with corresponding mechanisms of action, and hold promise for the discovery of new and better treatment approaches for the management of several chronic diseases. There are huge reserves of natural marine biological compounds, as 70 percent of the Earth is covered with oceans, indicating a diversity of chemical entities on the planet. The marine ecosystems are a rich source of bioactive products and have been explored for lead drug molecules that have proven to be novel therapeutic targets. Over the last 70 years, many structurally diverse drug products and their secondary metabolites have been isolated from marine sources. The drugs obtained from marine sources have displayed an exceptional potential in the management of a wide array of diseases, ranging from acute to chronic conditions. A beneficial role of marine drugs in human health has been recently proposed. The current review highlights various marine drugs and their compounds and role in the management of chronic diseases such as cancer, diabetes, neurodegenerative diseases, and cardiovascular disorders, which has led to the development of new drug treatment approaches.     

Previously undescribed antioxidative azocinyl morpholinone alkaloid from red seaweed Gracilaria opuntia with anti-cyclooxygenase and lipoxygenase properties

In vitro antioxidative and anti-inflammatory bioassay-guided fractionation of the methanol: ethyl acetate crude extract of the thalli of red seaweed Gracilaria opuntia collected from the Gulf of Mannar led to the isolation of a new morpholine alkaloid 3-(2-ethyl-6-((3Z,7Z)-1,2,5,6-tetrahydroazocin-5-yl)hexyl) morpholin-6-one. The substituted azocinyl morpholinone recorded significant 1,1-diphenyl-2-picryl-hydrazil free radical scavenging activities (IC₅₀ ~ 0.086 mg/mL) compared to the commercially available antioxidants, butylated hydroxyanisole, butylated hydroxytoluene, and α-tocopherol (IC₅₀ > 0.20 mg/mL). The title compound showed greater cyclooxygenase-2 (COX-2) inhibitory activity (IC₅₀ 0.84 mg/mL) in conjunction with in vitro 5-lipoxidase inhibitory activity (IC₅₀ 0.85 mg/mL) than non-steroidal anti-inflammatory drugs (NSAIDs). The test compound had better selectivity index (COX-1/COX-2 ratio) (1.17 mg/mL) compared to aspirin (0.02 mg/mL), Na salicylate (0.73 mg/mL) and ibuprofen (0.44 mg/mL). The animals challenged with the substituted azocinyl morpholinone significantly mitigated the carrageenan-induced paw edema in time-dependent manner till the end of 6 h.     

Antioxidative sulphated polygalactans from marine macroalgae as angiotensin-I converting enzyme inhibitors

Antioxidant and antihypertensive potential of the sulphated polygalactans isolated from the marine macroalgae Kappaphycus alvarezii and Gracilaria opuntia were assessed by utilising different in vitro systems. The galactans isolated from K. alvarezii possessed significantly greater antioxidative properties as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH IC₉₀ 0.97 mg/mL) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS^.+ IC₉₀ 0.72 mg/mL) scavenging activities than those isolated from G. opuntia (DPPH IC₉₀ 1.2 mg/mL and ABTS 0.86 mg/mL). The sulphated polygalactan →4)-4-O-sulphonato-(2-O-methyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-methyl)-α-D-galactopyranan from K. alvarezii showed greater angiotensin-I-converting enzyme (ACE) inhibitory activity (IC₅₀ 0.02 μg/mL) than →3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-xylosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranan motif extracted from G. opuntia (IC₅₀ 0.70 μg/mL). Structure activity correlation studies displayed that the ACE inhibitory properties of titled polygalactans were directly proportional to their electronic properties and inversely with the steric and hydrophobic characteristics. Putative ACE inhibitory mechanism of action of sulphated galactans from marine macroalgae corroborated the structure bioactivity correlation analysis.     

Oxidative stress induced antimicrobial efficacy of chitosan and silver nanoparticles coated Gutta-percha for endodontic applications

Root canal treatment is the most effective treatment for irreversible pulpal damage. However, it suffers the risk of failure due to micro-leakage at the Gutta-percha-sealer-tooth interface. Concerning the issue, it is important to enhance the antimicrobial properties of Gutta-percha. The current study describes a novel coating of the Gutta-percha with chitosan and silver nanoparticles to increase their antimicrobial efficacy. They were coated with chitosan and silver nanoparticles with concentrations of 1%, 2% using chemical methodology. Coated Gutta-percha were evaluated for their antimicrobial efficacy against E. faecalis, which is frequently isolated microorganism in failed endodontic cases using standard microbiological methods like growth curve analysis. Detailed analysis of the antimicrobial activity was performed by live-dead analysis with the help of flow cytometry and fluorescent microscopy. Although, the experimental analysis showed concentration-dependent antibacterial activity by both chitosan and silver NP coated Gutta-percha, the silver NP coating exhibited higher antibacterial activity compared to the Gutta percha coated with chitosan nanoparticles. Mechanistic evaluation unveiled the cause of antibacterial activates due to action of induced oxidative stress and membrane damage to the bacteria by coated nanoparticles. The information will be useful for the endodontist to have an alternative filling material with higher antibacterial potency for higher success rate of root canal therapies in clinical procedures.     

Design and Simulation of Broadband Beam Splitter on a Silicon Nitride Platform for Optical Coherence Tomography

ABSTRACT

Integrated photonics enables the miniaturization of bulk optical components for biosensing applications such as optical coherence tomography (OCT) and is therefore promising for future lab-on-chip solutions. Here, we report the design and simulation of a compact low loss broadband beam splitter with arbitrary coupling ratios on silicon nitride platform for OCT systems. The reported coupler uses asymmetric waveguide-based phase control section for 10:90, 20:80, 30:70, 40:60, and 50:50 splitting ratios and is broadband over 100 nm with the central wavelength of 850 nm. The couplers are realized for transverse electric, transverse magnetic, and fully vectorial modes, and maximum excess loss for all mode types is reported to be less than 0.19 dB. The design tolerance of waveguide width and thickness of the designed coupler is further calculated and is within fabrication limit.     

Comparison of extraction techniques for quantitative analysis of pendimethalin from soil and rice grain

The paper exploits the development, optimization, and comparison of fast, efficient, quantitative analytical extraction techniques such as ultrasonic-assisted extraction (UAE) and matrix solid-phase dispersion (MSPD) for proficient extraction of pendimethalin from soil and rice samples. Residues of pendimethalin were quantified using high-performance liquid chromatography. Impact of several experimental parameters of UAE and MSPD techniques on extraction of pendimethalin from soil and rice samples was also evaluated. Under the optimized conditions, the mean percent recoveries obtained from both methods were in the range of 80.3–101.3 and 81.7–103.1, respectively, with relative standard deviation <10. Linearity was in the range of 0.003–5.0?µg?mL^?1 with limit of detection and limit of quantification as 0.001 and 0.003?µg?g^?1, respectively. MSPD method was found superior in terms of low solvent consumption, small sample size, and reduced matrix coextracts due to simultaneous extraction and cleanup steps. Both extraction methodologies were successfully applied in monitoring routine soil and rice samples, in which pendimethalin residues (0.003–0.007?µg?g^?1) were detected in few rice samples while residues in soil samples were below the quantification limit.     

Insights into the Explicit Protective Activity of Herbals in Management of Neurodegenerative and Cerebrovascular Disorders

The longstanding progressive neurodegenerative conditions of the central nervous system arise mainly due to deterioration, degradation and eventual neuronal cell loss. As an individual ages, the irreversible neurodegenerative disorders associated with aging also begin to develop, and these have become exceedingly prominent and pose a significant burden mentally, socially and economically on both the individual and their family. These disorders express several symptoms, such as tremors, dystonia, loss of cognitive functions, impairment of motor activity leading to immobility, loss of memory and many more which worsen with time. The treatment employed in management of these debilitating neurodegenerative disorders, such as Parkinson’s disease (which mainly involves the loss of dopaminergic neurons in the nigrostriatal region), Alzheimer’s disease (which arises due to accumulation of Tau proteins causing diffusive atrophy in the brain), Huntington’s disease (which involves damage of striatal and spinal neurons, etc.), have several adverse effects, leading to exploration of several lead targets and molecules existing in herbal drugs. The current review highlights the mechanistic role of natural products in the treatment of several neurodegenerative and cerebrovascular diseases such as Parkinson’s disease, Alzheimer’s disease, ischemic stroke and depression.