The Emerging Role of Marine Natural Products for the Treatment of Parkinson's Disease.

Parkinson's Disease (PD), known as Parkinsonism, is a neurodegenerative disease that mainly affects the elderly and is characterized by an extensive and progressive loss of dopaminergic neurons in the Substantia Nigra pars compacta (SNpc). Owing to genetic, environmental, and lifestyle changes, the incidence of PD has recently risen among adults. The most widely used PD treatment strategies include the use of dopamine agonists, anticholinergics, and enzyme inhibitors. The aquatic flora and fauna have become the emerging source of novel, structurally diverse bioactive compounds and, at present, the researchers concentrate their efforts on isolating, characterizing, and identifying many secondary metabolites of different nature to treat various disorders, including, neuroprotective marine natural products (MNPs). The bioactive peptides, tannins, carotenoids, alkaloids, polyunsaturated fatty acids (PUFA), and sulfated polysaccharides from the MNP's and their synthetic derivatives have demonstrated important neuroprotective activity in preclinical studies through multiple mechanisms. An extensive literature survey was carried out, and published articles from PubMed, Scifinder, Google Scholar, Web of Science, and Scopus were carefully reviewed to compile information on the MNPs to treat PD. This current review focus on neuroprotective MNPs and their probable biological pathways to treat PD based on their structure and bioactivities reported from 1990 to 2020.

Neuroprotective role of coconut oil for the prevention and treatment of Parkinson's disease: potential mechanisms of action.

Neurodegenerative disease (ND) is a clinical condition in which neurons degenerate with a consequent loss of functions in the affected brain region. Parkinson's disease (PD) is the second most progressive ND after Alzheimer's disease (AD), which affects the motor system and is characterized by the loss of dopaminergic neurons from the nigrostriatal pathway in the midbrain, leading to bradykinesia, rigidity, resting tremor, postural instability and non-motor symptoms such as cognitive declines, psychiatric disturbances, autonomic failures, sleep difficulties, and pain syndrome. Coconut oil (CO) is an edible oil obtained from the meat of Cocos nucifera fruit that belongs to the palm family and contains 92% saturated fatty acids. CO has been shown to mediate oxidative stress, neuroinflammation, mitochondrial dysfunction, apoptosis and excitotoxicity-induced effects in PD in various in vitro and in vivo models as a multi-target bioagent. CO intake through diet has also been linked to a decreased incidence of PD in people. During digestion, CO is broken down into smaller molecules, like ketone bodies (KBs). The KBs then penetrate the blood-brain barrier (BBB) and are used as a source of energy its ability to cross BBB made this an important class of natural remedies for the treatment of ND. The current review describes the probable neuroprotective potential pathways of CO in PD, either prophylactic or therapeutic. In addition, we briefly addressed the important pathogenic pathways that might be considered to investigate the possible use of CO in neurodegeneration such as AD and PD.

Effects of Gymnema sylvestre extract on the pharmacokinetics and pharmacodynamics of glimepiride in streptozotocin induced diabetic rats.

Gymnema sylvestre, important Indian traditional herbal medicine has been used for diabetes from several years and marketed as single or multi-herb formulations globally. People are consuming G. sylvestre along with conventional hypoglycemic drugs. Therefore, there is need of evidence based assessment of risk versus benefits when G. sylvestre co-administered with conventional oral hypoglycemic drugs. In present investigation, pharmacodynamics and pharmacokinetic interactions with oral hypoglycemic drug, glimepiride (GLM) was studied in streptozotocin (STZ) induced diabetic rats. A specific and rapid HPLC-ESI-MS/MS method was established for simultaneous quantification of GLM and gymnemagenin (GMG) in rat plasma. Pharmacokinetic and pharmacodynamic interaction studies were carried out in STZ induced diabetic rats after concomitant administration of 400 mg/kg of G. sylvestre extract and 0.8 mg/kg of GLM for 28 days. The developed HPLC-ESI-MS/MS method was rapid, specific, and precise. Con-comitant oral administration of G. sylvestre extract (400 mg/kg) and GLM (0.8 mg/kg) in diabetic rats for 28 days showed beneficial pharmacodynamic interactions whereas no major alterations in the pharmacokinetics parameters of GLM and GMG were observed. This interaction demonstrated in animal model implies that significant clinical outcome might occur during concomitant administration of G. sylvestre extract and GLM especially in diabetic patients and warrants further studies in the same set up.

Peritoneal mast cell stabilization potential of Pothos scandens L.

OBJECTIVE: To investigate the peritoneal mast cell stabilization activity of Pothos scandens extracts. MATERIALS AND METHODS: Pothos scandens L. (family- Araceae) aerial part was successively extracted with ethanol and aqueous to prepare extract of the plant. The extracts of P. scandens were evaluated for stabilization of mast cell in rat allergic models. The extract of P. scandens ethanolic, 50% aqueous ethanolic and aqueous (1, 10 and 100 µg/ml) was studied for peritoneal mast cell stabilization activity in rat mesenteric preparation induced by C 48/80. RESULT: Preliminary phytochemical analysis revealed the presence of carbohydrates, fixed oil, proteins, alkaloids, glycosides, flavonoids and phenolic compounds. The ethanolic, 50% aqueous ethanolic and aqueous extracts of P. scandens L. showed dose dependent increase in the number of intact cells when compare with C48/80 at the concentration of 10 and 100 µg/ml. It virtues further work towards the isolation of phytoconstituents from this plant. CONCLUSION: This finding provides evidence that the P. scandens L. inhibits mast cell-derived immediate-type allergic reactions and mast cell degranulation. P. scandens has a potential as allergic anti- asthmatic agent.

Quantitative estimation of gymnemagenin in Gymnema sylvestre extract and its marketed formulations using the HPLC-ESI-MS/MS method.

INTRODUCTION: Gymnema sylvestre, with gymnemic acids as active pharmacological constituents, is a popular ayurvedic herb and has been used to treat diabetes, as a remedy for cough and as a diuretic. However, very few analytical methods are available for quality control of this herb and its marketed formulations. OBJECTIVES: To develop and validate a new, rapid, sensitive and selective HPLC-ESI (electrospray ionisation)-MS/MS method for quantitative estimation of gymnemagenin in G. sylvestre and its marketed formulations. METHOD: HPLC-ESI-MS/MS method using a multiple reactions monitoring mode was used for quantitation of gymnemagenin. Separation was carried out on a Luna C-18 column using gradient elution of water and methanol (with 0.1% formic acid and 0.3% ammonia). RESULTS: The developed method was validated as per International Conference on Harmonisation Guideline ICH-Q2B and found to be accurate, precise and linear over a relatively wide range of concentrations (5.280-305.920 ng/mL). Gymnemagenin contents were found from 0.056 ± 0.002 to 4.77 ± 0.59% w/w in G. sylvestre and its marketed formulations. CONCLUSION: The method established is simple, rapid, with high sample throughput, and can be used as a tool for quality control of G. sylvestre and its formulations.

Pharmacognostical studies of leaves of Combretum albidum G. Don.

BACKGROUND: Combretum albidum Don belonging to family Combretaceae is an unexplored medicinal plant in the Indian medicinal system. According to ethnobotanical information, the leaves are used in the treatment of peptic ulcer and its fruits are used in diarrhoea and dysentery. Stem bark is used in the treatment of jaundice and skin diseases. The problem encountered in standardisation of this medicinal plant is its identification by source. MATERIALS AND METHODS: The pharmacognostical studies were carried out in terms of organoleptic, macroscopic, microscopic, physicochemical, florescence and phytochemical analysis. Physicochemical parameters such as total ash, moisture content and extractive values are determined by World Health Organization guidelines. The microscopic features of leaf components are observed with Nikon lab photo device with microscopic units. RESULTS: Macroscopically, the leaves are simple, obovate in shape, acuminate apex, entire margin and smooth surface. Microscopically, the leaves showed a large vascular strand that consists of thick walled xylem elements mixed with xylem fibres and phloem which is present in a thin layer along inner and outer portions of xylem. External to the xylem occur a thin line of sclerenchyma. Powder microscopy revealed glandular trichomes in the adaxial epidermal peelings also shows the non-glandular trichomes fairly common in powder and epidermis with anisocytic stomata. Vessels elements are narrow, long, cylindrical and dense multi-seriate bordered pits. Xylem fibres are thin and long, with thick walls, which are lignified. Preliminary phytochemical screening showed the presence of carbohydrate, glycoside, saponin, flavonoid, phytosterols and phenolic compounds. CONCLUSIONS: The results of the study can serve as a valuable source of pharmacognostic information as suitable standards for identification of this plant material in future investigations and applications.

Pharmacognostical and phytochemical evaluation of the leaves of Ziziphus xylopyrus (Retz) Willd.

BACKGROUND: The fruit decoction of Ziziphus xylopyrus (Retz) Willd. is used toward increase sterility in woman intended birth control in some parts of Rajasthan, India. This plant is widely used in Turkish medicines as a potent sedative. One to two inches of the fresh stem bark of this species are chewed with 1-2 peppers, and the sap swallowed once a day for 5 days in the treatment of cough. Standardization is one of the challenges in herbal medicine. It is essential to evaluate the herbal plants scientifically and proper documentation should be made to know their medicinal properties. MATERIALS AND METHODS: Leaf samples of Z. xylopyrus were studied as recommended by World Health Organization for morphological, microscopic, physicochemical, phytochemical, powder characteristics and other methods for standardization. RESULTS: Morphologically the leaves are obovate or orbicular in shape, pinnate venation having aromatic odour and pungent taste. Microscopically leaves showed the presence of ground tissue, vascular strand, xylem and phloem. The crystals are mostly rosette type. Microscopic examination of powder showed the presence of stomata, covering trichomes, sclerenchyma, collenchyma, epidermal cells and vascular strands. Phytochemical screening of the plant part with various solvents revealed the presence of alkaloids, carbohydrates, steroids and sterol, glycosides, saponins, flavonoids, phenolic compounds, triterpenoids in it. Physicochemical parameters such as ash value extractive values were also determined and results showed that water soluble extractive value to be higher than alcohol soluble extractive value. CONCLUSION: Results may be helpful for further confirmation of selected species and in future these characters may be compared with the new batch of the same plant materials.

Pharmacognostical evaluation of Cardiospermum halicacabum Linn. leaf and stem.

BACKGROUND: Cardiospermum halicacabum Linn (Sapindaceae) is an important medicinal plant in the traditional system of medicine, known as karnasphota. The root of it is officially included in Ayurvedic Pharmacopoeia for its therapeutic uses such as jvara, kustha, pandu, ksaya and sandhivata etc. As no detailed analysis of macroscopy, microscopy characters of the plant, except root, have been carried out till date, it was thought worth to carry out the detailed macroscopic and microscopic study of leaves and stem, following standard pharmacognostical procedures. MATERIALS AND METHODS: Pharmacognostic studies of C. halicacabum were carried out, and in this, the macroscopic, microscopic, physicochemical, fluorescence and phytochemical analyses were done. Physicochemical parameters such as total ash, moisture content, extractive values were determined by World Health Organization guidelines. The microscopic features of leaf and stem components were observed. RESULTS: Macroscopically the leaves are bi-ternate, ovate-lanceolate in shape with dentate margin. Microscopically, leaf shows prominent midrib and thin dorsiventral lamina. The midrib shows the presence of epidermal layers, angular collenchyma, palisade cells and vascular strands comprised of thin walled xylem and thick walled phloem elements. The lamina shows prominent, narrow and cylindrical upper epidermis. The upper epidermal cells are large and contain mucilage, whereas lower epidermis possesses thin, small and elliptical epidermal cells. The mesophyll was differentiated into two zones upper and lower. The upper zones show narrow cylindrical palisade cells and lower zone shows 2-3 layers of loosely arranged spongy parenchyma cells. In the Paradermal section of the lamina we observe anomocytic stomata. The transverse section of stem shows a pentagonal appearance with five short blunt ridges and prominent cuticle. Parenchymatous cells, cortical sclerenchyma, lignified xylem fibers, phloem and pit were also found. In the powder microscopy of whole plant, glandular trichomes, non-glandular trichomes, fragments of lamina, xylem elements, parenchyma cells and fibers are observed. Phytochemical screening reveals that the C. halicacabum extract contains glycosides, carbohydrates, flavonoids, phytosterols, phenolic compounds and saponin. CONCLUSION: Various pharmacognostic characters observed in this study help in identification, quality, purity and standardization of C. halicacabum.

Studies on the antibacterial potential of Cryptostegia grandiflora R. Br. (Asclepiadaceae) extract.

Different extracts of Cryptostegia grandiflora (Roxb) Rbr. leaves were investigated for their antibacterial potential against Pseudomonus cepacia NCIM-2106, Bacillus megatorium NCIM-2087, Staphylococcus aureus NCIM-2492, Escherichia coli NCIM-2345, Bacillus subtilis NCIM-2349 and Bacillus coagulans NCIM 2323. Almost all the extracts produced significant antibacterial activity against all the microorganisms being tested and the effect so produced was comparable to the standard antibiotic, tetracycline hydrochloride. The petroleum ether (60 degrees-80 degrees C) extract showed maximum efficacy.