A REVIEW ON THE MEDICINAL PLANT PSIDIUM GUAJAVA LINN. (MYRTACEAE)

Psidium guajava is an important food crop and medicinal plant available in tropical and subtropical countries, widely used in food and folk medicines around the world. It contains important phytoconstituents such as tannins, triterpenes, flavonoid: quercetin, pentacyclic triterpenoid: guajanoic acid, saponins, carotenoids, lectins, leucocyanidin, ellagic acid, amritoside, beta-sitosterol, uvaol, oleanolic acid and ursolic acid. In view of the immense medicinal importance of the plant, this review is an effort to compile all the information reported on its ethanobotanical, phytochemical and pharmacological activities. The present work attempts to generate interest among the masses regarding its potential in preventing and treating several common diseases. Many pharmacological studies have demonstrated the ability of this plant to exhibit antioxidant, hepatoprotective, anti-allergy, antimicrobial, antigenotoxic, antiplasmodial, cytotoxic, antispasmodic, cardioactive, anticough, antidiabetic, antiinflamatory and antinociceptive activities, supporting its traditional uses. Suggesting a wide range of clinical applications for the treatment of infantile rotaviral enteritis, diarrhoea and diabetes. Key words: ethanobotany, myrtaceae, pharmacology, physicochemical, phytochemical, Psidium guajav

In vitro and in silico antidiabetic activity of pyran ester derivative isolated from Tragia cannabina

Objective: To investigate the in vitro antidiabetic effects of isolated 4-Oxo-4H-pyran-2,6-dicarboxylic acid bis-[6-methyl-heptyl] ester from the chloroform extract of root of Tragia cannabina (T. cannabina) and AMP kinase activation property of the isolated compound. Methods: The roots of T. cannabina were collected and extracted with ethanol [95% v/v] then chromatographed over silica gel 60–120 mesh of column length 100 cm and diameter 3 cm. Elution was carried out with solvents and solvent mixtures of increasing polarities. Then the chloroform extract was used for isolation. In vitro antidiabetic activity was performed with fertile eggs of White Leghorn chicks by induction of diabetes by streptozotocin. Results: The isolated pyran ester binds very efficiently within the active pocket of AMPK with the formation of hydrogen bond and consuming less binding energy, which is good when compared to orientation of standard drug metformin. In in vitro antidiabetic evaluation by streptozotocin treated chick embryo the administration of isolated compound at a doses of 0.5 mg/egg and 1 mg/egg produced a significant reduction in the blood glucose levels in a dose dependant manner (P<0.01). The blood glucose level of diabetic control was (244.20 ± 12.64) mg/dL, whereas it was (207.40 ± 2.43) mg/dL (P<0.001) for isolated compound 0.5 mg/egg and 174.800 ± 2.410 mg/dL (P<0.001) for 1 mg/egg of the isolated compound. Conclusions: The significant glucose levels were reduced (P<0.01) after administration of the pyran ester isolated from T. cannabina to streptozotocin treated chick embryo

Aqueous humor tyrosinase activity is indicative of iris melanocyte toxicity

Antibiotics such as fluoroquinolones (FQLs) are commonly used to treat ocular infections but are also known to cause dermal melanocyte toxicity. The release of dispersed pigments from the iris into the aqueous humor has been considered a possible ocular side effect of the systemic administration of FQLs such as Moxifloxacin, and this condition is known as bilateral acute iris transillumination (BAIT). Bilateral acute depigmentation of iris (BADI) is a similar condition, with iris pigment released into the aqueous, but it has not been reported as a side effect of FQL. Iris pigments are synthesized by the melanogenic enzyme tyrosinase (TYR) and can be detected but not quantified by using slit-lamp biomicroscopy. The correlation between dispersed pigments in the aqueous and the extent of melanocyte toxicity due to topical antibiotics in vivo is not well studied. Here, we aimed to study the effect of topical FQLs on iris tissue, the pigment release in the aqueous humor and the development of clinically evident iris atrophic changes. We evaluated this process by measuring the activity of TYR in the aqueous humor of 82 healthy eyes undergoing cataract surgery following topical application of FQLs such as Moxifloxacin (27 eyes, preservative-free) or Ciprofloxacin (29 eyes, with preservative) or the application of non-FQL Tobramycin (26 eyes, with preservative) as a control. In addition, the patients were questioned and examined for ocular side effects in pre- and post-operative periods. Our data showed a significantly higher mean TYR activity in the aqueous humor of Ciprofloxacin-treated eyes compared to Moxifloxacin- (preservative free, p < 0.0001) or Tobramycin-treated eyes (p < 0.0001), which indicated that few quinolones under certain conditions are toxic to the iris melanocytes. However, the reduced TYR activity in the aqueous of Moxifloxacin-treated eyes was possibly due to the presence of a higher drug concentration, which inhibits TYR activity. Consistently, immunoblotting analysis of the aqueous humor from both Ciprofloxacin- and Moxifloxacin-treated eyes showed the presence of soluble TYR enzyme, thus reflecting its toxicity to iris melanocytes and corresponding to its activity in the aqueous humor. Intriguingly, none of these patients developed any clinically appreciable ocular side effects characteristic of BAIT or BADI. Overall, our results suggest that topical antibiotics cause different levels of iris melanocyte toxicity, releasing dispersed pigments into the aqueous humor, which can be measured through TYR enzyme activity. Hence, we conclude that topical FQLs may cause subclinical toxicity to the iris melanocytes but may not be the sole cause of the development of BAIT or BADI. (C) 2017 The Authors. Published by Elsevier Ltd

Synthesis, ABTS-Radical Scavenging Activity, and Antiproliferative and Molecular Docking Studies of Novel Pyrrolo[1,2-<i>a</i>]quinoline Derivatives

<div><p></p><p>A new 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-radical scavenging and antiproliferative agents of pyrrolo[1,2-<i>a</i>]quinoline derivatives have been synthesized. An efficient method for the synthesis of 14 novel diversified pyrrolo[1,2-<i>a</i>]quinoline derivatives has been described using 4-(1,3-dioxolan-2-yl)quinoline and different phenacyl bromides in acetone and followed by reacting with different acetylenes in dimethylformamide/K₂CO₃. The structure of the newly synthesized compounds was determined by infrared, ¹H NMR, ¹³C NMR, mass spectrometry, and elemental analysis. The in vitro antioxidant activity revealed that among all the tested compounds <b>5n</b> exhibited maximum scavenging activity with ABTS. Compound <b>5b</b> has showed good antiproliferative activity as an inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase.</p></div