Identification of glucosyl transferase inhibitors from Psidium guajava against Streptococcus mutans in dental caries.

Dental caries is a multi factorial disease that starts with microbiological shifts affected by salivary flow, composition, exposure to fluoride, consumption of dietary sugars, and preventive behaviours. The Streptococcus mutans (S. mutans) is an initiator of caries because there is a variety of a virulence factor unique to the bacterium that has been isolated and plays an important role in caries formation. The aim of the present study is to identify the beneficial effect of bioactive compounds in Psidium guajava (P. guajava) and its inhibitory role against S. mutans in dental caries. The methanolic extract was used for analysis of GC-MS for the identification of bioactive compounds. The results confirm the existence of 7 different compounds. The identified bioactive compounds were corynan-17-ol, 18,19-didehydro-10-methyoxy-acetate, Copaene, 3Bicyclo(5.2.0)nonane, 2-methylene-4,8,8-trimethyl-4-vinyl,Azulene,1,2,3a,4,5,6,7-octahydro-1,4-dimethyl-7-methylethenyl) [1R- (1a,3aa',4a',7a')], α-Caryophyllene, Alloaromadendrene oxide-(1) and Androstan-17-one, 3-ethyl-3-hydroxy-, (5a). The saliva of dental caries during and after treatment of aqueous leaf extract was used for the analysis of bacterial load and determining the activity of Glucosyl transferase (GTF). The result obtained at different time intervals, showed significant decrease (P < 0.01) in the bacterial load of saliva on P. guajava treatment. The molecular docking studies identified the interaction between GTF and the bioactive compounds of P. guajava. The anticariogenic active compounds interacted through active sites of sucrose and inhibit the formation of glucan. The study suggested that it could be maximized the anticariogenic effect of the selected medicinal plant, and further focus is needed to identify the combined plant extract to explore the additional protection against dental caries.

Evaluation of antigenotoxic effects of carotenoids from green algae Chlorococcum humicola using human lymphocytes.

OBJECTIVE: To identify the available phytochemicals and carotenoids in the selected green algae and evaluate the potential genotoxic/antigenotoxic effect using lymphocytes. METHODS: Organic solvent extracts of Chlorococcum humicola (C. humicola) were used for the phytochemical analysis. The available carotenoids were assessed by HPLC, and LC-MS analysis. The genotoxicity was induced by the benzo(a)pyrene in the lymphocyte culture, the genotoxic and antigenotoxic effects of algal carotenoids with and without genotoxic inducer were evaluated by chromosomal aberration (CA), sister chromatid exchange (SCE) and micronucleus assay (MN). RESULTS: The results of the analysis showed that the algae were rich in carotenoids and fatty acids. In the total carotenoids lutein, ß-carotene and α-carotene were found to be present in higher concentration. The frequency of CA and SCE increased by benzo(a)pyrene were significantly decreased by the carotenoids (P<0.05 for CA, P<0.001 for SCE). The MN frequencies of the cells were significantly decreased by the treatment with carotenoids when compared with the positive controls (P<0.05). CONCLUSIONS: The findings of the present study demonstrate that, the green algae C. humicola is a rich source of bioactive compounds especially carotenoids which effectively fight against environmental genotoxic agents, the carotenoids itself is not a genotoxic substance and should be further considered for its beneficial effects.

Stabilization of membrane bound ATPases and lipid peroxidation by carotenoids from Chlorococcum humicola in Benzo(a)pyrene induced toxicity.

OBJECTIVE: To identify the alteration of the membrane potential and the effect of carotenoid extracts from Chlorococcum humicola (C. humicola) on membrane bound ATPases and lipid peroxidation. METHODS: The total carotenoids were extracted from C. humicola. Four groups of Swiss albino mice were treated as control, Benzo(a)pyrene [B(a)P], total carotenoids, B(a)P + total carotenoids respectively for a period of 60 days. Membrane lipid peroxidation and ATPases (Total ATPases, Ca(2+)- ATPases, Mg(2+) - ATPases, Na(+)K(+) - ATPase) were determined in lung, liver and erythrocyte samples. RESULTS: The activity of total ATPase was found to be significantly increased in the B(a)P treated liver and lung tissue. Erythrocyte membrane also showed higher ATPase activity which was significantly reverted on total carotenoid treatment. CONCLUSIONS: It can be concluded that the changes in membrane potential favour the functional deterioration of physiological system. The overall findings demonstrates that the animals post treated with carotenoid extract from C. humicola may maintains the alterations in membrane bound ATPase and lipid peroxidation in tissues against the carcinogenic chemical and hence aid in establishing the membrane potential action. Therefore C. humicola can be further extended to exploits its possible application for various health benefits as neutraceuticals and food additives.

Decreased bioavailability of rifampin and other antituberculosis drugs in patients with advanced human immunodeficiency virus disease.

We evaluated the effects of human immunodeficiency virus (HIV) disease on pharmacokinetics of antituberculosis medications by measuring concentrations of isoniazid and rifampin in blood and of pyrazinamide and ethambutol in urine. Peak concentration and exposure were reduced for rifampin, and rapid acetylators of isoniazid had lower drug levels. HIV and HIV-tuberculosis patients who have diarrhea and cryptosporidial infection exhibit decreased bioavailability of antituberculosis drugs.

Standardization of the method for estimation of ethambutol in pharmaceutical preparations and biological fluid.

A simple column chromatographic method for determination of ethambutol (EMB) in pharmaceutical preparations containing EMB in combination with other anti-TB drugs is presented. The method involved extraction of EMB into an organic solvent, followed by basification and column chromatographic separation on Amberlite CG 50 (100-200 mesh) and elution with suitable eluants and estimation at a wavelength of 270 nm. The assay was linear from 25 to 400 microg/ml. The relative standard deviations of intra and inter day assays were lower than 5%. Ethambutol was recovered from human urine quantitatively and stable for a period of at least one week in urine stored at -20 degrees C.