Leaf and Seed extracts of Bixa orellana L. exert anti-microbial activity against bacterial pathogens.

Methanol extracts of the leaf & seed of Bixa orellana L. were studied for in vitro antimicrobial activity against MTCC strains of Staphylococcus aureus, Salmonella typhi, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus fecalis, Vibrio cholera, Moraxella catarrhalis, Acinetobacter sp., Brucella sp. along with fungal pathogens Candida albicans, Aspergillus niger and the dermatophytes Trichophyton mentagrophytes & Trichophyton rubrum. Leaf extract of B. orellana at 1000 μg/ml concentration showed significant inhibition against all the tested bacteria and fungus, with highest inhibition zone (18±0.3 mm) against S. typhi, Acinetobacter sp., T. mentagrophytes and T. rubrum. Seed extract of B. orellana was comparitively less efficacious in most of the tested pathogens, except Brucella sp. which was appreciably inhibited (15±0.1 mm). Minimum Inhibitory Concentration (MIC) of leaf extract was determined as 15.62 μg/ml against S. aureus and 31.25 μg/ml for K. pneumoniae, P. aeruginosa, E. fecalis & S. typhi, on average. Among the dermatophytes, 78.2% inhibition was seen in T. mentagrophytes & T. rubrum. Scanning Electron Microscopic (SEM) studies of the treated P. aeruginosa cells revealed disintegration & aggregation of cells after treatment with the leaf extract. Phytochemical analysis of leaf & seed extracts suggested the presence of flavonoids, tannins, saponins, steroids. Alkaloids were detected only in the leaf & anthroquinones, in the seeds.

Composite fish culture for mosquito control in rice fields in southern India.

Composite culture of edible fishes (common carp, Cryprinus carpio; silver carp, Hypopthalmithys molitrix, grass carp, Ctenopharyngodon idella; catla, Catla catla; rohu, Labeo rohita; and mrigal, Cirrhinus mrigala) in rice fields in the Cauvery delta of Tamil Nadu, southern India, resulted in 81.0% reduction in the immature mosquito population of anophelines and 83.5% of culicines. Analysis of fish feces for mosquito larval head capsules showed that common carp and silver carp are effective larvivores. The selective feeding of common carp on culicines and silver carp on anophelines is correlated to their trophic niches. Net profit in the fish-cum-rice fields was 2.5 times greater than fields in which rice alone was cultured. Hence, rice-cum-fish culture can be recommended to the farming community in this area.

Metabolism of echitamine and plumbagin in rats.

When administered to rats, echitamine was absorbed rapidly from the tissues and was detected in circulation within 30 min. The drug level reached a maximum value by 2 h and then decreased steadily. The drug had completely disappeared from the blood in 6 h. The presence of echitamine was observed within 2 h in urine and the maximum amount of drug was excreted between 2 and 4 h. About 90% of the drug was excreted in urine in 24 h and the drug could not be detected in urine after 48 h. Along with echitamine, its metabolites were also detected in the urine. Plumbagin was not detected in blood upto 24 h when administered into rats. The drug was detected in urine within 4 h after administration; a major portion of the drug was excreted in urine by 24 h and traces of the drug were observed in the urine even after 48 h.