Possible dual roles of an allelopathic compound, cis-dehydromatricaria ester
The aqueous extract of the root ofSolidago altissima was lethal to nematodes. The major compound isolated from the toxic fraction wascis-dehydromatricaria ester (methyl 2-decene-4,6,8-triynoate), which is already known as an allelopathic compound of a composite showing growth-inhibition to a rice seedling. This compound showed high toxicity to plant-parasite nematodes. A composite exudes one defending substance against both competitive plants and plant-parasite nematodes.
Do allelochemicals operate independent of substratum factors
“The plant world is not colored green; it is colored morphine, caffeine, tannin, phenol, terpene, canavanine, latex, phytohaem-agglutinin, oxalic acid, saponin, L-dopa, etc.”Janzen [1].Plants synthesize a variety of secondary metabolites playing various roles in plant defense, plant interference (allelopathy), nutrient dynamics, waste elimination, mycorrhizae formation, and substratum ecology [2]. The term “plant allelochemical” was coined by Whittaker and Feeny [3]. Although both primary and secondary metabolites are being considered as allelochemicals, we will discuss only secondary metabolites as allelochemicals for the present discussion. Conn [4] suggested that secondary metabolites are compounds that do not have a direct role in the growth and reproduction of an organism. Although we should not use the terms “allelochemical” and “secondary metabolites” as synonyms, secondary substances largely act as allelochemicals [3]. Secondary metabolites can be very close to primary metabolites structurally. While kaurenoic acid and proline are primary metabolites, the closely related compounds abioetic acid and pipecolic acid are considered secondary metabolites [5]. Berenbaum [6] opined that the two terms (allelochemical and secondary metabolites) are not interchangeable. Secondary metabolites, however, may have some role in primary metabolism. For example, some allelochemicals may act as biosynthetic intermediates, growth regulators, or storage molecules for elements in short supply [7]. Secondary metabolites may exist in the dynamic equilibrium and may be recycled to primary metabolism [8]. Antioxidants such as vitamins A, C, and E can reduce phytotoxicity of photosensitizing allelochemicals [9]. Vitamins and the medicines we refer to as “antibiotics” could be considered allelochemicals, labeling the vitamins “pro-metabolites.” In their role of protection in the producing organisms, the antioxidants function as would be anticipated with and without the intrusion of allelochemical interpretation. Various forms of B I n are needed by different organisms, depending on what “repair” or “completion”
Diagnostic and therapeutic studies on chronic diarrhea in dairy animals
The study was conducted to determine the etiology of chronic diarrhea in dairy animals. Seven causes of chronic diarrhea were established in dairy cattle and buffaloes. Balantidiasis in 37.6 per cent, dietary diarrhea in 9.9 per cent, chronic salmonellosis in 6.9 per cent cases of chronic diarrhea, secondary copper deficiency and amphistomiasis in 6.9 per cent, clinical Johne‘s disease in 3.9 per cent and chronic peritonitis in 2.97 per cent of dairy animals, manifest chronic diarrhea. The precise diagnosis could not be established in 24.50 per cent of animals. Lymphosarcoma was confirmed in one of the dairy cattle. Body condition score was associated to the etiology of chronic diarrhea. B. coli infected cattle and buffalo revealed cysts in 32.3 per cent cases while 5 per cent positive cases revealed both cysts and trophozoites. Mean cyst count was 2.73±0.91 hpf in diarrheic animals compared to 0.11±0.447 hpf in healthy animals. Clinical Johne‘s disease was confirmed in four animals. Hematological changes revealed anemia and neutrophilia with morphological changes suggestive of regenerative to degenerative left shift. High plasma phosphorus, hypoproteinaemia and hypoalbuminaemia was seen in clinical Johne‘s disease. Salmonella isolates showed higher in-vitro sensitivity to enrofloxacin (87%), ciprofloxacin (87%), gentamicin (75%), and tetracycline (66.7 %) and were resistant to ampicillin and amoxicillin. Mean cyst count reduction from 2.41±1.16 to 0.11±.33 was observed in oral metronidazole treated group where as reduction of mean cyst count from 2.73±0.918 to 0.18±0.44 in intravenous metronidazole treated group. Recovery rate with oral and intravenous metronidazole was 42.1 and 63.1 per cent respectively. Recovery results in significant decrease in eiosionphil count and increase in total plasma protein in both oral and intravenous treatment groups. Complete recovery response approaches 60 per cent in balantidiasis affected adult dairy animals. Balantidiasis was the major cause of chronic diarrhea and intravenous administration of metronidazole was more effective than oral metronidazole.