In planta detection of Xanthomonas axonopodis pv. commiphorae using fyuA and rpoD genes.

Guggal is tapped for extraction of medicinally important oleo–gum–resin (guggul) by inoculating the stem bark with natural gum suspension containing pathogenic bacterium Xanthomonas axonopodis pv. commiphorae (Xac). The tree dies in the process. In absence of any specific medium for isolation of Xac, it is difficult to assess spread of the pathogen within the plant. A PCR based molecular detection technique using fyuA and rpoD gene specific primers is described here. The primers amplified products only from Xac and not from host tissues or common saprophytes. The method was sensitive enough to produce positive signals for up to 4.4 bacterial cells or 2 pg target DNA per reaction mixture. However, PCR inhibitors present in plant tissues drastically reduced the limit of detection. A simple overnight incubation of surface sterilised plant tissues in nutrient medium was introduced to increase pathogen titre and to overcome this problem. This technique was successfully used to measure spread of Xac in plant tissues away from the site of inoculation. The pathogen showed preference for acropetal movement and did not spread to 7–8 cm below the site of inoculation till 15 days after inoculation. This suggests possibility to manage the disease through plant surgery.

Extract of gum resins of Boswellia serrata L. inhibits lipopolysaccharide induced nitric oxide production in rat macrophages along with hypolipidemic property.

Boswellia serrata, Linn F (Burseraceae) is commonly used in Indian system of medicine (Ayurvedic) as an anti-inflammatory, analgesic, anti-arthritic and anti-proliferative agent. This study was planned to investigate the water-soluble fraction of the oleoresin gum of Boswellia serrata (BS extract) on lipopolysaccharide (LPS) induced nitric oxide (NO) production by macrophages under in vivo and in vitro conditions. In the previous condition, rats were fed on atherogenic diet (2.5% cholesterol, 1% cholic acid, 15.7 % saturated fat) along with the BS extract for 90 days. Blood was collected for lipid profile and toxicological safety parameters. Peritoneal macrophages were isolated and cultured to see the LPS induced NO production. Under in vivo experiment, BS extract significantly reduced serum total cholesterol (38-48 %), increased serum high-density lipoprotein- cholesterol (HDL-cholesterol, 22-30%). Under in vitro experiments with thioglycolate activated macrophages, it inhibited LPS induced (NO) production with IC 50 value at 662 ng /ml. Further, this fraction, in the dose of 15 mg/100 g body wt for 90 days, did not show any increase in serum glutamate-pyruvate transaminase (SGPT) and blood urea, in normal control animals. However, it significantly reversed the raised SGPT and blood urea in the atherogenic diet-fed animals. Transverse section of liver and kidney also supported its protective effect. Thus it may be concluded that water extract of Boswellia serrata possesses strong hypocholesterolemic property along with increase in serum HDL. It inhibits the LPS induced NO production by the activated rat peritoneal macrophages and show hepato-protective and reno-protective property.