Ontogenetic changes in foliar features and psoralen content of Psoralea corylifolia Linn. exposed to SO2 stress.

Field-grown Psoralea corylifolia plants were exposed to 0.5 ppm and 1.0 ppm concentrations of sulphur dioxide gas and sampled for observation at the pre-flowering, flowering and post-flowering stages of plant ontogeny. One ppm SO2 concentration caused a significant decline in leaf number and leaf area per plant, total leaf dry weight, and the size and amount of midrib vasculature. The density and size of stomata decreased and many stomata were damaged. Interestingly new epidermis developed oversome of the damaged leaf stomata, thus showing a unique defence strategy against SO2 stress through dedifferentiation of the epidermal cells. Decline in the concentrations of leafchlorophylls and carotenoids in treated plants were up to 20% and 29% respectively. Stomatal conductance, intercellular CO2 content and net photosynthetic rate lowered byover 52%, 20% and 35%, respectively under the SO2 stress. Concentration of psoralen, a basic linear furanocoumarin known for its use in the treatment of dermal diseases, was highest (5.32%) in seeds and lowest (0.28%) in roots. It was heavily reduced in SO2 treated plants, the maximum decline occurring in seeds (86.70%) and leaves (56.27%). In the roots and shoots of the treated plants, it was low in pre-flowering stage, compared with the control, but showed a recovery during the post-flowering phase of plant growth.

Phytochemical and some pharmacological properties of certain plants belonging to Asteraceae family

The aerial parts of three plants belonging to Family Asteraceae: Inula crithmoides, Iphiona scarab and Jasonia montana were investigated. Phytochemicals isolated from Inula crithmoides were identified as: isopimpinellin [I], scoparone [II], psoralene [III], kaempferol-3-O-alpha-L-rhamnopyranoside [IV], kaempferol -3, 7- di-O-alpha-L-rhamnopyranoside [V], kaempferol-3-O-beta- D-glucopyranoside-7-O-alpha-L-rhamnopyranoside [VI] and isorhamnetin-3-O-beta-D-glucopyranoside-7-O-alpha-L-rhamnopyranoside [VII]. From Iphiona scarba umbelliferone [VIII], xanthotoxol [IX], marmesin [X], alpha-amyrin [XI], stigmasterol [XII] and beta-sitosterol [XIII] were isolated. Moreover, Jasonia montana was found to contain 7-hydroxy-3, 5, 6, 3',. 4'-pentamethoxy flavone [XIV], 5, 7-dihydroxy- 3, 6, 3', 4' -tetramethoxy flavone [XV] and 5, 7-dihydroxy-3, 3', 4' -trimethoxy flavone [XVI], in addition to ferulic acid, caffeic acid, chrorogenic acid, alpha-amyrin, stigmasterol and beta-sitosterol. Inula crithmoides aqueous methanolic extract showed significant inhibitory effect on mouse lymphoma [Cell line L1210] in vitro study in concentration dependant manner starting from 12.5 up to 250 microg/ml [20 - 100% inhibition], respectively. In vivo study, the results indicated that Inula crithmoides methanolic extract had significant antioxidant effect against mycotoxin [Ochratoxin A]-induced oxidative stress in rat. Iphiona scabra and Jasonia montana ethanolic extracts showed potent acute anti-inflammatory, anticoagulant and hypotenssive activities comparing to the standard drugs [indomethacine]