ABSTRACT
In tropical countries, high temperature stress is the major abiotic stress, which controls the productivity and yield of crop plants. Two high yielding and low yielding genotypes of durum wheat were selected for detailed analysis of their photochemical efficiencies. In low yielding genotypes (Malvi local and Sawer local), the whole primary photochemical reactions are affected before and after heat stress. The results show that low yielding genotypes show less efficiency in the usage of the available excitation energy. This is a case study to establish use of chlorophyll a fluorescence measurement as an effective tool to screen plants for their stress tolerance. The study is important for stress physiology and may be useful for assessment of stress tolerant plants.
ABSTRACT
PURPOSE: Several epidemiologic studies have suggested a role of tomato products in decreasing the risk of the development of diseases related to oxidative stress (cancer and other chronic diseases). Oxidative stress may result in periodontal tissue damage either directly or indirectly. Lycopene, a powerful antioxidant and the main carotenoid in tomato products possesses the greatest quenching ability of singlet oxygen among the various carotenoids and is effective in protecting blood lymphocytes from NOO-radical damage. Hence, the aim of the present study is to compare the effect of systemically administered lycopene as an adjunct to scaling and root planing in patients with gingivitis and periodontitis. MATERIALS AND METHODS: Twenty systemically healthy patients were involved in a randomized, double-blind, parallel study and based on their clinical signs were divided into two groups of mild to moderate periodontitis (A) and moderate gingivitis (B). The subjects under the groups A and B were randomly distributed between the two treatment groups: test group (n = 5), 4 mg lycopene/day for 2 weeks with oral prophylaxis (full mouth scaling and root planing (SRP) completed within 24 hours) and controls (n = 5), receiving only oral prophylaxis. Pre- and post-therapeutic periodontal parameters were evaluated. RESULTS: In group A, statistically significant improvement in CAL was reported in test group as compared to control group. In group B, the difference between pretreatment and post-treatment bleeding on probing scores was found to be statistically non-significant in both groups. CONCLUSION: Results show that lycopene is a promising treatment modality as an adjunct to full mouth SRP of the oral cavity in patients with moderate periodontal disease. CLINICAL SIGNIFICANCE: Modulation of the free radical production seems to be essential for the inhibition of tissue destruction, and treatment with antioxidants, like lycopene, which is the most potent among them will block the production of free ROS or its effects might prove to be therapeutically valuable.
