Minh Hoang Vo Do

Recently, plant-derived anti-inflammatory products have received an increasing attention from researchers due to their excellent in vivo activity with limited side effects. Therefore, the extraction of natural active compounds from the plant with high purity for use in anti-inflammatory formulations is required. In this study, oily Capsicum oleoresin (OCO) was extracted from Capsicum frutescens L. in ethanol by the ultrasound-assisted extraction technique, followed by a centrifugation step for a high purity OCO extract, which can be applied to develop anti-inflammatory formulations. The impact of various conditions (ethanol concentration, sonicating temperature, extraction time, solvent-to-sample ratio, and extraction repetition) on the efficiency of the extraction process was investigated. The results showed that the optimized conditions for the high yield of OCO were 95 ethanol, 5060°C, 60 minutes, solvent-to-sample ratio of 5:1ml/g, and one extraction repetition, followed by centrifuging at 5000rpm in 2 hours. Then, the purity and in vivo anti-inflammatory activities of the obtained OCO was then determined by using the HPLC method and carrageenan-induced mice paw edema model, respectively. The purity of OCO was determined as 3.408mg capsaicin per gram of Capsicum powder; meanwhile, its anti-inflammatory effect value was approximate to that of the commercial drug diclofenac after 48 hours of treatment. The high purity OCO prepared by this low-cost and ecofriendly extraction process would be a promising material for anti-inflammatory formulations.

Replanting for sustainable development is one of the critical missions of the coffee industry in the Daklak province, Vietnam. However, this plan has been faced with many difficulties including poor survival and growth rates due to the low nematode tolerance of young coffee plants in replanted fields. Mycorrhizal symbiosis and grafting have been applied separately but not yet resulted in the expected results of the replanting plan. Whether the combination of them would help managing nematode in the soil and consequently enhance the replanted efficiency is largely unknown. Mycorrhizal symbiosis was applied to Coffea canephora plants or/and grafted onto Coffea liberica rootstock, which were grown and compared to the untreated ones in both net-house-pots and the replanted plantation. The survival rate, growth indicators and the soil pathogens were monitored during the experimental periods. The combination of grafting and mycorrhiza symbiotic techniques significantly decreased the nematode densities in the replanted soil. As a result, the survival rate and growth indicators of the coffee in the replanted soil treated by the combined technique were better than treated by the two separate techniques. The results suggested that the combination of grafting and mycorrhiza symbiotic techniques would propose a potentially effective Pratylenchus coffeae and Meloidogyne incognita nematode management in replanted coffee fields in the Daklak province, Vietnam.