World Aquacluture Magazine - September 2020

WWW.WA S.ORG • WORLD AQUACULTURE • SEP TEMBER 2020 43 of therapeutics in fish culture because these products provide a cheaper but effective source for treatment (Pandey et al . 2012). Herbal preparations play an essential role in infection control through active ingredients such as antioxidants and immunostimulants that are related to flavonoids, phenolics, steroids and alkaloids. Herbal medicines have been used in animal feeds. Nonetheless, many other medicinal herbs – with their fruits, stems, leaves, and roots – have been used the world over to treat many diseases (Bhadauria et al . 2002). In aquaculture, there are no reports of the medicinal use of lapsi as a diet supplement. Lapsi Cultivation in Nepal The lapsi, of the family Anacardiaceae, is a large dioecious fruit tree (Fig. 2). It is a cash-generating tree that has long been cultivated in rural Nepal for its fruit (Fig. 3), which has nutritive value and therapeutic effects (Poudel et al. 2003, Labh et al . 2016). The fruits of lapsi are rich in essential amino acids, minerals and vitamin C. Lapsi fruit are extraordinarily rich in antioxidant compounds, including phenolics, flavonoids, DPPH, FRAP, ABTS, and vitamin C (Doanh et al . 1996, Poudel et al . 2003, Wang et al ., 2008, Li et al . 2014, Labh et al . 2015, Li et al . 2016, 2018, Shakya and Labh 2019). Lapsi trees stand in small patches, scattered in farmlands at different religious sites. In Nepal, it is cultivated in the hills between 850-1900 m elevation, where it has high potential for income generation and nutrient supplementation. Lapsi also occurs in India, China, Hong Kong, Thailand, Japan, Vietnam and Mongolia (Labh et al . 2017). Private planting has been implemented in most of the hill districts of Nepal to produce bulk quantities of lapsi fruits for trading (Labh and Shakya 2016). Over 40,000 trees are at the fruit-bearing stage and more than 450,000 new trees have been planted in 301 Village Development Committees in 29 hill districts of Nepal. The main places for lapsi tree cultivation in Nepal are Machhaya gaon (Kirtipur), Pharping, Panchkhal, Phulbari, Namobuddha, Panauti, and Kavre of State number three, Charikot of Dholkha district and Chautara of Sindupalchowk district. At present, thirty-two districts have been producing lapsi fruits in Nepal. The total lapsi fruit production area is 1503 ha, the aggregate production is 10,488 t and productivity is 7.4 t/ha in Nepal. Marketed since the 1960s, the annual trade of lapsi fruit in Kathmandu alone is now estimated to be worth over US$ 1.5 million (Fig. 4). The fruit is slightly oval, about 3 cm long and 10-15 g in weight, and has a soft flesh and a large seed. The thin (<1 mm) skin of the fruit is green until maturity, at which point it turns yellow. The flesh is whitish to light yellow, fibrous and acidic, with a specific aromatic flavor. Fruit processing takes place on a commercial scale, and farmers in remote areas traditionally process lapsi for household needs for fresh consumption or as pickles. Application of Lapsi Fruits in Aquaculture Lapsi fruits contain abundant antioxidants that can be used as an immunostimulant in aquaculture. Lapsi fruits can be used as a dietary supplement prepared in the form of crude extracts (Fig. 5) using ethanol (70 to 80 percent) with distilled water (Labh et al . 2015). The phytochemical constituents of lapsi fruit extracts (LFE) are phenolics and flavonoids that exhibit potent antioxidant activity. Including a dietary antioxidant has the potential to scavenge various free radicals and thus protect fish from infection. An experiment was conducted to study the effects of lapsi on some hematological parameters of common carp Cyprinus ( C O N T I N U E D O N P A G E 4 4 ) FIGURE 3. Fruits of lapsi hanging in a tree (Photo: S.N. Labh). FIGURE 4. Ripe fruits of medicinal lapsi displayed for sale in Kathmandu (Photo: S.N. Labh). FIGURE 5. Extraction process for lapsi fruits used in aquaculture.