Ethnobotanical and nutraceutical investigation of wild edible fruits and vegetables used by the tribal communities of Lesser Himalayas - Pakistan

Abstract

Present research work is based on Ethnobotanical and nutraceutical investigation of wild edible fruits and vegetables of Lesser Himalayas, Pakistan. Ethnobotanical information was obtained through informed consent semi-structured interviews, questionnaires, market survey and focus group conversation from five major survey sites: Haripur, Abbottabad, Mansehra districts, Margalla Hills Islamabad and Murree. The plant samples were analysed for nutritional components (carbohydrates, fats, proteins, fibers, ash and energy vale), selected metals (Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Pb, Sr and Zn), phytochemical constituents (phenolics, flavonoids, flavonols and ascorbic acid) and antioxidant activity (DPPH scavenging activity, hydroxyl radical scavenging activity, hydrogen peroxide scavenging activity, Ferrous ion chelating activity, ferric ion reducing antioxidant power, Phosomolybdenum complex assay) by using standard analytical methods. A total of 80 wild edible plant species including 35 fruits (21 genera and 17 families) and 45 vegetables (38 genera and 24 families) were investigated in this study. About (57%) species of wild fruits were trees, followed by shrubs (34%), climbers (6%) and herbs (3%), whereas in the case of the vegetables herbs were dominating (89%), followed by trees (9%) and shrubs (2%). Inhabitant of the area used 50 medications based on wild edible fruits and 51 recipes based on wild edible vegetables to cure various ailments. Among wild fruit species 97% species are used as fodder; 86% as fuel; 74% in making tools handles and furniture; 86% in sheltering; 77% in fencing and as hedge plant and 80% for miscellaneous purpose. In case of vegetables 95% species are used as fodder; 9% as fuel; 4% in making tools handles/furniture and 7% each in sheltering; fencing and for miscellaneous purpose. Moraceae and Papilionoideae were most quoted botanical families of wild fruits and vegetables. Morus nigra showed highest mean culture importance values (mCI) within top ten fruit plants, followed by Morus alba, Olea ferruginea, Berberis lycium, Pyrus pashia, Ficus carica, Ficus palmata, Ziziphus mauritiana, Diospyros lotus and Ziziphus nummularia, whereas in the case of wild edible vegetables Ficus carica was most cited species, followed by Ficus palmata, Bauhinia variegata, Solanum nigrum, Amaranthus viridis, Medicago polymorpha, Chenopodium album, Cichorium intybus, Amaranthus hybridus and Vicia faba. Among the fruits, Juglans regia, Opuntia dillenii, Ziziphus nummularia, Berberis lycium, Pistacia integerrima, & Phoenix dactylifera and in wild vegetables Cichorium xxviiiintybus, Launaea procumbens, Tulipa stellata Dyropteris ramosa, Sonchus oleraceous & Lathyrus aphaca showed highest nutritional potential. Elemental analysis (mg/kg, dry weight) indicated that K exhibited highest average levels, followed by Ca, Mg, Na, Fe and Mn while lowest levels were observed for Li, Cd and Cr in the fruit and vegetable samples, which were also found rich in phytochemical contents and had good antioxidant activities. Significantly higher phenolics, flavonoids, flavonols, ascorbic acid contents and antioxidant activities were observed in Phoenix dactylifera, Juglans regia, Rosa moshata, Pistacia integerrima, Morus nigra and Pyrus pashia among the fruits, whereas among the vegetables, Origanum vulgare, Amaranthus viridis, Ficus palmata, Silene conoidea, Melilotus indicus and Bauhinia variegata showed highest potential. Mostly random and broad distribution of the nutrient, selected metals and phytochemical contents was found in the fruits and vegetables. Correlation study showed random variation of the nutrient, metals and phytochemicals in the plant samples. Antioxidant activities revealed significant correlation with most of the phytochemical contents. Correlations among the metal levels, phytochemical constituents and antioxidant activity in the fruits and vegetables were also investigated. Various groups of the fruits and vegetables were identified by cluster analysis (CA) based on their chemical composition. Principal component analysis (PCA) revealed significant anthropogenic contamination of the selected metals in the fruits and vegetables mostly contributed by transportation activities, industrial emissions and domestic waste. Most of the wild edible plant species in the study areas have no protection, but acquisition of economic benefits such as genetic improvement of existing crops from their wild ancestors and nutritional requirement from these wild edibles might promote local people’s interest in the conservation and maintenance of these important and threatened species. Further exploration is still required to investigate useful and toxic compounds, pharmacological study; skill training in home gardening, biotechnological techniques to improve yields and income generation through large scale promotion of these wild edible fruits and vegetables.