Ph.D

Wild foods or wild edible plants are considered as nutritional supplements rather than dietary staples. These plants are neither cultivated nor domesticated but utilised as food by tribal communities. Wild edible plants are said to be rich in nutrients as well as medicinal values. Nutraceuticals are nutrients or bioactive components found in foods that possess medicinal or health benefits. The present study has been formulated with the view of scientific assessment of the health protective properties of selected wild edible plants consumed by tribal communities and to preserve and utilise the valuable knowledge. The study assessed the nutraceutical properties of nine wild edible plants belonging to three categories such as leafy greens, fruits and tubers/rhizomes. The selected wild edible plants were Cassia tora L. now known as Senna tora L., AcalyphafruticosaForssk. and Talinumportulacifolium (Forssk.) Asch. ex Schweinf. among leafy greens, Ardisaelliptica Thunberg., Alangiumsalviifolium subsp. hexapetalum (Lam.) Wang. and Solanum nigrum L. among fruits, and Dioscoreapentaphylla L., Curcuma angustifoliaRoxb. and Asparagus racemosusWilld. among roots/tubers/rhizomes. These wild edible plants were collected from different parts of Western Ghats. The first experiment was to determine the phytochemical screening of the selected wild edible plants in four solvents viz., hexane, petroleum ether, ethyl acetate and methanol. Various phytochemicals were detected in the extracts of the wild edible plants such as phenols, alkaloids, saponins, tannins, glycosides, cardiac glycosides, flavonoids, proteins, terpenoids, carbohydrates and steroids depending on the solvents used. Majority of the phytochemicals were detected in methanol extract as compared to other solvents. In the second experiment, the bioactive compounds like anthocyanins, lycopene, ꞵ-carotene, ascorbic acid, total phenols and total flavonoids were determined in all the selected wild edible plants. The highest anthocyanin content among the nine plants was recorded in Ardisaelliptica (140.33 mg/100 g), followed by Talinumportulacifolium (23.62 mg/100 g), and Curcuma angustifolia (1.52 mg/100 g). The lycopene content was highest in Cassia tora (12.61 mg/100 g) among leafy greens, Ardisiaelliptica (7.98 mg/100 g) in fruits and Curcuma angustifolia (13.09 mg/100 g) among rhizomes. Similarly, ꞵ-carotene was highest in Cassia tora (13.80 mg/100 g) among leafy greens, Ardisiaelliptica (7.58 mg/100 g) among fruits and Curcuma angustifolia (13.39 mg/100 g) among rhizomes. Cassia tora (37.34 mg/100 g) exhibited highest ascorbic acid content among leafy greens, whereas Ardisiaelliptica (34.28 mg/100 g) and Curcuma angustifolia (14.84 mg/100g) recorded the highest among fruits and rhizomes, respectively. The highest total phenolic content was recorded in Alangiumsalviifolium subsp. hexapetalum (39.46 mg GAE/g), Acalyphafruticosa (23.22 mg GAE/g) and Curcuma angustifolia (24.18 mg GAE/g) among fruits, leafy greens and rhizomes, respectively whereas the highest total flavonoid content was obtained in Cassia tora (0.73 mg QE/g), Alangiumsalviifolium subsp. hexapetalum (3.07 mg QE/g) and Curcuma angustifolia (6.22 mg QE/g) among leafy greens, fruits and rhizomes respectively. The antioxidant activity was determined in these wild edible plants by DPPH, FRAP and ABTS assays. In all the three assays, highest antioxidant activity was obtained in Cassia tora, Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia among leafy greens, fruits and rhizomes respectively. In the DPPH assay, the lowest IC50 values were obtained in Cassia tora (431.94 μg/mL), Alangiumsalviifolium subsp. hexapetalum (209.43 μg/mL) and Curcuma angustifolia (47.19 μg/mL). Similarly, in FRAP assay, the lowest IC50 values were obtained in Cassia tora (30.58 μg/mL), Alangiumsalviifolium subsp. hexapetalum (4.32 μg/mL) and Curcuma angustifolia (10.72 μg/mL). The same trend was observed in the ABTS assay also, with IC50 values of 107.60 μg/mL, 29.44 μg/mL and 8.36 μg/mL in Cassia tora, Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia respectively. The wild edible plants with highest antioxidant activity were subjected to HR LCMS (High Resolution Liquid chromatography Mass Spectrometry) analysis to identify the various compounds present in them. The methanolic extract of Cassia tora contained quercetin, kaempferol, luteolin, Quercetin-3ꞵ-D-glucoside, trifolin, diosmetin, genistein, myricitrin, apigenin, arecoline, trigonelline, vindoline, guvacoline, chlorogenic acid, catechin, ferulic and isoferulic acid. The methanolic extract of Alangiumsalviifolium subsp. hexapetalum revealed various compounds such as quercetin, kaempferol, luteolin, eriodictyol (flavonoids), atropine, salsolinol, piperine, papaverine, laudanosine, 8-hydroxyquinoline (alkaloids), 4 Methoxycinnamic acid and 4-Hydroxyindole (phenols) etc. Various carboxylic acids, amino acids and fatty acids were also identified. In the methanolic extract of Curcuma angustifolia the presence of various polyphenols, alkaloids, terpenoids, amino acids and peptides like curcumin, 2,3,5,6-tetramethylpyrazine, piperine, linoleoylethanolamide, 8-hydroxyquinoline, nootkatone, 6-methylquinoline, 1-stearoylglycerol, cuminaldehyde, salsolinol, (+)-ar-turmerone, 2-methoxyflavone, methyl cinnamate, acetphenone, pyridoxine and carvone in positive mode and curcumin, 4-oxoproline, azelaic acid, 2-hydroxycinnamic acid and ferulic acid in negative mode were recorded. The immunomodulatory properties of the three selected wild edible plants viz., Cassia tora, Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia, were studied in the experimental animal model (balb/c mice). The immunomodulatory properties of mice treated with low (100 mg/kg bw), medium (150 mg/kg bw) and high (200 mg/kg bw) doses of aqueous extracts of these wild edible plants were studied along with a control, immunosuppressant (Cyclophosphamide) and positive control (Cyclophosphamide+Mesna). The various parameters recorded were weight of lymphoid organs (g), weight of lymphoid organs with reference to the body weight (%), bone marrow cellularity (BMC/femur/mL), α-esterase activity (no. of positive cells/400BMC), heamoglobin count (g/dL), total WBC count (cells/mm3), total RBC count (million/mm3), differential count (%) and total platelets count (lakh/mm3). Animals fed with extracts of wild edible plants recovered their immunity in spite of being treated with cyclophosphamide. Most of the above said parameters observed in groups treated with plant extracts were comparable with that of the positive control and some parameters were better than that of positive control. But, mortality of a mouse was observed in the experiment group treated with high dose of Cassia tora and in this group the haemoglobin count and RBC were above the reference range for mice. Therefore, Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia were selected for the subsequent experiment. The last experiment was to develop functional gummies by using powders of Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia. Other ingredients used to prepare the gummies were black pepper powder, ginger extract, palm sugar, gelatin, sodium benzoate, propylene glycol, citric acid and water. Gummies prepared with 1 g each of Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia were found organoleptically best. The physical, nutritional and biochemical properties of the product were determined. The pH, moisture content and water activity (aw) of the product was recorded as 3.50, 41.17 % and 0.949 respectively. The colour values obtained for the product were L* value of 39.55, a* value of 2.88 and b* value of 34.07. The hue and chroma values of the product were 34.20 and 85.16 respectively. With regard to the nutritional properties, gummies contained 1.9 % total carbohydrate, 72.6 mg/100 g total protein, 41.19 % total sugar, 2.01 % fat and 4.54 % ash content. Biochemically, TSS, titrable acidity, total phenolics, total carotenoids and total flavonoid content of the product were 20°B, 1.32 %, 16.80 mg GAE/g, 3.36 mg/g and 0.21 mg QE/g, respectively. The antioxidant activity of the product estimated in terms of IC50 value was 10 μg/mL (DPPH assay) and 5.99 μg/mL (FRAP assay). The gummies were sealed in LDPE (Low density polyethylene) pouches and stored in refrigerated condition for one month. The sensory evaluation at the end of the storage period of one month did not reveal any significant variation from that in the beginning. The microbial analysis was carried out at 15 days interval for one month and the total bacterial count was found to decrease during storage and was within the limits of the product (9 × 104 colony forming units [cfu]/g initially to 11 × 103 cfu/g at the end of storage period). Fungi and yeast were not detected during the entire storage period. The wild edible plants in this study were found to contain major bioactive compounds and had good antioxidant potential especially, Cassia tora, Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia. Among these, Alangiumsalviifolium subsp. hexapetalum and Curcuma angustifolia, were good immunopotentiating agents and there is ample scope to utilise these plants by including them in our diet.