Value addition and quality evaluation of holy basil (Ocimum tenuiflorum L.)

Abstract

Holy basil is the most renowned medicinal herb and is known as the mother of necessities for its infinite therapeutic benefits. It is referred to as the "Queen of Herbs," and the Sanskrit word "tulsi" means "incomparable." It is one of the oldest herbs in the Lamiaceae family and is widely cultivated throughout the subcontinent. The physicochemical composition of the holy basil accession (KAU-OC25) (IC-0640854) used in this research had a moisture content of 89.4%, and the levels of the macronutrients, protein and fat per 100 g were found to be 2.99 g and 0.61 g, respectively. It was revealed that the herb had a crude fibre content of 10.48 g/100 g. In terms of vitamin content, ascorbic acid was found to be 30.4 mg/g, and the amount of beta carotene was 2826.92 µg/100 g. In 100g of the sample, the holy basil contained 26.9 mg of calcium, 28 mg of iron, 4.2 mg of zinc, and 224 mg of phosphorus, respectively. The total flavonoid and phenol levels were 41.41 mg QE (quercetin equivalent) and 66.66 mg GAE (gallic acid equivalent) respectively. Holy basil has phytate, oxalate, and tannin concentrations of 3.99 mg/100 g, 2.33 mg/100 g, and 9.74 mg/100 g, respectively. The phytochemical makeup of the herb was analysed through chromatographical tools like O-HRLCMS and GCMS/Ms. The analysis revealed thirty eight medicinally active bioactive compounds namely eugenol, methyl eugenol, kaempferol, scutellarin, rosmarinic acid, luteolin, ursolic acid, vicenin, apigenin 7-O-glucuronide, genistein 4-O- glucuronide, betaine, ϒ- aminobutyric acid (GABA), fisetin, orientin, choline, DL-stachydrine, oleanolic acid, luteolin-7-Oglucuronide, baicalin, β-caryophyllene, ostruthin, hexadecanoic acid, 5 amino pentanoic acid, taxifolin, alpha-pinene, alpha-terpineol, chavicol, alpha cubabene, eucalyptol, estragole, alpha-caryophyllene, alpha-bisabolol, beta-ocimene, terpinene-4-ol and trans-4-thujanol and carvacrol. Eugenol has a number of protective qualities against a variety of conditions that can be fatal, including cancer, oxidative stress, inflammation, hyperglycemia, and elevated cholesterol. Kaempferol and scutellarin are powerful antioxidant flavonoids while rosmarinic acid is known to be effective against microorganisms like the herpes simplex virus. Luteolin and ursolic acid were reported to have potent anti-cancer properties. The active flavonoid derivative apigenin-7-O-D-glucuronide has a variety of pharmacological properties, such as antioxidant, anti-complement, and aldose reductase inhibitory properties. Fisetin, ursolic acid and oleanolic acid have proven anti-cancer activities. ϒaminobutyric acid (GABA) has a number of physiological effects, including lowering blood pressure, boosting immunity, improving cognitive function, inhibiting the proliferation of cancer cells, and reducing sleeplessness. The flavonol taxifolin exhibits strong antioxidant, reducing, radical-scavenging, and metal chelating properties. Anti-oxidative and anti-inflammatory activities are demonstrated by luteolin-7-O-glucuronide. Baicalin significantly reduces the replication of HIV 1. Carvacrol is a potent antioxidant and a great adaptogen to treat hepatic stress. Alpha-pinene, alpha-terpineol, estragole, alpha-caryophyllene and alpha-bisabolol had potent anti-inflammatory activity whereas beta-ocimene, chavicol, terpinene-4-ol and trans-4-thujanol has proven antimicrobial activities. Docking studies of the compounds revealed that six compounds namely kaempferol, baicalin, luteolin, rosmarinic acid and eugenol can be considered for further studies regarding the treatment of type 2 diabetes mellitus and fourteen compounds namely scutellarin, vicenin, ursolic acid, genistein 4-O-glucuronide, betaine, taxifolin, apigenin 7-O-glucuronide, ϒ-aminobutyric acid (GABA), 5 amino pentanoic acid, kaempferol, baicalin, luteolin, rosmarinic acid and eugenol display noteworthy anti-covid action. The successfully docked compounds were tested for drug-likeness using ADMET analysis which revealed that rosmarinic acid, kaempferol, luteolin, and taxifolin can be regarded as potential drug candidates. A dose-dependent inhibition of MCF-7 cell growth was seen by the methanolic extract of holy basil with an IC50 value of 24.80 µg/mL thus establishing its antiproliferative activity. Considering the immense therapeutic abilities of holy basil, it was developed into hard candy lozenges with varying concentrations of holy basil (10%, 15%, 20%, 25%, 30% and 35%) ginger and amla extract. The organoleptic evaluation of the lozenges revealed that hard candy lozenges made with 30 % holy basil extract were more acceptable, owing to which the shelf life studies were done. The physicochemical evaluation of 100 g of the selected candy revealed that it had a moisture content of 2.78 per cent, protein content of 2.39 g, fat content of 0.67 g, ash content of 0.81 mg and energy content of 376.05 kcal. The moisture level of the candy increased but all other parameters, including protein, fat, ash content, and energy, were found to decrease throughout the three month storage period. The bacterial growth of the candy was seen to be within tolerable limits. Throughout the shelf-life period, no fungal or yeast growth was seen. Holy basil should be exploited endlessly for its restorative and curative properties. Currently, the herb is primarily used to make herbal tea and ayurvedic medicines. Apart from this, it can also be considered as a culinary herb, due to its potential natural antioxidant properties and its immense scope for development of value added products.