Standardization of tissue culture techniques for propagation of Melochia corchorifolia L. and analysis of phytochemical and antioxidant activity of methanol extracts

Abstract

Melochia corchorifolia L. is a therapeutic herb because of its therapeutic compounds, but due to the lack of propagation, the availability of the herb is limited. The focus of the experiment was to establish an effective in vitro regeneration procedure and to determine the phytochemical and antioxidant properties of regenerated tissues. Explants of the leaf were grown in the Murashige and Skoog (MS) medium with varying ratios of the plant growth regulators to induce callus, shoot, and root. In vitro and field-grown plants were subjected to quantitative analyses (alkaloid (TAC), flavonoid (TFC), and phenolic (TPC) contents) and antioxidant assays (DPPH radical scavenging, reducing power (FRAP), and ferrous ion chelation (FIC)). The highest callus induction (89.58%) was obtained using 1.0 mg/L IBA + 0.5 mg/L TDZ + 1.0 mg/L 2,4-D. The maximum shoot regeneration (71.53%) and rooting (94.03%) were on the 0.5 mg/L kinetin + 1.0 mg/L BAP and 1.0 mg/L IAA + 0.5 mg/L IBA in half-strength MS, respectively. TPC (71.06 mg GAE/g) was high in callus, and TFC (63.57 mg QE/g) and TAC (44.72 mg AE/g) were high in field-grown leaves. A strong relationship between antioxidant activity and the levels of phytochemicals was observed; the callus extract had an IC₅₀ of 68.5 µg/mL (DPPH), 99.9 µg/mL (FRAP), and 155.07 µg/mL (FIC). Regression analysis found that there was an inverse relationship between phytochemical contents and IC₅₀ values, which is one of the reasons that phenolics and flavonoids were main contributors to antioxidant effectiveness. The in vitro regeneration and phytochemical determination are optimized, which makes tissue culture a promising method of sustainable propagation and increased bioactive metabolite synthesis in M. corchorifolia, which opens the gate to its pharmaceutical and conservation uses.