Enhanced Production of Anti-Inflammatory and Antibacterial Prenylated Isoflavonoids in Pigeon Pea (<i>Cajanus cajan</i>) Hairy Root Cultures

Isoflavonoids possess various health benefits such as antioxidant, anti-inflammatory, antibacterial, and pro-apoptotic properties. This study aimed to develop a sustainable method for producing isoflavonoids using pigeon pea hairy root cultures via <i>Agrobacterium rhizogenes</i> transformation. The cultures were treated with methyl jasmonate, methyl-β-cyclodextrin, hydrogen peroxide, and magnesium chloride for 192 h, resulting in the production of three new prenylated isoflavonoids─cajaisoflavanone A, cajaisoflavanone B, and cajasan─along with five known isoflavones, genistein, 2'-hydroxygenistein, isowighteone, eriosemaone D, and allolicoisoflavone A. The total yield of isoflavonoids upon the first elicitation of the hairy root cultures was 113.5 mg/g DW. The yield was further increased by 46% upon re-elicitation. Cajasan exhibited anti-inflammatory activity by reducing nitrite and IL-6 levels, whereas eriosemaone D showed strong antioxidant activity. Cajaisoflavanone B demonstrated potent antimicrobial effects against <i>Bacillus subtilis</i> and <i>Micrococcus luteus</i>. These results highlight pigeon pea hairy roots as a promising source of new bioactive isoflavonoids.