Cruciferae family vegetables are remarkably high in phytochemicals such as Indole-3-carbinol (I3C) and Diindolylmethane (DIM), which are widely known as nutritional supplements. I3C and DIM have been studied extensively in different types of cancers like breast, prostate, endometrial, colorectal, gallbladder, hepatic, and cervical, as well as cancers in other tissues. In this review, we summarized the protective effects of I3C and DIM against cardiovascular, neurological, reproductive, metabolic, bone, respiratory, liver, and immune diseases, infections, and drug- and radiation-induced toxicities. Experimental evidence suggests that I3C and DIM offer protection due to their antioxidant, anti-inflammatory, antiapoptotic, immunomodulatory, and xenobiotic properties. Apart from the beneficial effects, the present review also discusses the possible toxicities of I3C and DIM that are reported in various preclinical investigations. So far, most of the reports about I3C and DIM protective effects against various diseases are only from preclinical studies; this emphasizes the dire need for large-scale clinical trials on these phytochemicals against human diseases. Further, in-depth research is required to improve the bioavailability of these two phytochemicals to achieve the desirable protective effects. Overall, our review emphasizes that I3C and DIM may become potential drug candidates for combating dreadful human diseases.

Indole 3-carbinol (I3C), a natural compound found in cruciferous vegetables, has demonstrated neuroprotective effects by modulating oxidative stress, inflammation, and cholinergic pathways. This study aimed to evaluate the efficacy of I3C in preventing cognitive impairment induced by scopolamine in rats. Male Wistar rats were assigned to six groups: Control, Scopolamine (1 mg/kg), I3C (25 mg/kg), I3C (50 mg/kg), I3C (100 mg/kg), and Donepezil (5 mg/kg). Memory function was evaluated through behavioral assessments using the Y-maze and Novel Object Recognition (NOR) tests. Biochemical analyses were conducted to assess acetylcholinesterase (AChE) activity and oxidative stress markers, including malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT). ELISA were utilized to quantify oxidative stress regulators (NRF2 and HO-1), inflammatory cytokines (NF-kB, TNF-α, IL-6, and IL-10), and apoptosis-related markers (Cytochrome C, caspase 9, and caspase 3). Additionally, H&E and Nissl staining were performed to evaluate histopathological abnormalities. The findings revealed that I3C administration markedly enhanced cognitive performance in the Y-maze and NOR tests, which were attributed to decreased AChE activity and increased acetylcholine (ACh) levels. Furthermore, I3C significantly alleviated oxidative stress by upregulating antioxidant enzymes, including NRF2 and HO-1. Moreover, I3C mitigated inflammatory responses, as evidenced by elevated levels of IL-10 and reduced levels of NF-kB, TNF-α, and IL-6. These findings indicate that I3C exhibits neuroprotective effects by reducing oxidative stress, suppressing inflammation, and addressing abnormalities in the cholinergic pathway, highlighting its potential as a therapeutic approach for alleviating cognitive deficits. Graphical abstract

Introduction: Acute liver failure (ALF) is a life-threatening condition associated with hepatic encephalopathy (HE), characterised by neurological impairments, hyperammonemia, oxidative stress, and inflammation. Diindolylmethane (DIM), a bioactive compound derived from cruciferous vegetables, has shown potential hepatoprotective and neuroprotective effects via its antioxidant and anti-inflammatory properties. Despite beneficial effects, its protective effects have not been investigated against HE. The present study evaluated the hepatoprotective and neuroprotective effects of DIM in a rat model of thioacetamide (TAA)- induced ALF and HE. Methods: ALF was induced using thioacetamide (TAA; 300 mg/kg, i.p.). DIM at doses of 12.5, 25, and 50 mg/kg, p.o., was administered for 7 days prior to TAA injection. Behavioral assessments, including the open field test and Y-maze, were performed to evaluate motor and cognitive functions. Biochemical parameters (AST, ALT, ALP, and LDH), ammonia levels, oxidative stress markers (MDA, NRF2, SOD, GSH, and catalase), inflammatory cytokines (IL-6, TNF-α, and IL-10), and apoptotic markers (cytochrome c, caspase 9, and caspase 3) were analysed. Histopathological examinations of the liver, cortex, and hippocampus were conducted using hematoxylin and eosin staining. Results: DIM pretreatment significantly reduced liver enzyme levels (AST, ALT, ALP, and LDH), normalised organ weight ratios, and decreased ammonia levels in blood, liver, and brain. DIM attenuated oxidative stress by reducing MDA levels and enhancing NRF2, SOD, GSH, and catalase activity, suggesting its antioxidant potential. Further, DIM reduced IL-6 and TNF-α levels and increased IL-10 levels, indicating its antiinflammatory effects. Furthermore, DIM reduced the apoptotic markers, including cytochrome c, caspase 9, and caspase 3, suggesting attenuation of apoptosis. Additionally, DIM improved motor activity and spatial memory and exhibited an anxiolytic effect. DIM mitigated the TAA-induced liver, hippocampal, and cortical tissue abnormalities. Discussion: The findings suggest that DIM exerts protective effects against ALF-induced HE by modulating key pathological mechanisms, including oxidative stress, neuroinflammation, and apoptosis. The reduction in hyperammonemia and restoration of biochemical and behavioral parameters indicate its potential role in preserving liver and brain function. Conclusion: DIM demonstrates significant hepatoprotective and neuroprotective effects in TAA-induced ALF and HE. These effects are mediated through multiple mechanisms, suggesting DIM as a potential therapeutic candidate for managing ALF-associated neurological complications. Future studies require investigating the in-depth mechanism of DIM against HE.