Toxic heavy metals (THMs) are non-essential hazardous environmental pollutants with intractable health challenges in humans and animals. Exposure to lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), and chromium (Cr) are ubiquitous and unavoidable due to food contamination, mining, and industrial mobilization. They are triggers of tissue impairment and aberrant signaling pathways that cascade into several toxicities and pathologies. Each of Pb, Cd, Hg, As, Ni, and Cr aggravate oxidative inflammation, protein dysregulation, apoptotic induction, DNA damage, endocrine deficits, and mitochondrial dysfunction contributing to the pathophysiology of diseases. Hesperidin (HSD) and hesperetin (HST) are flavonoids from citrus fruits, and systematic investigations suggest their potential to combat the molecular alterations and toxicities induced by THMs. They mitigate heavy metal toxicity via antioxidant, anti-inflammatory, and anti-apoptotic effects via scavenging free radicals and modulation of ATPases, cell cycle proteins, and various cellular signaling pathways, including Nrf2/HO-1/ARE, PI3K/mTOR/Akt, MAPK/caspase-3/Bax/Bcl-2, iNOS/NF-κB/TNF-α/COX-2. This review summarized the mechanistic effects of heavy metal toxicity and the insights on molecular mechanisms underlying mitigation of heavy metal toxicity by HSD and HST. Hesperidin and hesperetin are potential flavonoids for the modulation of pathological signaling networks associated with THMs. Therefore, HSD and HST can be suggested as natural dietary agents and blockers of harmful effects of THMs.

Curcuma species are widely used as a food additive and also in various medicinal purposes. The plant is a rich source of essential oil and is predominantly extracted from the rhizomes. On the other hand, the leaves of the plants are usually considered as an agrowaste. The valorization of these Curcuma leaf wastes into essential oils is becoming accepted globally. In the present study, we aim to extract essential oils from the leaves of Curcuma longa (LEO), C. aromatica (REO), and C. anguistifolia (NEO). The chemical composition of these essential oils was analyzed by GC-MS. Free radical scavenging properties were evaluated against the radical sources, including DPPH, ABTS, and hydrogen peroxide. The antibacterial activity was assessed by the disc diffusion method and Minimum inhibitory concentration analysis against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica) bacteria. Results identified the compounds α-phellandrene, 2-carene, and eucalyptol as predominant in LEO. The REO was predominated by camphor, 2-bornanone, and curdione. The main components detected in NEO were eucalyptol, curzerenone, α-lemenone, longiverbenone, and α-curcumene. Antioxidant properties were higher in the LEO with IC₅₀ values of 8.62 ± 0.18, 9.21 ± 0.29, and 4.35 ± 0.16 μg/mL, against DPPH, ABTS, and hydrogen peroxide radicals. The cytotoxic activity was also evident against breast cancer cell lines MCF-7 and MDA-MB-231 cells; the LEO was found to be the most active against these two cell lines (IC₅₀ values of 40.74 ± 2.19 and 45.17 ± 2.36 μg/mL). Likewise, the results indicated a higher antibacterial activity for Curcuma longa essential oil with respective IC₅₀ values (20.6 ± 0.3, 22.2 ± 0.3, 20.4 ± 0.2, and 17.6 ± 0.2 mm). Hence, the present study confirms the possible utility of leaf agrowastes of different Curcuma spp. as a possible source of essential oils with pharmacological potential.

Objective: Gentamicin is an efficacious aminoglycoside antibiotic widely used to treat life-threatening Gram-negative bacteria infections. However, its specific non-targeted induction of nephrotoxicity is a worrying clinical challenge. The study explored the nephroprotective effect of Moringa oleifera seed oil (MOO) against gentamicin-induced oxidative nephrotoxicity, pro-inflammation, and apoptosis in male Wistar rats. Method: Twenty-four rats divided into 4 groups (n = 6) were administered MOO (5 ml/kg) for 16 days and/or gentamicin (100 mg/kg bw/d, ip) injected from day 11 to day 16. The renal antioxidant enzyme activities reduced glutathione, lipid peroxidation, and serum renal markers. Urea and creatinine levels were estimated. The renal expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) were determined. Renal levels of inducible nitric oxide synthase (iNOS), nuclear factor-ĸB (NF-ĸB), and caspase-3 were determined to detect possible mechanism of inflammation and apoptosis with histology. Results: MOO prominently reduced serum creatinine and urea levels with amelioration of histopathological abrasions induced by gentamicin (GM). It significantly depressed oxidative stress through lowering of renal malondialdehyde (MDA) and elevation of renal superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, and reduced glutathione (GSH) level. MOO restored renal content of IL-1β, IL-6, TNF-α, and NO, coupled with the mechanistic downregulation of NF-ĸB, iNOS, and caspase-3 activities. The histopathological alterations were ameliorated by MOO. Conclusions: MOO possesses marked nephroprotective effect against GM-induced renal damage via modulating oxidative stress, inflammation, and apoptosis in Wistar rats.

Natural bioactive compounds encompass a vast array of molecules derived from plants, fungi, marine organisms, and other natural sources