Soil microbes influence the uptake of toxic metals (TMs) by changing soil characteristics, bioavailability and translocation of TMs, and soil health indicators in polluted environment. The potential effect of Streptomyces pactum (Act12) and Bacillus consortium (B. subtilis and B. licheniformis; 1:1) on soil enzymes and bacterial abundance, bioavailability and translocation of Zn and Cd by Symphytum officinale, and physiological indicators in soil acquired from Fengxian (FX) mining site. Act12 and Bacillus consortium were applied at 0 (CK), 0.50 (T1), 1.50 (T2), and 2.50 (T3) g kg⁻¹ in a split plot design and three times harvested (H). Results showed that soil pH significantly dropped, whereas, electrical conductivity increased at higher Act12 and Bacillus doses. The extractable Zn lowered and Cd increased at each harvest compared to their controls. Soil β-glucosidase, alkaline phosphatase, urease and sucrase improved, whereas, dehydrogenase reduced in harvest 2 and 3 (H2 and H3) as compared to harvest 1 (H1) after Act12 and Bacillus treatments. The main soil phyla individually contributed ∼5–55.6%. Soil bacterial communities’ distribution was also altered by Act12 and Bacillus amendments. Proteobacteria, Acidobacteria, and Bacteroidetes increased, whereas, the Actinobacteria, Chloroflexi, and Gemmatimonadetes decreased during the one-year trial. The Zn and Cd concentration significantly decreased in shoots at each harvest, whereas, the roots concentration was far higher than the shoots, implicating the rhizoremediation by S. officinale. Accumulation factor (AF) and bioconcentration ratio (BCR) of Zn and Cd in shoots were lower and remained higher in case of roots than the standard level (≥1). BCR values of roots indicated that S. officinale can be used for rhizoremediation of TMs in smelter/mines-polluted soils. Thus, field trials in smelter/mines contaminated soils and the potential role of saponin and tannin exudation in metal translocation by plant will broaden our understanding about the mechanism of rhizoremediation of TMs by S. officinale.

The enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) by saponin, a plant-derived non-ionic biosurfactant, was investigated. The results indicated that the solubilization capabilities of saponin for PAHs were greater than some representative synthetic non-ionic surfactants and showed strong dependence on solution pH and ionic strength. The molar solubilization ratio (MSR) of saponin for phenanthrene was about 3–6 times of those of the synthetic non-ionic surfactants, and decreased by about 70% with the increase of solution pH from 4.0 to 8.0, but increased by approximately 1 times with NaCl concentration increased from 0.01 to 1.0 M. Heavy metal ions can enhance saponin solubilization for phenanthrene and the corresponding MSR values increased by about 25% with the presence of 0.01 M of Cd²⁺ or Zn²⁺. Saponin is more effective in enhancing PAHs solubilization than synthetic non-ionic surfactants and has potential application in removing organic pollutants from contaminated soils.

This study investigated the simultaneous desorption of trace metal elements and polychlorinated biphenyl (PCB) from mixed contaminated soil with a novel combination of biosurfactant saponin and biodegradable chelant S,S-ethylenediaminedisuccinic acid (EDDS). Results showed significant promotion and synergy on Pb, Cu and PCB desorption with the mixed solution of saponin and EDDS. The maximal desorption of Pb, Cu and PCB were achieved 99.8%, 85.7% and 45.7%, respectively, by addition of 10 mM EDDS and 3000 mg L−1 saponin. The marked interaction between EDDS and saponin contributed to the synergy performance. The sorption of EDDS and saponin on soil was inhibited by each other. EDDS could enhance the complexation of metals with the saponin micelles and the solubilization capabilities of saponin micelles for PCB. Our study suggests the combination of saponin and EDDS would be a promising alternative for remediation of co-contaminated soils caused by hydrophobic organic compounds (HOCs) and metals.

This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

Panax notoginseng (P. notoginseng) is a well-known traditional Chinese medicinal herb. Due to elevated arsenic (As) levels in some planting area, P. notoginseng and its derivatives are contaminated, and the As concentration in these products exceeds the standard limit (As concentration < 2 mg/kg). In this study, the effects of sulfate (S) application on As uptake and the physicological response of P. notoginseng were investigated in a pot-culture experiment. The results showed that the As concentration in the roots was significantly decreased by a maximum of 64.9 % in response to the application of 75 mg/kg S. The proportion of methylated arsenic, which is less toxic, in the roots was increased by 263.4 %. Moreover, the application of S alleviated the oxidative damage due to As stress, and the activities of superoxide dismutase (SOD) and peroxidase (POD) were improved by 26.2 and 29.4 %, respectively. Finally, the total saponin content in the roots increased by 26.0 % in response to a supply of 50 mg/kg S. These findings implied that the application of S fertilizer could effectively reduce As accumulation in P. notoginseng and promote the formation of pharmaceutical components.

The effects of a composite polyphenolic-rich extract (CPRE) on ruminal fermentation, nutrient utilisation, growth performance, excretion of nitrogen and phosphorus and methane emission were studied in growing buffaloes. Four herbal dry extracts prepared from Acacia arabica (babul; bark), Acacia catechu (cutch; bark), Punica granatum (pomegranate; peel) and Eugenia jambolana (Indian blackberry; seeds) were mixed in an equal proportion (1:1:1:1) to prepare the CPRE that contained mainly phenolic compounds (146 g/kg), flavonoids (41.7 g/kg) and saponins (40.5 g/kg). First, in vitro tests were performed for ruminal fermentation and feed degradability using ruminal fluid as inocula and CPRE at 0 to 40 g/kg substrate to decide an optimal dose of CPRE for an in vivo study on buffaloes. In the animal study, 20 buffaloes were randomly assigned to two groups (n = 10)—a control diet and a CPRE diet (control diet added with extra 20 g/kg of CPRE). The in vitro tests suggested that addition of CPRE at 20 g/kg substrate increased degradability of substrate, short-chain fatty acid concentration and propionate proportion, and reduced methane production, acetate proportion, acetate:propionate ratio and ammonia concentration in fermentation media, which were also noted in the rumen of buffaloes. Feeding CRPE to buffaloes did not affect feed intake, but increased daily body weight gain, dry matter and crude protein digestibility and nitrogen and phosphorus retention in the body. Total bacteria, methanogens and protozoal numbers were similar between two groups, but Fibrobacter succinogenes increased in the rumen of buffaloes fed CPRE. Concentrations of total, essential, non-essential and glucogenic amino acids were greater in the plasma of CPRE-fed buffaloes. Cell-mediated immune response improved in the CPRE-fed buffaloes compared with the control group. Estimated methane production and excretion of nitrogen and phosphorus per unit of body weight gain decreased in the CPRE group. The comprehensive results of this study clearly suggested that the composite polyphenol-rich feed additive at 20 g/kg diet improved growth performance, ruminal fermentation, immunity and plasma amino acids profile, whereas it reduced indicators of environmental impacts of buffalo production.

Exploring extractable phytochemicals from locally adapted sisal plant vegetation vary seasonally at different locations. This study elaborated proximate composition and phytochemical heterogeneity in sisal due to varying environmental conditions analyzed from five districts, i.e., Chakwal, Khushab, Rawalpindi, Faisalabad, and Layyah in Punjab, Pakistan. Extensive surveying and plant sampling across 2 years 2017–2018 and 2018–2019, during mid-spring, summer, autumn, and winter seasons were carried out for understanding the seasonal impact on sisal. The present study was designed in a randomized complete block design (RCBD) and analyzed considering seasonal, yearly, and locational impact. The spatial differences in phytochemicals concentration were strongly associated with environmental conditions prevailing in different seasons. Autumn season reflected saponins, tannins, and flavonoids in higher concentrations during 2018–2019 while steroids and terpenoids were higher during spring 2018–2019. Spatio-temporal variations in the proximate analysis were more apparent in different samples collected from different districts. Data recorded for the Khushab district and autumn season reflected the higher composition of a proximate analysis and phytochemical contents as compared to other seasons. Overall, the spatial differences in phytochemicals concentration were strongly associated with soils and environmental conditions prevailing in different seasons in selected districts.

Nicotine is the most abundant ingredient in cigarette smoking and has serious side effects on the lung, heart, reproductive system, and many other human organs. Saponins extracted from many plants exhibit multiple biological actions such as anti-cancer effects. Therefore, the possible protective effect of fenugreek saponin (FS) and nanofenugreek saponin (NFS) against nicotine-induced toxicity in male rats was investigated in this study. Animals were divided into a control group and the nicotine (1.5 mg/kg/day), FS (25, 50, and 100 mg/kg/day), or/and NFS (20, 40, and 80 mg/kg/day) administered groups. Micronucleus assay, histopathological, and sperm abnormality examinations as well as measurement of the acetylcholinesterase (AChE) gene expression were conducted. Our findings revealed that nicotine treatment induced significant increases in the incidence of micronucleus, sperm abnormalities, and expression levels of AChE in addition to inducing histopathological changes in rat testis. On the other hand, administration of FS or NFS with nicotine significantly decreased the incidence of micronuclei and the percentage of sperm abnormalities as well as the expression levels of AChE gene. Moreover, nicotine-induced histological alterations were reduced by given FS or NFS with nicotine. In conclusion, nicotine-induced sperm abnormalities, chromosomal damage, and histological injuries were mitigated by administration of FS or NFS with nicotine, and thus, FS and NFS could be used as ameliorating agents against nicotine toxicity.

The interfacial activity of dispersants can be enhanced by combining two or more surfactants to formulate the dispersant. This paper examines the effects of Bio-Saponin (BS), a phytogenic surfactant on the interfacial activity of synthetic dioctyl sulfosuccinate sodium salt (DOSS) usually adopted as a suitable surface-active agent in dispersants used in dealing with large-scale oil spills. The o/w emulsion created with the binary DOSS-BS was very stable and recorded the least average droplet size compared with that of DOSS only and BS only. Lower surface and interfacial tension values were also obtained from the DOSS-BS binary formulation. The dispersion effectiveness was also higher compared with that of DOSS and BS. However, they were dependent on the salinity and type of crude oil. These observations were attributed to the moderation of the interaction between the anionic head group of DOSS by the polysaccharide hydrophilic group of BS. The results revealed the potential application of DOSS-BS binary dispersant in oil spill remediation and in other processes that would require an effective emulsifier.

Surfactants are considered promising and practical substances for enhancing polycyclic aromatic hydrocarbon (PAHs) removal from contaminated soil. In order to explore the effects of single and mixed surfactants on the removal of high-concentration PAHs from soil, a series of experiments have been conducted. In this study, Tween80-saponin (a mixed surfactant), Tween80 (a nonionic surfactant), and saponin (a biosurfactant) were used to remove two typical and high concentration PAHs (anthracene and pyrene) from contaminated soil. Results showed that the mixed surfactant had better performance on the solubilization of anthracene and pyrene than Tween80, but its performance was worse than saponin. When the proportion and concentration of the mixed surfactant were 1:9 and 800 mg L⁻¹ respectively, the elution rate of anthracene could reach 97.67%, it was better than that by Tween80 and saponin. In addition, the Tween80-saponin mixed surfactant had good performance on actual PAHs contaminated soil remediation. When the proportion and concentration of Tween80-saponin were 1:9 and 800 mg L⁻¹ respectively, the PAHs elution rate of actual contaminated soil could reach 81.31%.