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Surface charge of the skin matrix is an extremely important parameter in leather making process because effectivity of the chemicals largely depends on the surface charge of the skin matrix. In the present research work, isoelectric point (Ip) and point of zero charge (pzc) are used to predict the distribution of electric potential and charge at the skin tissue–liquid interface after chemical and enzymatic unhairing of the skin. In this study, the determination of zeta potential and isoelectric point for relimed tissues processed by chemical and enzymatic methods was performed using a zeta potential analyzer and a titrimetric method. These results indicate that enzyme-treated tissues had lower isoelectric point than the chemical-treated tissues, which has been explained by studying the amino acid composition of the tissues. The tissue samples were also characterized by FTIR–ATR and solid-state 13C NMR spectroscopy to understand the chemical/structural changes occurred due to enzymatic treatment. The lower Ip/pzc of the tissue obtained by enzymatic process ensured maximum uptake of chemicals, making it an eco-benign process.

Enzymatic interventions in animal skin processing are increasingly being considered as safe and benign technology options due to the reduction and replacement of potential harmful chemicals. In this study, galactosidases have been employed for rehydration of preserved skins and hides to improve the process efficiency and minimize hazardous sodium sulfide. The purpose of rehydration is to ensure the skin is hydrated uniformly to facilitate subsequent physico-chemical processes of leather making. Improper rehydration leads to reduction in the quality and value of the leather. The efficacy of the enzymatic process was studied using histological images and scanning electron microscopic analysis. Pollution load changes and the extent of carbohydrate removal were also quantified. The study indicates possibility for substantial reduction in process duration and water input (up to 30%) during rehydration of preserved animal skins when galactosidases are used as rehydration aid without affecting the quality of the leather. Thus use of galactosidases in rehydration ensures uniform accelerated rehydration and provides significant environmental benefits to tanning industry, by reducing harmful substances in subsequent operations.

Environmental constraints have become the key issue for sustenance of industries worldwide. In leather industry, solid wastes create major problem to the environment, among which animal fleshing constitute a major portion. The main objective of this study is to evolve a simple, eco-benign method for the utilization of solid wastes to produce value added product. The product was developed by hydrolysis using alkaline protease (a novel Bacillus crolab 5468), which can be potentially used for surface upgradation of leather. Molecular mass of the polypeptides was found to be 9 kDa at 30 min and 6 kDa at 60 min of hydrolysis by MALDI-TOF. Furthermore, the polypeptides treated leather exhibited uniform grain pattern, better filling and strength properties compared to untreated leather. High value-added product presents a strong case for sustainable leather production as it adds both economic and environmental benefits to leather making.

The utilization of biotechnology in leather sector has more extensive in modern years; more particular to proteolytic enzymes and employed in several steps of the leather making such as soaking, dehairing, bating, solid waste management etc. The current study evaluates the performance of alkaline protease from Bacillus crolab MTCC 5468 in single soaking of goat skins matrix by comparing with the conventional multiple soaking processes. According to the obtained results, the optimum concentration for maximum rehydration of goat skins was accomplished at 1.0% (v/w) of alkaline protease at duration of 3 h over traditional rehydration method (4–6 h). The moisture level, total protein, chloride content and total organic carbon of enzymatic rehydration was superior to that of conventional rehydration and it was also used to measure the effectiveness of rehydration process. Scanning electron microscopic images of enzymatically processed leather exhibits enhanced opening of fiber bundles and smooth grain surface than conventional method. Furthermore, the alkaline protease treated leather exhibited improved moisture uptake, removal of chlorides and suppleness because of hydrolysis of non-collagenous proteins as indicated by well opened up fiber bundles in histological analysis. The application of alkaline protease in rehydration operation of leather production confirmed scope for diminishing water quantity around 66.6%, soaking duration at 50%, minimizing use of harmful dehairing chemicals at 50–60%, thereby, eliminating the bating operation during pre-tanning. These outcomes suggest that alkaline protease have potential application in rehydration of skins for immense environmental concerns of leather tanning sectors.

Conventional leather processing poses serious threat to the environment due to its numerous chemical treatments which include hazardous chemicals such as sodium sulphide and lime. To minimise the pollutants and harmful substances during leather processing, an enzymatic rehydration-dehairing-fibre-opening process has been achieved in shortest possible time compared to conventional process. The physicochemical characteristics of experimental leathers were found to be comparable with those of conventionally processed leathers. The releases of sugar and proteoglycans were found to be in congruence with the scanning electron micrographs and histology. TGA and DSC results ascertained the stability of enzymatically processed leathers. Pollution load in terms of TOC, BOD, COD, and TDS was reduced up to 80% compared to that of the conventional process. The present work provides immense potential for a new approach in leather making with environmental safeguards. Graphical abstract.

Aim: To optimize conditions for maximum recovery of protein from wet blue as large quantities of chromium containing biological solid wastes are generated in the tanning industry which poses environmental hazard. The chromium recovery from this acidic (pH ≃ 3. 5) solid waste is necessary for environmental protection and economic reasons. This study therefore focuses on the conditions that facilitate the optimum recovery of protein from the chrome - tanned biological matrix of tannery with minimum protein loss usin g H 2 SO 4. Methodology: The Chrome - tanned skin (wet blue) specimen before and after different concentrations of acid treatment were characterized for their mechanical property and thermal stability with a view to observe chemical and morphological characteri stics changes by Fourier Transform Infra - Red spectroscopy and Scanning Electron Microscopy respectively. The modification in functional group and chemical composition of the samples is correlated with that of

Background Callistemon citrinus has been traditionally known for its medicinal property. Recently, our research group identified 1,8-Cineole, as one of the predominant compound present in the hexane extract (HE-C), whose leaves have potent anticancer activity. Hypothesis/Purpose The present study was designed to isolate 1,8-Cineole from Callistemon citrinus plant and to determine their role in anticancer effects in in vitro using skin carcinoma cells. Moreover, the molecular mechanism of apoptosis and molecular docking studies were also investigated. Study design/Methods In vitro cytotoxicity test was performed with HE-C fractionates 1F, 2F, and 3F against A431 and HaCaT cell lines. MTT and AB assay demonstrated that 1F was toxic to cancer cells with no adverse effect to non-malignant cells and it was subjected to 1H NMR, 13C NMR spectroscopy and further characterized by FTIR and GC–MS analysis. On the basis of spectroscopic data, the metabolite was confirmed as 1,8-Cineole. Results Based on the cytotoxicity results, the well-characterized metabolite 1,8-Cineole was investigated upon to understand the mechanism that caused cancer cell death. In this process, the changes in mitochondrial membrane potential (ΔΨm) were confirmed by Rh-123/DAPI staining; the ultra structure was observed by TEM and quantified by flow cytometric analysis. These results proved that the compound effectively induced the apoptosis and G2/M phase arrest in A431 cells by increasing the expression of p53 and that it was monitored by FACS. Further, the expression of apoptotic proteins, such as Bax/Bcl-2, Cyt-c, caspase-9, and caspase-3 was confirmed by western blot. The molecular docking simulations predicted the hydrophobic interaction between 1,8-cineole with Bcl-2 and PARP1 receptor. Conclusions 1,8-Cineole is a potential candidate for skin carcinoma, which is possible by regulating the p53 apoptotic signaling pathway.

Plants are the source of a variety of secondary metabolites, which are often used in the anticancer activity. Discovering new anticancer drug from herbal source is more important in both biological and pharmacological activities. Hence, the objective of this study is to identify the anticancer agent in Callistemon citrinus (Curtis) Skeels (CC) for the treatment of cancer. Very recently we have reported an increased antioxidant activity in the ethanolic and methanolic extracts (EE and ME) of CC but significantly reduced activity (rather increased cytotoxicity), in the n-hexane extract (HE). In this study, the cytotoxicity of all the three solvent extracts was tested against A431, MG-63 and HaCaT cell lines by MTT assay. Interestingly HE has showed increased anti-proliferative effect against the cancer cells but was resisted by non-malignant cells. HPLC and GC-MS analysis revealed the presence of 1,8-Cineole as a predominant compound in HE, the semi-purified bioactive extract. Henceforth, this would be called HE-C and be used for further analyses to understand its mode of action on induced apoptosis/necrosis. Alamar blue assay of HE-C showed cytotoxicity and change in morphological characteristics, which was confirmed by AO/EB staining using fluorescence microscopy, ultra-structural features of apoptosis using SEM and TEM. HE-C induced cell death was also detected by FACS using FITC-labelled Annexin-V and Propidium iodide. ROS generation was monitored using DCF-DA by flow cytometry. The overall results suggested that the selective extract (HE-C) containing 1,8-Cineole has shown potential anti-cancer activity in a dose-dependent manner, and cell death was induced through ROS-mediated apoptosis. Our findings provide an insight into the potential of 1,8-Cineole as a novel drug for killing cancer cells.

Proteases are shown to have greener mode of application in leather processing for dehairing of goat skins and cow hides. Production of protease by submerged fermentation with potent activity is reported using a new isolate P. aeruginosa MTCC 10501. The production parameters were optimized by statistical methods such as Plackett-Burman and response surface methodology. The optimized production medium contained (g/L); tryptone, 2.5; yeast extract, 3.0; skim milk 30.0; dextrose 1.0; inoculum concentration 4%: initial pH 6.0; incubation temperature 30 degrees C and optimum production at 48 h with protease activity of 7.6 U/mL. The protease had the following characteristics: pH optima, 9.0; temperature optima 50 degrees C; pH stability between 5.0-10.0 and temperature stability between 10-40 degrees C. The protease was observed to have high potential for dehairing of goat skins in the pre- tanning process comparable to that of the chemical process as evidenced by histology. The method offers cleaner processing using enzyme only instead of toxic chemicals in the pre-tanning process of leather manufacture.