A Palaeoproterozoic dolomite (Vempalle Formation, Cuddapah Basin, India) showing Phanerozoic-type dolomitisation

© 2019 The Palaeoproterozoic Vempalle Formation of the Cuddapah Basin, India, significantly adds to our understanding of the evolution of Precambrian marine carbonate systems and the redox state of the Earth's early oceans. A facies-microfacies-diagenetic-geochemical examination of samples from a ∼1000-m long exposure in a freshly-cut canal section shows that 10–15% of precursor limestone is still preserved in the Vempalle Formation in the form of remnant patches of calcimicrite and ooids with calcite spar cement. The ooids, preserving primary radial and concentric fabrics and radial fractures, are considered to have been originally precipitated as calcite, which may have been low-Mg. In places the preserved calcite spar, that is partially replaced by fabric-destructive dolomite, shows Type I calcite twin lamellae. Petrographic observations demonstrate that Vempalle Formation dolomite formed through very early precipitation, which in stromatolites preserved microbial filaments, as well as through fabric-destructive dolomitization during shallow to moderate burial. Vempalle Formation dolomite is characterized by micritic dolomite crystals which suggest rapid early dolomitization of lime mud and micritic calcite from a supersaturated Mg-Ca-rich solution, probably near-surface or during shallow burial. Depletion of Na and Sr contents of Vempalle Formation dolomite along with negative δ18O values indicate dolomite recrystallisation during burial and further replacement. Dolomite δ13C values of −0.5 to 2‰ are likely inherited original marine values. Geochemical proxies (trace elements and rare earths) imply that Cuddapah Basin seawater and dolomitizing fluids were anoxic and ferruginous but not euxinic. Geochemical analyses also indicate that the burial diagenetic fluids evolved from Eu-enriched seawater that probably resulted from continental rifting around 1.9–2.0 Ga. This probable ocean chemistry is in contrast with the anoxic, ferruginous and extremely high Mg/Ca “dolomite oceans” that prevailed during Proterozoic time. The Vempalle dolomite shows more similarities with dolomitised Phanerozoic platform carbonates than typical Precambrian dolomite with its well-preserved textures and burial dolospar cements

An ANFIS model-based approach to investigate the effect of lockdown due to COVID-19 on public health

During the first and second quarters of the year 2020, most of the countries had implemented complete or partial lockdown policies to slow down the transmission of the COVID-19. To cultivate the effect of lockdown due to COVID-19 on public health, we have collected the data of six primary parameters, namely systolic blood pressure, diastolic blood pressure, fasting blood sugar, insomnia, cholesterol, and respiratory distress of 200 randomly chosen people from a municipality region of West Bengal, India before and after lockdown. With the help of these data and Adaptive Neuro-Fuzzy Inference System (ANFIS), we have formulated a model that has established that lockdown due to COVID-19 has negligible impacts on the individuals with better health condition but has significant effects on the health conditions to those populations who have poor health

In search of suitable extraction technique for large scale commercial production of bioactive fraction for the treatment of diabetes: The case Diospyros melanoxylon Roxb.

Diospyros melanoxylon Roxb. (D. melanoxylon) belongs to the family Ebenaceae and its leaves are very well known for making beedi throughout the World. The current study estimated the comparative extraction technique and its in-vitro antidiabetic prospective of the leaves of D. melanoxylon. Qualitative phytochemicals analysis of the samples from D. melanoxylon was carried out for the detection of secondary metabolites. Total phenolics, flavonoids, triterpenoids and tannins content of D. melanoxylon were estimated using colorimetric assay. Microwave-assisted extraction (MAE) technique with a low carbon output was observed for the speedy extraction of bioactive compounds obtained from Diospyros melanoxylon leaf extract. MAE produced a maximum yield of bioactive compounds which was found to be more efficient than ultrasound, soxhlet and maceration extraction. Qualitative HPLC analysis was performed for bioactive compounds. The in-vitro antidiabetic assay was performed using α-amylase and α-glucosidase inhibitory activity. In conclusion, the fractions exhibited the concentration-dependent inhibitory effect with significant (P < 0.0001) result. So the above performance might be accountable for the antidiabetic activity of D. Melanoxylon leaf extract due to presence of bioactive compounds. Keywords: D. melanoxylon, Extraction techniques, HPLC, Polyphenolics, Antidiabeti

ANTIOXIDANT AND ANTICANCER ACTIVITY OF EXTRACT AND FRACTIONS OBTAINED FROM DIOSPYROS MELANOXYLON ROXB. LEAVES AND CORRELATION WITH THEIR POLYPHENOLIC PROFILES

Objective: The current study evaluates the antioxidant and cytotoxic prospective of the leaves from Diospyros melanoxylon Roxb. (D. melanoxylon).Methods: Qualitative phytochemical analysis of the samples from D. melanoxylon was carried out for the detection of secondary metabolites. Total content of flavonoids, phenolics, triterpenoids, and tannins in D. melanoxylon was evaluated using colorimetric assay. Qualitative analysis of polyphenolic compounds was performed using HPLC method. The antioxidant activity was examined by assessing the various free radical scavenging assays. Five human cancerous cell lines (HeLa, MCF-7, HCT-116, PC-3, and HEK293), one rat colon cancer cell line (RCC 45) and two normal cell lines (NKE and WI-38) were used for evaluating the anticancer activity through methylene blue assay.Results: The results indicated that ethyl acetate fraction (EAF) and aqueous fraction (AQF) exhibited the remarkable content of flavonoids, phenolics, triterpenoids, and tannins. Both EAF and AQF have cytotoxic activity with significant IC50 values but not showed significant antioxidant activity. However, the most powerful anticancer activity was recorded by EAF followed by AQF in a dose-dependent manner. It was also revealed that EAF and AQF were biocompatible with the normal cell lines.Conclusion: Our principal finding exhibited a potent anticancer activity. Furthermore, it was also indicated that samples contain secondary metabolites like flavonoids, phenolics, triterpenoids, and tannins. We suggest that the further investigation on this herb is effective against various types of ailments including cancer.Keywords: Diospyros melanoxylon Roxb., Scanning Electron Microscopy (SEM), High-Pressure Liquid Chromatography (HPLC), Polyphenols, Antioxidant, Anticance

Preclinical and clinical trials of Indian medicinal plants in disease control

Since the ancient period, the medicinal plants have been used in pharmaceutical and cosmetic industries. Recently, it has gained extreme research importance for their nutraceuticals values. It has been confirmed by WHO that herbal medicines serve the health needs of about 80% of World’s population; especially for millions of people in the vast rural areas of developing countries. This book chapter summarizes the importance of several medicinal plants which are traditionally used in treatment and management of different ailments in India. In addition, some pharmacological models describe the possible mechanism of action of bioactive phytochemicals, which can be successfully used as drug candidates in near future. However, there is urgent need for basic scientific investigations on medicinal plants and this has been highlighted in current research trends in clinical trials