Summi Rai

In response to increasing natural surfactant demand and environmental concerns, natural plant-based surfactants have been replacing synthetic ones. Saponins belong to a class of plant metabolites with surfactant properties that are widely distributed in nature. They are eco-friendly because of their natural origin and biodegradable. To date, many plant-based saponins have been investigated for their surface activity. An overview of saponins with a particular focus on their surface-active properties is presented in this article. For this purpose, works published in the past few decades, which report better surfactant relevant properties of saponins than synthetic ones, were extensively studied. The investigations on the potential surfactant application of saponins are also documented. Moreover, some biological activities of saponins such as antimicrobial activity, antidiabetic activity, adjuvant potentials, anticancer activity, and others are reported. Plants rich in saponins are wid...

The greatest pandemic of the century, COVID-19, is an ongoing global public health problem. With a clinically approved treatment available only for those who are acutely ill and are hospitalized, the control of this disease in the general population is still largely dependent on the preventive measures issued by the World Health Organization. Among the general control measures other than immunization with the COVID-19 vaccines, handwashing with soap and water has been emphasized the most because it is cost-effective and easily accessible to the general public. Studies have reported that soaps offer unique chemical properties that can completely destroy enveloped viruses. However, the general public seems to be still uncertain about whether soaps can shield us from a highly contagious disease such as COVID-19. In an attempt to help eliminate the uncertainty, we analyzed the mechanisms underlying the efficacy of soap and its prospect for preventing the spread of COVID-19. In this paper, we provide an overview of the history and characteristics of the SARS-CoV-2 virus, the current global COVID-19 situation, the possible mechanisms of the deactivation of viruses by soaps, and the potential effectiveness of soap in eliminating coronaviruses including SARS-CoV-2.

Plants synthesize an unlimited number of bioactive chemical substances [10] that are less toxic and biodegradable than synthetic ones. Among the various bioactive chemical compounds derived from plants, saponins are the ones that exhibit surface-active properties [11]. In fact, they belong to a class of nonionic surfactants [8]. They got their name "saponin" derived from Latin word sapo, which means soap as they form soapy lather when agitated with water [12]. Structurally, they are composed of hydrophilic glycone moieties (sugars) glycosidically linked with hydrophobic aglycones moieties (steroids or triterpenoids [13]. This structural feature resembles that of a typical surfactant and hence attributes to their surface-active properties. Based on the aglycone counterpart of saponins, they are classified as (i) steroidal and (ii) triterpenoidal saponins [14]. Steroidal saponins are further classified as (i) spirostanols and (ii) furostanols glycosides [15]. Triterpenoidal saponins are most abundant in the plant kingdom [16]. Furthermore, phytochemical studies have reported the presence of saponins in more than 100 families of plants [17].