Functional Studies of Plant Latex as a Rich Source of Bioactive Compounds: Focus on Proteins and Alkaloids

Latex, a sticky emulsion produced by specialized cells called laticifers, is a crucial part of a plant’s defense system against herbivory and pathogens. It consists of a broad spectrum of active compounds, which are beneficial not only for plants, but for human health as well, enough to mention the use of morphine or codeine from poppy latex. Here, we reviewed latex’s general role in plant physiology and the significance of particular compounds (alkaloids and proteins) to its defense system with the example of Chelidonium majus L. from the poppy family. We further attempt to present latex chemicals used so far in medicine and then focus on functional studies of proteins and other compounds with potential pharmacological activities using modern techniques such as CRISPR/Cas9 gene editing. Despite the centuries-old tradition of using latex-bearing plants in therapies, there are still a lot of promising molecules waiting to be explored.

Investigating the Antioxidant and Antimicrobial Activity of Artocarpus heterophyllus Lam. (Jackfruit) Latex

Plant latex is well-established as a defensive exudate against natural herbivory. However, its bioactive properties and potential use as a clinical adjunct are not fully explored in the current literature. In this study, latex was procured from Artocarpus heterophyllus Lam. (jackfruit) and subsequently evaluated for its antioxidant and antimicrobial activity. Aqueous extract (AE) and trifluoroethanol extract (TFE) of jackfruit latex were prepared using distilled water and trifluoroethanol. Both extracts were then characterized via thin-layer chromatography (TLC), ultraviolet-visible (UV-Vis) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) analysis. Antimicrobial activity and antioxidant activity were determined for the extracts. Antibacterial activity was exhibited by TFE against P. aeruginosa, S. aureus, and Bacillus sp. The antioxidant activity of AE was significantly higher than TFE.

Latex mediated green synthesis of silver nanoparticles and its antibacterial evaluation

A functional role of plant latex extract in the growth and nucleation of silver nanoparticles synthesized by green method has been discussed. By varying the biological species as capping and reducing agents, silver nanoparticles (AgNPs) of different morphologies under similar reaction conditions were produced. The synthetic protocol involves the preparation of AgNPs derived from two plant latex extract i.e. plumeria obtusa and manilkara zapota. Synthesized AgNPs generate the surface plasmonic resonance peak at 435 nm in UV–Visible spectrophotometer. Fourier-transform infrared spectroscopy (FT-IR) analysis shows the major role of active phenolic constituents and protein in reduction and stabilization of AgNPs. Size and shape of AgNPs were characterized through transmission electron microscopy (TEM) which shows that the AgNPs are of spherical form and relatively uniform. X-ray diffraction (XRD) pattern of AgNPs corresponding to (111), (200), (220) and (311) planes reveals that the generated nanoparticles were face centered cubic crystalline in nature. The average crystalline size was found to be 32.97 and 35.15 nm for plumeria obtusa and manilkara zapota respectively. The role of capping agents in controlling the size and properties of silver nanoparticles has been studied. Phyto-fabricated AgNPs exhibit significant antimicrobial activity against Staphylococcus aures and Escherichia coli.

Antibacterial Activity of Silver Nanoparticles Synthesized from Plant Latex

Nanoparticles produced by plants are preferred in the medical field for its safe and unpolluted product; it is also accepted as an ecofriendly, non-expensive, and non-toxic nanomaterial. In this study, silver nitrate was successfully used to produce silver nanoparticles (AgNPs) by the use extractsof 4 different latex-producing plants which belong to 2 families (Moraceae and Euphorbiaceae). The synthesis was proved by Atomic Force Microscopy (AFM).The sizes of the AgNP grains were estimated by Granularity Cumulating Distribution (GCD). The results revealed the production of AgNPs in different sizes of 103 and 82 nm using the Moraceae family and 77 and74nm using the Euphorbiaceae family.Antibacterial activity was also detected against both Gram positive and Gram negative pathogenic bacteria using the well diffusion assay. In conclusion, this source of nanoparticles can be a very useful industrial project in a goal to find new safe and economic alternatives to antibiotics.

Use of Plant Latex for Nanocarrier Synthesis and Utilizing it in Drug Delivery

One of the most significant applications of nanomedicine is employing nanoparticles for targeted drug delivery. Using latex-based nanocarrier as a drug delivery system serves as better alternatives since it is eco-friendly and rendered non-toxic. The main aim of this study is to extract latex components, synthesize nanocarriers, and encapsulate with a specific drug for its usage in targeted drug delivery. The latex was collected from a latex secreting tree and extracted using polar and non-polar solvents. The synthesis of nanocarriers was done through a microemulsion technique with the use of surfactants. The extracts and nanocarriers were characterized using UV-Vis, FTIR and GC-MS and SEM analysis. The nanocarriers were then encapsulated with a drug, and the drug release profiles are examined. Antibacterial activity of the latex extracts and loaded nanocarriers was measured by agar well diffusion technique, and antioxidant activity was determined by DPPH and TLC analysis. The latex extracts had antioxidant properties, and the drug-loaded nanocarriers had antibacterial activity.

Investigating the possible mechanism for potency of latex of Plumeria alba L. in treating scabies

Human body has multiple complex processes that enable the regular and effective functioning of all the systems. During the process, organs undergo wear and tear and heal themselves on a rgular basis. But due to physiological stress, they tend to produce some free radicals which are the sole reasons for few diseases like alzhimers, tissue damage, parkinsons disease and some skin conditions like scabies, and aging. Herbs are used as best treatment for a numerous diseases which had an underlying mechanism of action as antioxidant activity. So it is confirmed that the oxidative free radicals are the reasons for the causing of most of the diseases. It is ideal that the herbs that are rich in flavonoids and poly phenols that has good antioxidant activity will pocess potency against many of the diseases. The latex of the plant Plumeria alba L. was used as a treatment of scabies (Sura et al., 2018). The plant latex was potent and used to treat many diseases. The under lying mechanism was not yet known. It is assumed on the fact that antioxidant activity of drugs is responsible for many other activities. So, the present research focus on the establishing and investigating the anti-oxidant activity of the plant latex invitro. The latex had shown a effective antioxidant activity and the mechanism of the above activities exactly correlate and support the anti scabies activity of the latex.

Antifungal Proteins from Plant Latex

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants’ defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.