Biotechnological applications of mangrove plants and their isolated compounds in medicine-a mechanistic overview.

Mangrove plants, also known as halophytes, are ecologically important plants that grow in various tropical and subtropical intertidal regions. Owing to the extreme abiotic and biotic stressful conditions they thrive in, these plants produce unique compounds with promising pharmacological propensities. Mangroves are inhabited by an astronomical number of fungal communities which produce a diverse array of extracellular degradative enzymes, namely: amylase, cellulase, xylanase, pectinase, cholesterol oxidase, etc. Such enzymes can be isolated from the mangrove fungi and harnessed for different biotechnological applications, for example, as replacements for chemical catalysts. Mangrove microbes attract considerable attention as they shelter the largest group of marine microorganisms that are resistant to extreme conditions and can produce novel biogenic substances. Vaccines developed from mangrove microbes may promise a safe future by developing effective immunization procedures with a minimum of economic burden. Interestingly, mangroves offer an exciting opportunity for synthesizing nanoparticles in a greener way as these plants are naturally rich in phytochemicals. Rhizophora mucronata Lam., Avicennia officinalis L. and Excoecaria agallocha L. are capable of synthesizing nanoparticles which have evolved recently as an alternative in various industries and are used for their biomedical application. Besides, the phytoconstituents isolated from mangrove plants, such as: gallic acid, galactose, lupeol, catechins, carotenoids, etc., were explored for various biological activities. These compounds are used in the pharmaceutical and nutraceutical industries to produce antimicrobial, antioxidant, anticancer, antidiabetic, and other therapeutic agents. The present review provides information on the biotechnological potentials of mangrove plants and their bioactive compounds as a new source of novel drugs, enzymes, nanoparticles and therapeutically important microbial pigments. Thus, this review forms a base of support and hasten the urgent research on biomedical applications of mangroves.

Detailed Chemical Characterization and Biological Propensities of Malabaila lasiocarpa Extracts: An Endemic Plant to Turkey.

This study focused on the biological evaluation and chemical characterization of Malabaila lasiocarpa Boiss. (M. lasiocarpa) (Family: Apiaceae). The phytochemical profile, antioxidant, enzyme inhibitory of the methanolic, aqueous, dichloromethane, hexane extracts were investigated. Based on UHPLC-HRMS analyses, a total of 101 peaks were annotated or identified for the first time in M. lasiocarpa extracts. They include hydroxybenzoic, hydroxycinnamic, acylquinic acids and their glycosides, C- and O-glycosyl and O-diglycosyl flavonoids. In addition, 10 simple mono- and disubstituted coumarins together with 10 furanocoumarins were tentatively annotated. The methanolic extract possessing the highest phenolic (24.36±0.60 mg gallic acid equivalent/g extract) and flavonoid (69.15±0.37 mg rutin equivalent/g extract) content also exhibited the strongest radical scavenging potential against 2,2-diphenyl-1 picrylhydrazyl (21.73±0.42 mg Trolox equivalent/g extract, respectively), and highest reducing capacity (57.81±0.97 and 28.00±0.40 mg Trolox equivalent/g extract, for cupric reducing antioxidant capacity and ferric reducing antioxidant power, respectively). The dichloromethane extract substantially depressed the tyrosinase (73.92±5.37 mg kojic acid equivalent/g extract), α-amylase (0.63±0.01 mmol acarbose equivalent/g extract) and α-glucosidase (0.69±0.02 mmol acarbose equivalent/g extract) enzymes. This study has produced critical scientific data on M. lasiocarpa which are potential contenders for the development of novel phyto-pharmaceuticals.

Two Medicinal Plants (Alkanna trichophila and Convolvulus galaticus) from Turkey: Chemical Characterization and Biological Perspectives.

The aim of the present study was to quantify selected phenolic compounds, determine antioxidant activity and enzyme inhibitory effects of the aerial parts of Alkanna trichophylla Hub.-Mor. (A. trichophylla) and Convolvulus galaticus Rost.ex Choisy (C. galaticus) extracts prepared by homogenizer-assisted extraction (HAE), maceration (MAC) and infusion techniques. This is the first time such study has been designed to validate the phytochemical composition and bioactivity of these plants. Multivariate analysis was conducted on collected data. Rutin and caffeoylquinic acid derivatives were the most significant compounds in A. trichophylla and C. galaticus, respectively. The highest antioxidant activity of A. trichophylla was mostly exhibited by HAE/methanolic extracts as determined by DPPH, ABTS, FRAP (51.39, 112.70 and 145.73 mg TE/g, respectively) and phosphomolybdenum (2.05 mmol TE/g) assays. However, significant antioxidant activities varied within the extracts of C. galaticus. HAE/methanolic extract of A. trichophylla significantly depressed AChE (2.70 mg GALAE/g), BChE (5.53 mg GALAE/g) and tyrosinase (26.34 mg KAE/g) activities and that of C. galaticus inhibited AChE (2.04 mg GALAE/g), tyrosinase (31.25 mg KAE/g) and α-amylase (0.53 mmol ACAE/g) activities significantly. We concluded that HAE was the most efficient extraction technique as high yield of compounds and promising bioactivities were recorded from extracts prepared. Multivariate analysis showed that types of solvents influenced recovery of compounds and biological activities. This research study can be used as one methodological starting point for further investigation on these plants as all results are clearly promising and open the door to further research challenges such as cytotoxicity evaluation, molecular docking analysis, and more screening of pharmacological actions.

HPLC-FRAP methodology and biological activities of different stem bark extracts of Cajanus cajan (L.) Millsp.

Cajanus cajan. (L.) Millsp. (C. cajan) (Family: Fabaceae) also known as pigeon pea, is a famous food and cover/forage crop bearing a high amount of key amino acids (methionine, lysine and tryptophan). This study investigated into the total phenolic (TPC), flavonoid content (TFC), antioxidant [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity, total antioxidant capacity (TAC) (phosphomolybdenum) and metal chelating] activities and enzyme [α-amylase, α-glucosidase, tyrosinase, acetyl-(AChE), butyryl-(BChE) cholinesterase] inhibitory effects of four extracts (methanol, hexane, ethyl acetate, aqueous) prepared from C. cajan stem bark. Direct identification of antioxidants was also conducted using the high performance liquid chromatography-ferric reducing antioxidant power (HPLC-FRAP) system. The highest TPC and TFC were recorded with the methanolic (23.22 ± 0.17 mg GAE/g) and ethyl acetate extracts (19.43 ± 0.24 mg RE/g), respectively. The methanolic extract exhibited important antioxidant activity with DPPH (38.41 ± 0.05 mg Trolox equivalent (TE)/g), ABTS (70.49 ± 3.62 mg TE/g), CUPRAC (81.86 ± 2.40 mg TE/g), FRAP (42.96 ± 0.59 mg TE/g) and metal chelating (17.00 ± 1.26 mg ethylenediaminetetraacetic acid equivalent/g). p-coumaric and caffeic acid were the predominant antioxidants in the samples. Results from enzymatic assays showed the potential abilities of hexane extract in inhibiting the AChE, BChE, α-amylase and α-glucosidase enzymes. From the results obtained in this study, it can be concluded that C. cajan can be considered as a promising source of antioxidants and key enzyme inhibitors that can be exploited for future bioproduct development.

Characterization of nutritionally important lipophilic constituents from brown kelp Ecklonia radiata (C. Ag.) J. Agardh.

This research study presents information for the first time on the nutritionally relevant lipophilic compounds obtained from Ecklonia radiata, a poorly studied brown kelp. The major lipophilic compounds were analyzed utilizing liquid chromatography (LC)-tandem mass spectrometry (MS/MS) and gas chromatography (GC)-mass spectrometry (MS). The LC-MS/MS results revealed the presence of eight major lipophilic compounds, including sterols, carotenoids, vitamin E, and phylloquinone (vitamin K1). Quantitative analysis showed that fucosterol was the most predominant phytosterol in the fronds and stipes of E. radiata. The carotenoids (all-E)-fucoxanthin and (all-E)-ß-carotene were present in higher yield. In terms of vitamin E, α-tocopherol was identified as the main tocol. The coenzyme, phylloquinone, important for protein synthesis, was also identified in E. radiata. GC-MS identified 13 fatty acids with palmitic (C16:0) and oleic acid (C18:1n9c) present in the highest quantities. To our knowledge, this is the first report on E. radiata, and the valuable data presented herein can be used as a baseline for developing novel nutraceuticals.

Antibiotic Potentiation of Natural Products: A Promising Target to Fight Pathogenic Bacteria.

Pathogenic microorganisms should be considered as the number one foe of human, as witnessed by recent outbreaks of coronavirus disease (COVID-19) and with bacteria no longer sensitive to existing antibiotics. The resistance of pathogenic bacteria and deaths attributable to bacterial infections is increasing exponentially. Bacteria used different mechanisms to counterattack to existing antibiotics, namely (i) enzymatic inhibition, (ii) penicillin-binding protein modification, (iii) porin mutations, (iv) efflux pumps and (v) molecular modifications of antibiotic targets. Developing new antibiotics would be time-consuming to address such a situation, thus one of the promising approaches is by potentiating existing antibiotics. Plants used synergism to naturally defend and protect themselves from microbes. Using the same strategy, several studies have shown that the combinations of natural products and antibiotics could effectively prolong the lifespan of existing antibiotics and minimize the impact and emergence of antibiotic resistance. Combining essential oils constituents, namely uvaol, ferruginol, farnesol and carvacrol, with antibiotics, have proved to be efficient efflux pump inhibitors. Plant-derived compounds such as gallic acid and tannic acid are effective potentiators of various antibiotics, including novobiocin, chlorobiocin, coumermycin, fusidic acid, and rifampicin, resulting in a 4-fold increase in the potencies of these antibiotics. Several lines of research, as discussed in this review, have demonstrated the effectiveness of natural products in potentiating existing antibiotics. For this reason, the search for more efficient combinations should be an ongoing process with the aim to extend the life of the ones that we have and may preserve the life for the ones that are yet to come.

Chemical characterization, antioxidant and enzyme inhibitory effects of Mitracarpus hirtus extracts.

Mitracarpus hirtus (L.) DC. (Family: Rubiaceae) is a tropical annual herb commonly found in America and Mexico. In the present study, the methanol, ethyl acetate, dichloromethane and aqueous extracts of the plant were tested for total phenolic (TPC) and flavonoid content (TFC) and antioxidant activities were evaluated using a battery of assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity, total antioxidant capacity (TAC) (phosphomolybdenum) and metal chelating. Enzyme inhibitory effects were investigated using acetylcholinesterase (AChE), tyrosinase, α-amylase and α-glucosidase as target enzymes. The phytochemical profile was obtained using liquid chromatography-diode array detection-electrospray ionization-mass spectrometry (LC-DAD-ESI-MSn), liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MSn) and nuclear magnetic resonance (NMR) experiments. Results showed that the dichloromethane and ethyl acetate extracts yielded the highest TPC (29.10 ± 0.07 mg gallic acid equivalent/g) and TFC (38.14 ± 0.91 mg rutin equivalent/g), respectively. Aqueous extract showed weak activity against tested enzymes but demonstrated the strongest ABTS scavenging activity (59.39 ± 1.19 mg trolox equivalent/g) and is the strongest Fe3+ reducer (59.42 ± 0.59 mg trolox equivalent/g). Phytochemical analysis revealed the presence of phenolics, pyrrolizidine alkaloids and triterpene acid. This is the first report gathering scientific data on antioxidant, enzyme inhibitory activities and phytochemical composition of M. hirtus and the obtained results can be used as starting point for further investigation on this traditional medicinal herb.

Phenolic compounds analysis of three Euphorbia species by LC-DAD-MSn and their biological properties.

Members of the genus Euphorbia have attracted much interest as potential sources of bioactive compounds. In this study, the ethyl acetate, methanolic and aqueous extracts of aerial parts of three Euphorbia species namely Euphorbia hirta L., Euphorbia heterophylla L. and Euphorbia convolvuloides Hochst. ex Benth. were screened for their antioxidant [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), cupric antioxidant reducing capacity (CUPRAC), metal chelating, total antioxidant capacity (phosphomolybdenum)], and enzymatic properties [α-amylase, α-glucosidase, tyrosinase, acetyl- (AChE), butyryl-cholinesterase (BChE)]. Total phenolic (TPC), total flavonoid content (TFC) and phytochemical profile were established via LC-DAD-MSn. Results showed that the methanolic and aqueous extracts of the three plants yielded the highest TPC with values ranging from 35.84-141.90 mg gallic acid equivalent/g. E. hirta was the most potent DPPH scavenger and chelator reporting the highest equivalent [DPPH: 195.22 mg Trolox equivalent (TE)/g, chelator: 30.73 mg ethylenediaminetetraacetic acid equivalent (EDTAE)/g], while E. heterophylla demonstrated the most significant Fe3+ and Cu2+ reducing potential (FRAP: 194.28 mg TE/g; CUPRAC: 631.25 mg TE/g) and possessed the highest total antioxidant capacity (3.76 mmol TE/g). The AChE, BChE, α-amylase and α-glucosidase enzyme inhibitory effects of the three species were relatively the same. However, E. hirta exhibited the highest anti-tyrosinase activity (109.71 mg kojic acid equivalent /g). Euphorbia convolvuloides showed low antioxidant activities and enzymatic inhibitory effects compared to other. LC-DAD-MSn fingerprint of the phenolics of the three species showed the presence of different derivatives. Quantitative data revealed tannins and flavonoids (25 and 20 mg/g respectively) for E. hirta, high amount of tannins 63 and 21 mg/g of flavonoids for E. heterophylla, while high flavonoid contents for E. convolvuloides, 56 mg/g. Euphorbia hirta proved to the most promising among the three tested species and thus can be explored further by isolating and characterizing active bioactive agents that could be used to manage oxidative stress-related diseases and hyperpigmentation problems.