A comparative analysis of immunomodulatory potential of Seabuckthorn leaf extract in young and old mice

Comprehensive review of extraction, purification, structural characteristics, pharmacological activities, structure-activity relationship and application of seabuckthorn protein and peptides

Seabuckthorn (Hippophae rhamnoides) is an excellent plant that has the concomitant function of both medicine and foodstuff with high nutritional and health-promoting properties. As a pivotal bioactive component mainly existing in the seeds and leaves, seabuckthorn protein and its derived peptides have aroused wide attention owing to their multifaceted pharmacological activities, including anti-hypertensive, hypoglycemic, anti-obesity, anti-freeze, immunomodulatory, anti-inflammatory, sobriety, anti-oxidant and anti-neurodegenerative functions. Despite these promising attributes, the application of seabuckthorn peptides as functional food and medicines are impeded due to lack of a comprehensive understanding of pharmacological activities and intricate structure-activity relationship. Therefore, this review systematically summarizes the latest advancements in the extraction, purification, structural characteristics, pharmacological activities, digestion, absorption and transport, and application of seabuckthorn protein or peptides. Noteworthily, the structure-activity relationship is specifically delved into the hypoglycemic, anti-hypertensive, anti-obesity, anti-neurodegenerative and anti-oxidant peptides. Moreover, the shortcomings of current research and promising prospects are also highlighted. This comprehensive overview will provide a framework for future exploration and application of seabuckthorn protein or peptides in the realms of food and pharmaceuticals, offering a promising horizon for health benefits.

Chromosome-level genome assembly of Hippophae rhamnoides variety

Fructus hippophae (Hippophae rhamnoides spp. mongolica×Hippophae rhamnoides sinensis), a hybrid variety of sea buckthorn that Hippophae rhamnoides spp. mongolica serves as the female parent and Hippophae rhamnoides sinensis serves as the male parent, is a traditional plant with great potentials of economic and medical values. Herein, we gained a chromosome-level genome of Fructus hippophae about 918.59 Mb, with the scaffolds N50 reaching 83.65 Mb. Then, we anchored 440 contigs with 97.17% of the total genome sequences onto 12 pseudochromosomes. Next, de-novo, homology and transcriptome assembly strategies were adopted for gene structure prediction. This predicted 36475 protein-coding genes, of which 36226 genes could be functionally annotated. Simultaneously, various strategies were used for quality assessment, both the complete BUSCO value (98.80%) and the mapping rate indicated the high assembly quality. Repetitive elements, which occupied 63.68% of the genome, and 1483600 bp of non-coding RNA were annotated. Here, we provide genomic information on female plants of a popular variety, which can provide data for pan-genomic construction of sea buckthorn and for the resolution of the mechanism of sex differentiation.

From by-products to new application opportunities: the enhancement of the leaves deriving from the fruit plants for new potential healthy products

In the last decades, the world population and demand for any kind of product have grown exponentially. The rhythm of production to satisfy the request of the population has become unsustainable and the concept of the linear economy, introduced after the Industrial Revolution, has been replaced by a new economic approach, the circular economy. In this new economic model, the concept of "the end of life" is substituted by the concept of restoration, providing a new life to many industrial wastes. Leaves are a by-product of several agricultural cultivations. In recent years, the scientific interest regarding leaf biochemical composition grew, recording that plant leaves may be considered an alternative source of bioactive substances. Plant leaves' main bioactive compounds are similar to those in fruits, i.e., phenolic acids and esters, flavonols, anthocyanins, and procyanidins. Bioactive compounds can positively influence human health; in fact, it is no coincidence that the leaves were used by our ancestors as a natural remedy for various pathological conditions. Therefore, leaves can be exploited to manufacture many products in food (e.g., being incorporated in food formulations as natural antioxidants, or used to create edible coatings or films for food packaging), cosmetic and pharmaceutical industries (e.g., promising ingredients in anti-aging cosmetics such as oils, serums, dermatological creams, bath gels, and other products). This review focuses on the leaves' main bioactive compounds and their beneficial health effects, indicating their applications until today to enhance them as a harvesting by-product and highlight their possible reuse for new potential healthy products.

Hippophae rhamnoides L. leaf and twig extracts as rich sources of nutrients and bioactive compounds with antioxidant activity

Plants have served for centuries as sources of compounds useful for human health such as antioxidant, anti-diabetic and antitumor agents. They are also rich in nutrients that improve the human diet. Growing demands for these compounds make it important to seek new sources for them. Hippophae rhamnoides L. is known as a plant with health-promoting properties. In this study we investigated the chemical composition and biological properties of bioactive components of ethanol extracts from leaves and twigs of H. rhamnoides L. Chemical components such as the total content of phenolic compounds, vitamins and amino acids and the antioxidant activities of these compounds in cellular and cell-free systems were assessed. The results suggest that the studied extracts are rich in bioactive compounds with potent antioxidant properties. Cytotoxicity and hemotoxicity assays showed that the extracts had low toxicity on human cells over the range of concentrations tested. Interaction with human serum albumin was investigated and conformational changes were observed. Our results indicate that leaf and twig extracts of H. rhamnoides L. should be considered as a non-toxic source of bioactive compounds which may be of interest to the food, pharmaceutical and cosmetic industries.

Wide Spectrum of Active Compounds in Sea Buckthorn (Hippophae rhamnoides) for Disease Prevention and Food Production

Growing demand for value-added products and functional foods is encouraging manufacturers to consider new additives that can enrich their products and help combat lifestyle diseases. The healthy properties of sea buckthorn have been recognized for centuries. This plant has a high content of bioactive compounds, including antioxidants, phytosterols, essential fatty acids, and amino acids, as well as vitamins C, K, and E. It also has a low content of sugar and a wide spectrum of volatiles, which contribute to its unique aroma. Sea buckthorn shows antimicrobial and antiviral properties, and is a potential nutraceutical or cosmeceutical. It was proven to help treat cardiovascular disease, tumors, and diabetes, as well as gastrointestinal and skin problems. The numerous health benefits of sea buckthorn make it a good candidate for incorporation into novel food products.

The bioactive components as well as the nutritional and health effects of sea buckthorn

Sea buckthorn (SB), also named sea berry, Hippophae rhamnoides L. or Elaeagnus rhamnoides L., has been used in daily life for centuries with kinds of purposes ranging from a beverage with a pleasant taste and flavor, to an agent for treatment of many disorders and diseases. SB is well known more than just a fruit. So far, a unique mixture of bioactive components was elucidated in SB including flavonoids, phenolic acids, proanthocyanidins, carotenoids, fatty acids, triterpenoids, vitamins and phytosterols, which implied the great medicinal worth of this seaberry. Both in vitro and in vivo experiments, ranged from cell lines to animals as well as a few in patients and healthy volunteers, indicated that SB possessed various biological activities including anti-inflammatory and immunomodulatory effects, antioxidant properties, anti-cancer activities, hepato-protection, cardiovascular-protection, neuroprotection, radioprotection, skin protection effect as well as the protective effect against some eye and gastrointestinal sickness. Furthermore, the toxicological results revealed neither the fruits, nor the seeds of SB were toxic. The present review summarizes the unique profile of the chemical compounds, the nutritional and health effects as well as the toxicological properties of SB, which lay the foundation for practical applications of SB in treatment of human diseases.

Sea buckthorn (SB), also named sea berry, has been used in daily life for centuries with kinds of purposes ranging from a beverage with a pleasant taste and flavor, to an agent for treatment of many disorders and diseases.

Adjuvant activity of ethanol extract of Hippophae rhamnoides leaves with inactivated rabies virus antigen

CONTEXT

Hippophae rhamnoides L. (Elaeagnaceae), commonly known as seabuckthorn (SBT), is known for its medicinal and nutritional properties.

OBJECTIVE

Evaluation of in vivo adjuvant activity of SBT leaf extract (SBTE) with inactivated rabies virus antigen (Rb).

MATERIALS AND METHODS

Swiss albino mice were immunized with aqueous-alcoholic SBTE (100 mg/kg body weight) or algel (aluminium hydroxide gel) with or without Rb (5% v/v). After priming, booster was administered on day 14. Rabies virus neutralizing antibody (RVNA) titers were estimated by rapid fluorescent focus inhibition test in sera samples collected on days 7, 14, 21, 28 and 35. Effect of adjuvant administration on cytotoxic T lymphocytes (CTLs), memory T cells, plasma and CD11c⁺ cells was studied by flow cytometry. In vitro hemolysis was assayed in human RBC.

RESULTS

RVNA titers were significantly enhanced (p < 0.05) after booster administration in mice immunized with SBTE + Rb as compared to the controls. In combination, SBTE, algel and Rb, enhanced the RVNA titers. CTLs significantly increased (p < 0.05) in SBTE + Rb immunized mice. Memory T cells and plasma cells were 27.9 and 15.9%, respectively, in SBTE + Rb immunized mice as compared to that of 20.3 and 11.3%, respectively, in Rb immunized group. SBTE + Rb enhanced peritoneal CD11c⁺ cells (25.8%) as compared to 9.4% cells in Rb immunized mice, showed 3.2-fold increment in LPS induced IL-1β. No RBC hemolysis was observed with SBTE.

CONCLUSIONS

This study demonstrates the potential adjuvant activity of SBTE with Rb by increasing RVNA titers and CTL response.

Anti-inflammatory activity of the functional groups present in Hippophae rhamnoides (Seabuckthorn) leaf extract

ETHNO PHARMACOLOGICAL RELEVANCE

The study explores the anti-inflammatory activity of components present in fractions obtained from leaves of Hippophae rhamnoides in mouse peritoneal macrophages.

AIM OF THE STUDY

Immunomodulators salvage the immune response by enhancing or reducing its capacity to the required level. Plant extracts are extensively used as immunomodulators because of their easy availability, simple methods of preparation and minimum side effects with maximum efficacy.

MATERIALS AND METHODS

The present study was conducted to assess the immunomodulatory activities of phyto constituents present in Seabuckthorn leaves. The aqueous-alcoholic leaf extract was subjected to successive and parallel extraction in the presence of polar and non-polar solvents for fractionation of compounds. Based on the yield, three fractions were selected viz. parallel methanol (PM), successive chloroform (SC) and successive methanol (SM) and screened for in vitro immunomodulatory activities. Peritoneal macrophages were isolated from Balb/c mice and cultured with or without LPS to evaluate the immunomodulatory effect of the three fractions on cell viability, hemolytic activity, nitric oxide (NO) production, cytokine levels, iNOS and COX-2 expressions.

RESULTS

The results revealed that none of the three fractions induced hemolysis. Cells treated with PM fraction significantly suppressed LPS-induced NO production and pro-inflammatory cytokines such as TNF-α, IL-6 and IFN-γ as compared to SC and SM treatment. The iNOS and COX-2 expressions were also significantly reduced after treatment with PM fraction.

CONCLUSIONS

The decrease in LPS-induced NO production, pro-inflammatory cytokine secretion, iNOS and COX-2 expression signifies anti-inflammatory properties of PM fraction containing tannins, proteins and carbohydrate groups. Hence, this plant-derived immunomodulator can be used as a therapeutic agent in inflammatory diseases.

Augmentation of humoral and cellular immunity in response to Tetanus and Diphtheria toxoids by supercritical carbon dioxide extracts of Hippophae rhamnoides L. leaves

Hippophae rhamnoides L. commonly known as Seabuckthorn (SBT), a wild shrub of family Elaegnacea, has extensively used for treating various ailments like skin diseases, jaundice, asthma, lung troubles. SBT leaves have been reported to possess several pharmacological properties including immunomodulatory, antioxidant, anti-inflammatory, antimicrobial and tissue regeneration etc. The present study was undertaken to evaluate the adjuvant property of supercritical carbon dioxide extracts (SCEs 300ET and 350ET) of SBT leaves in balb/c mice immunized with Tetanus and Diphtheria toxoids. The dynamic changes in the immune response were measured in terms of humoral and cell-mediated immune responses. We have seen the effect of SCEs on immunoglobulin subtypes and secondary immune response generation. In addition, the effect of SCEs on antigen specific cellular immunity was evaluated. Our results show that SCEs 300ET and 350ET significantly enhanced antibody titers in response to both TT and DT antigens. The secondary immune response generated was significantly increased in case of TT immunized animals. SCEs also enhanced cytokine levels (IFN-γ, IL-4, TNF-α and IL-1β) and increased lymphoproliferation. Besides, both SCEs did not show any toxic effects. Therefore, the study suggests that SCEs are safe and have potent immunostimulatory activity and hence, seems to be a promising balanced Th1 and Th2 directing immunological adjuvant for various veterinary as well as human vaccines.

Medicinal and therapeutic potential of Sea buckthorn (Hippophae rhamnoides L.)

ETHNOPHARMACOLOGICAL CONTEXT: This review explores the medicinal and therapeutic applications of Sea buckthorn (Hippophae rhamnoides L.) in curtailing different types of acute as well as chronic maladies. The plant is being used in different parts of the world for its nutritional and medicinal properties.

MATERIALS AND METHODS

Sea buckthorn based preparations have been extensively exploited in folklore treatment of slow digestion, stomach malfunctioning, cardiovascular problems, liver injury, tendon and ligament injuries, skin diseases and ulcers. In the recent years, medicinal and pharmacological activities of Sea buckthorn have been well investigated using various in vitro and in vivo models as well as limited clinical trials.

RESULTS

Sea buckthorn has been scientifically analyzed and many of its traditional uses have been established using several biochemical and pharmacological studies. Various pharmacological activities such as cytoprotective, anti-stress, immunomodulatory, hepatoprotective, radioprotective, anti-atherogenic, anti-tumor, anti-microbial and tissue regeneration have been reported.

CONCLUSION

It is clear that Sea buckthorn is an important plant because of its immense medicinal and therapeutic potential. However, several knowledge gaps identified in this paper would give impetus to new academic and R&D activities especially for the development of Sea buckthorn based herbal medicine and nutraceuticals.