# Cape Myrtle (Myrsine africana)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/cape-myrtle-myrsine-africana
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-01
**Evidence Score:** 1 / 10
**Category:** African
**Also Known As:** Myrsine africana, African Boxwood, Thakisa, Cape Myrtle shrub, Myrsine rotundifolia

## Overview

Cape Myrtle contains quercetin, rutin, p-coumaric acid, and the saponin myrsinoside B, which exert antioxidant, [anti-inflammatory](/ingredients/condition/inflammation), and [hepatoprotective](/ingredients/condition/detox) effects primarily through [free radical scaveng](/ingredients/condition/antioxidant)ing and 5-lipoxygenase inhibition. In animal models, methanol leaf extract at 300 mg/kg body weight demonstrated the strongest hepatoprotective activity against CCl₄-induced liver damage, while crude ethanolic extract achieved an IC₅₀ of 29.65 ± 2.92 µg/ml for 5-lipoxygenase inhibition in vitro.

## Health Benefits

- **Gastrointestinal Support**: The astringent tannin content of Myrsine africana has been used in Xhosa traditional medicine to manage diarrhea and stomach pains, with tannins mechanistically reducing intestinal secretion and exerting [antimicrobial](/ingredients/condition/immune-support) activity against enteric pathogens.
- **[Hepatoprotective](/ingredients/condition/detox) Activity**: Methanol leaf extract at 300 mg/kg body weight significantly attenuated CCl₄-induced hepatotoxicity in mice by normalizing liver marker enzymes and [antioxidant](/ingredients/condition/antioxidant) enzyme levels, with activity comparable to the reference hepatoprotectant silymarin.
- **Antioxidant Defense**: Crude ethanolic extract scavenged hydrogen peroxide with an IC₅₀ of 56.08 ± 2.88 µg/ml and superoxide radicals with an IC₅₀ of 132.74 ± 1.64 µg/ml, attributable to the combined action of quercetin, rutin, and polyphenolic constituents.
- **[Anti-inflammatory](/ingredients/condition/inflammation) Effects**: Inhibition of 5-lipoxygenase (IC₅₀ of 29.65 ± 2.92 µg/ml for crude extract; 29.23 ± 3.08 µg/ml for isolated myrsinoside B) reduces production of pro-inflammatory leukotrienes, supporting the traditional use for skin boils and inflammatory skin conditions.
- **Antimicrobial and Anti-tuberculosis Activity**: Fruit extracts demonstrated inhibitory activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis, and Mycobacterium tuberculosis in vitro, with phenolic and flavonoid constituents considered primarily responsible.
- **[Skin Health](/ingredients/condition/skin-health) and Elastase Inhibition**: Isolated myrsinoside B exhibited elastase inhibitory activity of 13.00 ± 1.04% at 125 pg/mL, suggesting potential to reduce skin aging by limiting elastin degradation, and research into maltose microneedle delivery systems is underway to enhance transdermal bioavailability.
- **Antiproliferative and Cytotoxic Activity**: Methanolic fruit extracts demonstrated significant antiproliferative and cytotoxic effects in vitro, with higher total phenol, total flavonoid, and tannin concentrations in methanolic preparations correlating with greater biological activity.

## Mechanism of Action

The primary antioxidant mechanism involves direct [free radical scaveng](/ingredients/condition/antioxidant)ing by flavonoids quercetin and rutin, which donate hydrogen atoms to neutralize hydrogen peroxide and superoxide radicals, thereby interrupting oxidative stress cascades responsible for cellular and hepatic damage. Quercetin has been shown to bind multiple sites on human estrogen receptor protein, which is structurally linked to alkaline phosphatase, suggesting a potential hormonal modulatory mechanism relevant to tissue protection and metabolic regulation. The saponin myrsinoside B inhibits 5-lipoxygenase, the enzyme responsible for converting arachidonic acid to pro-inflammatory leukotrienes (LTB4, LTC4), thereby attenuating the leukotriene-mediated inflammatory cascade implicated in skin conditions and systemic [inflammation](/ingredients/condition/inflammation). Tannins contribute an additional astringent mechanism in the gastrointestinal tract, precipitating surface proteins on mucous membranes to reduce secretion, limit microbial adhesion, and provide a physical barrier against enteric pathogens relevant to the traditional use for diarrhea.

## Clinical Summary

No human clinical trials have been conducted on Myrsine africana, limiting the clinical summary to animal and in vitro data. The most structured in vivo evidence comes from a CCl₄-hepatotoxicity mouse model where methanol extract at 300 mg/kg produced statistically significant normalization of hepatic biomarkers, but sample sizes, exact p-values, and effect sizes were not fully disclosed in available literature. In vitro [antioxidant](/ingredients/condition/antioxidant) and enzyme inhibition assays provide quantified IC₅₀ benchmarks that allow comparison with reference compounds, but these do not predict clinical efficacy or safe human doses. Confidence in translating these findings to human health applications is low, and rigorous Phase I/II clinical trials are needed before evidence-based therapeutic recommendations can be established.

## Nutritional Profile

Myrsine africana leaves and fruits are not consumed as a dietary staple and no standard macronutrient profile has been characterized for food use. Phytochemically, methanolic fruit extracts are rich in total phenolics, total flavonoids (including quantified quercetin and rutin), and condensed tannins, with p-coumaric acid identified as a notable hydroxycinnamic acid constituent. Leaf extracts contain three identified flavonoids and common fatty acids detected by GC-MS, though specific fatty acid identities and concentrations are not fully reported in available literature. Bioavailability of the key compound myrsinoside B is under investigation for topical delivery via microneedle systems, and oral bioavailability data for any constituent following human consumption has not been established.

## Dosage & Preparation

- **Traditional Decoction (Xhosa)**: Bark or leaf material is boiled in water and the decoction consumed orally for diarrhea and stomach pains; no standardized volume or concentration has been formally documented.
- **Methanolic Extract (Research Grade)**: Used in animal [hepatoprotect](/ingredients/condition/detox)ion studies at 100–300 mg/kg body weight in rodents; human equivalent doses cannot be directly extrapolated without allometric scaling and clinical validation.
- **Ethanolic Crude Extract (In Vitro)**: Demonstrated [antioxidant activity](/ingredients/condition/antioxidant) at concentrations yielding IC₅₀ values of 56.08 µg/ml (H₂O₂) and 29.65 µg/ml (5-LOX); no commercial standardization exists.
- **Topical / Transdermal (Experimental)**: Myrsinoside B is under investigation for delivery via maltose microneedle systems to enhance skin penetration for dermatological applications; not yet commercially available.
- **No Established Human Supplemental Dose**: No standardized capsule, tablet, or tincture dosage has been clinically validated for human use; any commercial preparation should be approached with caution pending safety and efficacy data.

## Safety & Drug Interactions

No formal human safety studies, adverse event reports, or toxicology data have been published for Myrsine africana extracts or isolated constituents, making it impossible to establish a maximum safe dose or confirmed safety profile for human supplemental use. Animal studies using methanol and chloroform extracts at up to 300 mg/kg did not report acute adverse effects, but the absence of reported toxicity in rodent studies does not constitute proof of human safety, and sub-chronic or chronic toxicity data are lacking. No drug interaction studies exist; however, quercetin—a principal flavonoid constituent—is known in other contexts to inhibit CYP3A4 and P-glycoprotein, theoretically affecting the [metabolism](/ingredients/condition/weight-management) of co-administered drugs including immunosuppressants, anticoagulants, and certain antibiotics. Use during pregnancy and lactation is not recommended given the complete absence of safety data, and individuals with known hypersensitivity to plants in the Primulaceae family should exercise caution.

## Scientific Research

The available body of evidence for Myrsine africana consists entirely of in vitro phytochemical characterization and a small number of animal studies, with no published human clinical trials identified to date. One in vivo mouse study evaluated methanol and chloroform leaf extracts at doses of 100, 200, and 300 mg/kg against CCl₄-induced hepatotoxicity, using silymarin as a positive control and measuring liver enzymes, [antioxidant](/ingredients/condition/antioxidant) markers, bilirubin, and total protein, with the 300 mg/kg methanol extract performing best. In vitro studies have quantified antioxidant IC₅₀ values for crude ethanolic extract and isolated myrsinoside B, and separate fruit extract studies documented antibacterial, anti-tuberculosis, antiproliferative, and cytotoxic activity. The overall evidence base is preclinical and preliminary; extrapolation to human therapeutic dosing is not yet scientifically justified, and the absence of pharmacokinetic, bioavailability, or human safety data represents a significant gap in the literature.

## Historical & Cultural Context

In Xhosa traditional medicine of southern Africa, Myrsine africana (locally called Cape Myrtle or African Boxwood) has been used for generations to treat diarrhea and stomach pains, representing one of the primary gastrointestinal remedies in the Eastern Cape region's ethnobotanical pharmacopoeia. The plant is also documented in traditional systems across Pakistan and the broader Himalayan region, where it is known as Thakisa and used for skin allergies, boils, and blood purification, reflecting a cross-cultural convergence on its [anti-inflammatory](/ingredients/condition/inflammation) and astringent properties. In southern Africa, its dense, slow-growing habit has made it a valued garden hedge plant as well as a medicinal resource, with bark and leaf preparations employed as astringents to treat a range of inflammatory and infectious conditions. Ethnobotanical surveys across the African continent consistently cite Myrsine africana among widely-used medicinal plants, lending it significance as a candidate for formal phytomedicinal investigation.

## Synergistic Combinations

Quercetin, a constituent of Cape Myrtle, is well-documented to exhibit enhanced oral bioavailability and antioxidant synergy when combined with bromelain and vitamin C, a stack commonly used in [anti-inflammatory](/ingredients/condition/inflammation) formulations. The 5-lipoxygenase inhibitory activity of myrsinoside B may complement the COX-2 inhibitory effects of other polyphenols such as resveratrol or boswellic acids, potentially providing broader dual-pathway anti-inflammatory coverage. For [hepatoprotective](/ingredients/condition/detox) applications, the combination of Myrsine africana methanol extract with milk thistle (silymarin), which served as the positive control in the key animal study, represents a mechanistically complementary pairing targeting both [free radical scaveng](/ingredients/condition/antioxidant)ing and hepatocyte membrane stabilization.

## Frequently Asked Questions

### What is Cape Myrtle used for in traditional Xhosa medicine?

In Xhosa traditional medicine, Cape Myrtle (Myrsine africana) is primarily used to treat diarrhea and stomach pains, with bark and leaf decoctions prepared by boiling plant material in water and consuming the liquid orally. The astringent tannin content is believed to reduce intestinal secretion and exert antimicrobial effects against enteric pathogens responsible for gastrointestinal infections.

### What are the key bioactive compounds in Myrsine africana?

The major bioactive compounds identified in Myrsine africana include the flavonoids quercetin and rutin, the hydroxycinnamic acid p-coumaric acid (found in fruit extracts), and the saponin glycoside myrsinoside B (isolated from leaf extracts). Condensed tannins and total polyphenolics are also present at significant concentrations, particularly in methanolic fruit preparations, and these collectively account for the plant's antioxidant, anti-inflammatory, and astringent activities.

### Is there clinical evidence supporting the use of Cape Myrtle supplements?

No human clinical trials have been conducted on Cape Myrtle or Myrsine africana, and the current evidence base is limited to in vitro studies and a single mouse model of CCl₄-induced liver toxicity. While the animal study showed promising hepatoprotective effects at 300 mg/kg methanol extract and in vitro assays have quantified antioxidant IC₅₀ values, these findings cannot be directly translated into evidence-based supplemental recommendations for humans without further clinical research.

### What is the safe dose of Cape Myrtle for humans?

No safe human dose for Cape Myrtle has been established through clinical trials, and no standardized commercial supplement formulation currently exists with validated dosing guidelines. Animal studies employed 100–300 mg/kg body weight of leaf extracts, but these doses cannot be directly extrapolated to humans without allometric scaling, pharmacokinetic data, and safety validation; therefore, human supplemental use is not recommended outside of supervised ethnomedicinal contexts until further research is completed.

### Does Cape Myrtle have anti-inflammatory properties?

Yes, Myrsine africana demonstrates anti-inflammatory activity primarily through inhibition of 5-lipoxygenase, the enzyme that converts arachidonic acid to pro-inflammatory leukotrienes; the crude ethanolic extract achieved an IC₅₀ of 29.65 ± 2.92 µg/ml and the isolated compound myrsinoside B achieved 29.23 ± 3.08 µg/ml in this assay. Additionally, the plant's quercetin and rutin constituents provide complementary anti-inflammatory activity through free radical scavenging and potential modulation of estrogen receptor-linked signaling pathways, although these mechanisms have only been demonstrated in vitro to date.

### Does Cape Myrtle interact with medications used to treat diarrhea or gastrointestinal disorders?

Cape Myrtle's astringent tannin content may potentiate the effects of antidiarrheal medications like loperamide or bismuth subsalicylate, potentially increasing the risk of constipation or reduced intestinal motility. Concurrent use with antimicrobial medications should be monitored, as Myrsine africana itself possesses antimicrobial activity against enteric pathogens and may have additive or competitive effects. Individuals taking prescription gastrointestinal medications should consult a healthcare provider before supplementing with Cape Myrtle to avoid unwanted interactions.

### Is Cape Myrtle safe for children or during pregnancy and breastfeeding?

There is currently insufficient clinical safety data on Cape Myrtle use in children, pregnant women, or nursing mothers to establish safe dosing or rule out potential risks. The tannin content and hepatoprotective mechanisms have not been evaluated in these vulnerable populations, and traditional use alone does not confirm safety. Pregnant, breastfeeding, and pediatric populations should avoid Cape Myrtle supplementation unless explicitly advised by a qualified healthcare provider.

### What is the most bioavailable form of Cape Myrtle supplement—leaf extract, powder, or tincture?

Methanol and aqueous leaf extracts have demonstrated the strongest bioavailability of active compounds and hepatoprotective effects in research models, suggesting that concentrated extracts may be more effective than whole leaf powders. Tinctures (alcohol-based extracts) may improve the solubility and absorption of tannins and other bioactive constituents compared to water-based forms. However, direct comparative bioavailability studies in humans are lacking, so the optimal form remains dependent on individual absorption capacity and intended therapeutic use.

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